webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

85 files changed, 20345 insertions, 7029 deletions

diff --git a/Source/JavaScriptCore/ftl/FTLAbbreviatedTypes.h b/Source/JavaScriptCore/ftl/FTLAbbreviatedTypes.h
index 06a68cd67..7a64d4d4f 100644
--- a/Source/JavaScriptCore/ftl/FTLAbbreviatedTypes.h
+++ b/Source/JavaScriptCore/ftl/FTLAbbreviatedTypes.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,32 +23,24 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLAbbreviatedTypes_h
-#define FTLAbbreviatedTypes_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
-#include "LLVMAPI.h"
+#include "DFGCommon.h"
+
+namespace JSC { namespace B3 {
+class BasicBlock;
+class Value;
+enum Type : int8_t;
+} }
 
 namespace JSC { namespace FTL {
 
-typedef LLVMAtomicOrdering LAtomicOrdering;
-typedef LLVMBasicBlockRef LBasicBlock;
-typedef LLVMBuilderRef LBuilder;
-typedef LLVMCallConv LCallConv;
-typedef LLVMContextRef LContext;
-typedef LLVMIntPredicate LIntPredicate;
-typedef LLVMLinkage LLinkage;
-typedef LLVMModuleRef LModule;
-typedef LLVMRealPredicate LRealPredicate;
-typedef LLVMTypeRef LType;
-typedef LLVMValueRef LValue;
+typedef B3::BasicBlock* LBasicBlock;
+typedef B3::Type LType;
+typedef B3::Value* LValue;
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLAbbreviatedTypes_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLAbbreviations.h b/Source/JavaScriptCore/ftl/FTLAbbreviations.h
deleted file mode 100644
index 02e0c04c3..000000000
--- a/Source/JavaScriptCore/ftl/FTLAbbreviations.h
+++ /dev/null
@@ -1,313 +0,0 @@
-/*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
- */
-
-#ifndef FTLAbbreviations_h
-#define FTLAbbreviations_h
-
-#include <wtf/Platform.h>
-
-#if ENABLE(FTL_JIT)
-
-#include "FTLAbbreviatedTypes.h"
-#include "FTLSwitchCase.h"
-#include "FTLValueFromBlock.h"
-#include "LLVMAPI.h"
-#include <cstring>
-
-namespace JSC { namespace FTL {
-
-// This file contains short-form calls into the LLVM C API. It is meant to
-// save typing and make the lowering code clearer. If we ever call an LLVM C API
-// function more than once in the FTL lowering code, we should add a shortcut for
-// it here.
-
-#if USE(JSVALUE32_64)
-#error "The FTL backend assumes that pointers are 64-bit."
-#endif
-
-static inline LType voidType(LContext context) { return llvm->VoidTypeInContext(context); }
-static inline LType int1Type(LContext context) { return llvm->Int1TypeInContext(context); }
-static inline LType int8Type(LContext context) { return llvm->Int8TypeInContext(context); }
-static inline LType int16Type(LContext context) { return llvm->Int16TypeInContext(context); }
-static inline LType int32Type(LContext context) { return llvm->Int32TypeInContext(context); }
-static inline LType int64Type(LContext context) { return llvm->Int64TypeInContext(context); }
-static inline LType intPtrType(LContext context) { return llvm->Int64TypeInContext(context); }
-static inline LType floatType(LContext context) { return llvm->FloatTypeInContext(context); }
-static inline LType doubleType(LContext context) { return llvm->DoubleTypeInContext(context); }
-
-static inline LType pointerType(LType type) { return llvm->PointerType(type, 0); }
-static inline LType vectorType(LType type, unsigned count) { return llvm->VectorType(type, count); }
-
-enum PackingMode { NotPacked, Packed };
-static inline LType structType(LContext context, LType* elementTypes, unsigned elementCount, PackingMode packing = NotPacked)
-{
-    return llvm->StructTypeInContext(context, elementTypes, elementCount, packing == Packed);
-}
-static inline LType structType(LContext context, PackingMode packing = NotPacked)
-{
-    return structType(context, 0, 0, packing);
-}
-static inline LType structType(LContext context, LType element1, PackingMode packing = NotPacked)
-{
-    return structType(context, &element1, 1, packing);
-}
-static inline LType structType(LContext context, LType element1, LType element2, PackingMode packing = NotPacked)
-{
-    LType elements[] = { element1, element2 };
-    return structType(context, elements, 2, packing);
-}
-
-enum Variadicity { NotVariadic, Variadic };
-static inline LType functionType(LType returnType, const LType* paramTypes, unsigned paramCount, Variadicity variadicity)
-{
-    return llvm->FunctionType(returnType, const_cast<LType*>(paramTypes), paramCount, variadicity == Variadic);
-}
-template<typename VectorType>
-inline LType functionType(LType returnType, const VectorType& vector, Variadicity variadicity = NotVariadic)
-{
-    return functionType(returnType, vector.begin(), vector.size(), variadicity);
-}
-static inline LType functionType(LType returnType, Variadicity variadicity = NotVariadic)
-{
-    return functionType(returnType, 0, 0, variadicity);
-}
-static inline LType functionType(LType returnType, LType param1, Variadicity variadicity = NotVariadic)
-{
-    return functionType(returnType, &param1, 1, variadicity);
-}
-static inline LType functionType(LType returnType, LType param1, LType param2, Variadicity variadicity = NotVariadic)
-{
-    LType paramTypes[] = { param1, param2 };
-    return functionType(returnType, paramTypes, 2, variadicity);
-}
-static inline LType functionType(LType returnType, LType param1, LType param2, LType param3, Variadicity variadicity = NotVariadic)
-{
-    LType paramTypes[] = { param1, param2, param3 };
-    return functionType(returnType, paramTypes, 3, variadicity);
-}
-static inline LType functionType(LType returnType, LType param1, LType param2, LType param3, LType param4, Variadicity variadicity = NotVariadic)
-{
-    LType paramTypes[] = { param1, param2, param3, param4 };
-    return functionType(returnType, paramTypes, 4, variadicity);
-}
-
-static inline LType typeOf(LValue value) { return llvm->TypeOf(value); }
-
-static inline unsigned mdKindID(LContext context, const char* string) { return llvm->GetMDKindIDInContext(context, string, std::strlen(string)); }
-static inline LValue mdString(LContext context, const char* string, unsigned length) { return llvm->MDStringInContext(context, string, length); }
-static inline LValue mdString(LContext context, const char* string) { return mdString(context, string, std::strlen(string)); }
-static inline LValue mdNode(LContext context, LValue* args, unsigned numArgs) { return llvm->MDNodeInContext(context, args, numArgs); }
-static inline LValue mdNode(LContext context) { return mdNode(context, 0, 0); }
-static inline LValue mdNode(LContext context, LValue arg1) { return mdNode(context, &arg1, 1); }
-static inline LValue mdNode(LContext context, LValue arg1, LValue arg2)
-{
-    LValue args[] = { arg1, arg2 };
-    return mdNode(context, args, 2);
-}
-
-static inline void setMetadata(LValue instruction, unsigned kind, LValue metadata) { llvm->SetMetadata(instruction, kind, metadata); }
-
-static inline LValue addFunction(LModule module, const char* name, LType type) { return llvm->AddFunction(module, name, type); }
-static inline void setLinkage(LValue global, LLinkage linkage) { llvm->SetLinkage(global, linkage); }
-static inline void setFunctionCallingConv(LValue function, LCallConv convention) { llvm->SetFunctionCallConv(function, convention); }
-
-static inline LValue addExternFunction(LModule module, const char* name, LType type)
-{
-    LValue result = addFunction(module, name, type);
-    setLinkage(result, LLVMExternalLinkage);
-    return result;
-}
-
-static inline LValue getParam(LValue function, unsigned index) { return llvm->GetParam(function, index); }
-static inline LValue getUndef(LType type) { return llvm->GetUndef(type); }
-
-enum BitExtension { ZeroExtend, SignExtend };
-static inline LValue constInt(LType type, unsigned long long value, BitExtension extension = ZeroExtend) { return llvm->ConstInt(type, value, extension == SignExtend); }
-static inline LValue constReal(LType type, double value) { return llvm->ConstReal(type, value); }
-static inline LValue constIntToPtr(LValue value, LType type) { return llvm->ConstIntToPtr(value, type); }
-static inline LValue constNull(LType type) { return llvm->ConstNull(type); }
-static inline LValue constBitCast(LValue value, LType type) { return llvm->ConstBitCast(value, type); }
-
-static inline LBasicBlock appendBasicBlock(LContext context, LValue function, const char* name = "") { return llvm->AppendBasicBlockInContext(context, function, name); }
-static inline LBasicBlock insertBasicBlock(LContext context, LBasicBlock beforeBasicBlock, const char* name = "") { return llvm->InsertBasicBlockInContext(context, beforeBasicBlock, name); }
-
-static inline LValue buildPhi(LBuilder builder, LType type) { return llvm->BuildPhi(builder, type, ""); }
-static inline void addIncoming(LValue phi, const LValue* values, const LBasicBlock* blocks, unsigned numPredecessors)
-{
-    llvm->AddIncoming(phi, const_cast<LValue*>(values), const_cast<LBasicBlock*>(blocks), numPredecessors);
-}
-static inline void addIncoming(LValue phi, ValueFromBlock value1)
-{
-    LValue value = value1.value();
-    LBasicBlock block = value1.block();
-    addIncoming(phi, &value, &block, 1);
-}
-static inline void addIncoming(LValue phi, ValueFromBlock value1, ValueFromBlock value2)
-{
-    LValue values[] = { value1.value(), value2.value() };
-    LBasicBlock blocks[] = { value1.block(), value2.block() };
-    addIncoming(phi, values, blocks, 2);
-}
-static inline LValue buildPhi(LBuilder builder, LType type, ValueFromBlock value1)
-{
-    LValue result = buildPhi(builder, type);
-    addIncoming(result, value1);
-    return result;
-}
-static inline LValue buildPhi(
-    LBuilder builder, LType type, ValueFromBlock value1, ValueFromBlock value2)
-{
-    LValue result = buildPhi(builder, type);
-    addIncoming(result, value1, value2);
-    return result;
-}
-
-static inline LValue buildAlloca(LBuilder builder, LType type) { return llvm->BuildAlloca(builder, type, ""); }
-static inline LValue buildAdd(LBuilder builder, LValue left, LValue right) { return llvm->BuildAdd(builder, left, right, ""); }
-static inline LValue buildSub(LBuilder builder, LValue left, LValue right) { return llvm->BuildSub(builder, left, right, ""); }
-static inline LValue buildMul(LBuilder builder, LValue left, LValue right) { return llvm->BuildMul(builder, left, right, ""); }
-static inline LValue buildDiv(LBuilder builder, LValue left, LValue right) { return llvm->BuildSDiv(builder, left, right, ""); }
-static inline LValue buildRem(LBuilder builder, LValue left, LValue right) { return llvm->BuildSRem(builder, left, right, ""); }
-static inline LValue buildNeg(LBuilder builder, LValue value) { return llvm->BuildNeg(builder, value, ""); }
-static inline LValue buildFAdd(LBuilder builder, LValue left, LValue right) { return llvm->BuildFAdd(builder, left, right, ""); }
-static inline LValue buildFSub(LBuilder builder, LValue left, LValue right) { return llvm->BuildFSub(builder, left, right, ""); }
-static inline LValue buildFMul(LBuilder builder, LValue left, LValue right) { return llvm->BuildFMul(builder, left, right, ""); }
-static inline LValue buildFDiv(LBuilder builder, LValue left, LValue right) { return llvm->BuildFDiv(builder, left, right, ""); }
-static inline LValue buildFRem(LBuilder builder, LValue left, LValue right) { return llvm->BuildFRem(builder, left, right, ""); }
-static inline LValue buildFNeg(LBuilder builder, LValue value) { return llvm->BuildFNeg(builder, value, ""); }
-static inline LValue buildAnd(LBuilder builder, LValue left, LValue right) { return llvm->BuildAnd(builder, left, right, ""); }
-static inline LValue buildOr(LBuilder builder, LValue left, LValue right) { return llvm->BuildOr(builder, left, right, ""); }
-static inline LValue buildXor(LBuilder builder, LValue left, LValue right) { return llvm->BuildXor(builder, left, right, ""); }
-static inline LValue buildShl(LBuilder builder, LValue left, LValue right) { return llvm->BuildShl(builder, left, right, ""); }
-static inline LValue buildAShr(LBuilder builder, LValue left, LValue right) { return llvm->BuildAShr(builder, left, right, ""); }
-static inline LValue buildLShr(LBuilder builder, LValue left, LValue right) { return llvm->BuildLShr(builder, left, right, ""); }
-static inline LValue buildNot(LBuilder builder, LValue value) { return llvm->BuildNot(builder, value, ""); }
-static inline LValue buildLoad(LBuilder builder, LValue pointer) { return llvm->BuildLoad(builder, pointer, ""); }
-static inline LValue buildStore(LBuilder builder, LValue value, LValue pointer) { return llvm->BuildStore(builder, value, pointer); }
-static inline LValue buildSExt(LBuilder builder, LValue value, LType type) { return llvm->BuildSExt(builder, value, type, ""); }
-static inline LValue buildZExt(LBuilder builder, LValue value, LType type) { return llvm->BuildZExt(builder, value, type, ""); }
-static inline LValue buildFPToSI(LBuilder builder, LValue value, LType type) { return llvm->BuildFPToSI(builder, value, type, ""); }
-static inline LValue buildFPToUI(LBuilder builder, LValue value, LType type) { return llvm->BuildFPToUI(builder, value, type, ""); }
-static inline LValue buildSIToFP(LBuilder builder, LValue value, LType type) { return llvm->BuildSIToFP(builder, value, type, ""); }
-static inline LValue buildUIToFP(LBuilder builder, LValue value, LType type) { return llvm->BuildUIToFP(builder, value, type, ""); }
-static inline LValue buildIntCast(LBuilder builder, LValue value, LType type) { return llvm->BuildIntCast(builder, value, type, ""); }
-static inline LValue buildFPCast(LBuilder builder, LValue value, LType type) { return llvm->BuildFPCast(builder, value, type, ""); }
-static inline LValue buildIntToPtr(LBuilder builder, LValue value, LType type) { return llvm->BuildIntToPtr(builder, value, type, ""); }
-static inline LValue buildPtrToInt(LBuilder builder, LValue value, LType type) { return llvm->BuildPtrToInt(builder, value, type, ""); }
-static inline LValue buildBitCast(LBuilder builder, LValue value, LType type) { return llvm->BuildBitCast(builder, value, type, ""); }
-static inline LValue buildICmp(LBuilder builder, LIntPredicate cond, LValue left, LValue right) { return llvm->BuildICmp(builder, cond, left, right, ""); }
-static inline LValue buildFCmp(LBuilder builder, LRealPredicate cond, LValue left, LValue right) { return llvm->BuildFCmp(builder, cond, left, right, ""); }
-static inline LValue buildInsertElement(LBuilder builder, LValue vector, LValue element, LValue index) { return llvm->BuildInsertElement(builder, vector, element, index, ""); }
-
-enum SynchronizationScope { SingleThread, CrossThread };
-static inline LValue buildFence(LBuilder builder, LAtomicOrdering ordering, SynchronizationScope scope = CrossThread)
-{
-    return llvm->BuildFence(builder, ordering, scope == SingleThread, "");
-}
-
-static inline LValue buildCall(LBuilder builder, LValue function, const LValue* args, unsigned numArgs)
-{
-    return llvm->BuildCall(builder, function, const_cast<LValue*>(args), numArgs, "");
-}
-template<typename VectorType>
-inline LValue buildCall(LBuilder builder, LValue function, const VectorType& vector)
-{
-    return buildCall(builder, function, vector.begin(), vector.size());
-}
-static inline LValue buildCall(LBuilder builder, LValue function)
-{
-    return buildCall(builder, function, 0, 0);
-}
-static inline LValue buildCall(LBuilder builder, LValue function, LValue arg1)
-{
-    return buildCall(builder, function, &arg1, 1);
-}
-static inline LValue buildCall(LBuilder builder, LValue function, LValue arg1, LValue arg2)
-{
-    LValue args[] = { arg1, arg2 };
-    return buildCall(builder, function, args, 2);
-}
-static inline LValue buildCall(LBuilder builder, LValue function, LValue arg1, LValue arg2, LValue arg3)
-{
-    LValue args[] = { arg1, arg2, arg3 };
-    return buildCall(builder, function, args, 3);
-}
-static inline LValue buildCall(LBuilder builder, LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4)
-{
-    LValue args[] = { arg1, arg2, arg3, arg4 };
-    return buildCall(builder, function, args, 4);
-}
-static inline LValue buildCall(LBuilder builder, LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4, LValue arg5)
-{
-    LValue args[] = { arg1, arg2, arg3, arg4, arg5 };
-    return buildCall(builder, function, args, 5);
-}
-static inline LValue buildCall(LBuilder builder, LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4, LValue arg5, LValue arg6)
-{
-    LValue args[] = { arg1, arg2, arg3, arg4, arg5, arg6 };
-    return buildCall(builder, function, args, 6);
-}
-static inline LValue buildCall(LBuilder builder, LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4, LValue arg5, LValue arg6, LValue arg7)
-{
-    LValue args[] = { arg1, arg2, arg3, arg4, arg5, arg6, arg7 };
-    return buildCall(builder, function, args, 7);
-}
-static inline LValue buildCall(LBuilder builder, LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4, LValue arg5, LValue arg6, LValue arg7, LValue arg8)
-{
-    LValue args[] = { arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8 };
-    return buildCall(builder, function, args, 8);
-}
-static inline void setInstructionCallingConvention(LValue instruction, LCallConv callingConvention) { llvm->SetInstructionCallConv(instruction, callingConvention); }
-static inline LValue buildExtractValue(LBuilder builder, LValue aggVal, unsigned index) { return llvm->BuildExtractValue(builder, aggVal, index, ""); }
-static inline LValue buildSelect(LBuilder builder, LValue condition, LValue taken, LValue notTaken) { return llvm->BuildSelect(builder, condition, taken, notTaken, ""); }
-static inline LValue buildBr(LBuilder builder, LBasicBlock destination) { return llvm->BuildBr(builder, destination); }
-static inline LValue buildCondBr(LBuilder builder, LValue condition, LBasicBlock taken, LBasicBlock notTaken) { return llvm->BuildCondBr(builder, condition, taken, notTaken); }
-static inline LValue buildSwitch(LBuilder builder, LValue value, LBasicBlock fallThrough, unsigned numCases) { return llvm->BuildSwitch(builder, value, fallThrough, numCases); }
-static inline void addCase(LValue switchInst, LValue value, LBasicBlock target) { llvm->AddCase(switchInst, value, target); }
-template<typename VectorType>
-static inline LValue buildSwitch(LBuilder builder, LValue value, const VectorType& cases, LBasicBlock fallThrough)
-{
-    LValue result = buildSwitch(builder, value, fallThrough, cases.size());
-    for (unsigned i = 0; i < cases.size(); ++i)
-        addCase(result, cases[i].value(), cases[i].target());
-    return result;
-}
-static inline LValue buildRet(LBuilder builder, LValue value) { return llvm->BuildRet(builder, value); }
-static inline LValue buildUnreachable(LBuilder builder) { return llvm->BuildUnreachable(builder); }
-
-static inline void dumpModule(LModule module) { llvm->DumpModule(module); }
-static inline void verifyModule(LModule module)
-{
-    char* error = 0;
-    llvm->VerifyModule(module, LLVMAbortProcessAction, &error);
-    llvm->DisposeMessage(error);
-}
-
-} } // namespace JSC::FTL
-
-#endif // ENABLE(FTL_JIT)
-
-#endif // FTLAbbreviations_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLAbstractHeap.cpp b/Source/JavaScriptCore/ftl/FTLAbstractHeap.cpp
index eadd5af97..90211fd94 100644
--- a/Source/JavaScriptCore/ftl/FTLAbstractHeap.cpp
+++ b/Source/JavaScriptCore/ftl/FTLAbstractHeap.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2015-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -28,51 +28,114 @@
 
 #if ENABLE(FTL_JIT)
 
-#include "FTLAbbreviations.h"
+#include "DFGCommon.h"
+#include "FTLAbbreviatedTypes.h"
 #include "FTLAbstractHeapRepository.h"
 #include "FTLOutput.h"
 #include "FTLTypedPointer.h"
-#include "Operations.h"
+#include "JSCInlines.h"
 #include "Options.h"
 
 namespace JSC { namespace FTL {
 
-LValue AbstractHeap::tbaaMetadataSlow(const AbstractHeapRepository& repository) const
+using namespace B3;
+
+AbstractHeap::AbstractHeap(AbstractHeap* parent, const char* heapName, ptrdiff_t offset)
+    : m_offset(offset)
+    , m_heapName(heapName)
 {
-    m_tbaaMetadata = mdNode(
-        repository.m_context,
-        mdString(repository.m_context, m_heapName),
-        m_parent->tbaaMetadata(repository));
-    return m_tbaaMetadata;
+    changeParent(parent);
 }
 
-void AbstractHeap::decorateInstruction(LValue instruction, const AbstractHeapRepository& repository) const
+void AbstractHeap::changeParent(AbstractHeap* parent)
 {
-    if (!Options::useFTLTBAA())
+    if (m_parent) {
+        bool result = m_parent->m_children.removeFirst(this);
+        RELEASE_ASSERT(result);
+    }
+
+    m_parent = parent;
+
+    if (parent) {
+        ASSERT(!m_parent->m_children.contains(this));
+        m_parent->m_children.append(this);
+    }
+}
+
+void AbstractHeap::compute(unsigned begin)
+{
+    // This recursively computes the ranges of the tree. This solves the following constraints
+    // in linear time:
+    //
+    // - A node's end is greater than its begin.
+    // - A node's begin is greater than or equal to its parent's begin.
+    // - A node's end is less than or equal to its parent's end.
+    // - The ranges are as small as possible.
+    //
+    // It's OK to recurse because we keep the depth of our abstract heap hierarchy fairly sane.
+    // I think that it gets 4 deep at most.
+
+    if (m_children.isEmpty()) {
+        // Must special-case leaves so that they use just one slot on the number line.
+        m_range = HeapRange(begin);
         return;
-    setMetadata(instruction, repository.m_tbaaKind, tbaaMetadata(repository));
+    }
+
+    unsigned current = begin;
+    for (AbstractHeap* child : m_children) {
+        child->compute(current);
+        current = child->range().end();
+    }
+
+    m_range = HeapRange(begin, current);
+}
+
+void AbstractHeap::shallowDump(PrintStream& out) const
+{
+    out.print(heapName(), "(", m_offset, ")");
+    if (m_range)
+        out.print("<", m_range, ">");
+}
+
+void AbstractHeap::dump(PrintStream& out) const
+{
+    shallowDump(out);
+    if (m_parent)
+        out.print("->", *m_parent);
 }
 
-IndexedAbstractHeap::IndexedAbstractHeap(LContext context, AbstractHeap* parent, const char* heapName, size_t elementSize)
+void AbstractHeap::deepDump(PrintStream& out, unsigned indent) const
+{
+    auto printIndent = [&] () {
+        for (unsigned i = indent; i--;)
+            out.print("    ");
+    };
+
+    printIndent();
+    shallowDump(out);
+
+    if (m_children.isEmpty()) {
+        out.print("\n");
+        return;
+    }
+
+    out.print(":\n");
+    for (AbstractHeap* child : m_children)
+        child->deepDump(out, indent + 1);
+}
+
+void AbstractHeap::badRangeError() const
+{
+    dataLog("Heap does not have range: ", *this, "\n");
+    RELEASE_ASSERT_NOT_REACHED();
+}
+
+IndexedAbstractHeap::IndexedAbstractHeap(AbstractHeap* parent, const char* heapName, ptrdiff_t offset, size_t elementSize)
     : m_heapForAnyIndex(parent, heapName)
     , m_heapNameLength(strlen(heapName))
+    , m_offset(offset)
     , m_elementSize(elementSize)
-    , m_scaleTerm(0)
-    , m_canShift(false)
-{
-    // See if there is a common shift amount we could use instead of multiplying. Don't
-    // try too hard. This is just a speculative optimization to reduce load on LLVM.
-    for (unsigned i = 0; i < 4; ++i) {
-        if ((1 << i) == m_elementSize) {
-            if (i)
-                m_scaleTerm = constInt(intPtrType(context), i, ZeroExtend);
-            m_canShift = true;
-            break;
-        }
-    }
-    
-    if (!m_canShift)
-        m_scaleTerm = constInt(intPtrType(context), m_elementSize, ZeroExtend);
+{
 }
 
 IndexedAbstractHeap::~IndexedAbstractHeap()
@@ -83,36 +146,29 @@ TypedPointer IndexedAbstractHeap::baseIndex(Output& out, LValue base, LValue ind
 {
     if (indexAsConstant.isInt32())
         return out.address(base, at(indexAsConstant.asInt32()), offset);
+
+    LValue result = out.add(base, out.mul(index, out.constIntPtr(m_elementSize)));
     
-    LValue result;
-    if (m_canShift) {
-        if (!m_scaleTerm)
-            result = out.add(base, index);
-        else
-            result = out.add(base, out.shl(index, m_scaleTerm));
-    } else
-        result = out.add(base, out.mul(index, m_scaleTerm));
-    
-    return TypedPointer(atAnyIndex(), out.addPtr(result, offset));
+    return TypedPointer(atAnyIndex(), out.addPtr(result, m_offset + offset));
 }
 
-const AbstractField& IndexedAbstractHeap::atSlow(ptrdiff_t index)
+const AbstractHeap& IndexedAbstractHeap::atSlow(ptrdiff_t index)
 {
     ASSERT(static_cast<size_t>(index) >= m_smallIndices.size());
     
     if (UNLIKELY(!m_largeIndices))
-        m_largeIndices = adoptPtr(new MapType());
+        m_largeIndices = std::make_unique<MapType>();
 
-    std::unique_ptr<AbstractField>& field = m_largeIndices->add(index, nullptr).iterator->value;
+    std::unique_ptr<AbstractHeap>& field = m_largeIndices->add(index, nullptr).iterator->value;
     if (!field) {
-        field = std::make_unique<AbstractField>();
+        field = std::make_unique<AbstractHeap>();
         initialize(*field, index);
     }
 
     return *field;
 }
 
-void IndexedAbstractHeap::initialize(AbstractField& field, ptrdiff_t signedIndex)
+void IndexedAbstractHeap::initialize(AbstractHeap& field, ptrdiff_t signedIndex)
 {
     // Build up a name of the form:
     //
@@ -131,7 +187,10 @@ void IndexedAbstractHeap::initialize(AbstractField& field, ptrdiff_t signedIndex
     //
     //    Blah_neg_A
     //
-    // This is important because LLVM uses the string to distinguish the types.
+    // This naming convention comes from our previous use of LLVM. It's not clear that we need
+    // it anymore, though it is sort of nifty. Basically, B3 doesn't need string names for
+    // abstract heaps, but the fact that we have a reasonably efficient way to always name the
+    // heaps will probably come in handy for debugging.
     
     static const char* negSplit = "_neg_";
     static const char* posSplit = "_";
@@ -168,16 +227,20 @@ void IndexedAbstractHeap::initialize(AbstractField& field, ptrdiff_t signedIndex
             accumulator >>= 4;
         }
         
-        field.initialize(&m_heapForAnyIndex, characters, signedIndex * m_elementSize);
+        field.initialize(&m_heapForAnyIndex, characters, m_offset + signedIndex * m_elementSize);
         return;
     }
     
     RELEASE_ASSERT_NOT_REACHED();
 }
 
-NumberedAbstractHeap::NumberedAbstractHeap(
-    LContext context, AbstractHeap* heap, const char* heapName)
-    : m_indexedHeap(context, heap, heapName, 1)
+void IndexedAbstractHeap::dump(PrintStream& out) const
+{
+    out.print("Indexed:", atAnyIndex());
+}
+
+NumberedAbstractHeap::NumberedAbstractHeap(AbstractHeap* heap, const char* heapName)
+    : m_indexedHeap(heap, heapName, 0, 1)
 {
 }
 
@@ -185,9 +248,13 @@ NumberedAbstractHeap::~NumberedAbstractHeap()
 {
 }
 
-AbsoluteAbstractHeap::AbsoluteAbstractHeap(
-    LContext context, AbstractHeap* heap, const char* heapName)
-    : m_indexedHeap(context, heap, heapName, 1)
+void NumberedAbstractHeap::dump(PrintStream& out) const
+{
+    out.print("Numbered: ", atAnyNumber());
+}
+
+AbsoluteAbstractHeap::AbsoluteAbstractHeap(AbstractHeap* heap, const char* heapName)
+    : m_indexedHeap(heap, heapName, 0, 1)
 {
 }
 
@@ -195,6 +262,11 @@ AbsoluteAbstractHeap::~AbsoluteAbstractHeap()
 {
 }
 
+void AbsoluteAbstractHeap::dump(PrintStream& out) const
+{
+    out.print("Absolute:", atAnyAddress());
+}
+
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLAbstractHeap.h b/Source/JavaScriptCore/ftl/FTLAbstractHeap.h
index e92a2fc2c..ae883a620 100644
--- a/Source/JavaScriptCore/ftl/FTLAbstractHeap.h
+++ b/Source/JavaScriptCore/ftl/FTLAbstractHeap.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2015-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,29 +23,22 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLAbstractHeap_h
-#define FTLAbstractHeap_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
-#include "FTLAbbreviations.h"
+#include "B3HeapRange.h"
+#include "FTLAbbreviatedTypes.h"
 #include "JSCJSValue.h"
 #include <array>
 #include <wtf/FastMalloc.h>
 #include <wtf/HashMap.h>
 #include <wtf/Noncopyable.h>
-#include <wtf/OwnPtr.h>
 #include <wtf/Vector.h>
 #include <wtf/text/CString.h>
 
 namespace JSC { namespace FTL {
 
-// The FTL JIT tries to aid LLVM's TBAA. The FTL's notion of how this
-// happens is the AbstractHeap. AbstractHeaps are a simple type system
-// with sub-typing.
-
 class AbstractHeapRepository;
 class Output;
 class TypedPointer;
@@ -54,132 +47,120 @@ class AbstractHeap {
     WTF_MAKE_NONCOPYABLE(AbstractHeap); WTF_MAKE_FAST_ALLOCATED;
 public:
     AbstractHeap()
-        : m_parent(0)
-        , m_heapName(0)
-        , m_tbaaMetadata(0)
-    {
-    }
-    
-    AbstractHeap(AbstractHeap* parent, const char* heapName)
-        : m_parent(parent)
-        , m_heapName(heapName)
-        , m_tbaaMetadata(0)
     {
     }
     
+    AbstractHeap(AbstractHeap* parent, const char* heapName, ptrdiff_t offset = 0);
+
     bool isInitialized() const { return !!m_heapName; }
     
-    void initialize(AbstractHeap* parent, const char* heapName)
+    void initialize(AbstractHeap* parent, const char* heapName, ptrdiff_t offset = 0)
     {
-        m_parent = parent;
+        changeParent(parent);
         m_heapName = heapName;
+        m_offset = offset;
     }
+    
+    void changeParent(AbstractHeap* parent);
 
     AbstractHeap* parent() const
     {
         ASSERT(isInitialized());
         return m_parent;
     }
+
+    const Vector<AbstractHeap*>& children() const;
     
     const char* heapName() const
     {
         ASSERT(isInitialized());
         return m_heapName;
     }
-    
-    LValue tbaaMetadata(const AbstractHeapRepository& repository) const
-    {
-        ASSERT(isInitialized());
-        if (LIKELY(!!m_tbaaMetadata))
-            return m_tbaaMetadata;
-        return tbaaMetadataSlow(repository);
-    }
-    
-    void decorateInstruction(LValue instruction, const AbstractHeapRepository&) const;
 
-private:
-    friend class AbstractHeapRepository;
-    
-    LValue tbaaMetadataSlow(const AbstractHeapRepository&) const;
-    
-    AbstractHeap* m_parent;
-    const char* m_heapName;
-    mutable LValue m_tbaaMetadata;
-};
-
-// Think of "AbstractField" as being an "AbstractHeapWithOffset". I would have named
-// it the latter except that I don't like typing that much.
-class AbstractField : public AbstractHeap {
-public:
-    AbstractField()
-    {
-    }
-    
-    AbstractField(AbstractHeap* parent, const char* heapName, ptrdiff_t offset)
-        : AbstractHeap(parent, heapName)
-        , m_offset(offset)
-    {
-    }
-    
-    void initialize(AbstractHeap* parent, const char* heapName, ptrdiff_t offset)
+    B3::HeapRange range() const
     {
-        AbstractHeap::initialize(parent, heapName);
-        m_offset = offset;
+        // This will not have a valid value until after all lowering is done. Do associate an
+        // AbstractHeap with a B3::Value*, use AbstractHeapRepository::decorateXXX().
+        if (!m_range)
+            badRangeError();
+        
+        return m_range;
     }
-    
+
+    // WARNING: Not all abstract heaps have a meaningful offset.
     ptrdiff_t offset() const
     {
         ASSERT(isInitialized());
         return m_offset;
     }
-    
+
+    void compute(unsigned begin = 0);
+
+    // Print information about just this heap.
+    void shallowDump(PrintStream&) const;
+
+    // Print information about this heap and its ancestors. This is the default.
+    void dump(PrintStream&) const;
+
+    // Print information about this heap and its descendents. This is a multi-line dump.
+    void deepDump(PrintStream&, unsigned indent = 0) const;
+
 private:
-    ptrdiff_t m_offset;
+    friend class AbstractHeapRepository;
+
+    NO_RETURN_DUE_TO_CRASH void badRangeError() const;
+
+    AbstractHeap* m_parent { nullptr };
+    Vector<AbstractHeap*> m_children;
+    intptr_t m_offset { 0 };
+    B3::HeapRange m_range;
+    const char* m_heapName { nullptr };
 };
 
 class IndexedAbstractHeap {
 public:
-    IndexedAbstractHeap(LContext, AbstractHeap* parent, const char* heapName, size_t elementSize);
+    IndexedAbstractHeap(AbstractHeap* parent, const char* heapName, ptrdiff_t offset, size_t elementSize);
     ~IndexedAbstractHeap();
     
     const AbstractHeap& atAnyIndex() const { return m_heapForAnyIndex; }
     
-    const AbstractField& at(ptrdiff_t index)
+    const AbstractHeap& at(ptrdiff_t index)
     {
         if (static_cast<size_t>(index) < m_smallIndices.size())
             return returnInitialized(m_smallIndices[index], index);
         return atSlow(index);
     }
     
-    const AbstractField& operator[](ptrdiff_t index) { return at(index); }
+    const AbstractHeap& operator[](ptrdiff_t index) { return at(index); }
     
     TypedPointer baseIndex(Output& out, LValue base, LValue index, JSValue indexAsConstant = JSValue(), ptrdiff_t offset = 0);
     
+    void dump(PrintStream&) const;
+
 private:
-    const AbstractField& returnInitialized(AbstractField& field, ptrdiff_t index)
+    const AbstractHeap& returnInitialized(AbstractHeap& field, ptrdiff_t index)
     {
         if (UNLIKELY(!field.isInitialized()))
             initialize(field, index);
         return field;
     }
 
-    const AbstractField& atSlow(ptrdiff_t index);
-    void initialize(AbstractField& field, ptrdiff_t index);
+    const AbstractHeap& atSlow(ptrdiff_t index);
+    void initialize(AbstractHeap& field, ptrdiff_t index);
 
     AbstractHeap m_heapForAnyIndex;
     size_t m_heapNameLength;
+    ptrdiff_t m_offset;
     size_t m_elementSize;
-    LValue m_scaleTerm;
-    bool m_canShift;
-    std::array<AbstractField, 16> m_smallIndices;
+    std::array<AbstractHeap, 16> m_smallIndices;
     
     struct WithoutZeroOrOneHashTraits : WTF::GenericHashTraits<ptrdiff_t> {
         static void constructDeletedValue(ptrdiff_t& slot) { slot = 1; }
         static bool isDeletedValue(ptrdiff_t value) { return value == 1; }
     };
-    typedef HashMap<ptrdiff_t, std::unique_ptr<AbstractField>, WTF::IntHash<ptrdiff_t>, WithoutZeroOrOneHashTraits> MapType;
+    typedef HashMap<ptrdiff_t, std::unique_ptr<AbstractHeap>, WTF::IntHash<ptrdiff_t>, WithoutZeroOrOneHashTraits> MapType;
     
-    OwnPtr<MapType> m_largeIndices;
+    std::unique_ptr<MapType> m_largeIndices;
     Vector<CString, 16> m_largeIndexNames;
 };
 
@@ -190,7 +171,7 @@ private:
 
 class NumberedAbstractHeap {
 public:
-    NumberedAbstractHeap(LContext, AbstractHeap* parent, const char* heapName);
+    NumberedAbstractHeap(AbstractHeap* parent, const char* heapName);
     ~NumberedAbstractHeap();
     
     const AbstractHeap& atAnyNumber() const { return m_indexedHeap.atAnyIndex(); }
@@ -198,6 +179,8 @@ public:
     const AbstractHeap& at(unsigned number) { return m_indexedHeap.at(number); }
     const AbstractHeap& operator[](unsigned number) { return at(number); }
 
+    void dump(PrintStream&) const;
+
 private:
     
     // We use the fact that the indexed heap already has a superset of the
@@ -207,17 +190,19 @@ private:
 
 class AbsoluteAbstractHeap {
 public:
-    AbsoluteAbstractHeap(LContext, AbstractHeap* parent, const char* heapName);
+    AbsoluteAbstractHeap(AbstractHeap* parent, const char* heapName);
     ~AbsoluteAbstractHeap();
     
     const AbstractHeap& atAnyAddress() const { return m_indexedHeap.atAnyIndex(); }
     
-    const AbstractHeap& at(void* address)
+    const AbstractHeap& at(const void* address)
     {
         return m_indexedHeap.at(bitwise_cast<ptrdiff_t>(address));
     }
     
-    const AbstractHeap& operator[](void* address) { return at(address); }
+    const AbstractHeap& operator[](const void* address) { return at(address); }
+
+    void dump(PrintStream&) const;
 
 private:
     // The trick here is that the indexed heap is "indexed" by a pointer-width
@@ -229,6 +214,3 @@ private:
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLAbstractHeap_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLAbstractHeapRepository.cpp b/Source/JavaScriptCore/ftl/FTLAbstractHeapRepository.cpp
index d7f83c960..0b48c4b19 100644
--- a/Source/JavaScriptCore/ftl/FTLAbstractHeapRepository.cpp
+++ b/Source/JavaScriptCore/ftl/FTLAbstractHeapRepository.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -28,14 +28,29 @@
 
 #if ENABLE(FTL_JIT)
 
+#include "B3CCallValue.h"
+#include "B3FenceValue.h"
+#include "B3MemoryValue.h"
+#include "B3PatchpointValue.h"
+#include "B3ValueInlines.h"
+#include "DirectArguments.h"
+#include "FTLState.h"
+#include "GetterSetter.h"
+#include "JSPropertyNameEnumerator.h"
 #include "JSScope.h"
-#include "JSVariableObject.h"
-#include "Operations.h"
+#include "JSCInlines.h"
+#include "RegExpConstructor.h"
+#include "RegExpObject.h"
+#include "ScopedArguments.h"
+#include "ScopedArgumentsTable.h"
+#include "ShadowChicken.h"
 
 namespace JSC { namespace FTL {
 
-AbstractHeapRepository::AbstractHeapRepository(LContext context)
-    : root(0, "jscRoot")
+using namespace B3;
+
+AbstractHeapRepository::AbstractHeapRepository()
+    : root(nullptr, "jscRoot")
 
 #define ABSTRACT_HEAP_INITIALIZATION(name) , name(&root, #name)
     FOR_EACH_ABSTRACT_HEAP(ABSTRACT_HEAP_INITIALIZATION)
@@ -45,25 +60,31 @@ AbstractHeapRepository::AbstractHeapRepository(LContext context)
     FOR_EACH_ABSTRACT_FIELD(ABSTRACT_FIELD_INITIALIZATION)
 #undef ABSTRACT_FIELD_INITIALIZATION
     
-    , JSCell_freeListNext(JSCell_structure)
+    , JSCell_freeListNext(JSCell_header)
     
-#define INDEXED_ABSTRACT_HEAP_INITIALIZATION(name, size) , name(context, &root, #name, size)
+#define INDEXED_ABSTRACT_HEAP_INITIALIZATION(name, offset, size) , name(&root, #name, offset, size)
     FOR_EACH_INDEXED_ABSTRACT_HEAP(INDEXED_ABSTRACT_HEAP_INITIALIZATION)
 #undef INDEXED_ABSTRACT_HEAP_INITIALIZATION
     
-#define NUMBERED_ABSTRACT_HEAP_INITIALIZATION(name) , name(context, &root, #name)
+#define NUMBERED_ABSTRACT_HEAP_INITIALIZATION(name) , name(&root, #name)
     FOR_EACH_NUMBERED_ABSTRACT_HEAP(NUMBERED_ABSTRACT_HEAP_INITIALIZATION)
 #undef NUMBERED_ABSTRACT_HEAP_INITIALIZATION
 
-    , absolute(context, &root, "absolute")
-    , m_context(context)
-    , m_tbaaKind(mdKindID(m_context, "tbaa"))
+    , absolute(&root, "absolute")
 {
-    root.m_tbaaMetadata = mdNode(m_context, mdString(m_context, root.m_heapName));
-    
-    RELEASE_ASSERT(m_tbaaKind);
-    RELEASE_ASSERT(root.m_tbaaMetadata);
-    
+    // Make sure that our explicit assumptions about the StructureIDBlob match reality.
+    RELEASE_ASSERT(!(JSCell_indexingTypeAndMisc.offset() & (sizeof(int32_t) - 1)));
+    RELEASE_ASSERT(JSCell_indexingTypeAndMisc.offset() + 1 == JSCell_typeInfoType.offset());
+    RELEASE_ASSERT(JSCell_indexingTypeAndMisc.offset() + 2 == JSCell_typeInfoFlags.offset());
+    RELEASE_ASSERT(JSCell_indexingTypeAndMisc.offset() + 3 == JSCell_cellState.offset());
+
+    JSCell_structureID.changeParent(&JSCell_header);
+    JSCell_usefulBytes.changeParent(&JSCell_header);
+    JSCell_indexingTypeAndMisc.changeParent(&JSCell_usefulBytes);
+    JSCell_typeInfoType.changeParent(&JSCell_usefulBytes);
+    JSCell_typeInfoFlags.changeParent(&JSCell_usefulBytes);
+    JSCell_cellState.changeParent(&JSCell_usefulBytes);
+
     RELEASE_ASSERT(!JSCell_freeListNext.offset());
 }
 
@@ -71,6 +92,72 @@ AbstractHeapRepository::~AbstractHeapRepository()
 {
 }
 
+void AbstractHeapRepository::decorateMemory(const AbstractHeap* heap, Value* value)
+{
+    m_heapForMemory.append(HeapForValue(heap, value));
+}
+
+void AbstractHeapRepository::decorateCCallRead(const AbstractHeap* heap, Value* value)
+{
+    m_heapForCCallRead.append(HeapForValue(heap, value));
+}
+
+void AbstractHeapRepository::decorateCCallWrite(const AbstractHeap* heap, Value* value)
+{
+    m_heapForCCallWrite.append(HeapForValue(heap, value));
+}
+
+void AbstractHeapRepository::decoratePatchpointRead(const AbstractHeap* heap, Value* value)
+{
+    m_heapForPatchpointRead.append(HeapForValue(heap, value));
+}
+
+void AbstractHeapRepository::decoratePatchpointWrite(const AbstractHeap* heap, Value* value)
+{
+    m_heapForPatchpointWrite.append(HeapForValue(heap, value));
+}
+
+void AbstractHeapRepository::decorateFenceRead(const AbstractHeap* heap, Value* value)
+{
+    m_heapForFenceRead.append(HeapForValue(heap, value));
+}
+
+void AbstractHeapRepository::decorateFenceWrite(const AbstractHeap* heap, Value* value)
+{
+    m_heapForFenceWrite.append(HeapForValue(heap, value));
+}
+
+void AbstractHeapRepository::computeRangesAndDecorateInstructions()
+{
+    root.compute();
+
+    if (verboseCompilationEnabled()) {
+        dataLog("Abstract Heap Repository:\n");
+        root.deepDump(WTF::dataFile());
+    }
+    
+    auto rangeFor = [&] (const AbstractHeap* heap) -> HeapRange {
+        if (heap)
+            return heap->range();
+        return HeapRange();
+    };
+
+    for (HeapForValue entry : m_heapForMemory)
+        entry.value->as<MemoryValue>()->setRange(rangeFor(entry.heap));
+    for (HeapForValue entry : m_heapForCCallRead)
+        entry.value->as<CCallValue>()->effects.reads = rangeFor(entry.heap);
+    for (HeapForValue entry : m_heapForCCallWrite)
+        entry.value->as<CCallValue>()->effects.writes = rangeFor(entry.heap);
+    for (HeapForValue entry : m_heapForPatchpointRead)
+        entry.value->as<PatchpointValue>()->effects.reads = rangeFor(entry.heap);
+    for (HeapForValue entry : m_heapForPatchpointWrite)
+        entry.value->as<PatchpointValue>()->effects.writes = rangeFor(entry.heap);
+    for (HeapForValue entry : m_heapForFenceRead)
+        entry.value->as<FenceValue>()->read = rangeFor(entry.heap);
+    for (HeapForValue entry : m_heapForFenceWrite)
+        entry.value->as<FenceValue>()->write = rangeFor(entry.heap);
+}
+
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLAbstractHeapRepository.h b/Source/JavaScriptCore/ftl/FTLAbstractHeapRepository.h
index f811c8be5..4268179c3 100644
--- a/Source/JavaScriptCore/ftl/FTLAbstractHeapRepository.h
+++ b/Source/JavaScriptCore/ftl/FTLAbstractHeapRepository.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2017 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,55 +23,122 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLAbstractHeapRepository_h
-#define FTLAbstractHeapRepository_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
+#include "B3Value.h"
+#include "DFGArrayMode.h"
 #include "FTLAbstractHeap.h"
+#include "HasOwnPropertyCache.h"
 #include "IndexingType.h"
+#include "JSFixedArray.h"
+#include "JSMap.h"
+#include "JSSet.h"
+#include "Symbol.h"
 
 namespace JSC { namespace FTL {
 
 #define FOR_EACH_ABSTRACT_HEAP(macro) \
-    macro(length) \
-    macro(typedArrayProperties) \
-    macro(WriteBarrierBuffer_bufferContents)
+    macro(typedArrayProperties)
 
 #define FOR_EACH_ABSTRACT_FIELD(macro) \
+    macro(ArrayBuffer_data, ArrayBuffer::offsetOfData()) \
+    macro(Butterfly_arrayBuffer, Butterfly::offsetOfArrayBuffer()) \
     macro(Butterfly_publicLength, Butterfly::offsetOfPublicLength()) \
     macro(Butterfly_vectorLength, Butterfly::offsetOfVectorLength()) \
     macro(CallFrame_callerFrame, CallFrame::callerFrameOffset()) \
+    macro(DirectArguments_callee, DirectArguments::offsetOfCallee()) \
+    macro(DirectArguments_length, DirectArguments::offsetOfLength()) \
+    macro(DirectArguments_minCapacity, DirectArguments::offsetOfMinCapacity()) \
+    macro(DirectArguments_mappedArguments, DirectArguments::offsetOfMappedArguments()) \
+    macro(DirectArguments_modifiedArgumentsDescriptor, DirectArguments::offsetOfModifiedArgumentsDescriptor()) \
+    macro(GetterSetter_getter, GetterSetter::offsetOfGetter()) \
+    macro(GetterSetter_setter, GetterSetter::offsetOfSetter()) \
     macro(JSArrayBufferView_length, JSArrayBufferView::offsetOfLength()) \
     macro(JSArrayBufferView_mode, JSArrayBufferView::offsetOfMode()) \
     macro(JSArrayBufferView_vector, JSArrayBufferView::offsetOfVector()) \
-    macro(JSCell_structure, JSCell::structureOffset()) \
+    macro(JSCell_cellState, JSCell::cellStateOffset()) \
+    macro(JSCell_header, 0) \
+    macro(JSCell_indexingTypeAndMisc, JSCell::indexingTypeAndMiscOffset()) \
+    macro(JSCell_structureID, JSCell::structureIDOffset()) \
+    macro(JSCell_typeInfoFlags, JSCell::typeInfoFlagsOffset()) \
+    macro(JSCell_typeInfoType, JSCell::typeInfoTypeOffset()) \
+    macro(JSCell_usefulBytes, JSCell::indexingTypeAndMiscOffset()) \
+    macro(JSFunction_executable, JSFunction::offsetOfExecutable()) \
+    macro(JSFunction_scope, JSFunction::offsetOfScopeChain()) \
+    macro(JSFunction_rareData, JSFunction::offsetOfRareData()) \
     macro(JSObject_butterfly, JSObject::butterflyOffset()) \
+    macro(JSPropertyNameEnumerator_cachedInlineCapacity, JSPropertyNameEnumerator::cachedInlineCapacityOffset()) \
+    macro(JSPropertyNameEnumerator_cachedPropertyNamesVector, JSPropertyNameEnumerator::cachedPropertyNamesVectorOffset()) \
+    macro(JSPropertyNameEnumerator_cachedStructureID, JSPropertyNameEnumerator::cachedStructureIDOffset()) \
+    macro(JSPropertyNameEnumerator_endGenericPropertyIndex, JSPropertyNameEnumerator::endGenericPropertyIndexOffset()) \
+    macro(JSPropertyNameEnumerator_endStructurePropertyIndex, JSPropertyNameEnumerator::endStructurePropertyIndexOffset()) \
+    macro(JSPropertyNameEnumerator_indexLength, JSPropertyNameEnumerator::indexedLengthOffset()) \
     macro(JSScope_next, JSScope::offsetOfNext()) \
+    macro(JSString_flags, JSString::offsetOfFlags()) \
     macro(JSString_length, JSString::offsetOfLength()) \
     macro(JSString_value, JSString::offsetOfValue()) \
-    macro(JSVariableObject_registers, JSVariableObject::offsetOfRegisters()) \
-    macro(MarkedAllocator_freeListHead, MarkedAllocator::offsetOfFreeListHead()) \
-    macro(MarkedBlock_markBits, MarkedBlock::offsetOfMarks()) \
+    macro(JSSymbolTableObject_symbolTable, JSSymbolTableObject::offsetOfSymbolTable()) \
+    macro(JSWrapperObject_internalValue, JSWrapperObject::internalValueOffset()) \
+    macro(RegExpConstructor_cachedResult_lastRegExp, RegExpConstructor::offsetOfCachedResult() + RegExpCachedResult::offsetOfLastRegExp()) \
+    macro(RegExpConstructor_cachedResult_lastInput, RegExpConstructor::offsetOfCachedResult() + RegExpCachedResult::offsetOfLastInput()) \
+    macro(RegExpConstructor_cachedResult_result_start, RegExpConstructor::offsetOfCachedResult() + RegExpCachedResult::offsetOfResult() + OBJECT_OFFSETOF(MatchResult, start)) \
+    macro(RegExpConstructor_cachedResult_result_end, RegExpConstructor::offsetOfCachedResult() + RegExpCachedResult::offsetOfResult() + OBJECT_OFFSETOF(MatchResult, end)) \
+    macro(RegExpConstructor_cachedResult_reified, RegExpConstructor::offsetOfCachedResult() + RegExpCachedResult::offsetOfReified()) \
+    macro(RegExpObject_lastIndex, RegExpObject::offsetOfLastIndex()) \
+    macro(RegExpObject_lastIndexIsWritable, RegExpObject::offsetOfLastIndexIsWritable()) \
+    macro(ShadowChicken_Packet_callee, OBJECT_OFFSETOF(ShadowChicken::Packet, callee)) \
+    macro(ShadowChicken_Packet_frame, OBJECT_OFFSETOF(ShadowChicken::Packet, frame)) \
+    macro(ShadowChicken_Packet_callerFrame, OBJECT_OFFSETOF(ShadowChicken::Packet, callerFrame)) \
+    macro(ShadowChicken_Packet_thisValue, OBJECT_OFFSETOF(ShadowChicken::Packet, thisValue)) \
+    macro(ShadowChicken_Packet_scope, OBJECT_OFFSETOF(ShadowChicken::Packet, scope)) \
+    macro(ShadowChicken_Packet_codeBlock, OBJECT_OFFSETOF(ShadowChicken::Packet, codeBlock)) \
+    macro(ShadowChicken_Packet_callSiteIndex, OBJECT_OFFSETOF(ShadowChicken::Packet, callSiteIndex)) \
+    macro(ScopedArguments_overrodeThings, ScopedArguments::offsetOfOverrodeThings()) \
+    macro(ScopedArguments_scope, ScopedArguments::offsetOfScope()) \
+    macro(ScopedArguments_table, ScopedArguments::offsetOfTable()) \
+    macro(ScopedArguments_totalLength, ScopedArguments::offsetOfTotalLength()) \
+    macro(ScopedArgumentsTable_arguments, ScopedArgumentsTable::offsetOfArguments()) \
+    macro(ScopedArgumentsTable_length, ScopedArgumentsTable::offsetOfLength()) \
     macro(StringImpl_data, StringImpl::dataOffset()) \
     macro(StringImpl_hashAndFlags, StringImpl::flagsOffset()) \
+    macro(StringImpl_length, StringImpl::lengthMemoryOffset()) \
     macro(Structure_classInfo, Structure::classInfoOffset()) \
     macro(Structure_globalObject, Structure::globalObjectOffset()) \
-    macro(Structure_indexingType, Structure::indexingTypeOffset()) \
-    macro(Structure_typeInfoFlags, Structure::typeInfoFlagsOffset()) \
-    macro(Structure_typeInfoType, Structure::typeInfoTypeOffset())
+    macro(Structure_prototype, Structure::prototypeOffset()) \
+    macro(Structure_structureID, Structure::structureIDOffset()) \
+    macro(Structure_inlineCapacity, Structure::inlineCapacityOffset()) \
+    macro(Structure_indexingTypeIncludingHistory, Structure::indexingTypeIncludingHistoryOffset()) \
+    macro(JSMap_hashMapImpl, JSMap::offsetOfHashMapImpl()) \
+    macro(JSSet_hashMapImpl, JSSet::offsetOfHashMapImpl()) \
+    macro(HashMapImpl_capacity, HashMapImpl<HashMapBucket<HashMapBucketDataKey>>::offsetOfCapacity()) \
+    macro(HashMapImpl_buffer,  HashMapImpl<HashMapBucket<HashMapBucketDataKey>>::offsetOfBuffer()) \
+    macro(HashMapBucket_value, HashMapBucket<HashMapBucketDataKeyValue>::offsetOfValue()) \
+    macro(HashMapBucket_key, HashMapBucket<HashMapBucketDataKeyValue>::offsetOfKey()) \
+    macro(Symbol_symbolImpl, Symbol::offsetOfSymbolImpl()) \
+    macro(JSFixedArray_size, JSFixedArray::offsetOfSize()) \
 
 #define FOR_EACH_INDEXED_ABSTRACT_HEAP(macro) \
-    macro(characters8, sizeof(LChar)) \
-    macro(characters16, sizeof(UChar)) \
-    macro(indexedInt32Properties, sizeof(EncodedJSValue)) \
-    macro(indexedDoubleProperties, sizeof(double)) \
-    macro(indexedContiguousProperties, sizeof(EncodedJSValue)) \
-    macro(indexedArrayStorageProperties, sizeof(EncodedJSValue)) \
-    macro(singleCharacterStrings, sizeof(JSString*)) \
-    macro(variables, sizeof(Register))
+    macro(DirectArguments_storage, DirectArguments::storageOffset(), sizeof(EncodedJSValue)) \
+    macro(JSEnvironmentRecord_variables, JSEnvironmentRecord::offsetOfVariables(), sizeof(EncodedJSValue)) \
+    macro(JSPropertyNameEnumerator_cachedPropertyNamesVectorContents, 0, sizeof(WriteBarrier<JSString>)) \
+    macro(JSRopeString_fibers, JSRopeString::offsetOfFibers(), sizeof(WriteBarrier<JSString>)) \
+    macro(ScopedArguments_overflowStorage, ScopedArguments::overflowStorageOffset(), sizeof(EncodedJSValue)) \
+    macro(Subspace_allocatorForSizeStep, Subspace::offsetOfAllocatorForSizeStep(), sizeof(MarkedAllocator*)) \
+    macro(WriteBarrierBuffer_bufferContents, 0, sizeof(JSCell*)) \
+    macro(characters8, 0, sizeof(LChar)) \
+    macro(characters16, 0, sizeof(UChar)) \
+    macro(indexedInt32Properties, 0, sizeof(EncodedJSValue)) \
+    macro(indexedDoubleProperties, 0, sizeof(double)) \
+    macro(indexedContiguousProperties, 0, sizeof(EncodedJSValue)) \
+    macro(indexedArrayStorageProperties, 0, sizeof(EncodedJSValue)) \
+    macro(scopedArgumentsTableArguments, 0, sizeof(int32_t)) \
+    macro(singleCharacterStrings, 0, sizeof(JSString*)) \
+    macro(structureTable, 0, sizeof(Structure*)) \
+    macro(variables, 0, sizeof(Register)) \
+    macro(HasOwnPropertyCache, 0, sizeof(HasOwnPropertyCache::Entry)) \
+    macro(JSFixedArray_buffer, JSFixedArray::offsetOfData(), sizeof(EncodedJSValue)) \
     
 #define FOR_EACH_NUMBERED_ABSTRACT_HEAP(macro) \
     macro(properties)
@@ -82,7 +149,7 @@ namespace JSC { namespace FTL {
 class AbstractHeapRepository {
     WTF_MAKE_NONCOPYABLE(AbstractHeapRepository);
 public:
-    AbstractHeapRepository(LContext);
+    AbstractHeapRepository();
     ~AbstractHeapRepository();
     
     AbstractHeap root;
@@ -91,13 +158,13 @@ public:
     FOR_EACH_ABSTRACT_HEAP(ABSTRACT_HEAP_DECLARATION)
 #undef ABSTRACT_HEAP_DECLARATION
 
-#define ABSTRACT_FIELD_DECLARATION(name, offset) AbstractField name;
+#define ABSTRACT_FIELD_DECLARATION(name, offset) AbstractHeap name;
     FOR_EACH_ABSTRACT_FIELD(ABSTRACT_FIELD_DECLARATION)
 #undef ABSTRACT_FIELD_DECLARATION
     
-    AbstractField& JSCell_freeListNext;
+    AbstractHeap& JSCell_freeListNext;
     
-#define INDEXED_ABSTRACT_HEAP_DECLARATION(name, size) IndexedAbstractHeap name;
+#define INDEXED_ABSTRACT_HEAP_DECLARATION(name, offset, size) IndexedAbstractHeap name;
     FOR_EACH_INDEXED_ABSTRACT_HEAP(INDEXED_ABSTRACT_HEAP_DECLARATION)
 #undef INDEXED_ABSTRACT_HEAP_DECLARATION
     
@@ -131,17 +198,61 @@ public:
             return 0;
         }
     }
+    
+    IndexedAbstractHeap& forArrayType(DFG::Array::Type type)
+    {
+        switch (type) {
+        case DFG::Array::Int32:
+            return indexedInt32Properties;
+        case DFG::Array::Double:
+            return indexedDoubleProperties;
+        case DFG::Array::Contiguous:
+            return indexedContiguousProperties;
+        case DFG::Array::ArrayStorage:
+        case DFG::Array::SlowPutArrayStorage:
+            return indexedArrayStorageProperties;
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+            return indexedInt32Properties;
+        }
+    }
+
+    void decorateMemory(const AbstractHeap*, B3::Value*);
+    void decorateCCallRead(const AbstractHeap*, B3::Value*);
+    void decorateCCallWrite(const AbstractHeap*, B3::Value*);
+    void decoratePatchpointRead(const AbstractHeap*, B3::Value*);
+    void decoratePatchpointWrite(const AbstractHeap*, B3::Value*);
+    void decorateFenceRead(const AbstractHeap*, B3::Value*);
+    void decorateFenceWrite(const AbstractHeap*, B3::Value*);
+
+    void computeRangesAndDecorateInstructions();
 
 private:
-    friend class AbstractHeap;
-    
-    LContext m_context;
-    unsigned m_tbaaKind;
+
+    struct HeapForValue {
+        HeapForValue()
+        {
+        }
+
+        HeapForValue(const AbstractHeap* heap, B3::Value* value)
+            : heap(heap)
+            , value(value)
+        {
+        }
+        
+        const AbstractHeap* heap { nullptr };
+        B3::Value* value { nullptr };
+    };
+
+    Vector<HeapForValue> m_heapForMemory;
+    Vector<HeapForValue> m_heapForCCallRead;
+    Vector<HeapForValue> m_heapForCCallWrite;
+    Vector<HeapForValue> m_heapForPatchpointRead;
+    Vector<HeapForValue> m_heapForPatchpointWrite;
+    Vector<HeapForValue> m_heapForFenceRead;
+    Vector<HeapForValue> m_heapForFenceWrite;
 };
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLAbstractHeapRepository_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLAvailableRecovery.cpp b/Source/JavaScriptCore/ftl/FTLAvailableRecovery.cpp
new file mode 100644
index 000000000..6c00fa4d9
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLAvailableRecovery.cpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLAvailableRecovery.h"
+
+#if ENABLE(FTL_JIT)
+
+namespace JSC { namespace FTL {
+
+void AvailableRecovery::dump(PrintStream& out) const
+{
+    out.print(node(), " => ", opcode(), ", ", RawPointer(m_left), ", ", RawPointer(m_right), ", ", m_format);
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLAvailableRecovery.h b/Source/JavaScriptCore/ftl/FTLAvailableRecovery.h
new file mode 100644
index 000000000..1f36c3b87
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLAvailableRecovery.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+#include "DFGNode.h"
+#include "DataFormat.h"
+#include "FTLAbbreviatedTypes.h"
+#include "FTLRecoveryOpcode.h"
+
+namespace JSC { namespace FTL {
+
+class AvailableRecovery {
+public:
+    AvailableRecovery()
+        : m_node(0)
+        , m_format(DataFormatNone)
+        , m_opcode(AddRecovery)
+        , m_left(0)
+        , m_right(0)
+    {
+    }
+    
+    AvailableRecovery(DFG::Node* node, RecoveryOpcode opcode, LValue left, LValue right, DataFormat format)
+        : m_node(node)
+        , m_format(format)
+        , m_opcode(opcode)
+        , m_left(left)
+        , m_right(right)
+    {
+    }
+    
+    DFG::Node* node() const { return m_node; }
+    DataFormat format() const { return m_format; }
+    RecoveryOpcode opcode() const { return m_opcode; }
+    LValue left() const { return m_left; }
+    LValue right() const { return m_right; }
+    
+    void dump(PrintStream&) const;
+    
+private:
+    DFG::Node* m_node;
+    DataFormat m_format;
+    RecoveryOpcode m_opcode;
+    LValue m_left;
+    LValue m_right;
+};
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLCapabilities.cpp b/Source/JavaScriptCore/ftl/FTLCapabilities.cpp
index 86a28cf8a..81d566583 100644
--- a/Source/JavaScriptCore/ftl/FTLCapabilities.cpp
+++ b/Source/JavaScriptCore/ftl/FTLCapabilities.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -32,6 +32,11 @@ namespace JSC { namespace FTL {
 
 using namespace DFG;
 
+static bool verboseCapabilities()
+{
+    return verboseCompilationEnabled() || Options::verboseFTLFailure();
+}
+
 inline CapabilityLevel canCompile(Node* node)
 {
     // NOTE: If we ever have phantom arguments, we can compile them but we cannot
@@ -39,11 +44,15 @@ inline CapabilityLevel canCompile(Node* node)
     
     switch (node->op()) {
     case JSConstant:
-    case WeakJSConstant:
+    case LazyJSConstant:
     case GetLocal:
     case SetLocal:
+    case PutStack:
+    case KillStack:
+    case GetStack:
     case MovHint:
     case ZombieHint:
+    case ExitOK:
     case Phantom:
     case Flush:
     case PhantomLocal:
@@ -56,20 +65,28 @@ inline CapabilityLevel canCompile(Node* node)
     case BitLShift:
     case BitURShift:
     case CheckStructure:
-    case StructureTransitionWatchpoint:
+    case DoubleAsInt32:
     case ArrayifyToStructure:
     case PutStructure:
-    case PhantomPutStructure:
     case GetButterfly:
     case NewObject:
     case NewArray:
+    case NewArrayWithSpread:
+    case Spread:
     case NewArrayBuffer:
+    case NewTypedArray:
     case GetByOffset:
+    case GetGetterSetterByOffset:
+    case GetGetter:
+    case GetSetter:
     case PutByOffset:
     case GetGlobalVar:
-    case PutGlobalVar:
+    case GetGlobalLexicalVariable:
+    case PutGlobalVariable:
     case ValueAdd:
+    case StrCat:
     case ArithAdd:
+    case ArithClz32:
     case ArithSub:
     case ArithMul:
     case ArithDiv:
@@ -77,61 +94,213 @@ inline CapabilityLevel canCompile(Node* node)
     case ArithMin:
     case ArithMax:
     case ArithAbs:
+    case ArithSin:
+    case ArithCos:
+    case ArithTan:
+    case ArithPow:
+    case ArithRandom:
+    case ArithRound:
+    case ArithFloor:
+    case ArithCeil:
+    case ArithTrunc:
+    case ArithSqrt:
+    case ArithLog:
+    case ArithFRound:
     case ArithNegate:
     case UInt32ToNumber:
-    case Int32ToDouble:
-    case CompareEqConstant:
-    case CompareStrictEqConstant:
     case Jump:
     case ForceOSRExit:
     case Phi:
     case Upsilon:
     case ExtractOSREntryLocal:
     case LoopHint:
-    case Call:
-    case Construct:
-    case GetMyScope:
     case SkipScope:
-    case GetClosureRegisters:
+    case GetGlobalObject:
+    case CreateActivation:
+    case NewFunction:
+    case NewGeneratorFunction:
+    case NewAsyncFunction:
     case GetClosureVar:
     case PutClosureVar:
-    case Int52ToValue:
+    case CreateDirectArguments:
+    case CreateScopedArguments:
+    case CreateClonedArguments:
+    case GetFromArguments:
+    case PutToArguments:
+    case GetArgument:
     case InvalidationPoint:
     case StringCharAt:
-    case CheckFunction:
+    case CheckCell:
+    case CheckBadCell:
+    case CheckNotEmpty:
+    case CheckStringIdent:
+    case CheckWatchdogTimer:
     case StringCharCodeAt:
+    case StringFromCharCode:
     case AllocatePropertyStorage:
-    case FunctionReentryWatchpoint:
-    case TypedArrayWatchpoint:
-    case VariableWatchpoint:
+    case ReallocatePropertyStorage:
+    case NukeStructureAndSetButterfly:
+    case GetTypedArrayByteOffset:
     case NotifyWrite:
     case StoreBarrier:
-    case ConditionalStoreBarrier:
-    case StoreBarrierWithNullCheck:
+    case FencedStoreBarrier:
+    case Call:
+    case DirectCall:
+    case TailCall:
+    case DirectTailCall:
+    case TailCallInlinedCaller:
+    case DirectTailCallInlinedCaller:
+    case Construct:
+    case DirectConstruct:
+    case CallVarargs:
+    case CallEval:
+    case TailCallVarargs:
+    case TailCallVarargsInlinedCaller:
+    case ConstructVarargs:
+    case CallForwardVarargs:
+    case TailCallForwardVarargs:
+    case TailCallForwardVarargsInlinedCaller:
+    case ConstructForwardVarargs:
+    case LoadVarargs:
     case ValueToInt32:
     case Branch:
     case LogicalNot:
     case CheckInBounds:
     case ConstantStoragePointer:
     case Check:
-        // These are OK.
-        break;
+    case CountExecution:
+    case GetExecutable:
+    case GetScope:
+    case GetCallee:
+    case GetArgumentCountIncludingThis:
+    case ToNumber:
+    case ToString:
+    case CallObjectConstructor:
+    case CallStringConstructor:
+    case MakeRope:
+    case NewArrayWithSize:
+    case TryGetById:
     case GetById:
-    case PutById:
-        if (node->child1().useKind() == CellUse)
-            break;
-        return CannotCompile;
+    case GetByIdFlush:
+    case GetByIdWithThis:
+    case ToThis:
+    case MultiGetByOffset:
+    case MultiPutByOffset:
+    case ToPrimitive:
+    case Throw:
+    case ThrowStaticError:
+    case Unreachable:
+    case In:
+    case HasOwnProperty:
+    case IsCellWithType:
+    case MapHash:
+    case GetMapBucket:
+    case LoadFromJSMapBucket:
+    case IsNonEmptyMapBucket:
+    case IsEmpty:
+    case IsUndefined:
+    case IsBoolean:
+    case IsNumber:
+    case IsObject:
+    case IsObjectOrNull:
+    case IsFunction:
+    case IsTypedArrayView:
+    case CheckTypeInfoFlags:
+    case OverridesHasInstance:
+    case InstanceOf:
+    case InstanceOfCustom:
+    case DoubleRep:
+    case ValueRep:
+    case Int52Rep:
+    case DoubleConstant:
+    case Int52Constant:
+    case BooleanToNumber:
+    case HasGenericProperty:
+    case HasStructureProperty:
+    case GetDirectPname:
+    case GetEnumerableLength:
     case GetIndexedPropertyStorage:
-        if (node->arrayMode().type() == Array::String)
-            break;
-        if (isTypedView(node->arrayMode().typedArrayType()))
-            break;
-        return CannotCompile;
+    case GetPropertyEnumerator:
+    case GetEnumeratorStructurePname:
+    case GetEnumeratorGenericPname:
+    case ToIndexString:
+    case BottomValue:
+    case PhantomNewObject:
+    case PhantomNewFunction:
+    case PhantomNewGeneratorFunction:
+    case PhantomNewAsyncFunction:
+    case PhantomCreateActivation:
+    case PutHint:
+    case CheckStructureImmediate:
+    case MaterializeNewObject:
+    case MaterializeCreateActivation:
+    case PhantomDirectArguments:
+    case PhantomCreateRest:
+    case PhantomSpread:
+    case PhantomNewArrayWithSpread:
+    case PhantomClonedArguments:
+    case GetMyArgumentByVal:
+    case GetMyArgumentByValOutOfBounds:
+    case ForwardVarargs:
+    case Switch:
+    case TypeOf:
+    case PutById:
+    case PutByIdDirect:
+    case PutByIdFlush:
+    case PutByIdWithThis:
+    case PutGetterById:
+    case PutSetterById:
+    case PutGetterSetterById:
+    case PutGetterByVal:
+    case PutSetterByVal:
+    case CreateRest:
+    case GetRestLength:
+    case RegExpExec:
+    case RegExpTest:
+    case NewRegexp:
+    case StringReplace:
+    case StringReplaceRegExp: 
+    case GetRegExpObjectLastIndex:
+    case SetRegExpObjectLastIndex:
+    case RecordRegExpCachedResult:
+    case SetFunctionName:
+    case LogShadowChickenPrologue:
+    case LogShadowChickenTail:
+    case ResolveScope:
+    case GetDynamicVar:
+    case PutDynamicVar:
+    case CompareEq:
+    case CompareEqPtr:
+    case CompareLess:
+    case CompareLessEq:
+    case CompareGreater:
+    case CompareGreaterEq:
+    case CompareStrictEq:
+    case DefineDataProperty:
+    case DefineAccessorProperty:
+    case ToLowerCase:
+    case NumberToStringWithRadix:
+    case CheckDOM:
+    case CallDOM:
+    case CallDOMGetter:
+    case ArraySlice:
+    case ParseInt:
+        // These are OK.
+        break;
+
+    case Identity:
+        // No backend handles this because it will be optimized out. But we may check
+        // for capabilities before optimization. It would be a deep error to remove this
+        // case because it would prevent us from catching bugs where the FTL backend
+        // pipeline failed to optimize out an Identity.
+        break;
     case CheckArray:
         switch (node->arrayMode().type()) {
         case Array::Int32:
         case Array::Double:
         case Array::Contiguous:
+        case Array::DirectArguments:
+        case Array::ScopedArguments:
             break;
         default:
             if (isTypedView(node->arrayMode().typedArrayType()))
@@ -141,17 +310,31 @@ inline CapabilityLevel canCompile(Node* node)
         break;
     case GetArrayLength:
         switch (node->arrayMode().type()) {
+        case Array::Undecided:
         case Array::Int32:
         case Array::Double:
         case Array::Contiguous:
         case Array::String:
+        case Array::DirectArguments:
+        case Array::ScopedArguments:
             break;
         default:
-            if (isTypedView(node->arrayMode().typedArrayType()))
+            if (node->arrayMode().isSomeTypedArrayView())
                 break;
             return CannotCompile;
         }
         break;
+    case HasIndexedProperty:
+        switch (node->arrayMode().type()) {
+        case Array::ForceExit:
+        case Array::Int32:
+        case Array::Double:
+        case Array::Contiguous:
+            break;
+        default:
+            return CannotCompile;
+        }
+        break;
     case GetByVal:
         switch (node->arrayMode().type()) {
         case Array::ForceExit:
@@ -160,6 +343,9 @@ inline CapabilityLevel canCompile(Node* node)
         case Array::Int32:
         case Array::Double:
         case Array::Contiguous:
+        case Array::Undecided:
+        case Array::DirectArguments:
+        case Array::ScopedArguments:
             break;
         default:
             if (isTypedView(node->arrayMode().typedArrayType()))
@@ -167,6 +353,8 @@ inline CapabilityLevel canCompile(Node* node)
             return CannotCompile;
         }
         break;
+    case GetByValWithThis:
+        break;
     case PutByVal:
     case PutByValAlias:
     case PutByValDirect:
@@ -183,45 +371,14 @@ inline CapabilityLevel canCompile(Node* node)
             return CannotCompile;
         }
         break;
-    case CompareEq:
-        if (node->isBinaryUseKind(Int32Use))
-            break;
-        if (node->isBinaryUseKind(MachineIntUse))
-            break;
-        if (node->isBinaryUseKind(NumberUse))
-            break;
-        if (node->isBinaryUseKind(ObjectUse))
-            break;
-        if (node->isBinaryUseKind(UntypedUse))
-            break;
-        return CannotCompile;
-    case CompareStrictEq:
-        if (node->isBinaryUseKind(Int32Use))
-            break;
-        if (node->isBinaryUseKind(MachineIntUse))
-            break;
-        if (node->isBinaryUseKind(NumberUse))
-            break;
-        if (node->isBinaryUseKind(ObjectUse))
-            break;
-        return CannotCompile;
-    case CompareLess:
-    case CompareLessEq:
-    case CompareGreater:
-    case CompareGreaterEq:
-        if (node->isBinaryUseKind(Int32Use))
-            break;
-        if (node->isBinaryUseKind(MachineIntUse))
-            break;
-        if (node->isBinaryUseKind(NumberUse))
-            break;
-        if (node->isBinaryUseKind(UntypedUse))
-            break;
-        return CannotCompile;
-    case Switch:
-        switch (node->switchData()->kind) {
-        case SwitchImm:
-        case SwitchChar:
+    case PutByValWithThis:
+        break;
+    case ArrayPush:
+    case ArrayPop:
+        switch (node->arrayMode().type()) {
+        case Array::Int32:
+        case Array::Contiguous:
+        case Array::Double:
             break;
         default:
             return CannotCompile;
@@ -236,9 +393,21 @@ inline CapabilityLevel canCompile(Node* node)
 
 CapabilityLevel canCompile(Graph& graph)
 {
+    if (graph.m_codeBlock->instructionCount() > Options::maximumFTLCandidateInstructionCount()) {
+        if (verboseCapabilities())
+            dataLog("FTL rejecting ", *graph.m_codeBlock, " because it's too big.\n");
+        return CannotCompile;
+    }
+    
     if (graph.m_codeBlock->codeType() != FunctionCode) {
-        if (verboseCompilationEnabled())
-            dataLog("FTL rejecting code block that doesn't belong to a function.\n");
+        if (verboseCapabilities())
+            dataLog("FTL rejecting ", *graph.m_codeBlock, " because it doesn't belong to a function.\n");
+        return CannotCompile;
+    }
+
+    if (UNLIKELY(graph.m_codeBlock->ownerScriptExecutable()->neverFTLOptimize())) {
+        if (verboseCapabilities())
+            dataLog("FTL rejecting ", *graph.m_codeBlock, " because it is marked as never FTL compile.\n");
         return CannotCompile;
     }
     
@@ -264,23 +433,46 @@ CapabilityLevel canCompile(Graph& graph)
                 case UntypedUse:
                 case Int32Use:
                 case KnownInt32Use:
-                case MachineIntUse:
+                case Int52RepUse:
                 case NumberUse:
-                case KnownNumberUse:
                 case RealNumberUse:
+                case DoubleRepUse:
+                case DoubleRepRealUse:
                 case BooleanUse:
+                case KnownBooleanUse:
                 case CellUse:
                 case KnownCellUse:
+                case CellOrOtherUse:
                 case ObjectUse:
+                case ArrayUse:
+                case FunctionUse:
                 case ObjectOrOtherUse:
                 case StringUse:
+                case StringOrOtherUse:
+                case KnownStringUse:
+                case KnownPrimitiveUse:
+                case StringObjectUse:
+                case StringOrStringObjectUse:
+                case SymbolUse:
+                case MapObjectUse:
+                case SetObjectUse:
                 case FinalObjectUse:
+                case RegExpObjectUse:
+                case ProxyObjectUse:
+                case DerivedArrayUse:
+                case NotCellUse:
+                case OtherUse:
+                case MiscUse:
+                case StringIdentUse:
+                case NotStringVarUse:
+                case AnyIntUse:
+                case DoubleRepAnyIntUse:
                     // These are OK.
                     break;
                 default:
                     // Don't know how to handle anything else.
-                    if (verboseCompilationEnabled()) {
-                        dataLog("FTL rejecting node because of bad use kind: ", edge.useKind(), " in node:\n");
+                    if (verboseCapabilities()) {
+                        dataLog("FTL rejecting node in ", *graph.m_codeBlock, " because of bad use kind: ", edge.useKind(), " in node:\n");
                         graph.dump(WTF::dataFile(), "    ", node);
                     }
                     return CannotCompile;
@@ -289,8 +481,8 @@ CapabilityLevel canCompile(Graph& graph)
             
             switch (canCompile(node)) {
             case CannotCompile: 
-                if (verboseCompilationEnabled()) {
-                    dataLog("FTL rejecting node:\n");
+                if (verboseCapabilities()) {
+                    dataLog("FTL rejecting node in ", *graph.m_codeBlock, ":\n");
                     graph.dump(WTF::dataFile(), "    ", node);
                 }
                 return CannotCompile;
diff --git a/Source/JavaScriptCore/ftl/FTLCapabilities.h b/Source/JavaScriptCore/ftl/FTLCapabilities.h
index 75a426df1..ab3a62b9f 100644
--- a/Source/JavaScriptCore/ftl/FTLCapabilities.h
+++ b/Source/JavaScriptCore/ftl/FTLCapabilities.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLCapabilities_h
-#define FTLCapabilities_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -45,6 +42,3 @@ CapabilityLevel canCompile(DFG::Graph&);
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLCapabilities_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLCommonValues.cpp b/Source/JavaScriptCore/ftl/FTLCommonValues.cpp
index 653bb7ddd..5b4925cff 100644
--- a/Source/JavaScriptCore/ftl/FTLCommonValues.cpp
+++ b/Source/JavaScriptCore/ftl/FTLCommonValues.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2014 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -26,44 +26,38 @@
 #include "config.h"
 #include "FTLCommonValues.h"
 
+#include "B3BasicBlockInlines.h"
+#include "B3Const32Value.h"
+#include "B3Const64Value.h"
+#include "B3ConstDoubleValue.h"
+#include "B3ConstPtrValue.h"
+#include "B3ProcedureInlines.h"
+#include "B3Type.h"
+#include "B3ValueInlines.h"
+
 #if ENABLE(FTL_JIT)
 
 namespace JSC { namespace FTL {
 
-CommonValues::CommonValues(LContext context)
-    : voidType(FTL::voidType(context))
-    , boolean(int1Type(context))
-    , int8(int8Type(context))
-    , int16(int16Type(context))
-    , int32(int32Type(context))
-    , int64(int64Type(context))
-    , intPtr(intPtrType(context))
-    , floatType(FTL::floatType(context))
-    , doubleType(FTL::doubleType(context))
-    , ref8(pointerType(int8))
-    , ref16(pointerType(int16))
-    , ref32(pointerType(int32))
-    , ref64(pointerType(int64))
-    , refPtr(pointerType(intPtr))
-    , refFloat(pointerType(floatType))
-    , refDouble(pointerType(doubleType))
-    , booleanTrue(constInt(boolean, true, ZeroExtend))
-    , booleanFalse(constInt(boolean, false, ZeroExtend))
-    , int8Zero(constInt(int8, 0, SignExtend))
-    , int32Zero(constInt(int32, 0, SignExtend))
-    , int32One(constInt(int32, 1, SignExtend))
-    , int64Zero(constInt(int64, 0, SignExtend))
-    , intPtrZero(constInt(intPtr, 0, SignExtend))
-    , intPtrOne(constInt(intPtr, 1, SignExtend))
-    , intPtrTwo(constInt(intPtr, 2, SignExtend))
-    , intPtrThree(constInt(intPtr, 3, SignExtend))
-    , intPtrFour(constInt(intPtr, 4, SignExtend))
-    , intPtrEight(constInt(intPtr, 8, SignExtend))
-    , intPtrPtr(constInt(intPtr, sizeof(void*), SignExtend))
-    , doubleZero(constReal(doubleType, 0))
-    , m_context(context)
-    , m_module(0)
+using namespace B3;
+
+CommonValues::CommonValues()
+{
+}
+
+void CommonValues::initializeConstants(B3::Procedure& proc, B3::BasicBlock* block)
 {
+    int32Zero = block->appendNew<Const32Value>(proc, Origin(), 0);
+    int32One = block->appendNew<Const32Value>(proc, Origin(), 1);
+    booleanTrue = int32One;
+    booleanFalse = int32Zero;
+    int64Zero = block->appendNew<Const64Value>(proc, Origin(), 0);
+    intPtrZero = block->appendNew<ConstPtrValue>(proc, Origin(), 0);
+    intPtrOne = block->appendNew<ConstPtrValue>(proc, Origin(), 1);
+    intPtrTwo = block->appendNew<ConstPtrValue>(proc, Origin(), 2);
+    intPtrThree = block->appendNew<ConstPtrValue>(proc, Origin(), 3);
+    intPtrEight = block->appendNew<ConstPtrValue>(proc, Origin(), 8);
+    doubleZero = block->appendNew<ConstDoubleValue>(proc, Origin(), 0.);
 }
 
 } } // namespace JSC::FTL
diff --git a/Source/JavaScriptCore/ftl/FTLCommonValues.h b/Source/JavaScriptCore/ftl/FTLCommonValues.h
index 848090210..c1d6d5a55 100644
--- a/Source/JavaScriptCore/ftl/FTLCommonValues.h
+++ b/Source/JavaScriptCore/ftl/FTLCommonValues.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2014 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,64 +23,47 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLCommonValues_h
-#define FTLCommonValues_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
-#include "FTLAbbreviations.h"
+#include "FTLAbbreviatedTypes.h"
+#include "FTLValueRange.h"
+
+namespace JSC {
+
+namespace B3 {
+class BasicBlock;
+class Procedure;
+}
 
-namespace JSC { namespace FTL {
+namespace FTL {
 
 class CommonValues {
 public:
-    CommonValues(LContext context);
+    CommonValues();
+
+    void initializeConstants(B3::Procedure&, B3::BasicBlock*);
     
-    void initialize(LModule module)
-    {
-        m_module = module;
-    }
+    LValue booleanTrue { nullptr };
+    LValue booleanFalse { nullptr };
+    LValue int32Zero { nullptr };
+    LValue int32One { nullptr };
+    LValue int64Zero { nullptr };
+    LValue intPtrZero { nullptr };
+    LValue intPtrOne { nullptr };
+    LValue intPtrTwo { nullptr };
+    LValue intPtrThree { nullptr };
+    LValue intPtrEight { nullptr };
+    LValue doubleZero { nullptr };
     
-    const LType voidType;
-    const LType boolean;
-    const LType int8;
-    const LType int16;
-    const LType int32;
-    const LType int64;
-    const LType intPtr;
-    const LType floatType;
-    const LType doubleType;
-    const LType ref8;
-    const LType ref16;
-    const LType ref32;
-    const LType ref64;
-    const LType refPtr;
-    const LType refFloat;
-    const LType refDouble;
-    const LValue booleanTrue;
-    const LValue booleanFalse;
-    const LValue int8Zero;
-    const LValue int32Zero;
-    const LValue int32One;
-    const LValue int64Zero;
-    const LValue intPtrZero;
-    const LValue intPtrOne;
-    const LValue intPtrTwo;
-    const LValue intPtrThree;
-    const LValue intPtrFour;
-    const LValue intPtrEight;
-    const LValue intPtrPtr;
-    const LValue doubleZero;
+    const unsigned rangeKind { 0 };
+    const unsigned profKind { 0 };
+    const LValue branchWeights { nullptr };
     
-    LContext const m_context;
-    LModule m_module;
+    const ValueRange nonNegativeInt32;
 };
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLCommonValues_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLCompile.cpp b/Source/JavaScriptCore/ftl/FTLCompile.cpp
index 6c01f4fa5..e85e28778 100644
--- a/Source/JavaScriptCore/ftl/FTLCompile.cpp
+++ b/Source/JavaScriptCore/ftl/FTLCompile.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -28,409 +28,129 @@
 
 #if ENABLE(FTL_JIT)
 
+#include "AirCode.h"
+#include "B3Generate.h"
+#include "B3ProcedureInlines.h"
+#include "B3StackSlot.h"
 #include "CodeBlockWithJITType.h"
 #include "CCallHelpers.h"
 #include "DFGCommon.h"
+#include "DFGGraphSafepoint.h"
+#include "DFGOperations.h"
 #include "DataView.h"
 #include "Disassembler.h"
-#include "FTLExitThunkGenerator.h"
-#include "FTLInlineCacheSize.h"
 #include "FTLJITCode.h"
 #include "FTLThunks.h"
-#include "JITStubs.h"
-#include "LLVMAPI.h"
+#include "JITSubGenerator.h"
+#include "JSCInlines.h"
 #include "LinkBuffer.h"
-#include "RepatchBuffer.h"
+#include "PCToCodeOriginMap.h"
+#include "ScratchRegisterAllocator.h"
 
 namespace JSC { namespace FTL {
 
 using namespace DFG;
 
-static uint8_t* mmAllocateCodeSection(
-    void* opaqueState, uintptr_t size, unsigned alignment, unsigned, const char* sectionName)
+void compile(State& state, Safepoint::Result& safepointResult)
 {
-    
-    State& state = *static_cast<State*>(opaqueState);
-    
-    RELEASE_ASSERT(alignment <= jitAllocationGranule);
-    
-    RefPtr<ExecutableMemoryHandle> result =
-        state.graph.m_vm.executableAllocator.allocate(
-            state.graph.m_vm, size, state.graph.m_codeBlock, JITCompilationMustSucceed);
-    
-    state.jitCode->addHandle(result);
-    state.codeSectionNames.append(sectionName);
-    
-    return static_cast<uint8_t*>(result->start());
-}
-
-static uint8_t* mmAllocateDataSection(
-    void* opaqueState, uintptr_t size, unsigned alignment, unsigned sectionID,
-    const char* sectionName, LLVMBool isReadOnly)
-{
-    UNUSED_PARAM(sectionID);
-    UNUSED_PARAM(isReadOnly);
-
-    State& state = *static_cast<State*>(opaqueState);
-    
-    RELEASE_ASSERT(alignment <= sizeof(LSectionWord));
-    
-    RefCountedArray<LSectionWord> section(
-        (size + sizeof(LSectionWord) - 1) / sizeof(LSectionWord));
-    
-    if (!strcmp(sectionName, "__llvm_stackmaps"))
-        state.stackmapsSection = section;
-    else {
-        state.jitCode->addDataSection(section);
-        state.dataSectionNames.append(sectionName);
-    }
-    
-    return bitwise_cast<uint8_t*>(section.data());
-}
+    Graph& graph = state.graph;
+    CodeBlock* codeBlock = graph.m_codeBlock;
+    VM& vm = graph.m_vm;
 
-static LLVMBool mmApplyPermissions(void*, char**)
-{
-    return false;
-}
-
-static void mmDestroy(void*)
-{
-}
+    {
+        GraphSafepoint safepoint(state.graph, safepointResult);
 
-static void dumpDataSection(RefCountedArray<LSectionWord> section, const char* prefix)
-{
-    for (unsigned j = 0; j < section.size(); ++j) {
-        char buf[32];
-        snprintf(buf, sizeof(buf), "0x%lx", static_cast<unsigned long>(bitwise_cast<uintptr_t>(section.data() + j)));
-        dataLogF("%s%16s: 0x%016llx\n", prefix, buf, static_cast<long long>(section[j]));
+        B3::prepareForGeneration(*state.proc);
     }
-}
 
-template<typename DescriptorType>
-void generateICFastPath(
-    State& state, CodeBlock* codeBlock, GeneratedFunction generatedFunction,
-    StackMaps::RecordMap& recordMap, DescriptorType& ic, size_t sizeOfIC)
-{
-    VM& vm = state.graph.m_vm;
-
-    StackMaps::RecordMap::iterator iter = recordMap.find(ic.stackmapID());
-    if (iter == recordMap.end()) {
-        // It was optimized out.
+    if (safepointResult.didGetCancelled())
         return;
-    }
+    RELEASE_ASSERT(!state.graph.m_vm.heap.collectorBelievesThatTheWorldIsStopped());
     
-    StackMaps::Record& record = iter->value;
-
-    CCallHelpers fastPathJIT(&vm, codeBlock);
-    ic.m_generator.generateFastPath(fastPathJIT);
-
-    char* startOfIC =
-        bitwise_cast<char*>(generatedFunction) + record.instructionOffset;
-            
-    LinkBuffer linkBuffer(vm, &fastPathJIT, startOfIC, sizeOfIC);
-    // Note: we could handle the !isValid() case. We just don't appear to have a
-    // reason to do so, yet.
-    RELEASE_ASSERT(linkBuffer.isValid());
-    
-    MacroAssembler::AssemblerType_T::fillNops(
-        startOfIC + linkBuffer.size(), sizeOfIC - linkBuffer.size());
+    if (state.allocationFailed)
+        return;
     
-    state.finalizer->sideCodeLinkBuffer->link(
-        ic.m_slowPathDone, CodeLocationLabel(startOfIC + sizeOfIC));
-            
-    linkBuffer.link(
-        ic.m_generator.slowPathJump(),
-        state.finalizer->sideCodeLinkBuffer->locationOf(ic.m_generator.slowPathBegin()));
-            
-    ic.m_generator.finalize(linkBuffer, *state.finalizer->sideCodeLinkBuffer);
-}
-
-static void fixFunctionBasedOnStackMaps(
-    State& state, CodeBlock* codeBlock, JITCode* jitCode, GeneratedFunction generatedFunction,
-    StackMaps::RecordMap& recordMap)
-{
-    VM& vm = state.graph.m_vm;
-    StackMaps stackmaps = jitCode->stackmaps;
-
-    ExitThunkGenerator exitThunkGenerator(state);
-    exitThunkGenerator.emitThunks();
-    if (exitThunkGenerator.didThings()) {
-        OwnPtr<LinkBuffer> linkBuffer = adoptPtr(new LinkBuffer(
-            vm, &exitThunkGenerator, codeBlock, JITCompilationMustSucceed));
-        
-        ASSERT(state.finalizer->osrExit.size() == state.jitCode->osrExit.size());
-        
-        for (unsigned i = 0; i < state.jitCode->osrExit.size(); ++i) {
-            OSRExitCompilationInfo& info = state.finalizer->osrExit[i];
-            OSRExit& exit = jitCode->osrExit[i];
-            
-            if (Options::verboseCompilation())
-                dataLog("Handling OSR stackmap #", exit.m_stackmapID, " for ", exit.m_codeOrigin, "\n");
-            
-            StackMaps::RecordMap::iterator iter = recordMap.find(exit.m_stackmapID);
-            if (iter == recordMap.end()) {
-                // It was optimized out.
-                continue;
-            }
-            
-            info.m_thunkAddress = linkBuffer->locationOf(info.m_thunkLabel);
-            
-            exit.m_patchableCodeOffset = linkBuffer->offsetOf(info.m_thunkJump);
-        }
-        
-        state.finalizer->exitThunksLinkBuffer = linkBuffer.release();
+    std::unique_ptr<RegisterAtOffsetList> registerOffsets =
+        std::make_unique<RegisterAtOffsetList>(state.proc->calleeSaveRegisters());
+    if (shouldDumpDisassembly()) {
+        dataLog("Unwind info for ", CodeBlockWithJITType(state.graph.m_codeBlock, JITCode::FTLJIT), ":\n");
+        dataLog("    ", *registerOffsets, "\n");
     }
-
-    if (!state.getByIds.isEmpty() || !state.putByIds.isEmpty()) {
-        CCallHelpers slowPathJIT(&vm, codeBlock);
-        
-        for (unsigned i = state.getByIds.size(); i--;) {
-            GetByIdDescriptor& getById = state.getByIds[i];
-            
-            if (Options::verboseCompilation())
-                dataLog("Handling GetById stackmap #", getById.stackmapID(), "\n");
-            
-            StackMaps::RecordMap::iterator iter = recordMap.find(getById.stackmapID());
-            if (iter == recordMap.end()) {
-                // It was optimized out.
-                continue;
-            }
-            
-            StackMaps::Record& record = iter->value;
-            
-            // FIXME: LLVM should tell us which registers are live.
-            RegisterSet usedRegisters = RegisterSet::allRegisters();
-            
-            GPRReg result = record.locations[0].directGPR();
-            GPRReg callFrameRegister = record.locations[1].directGPR();
-            GPRReg base = record.locations[2].directGPR();
-            
-            JITGetByIdGenerator gen(
-                codeBlock, getById.codeOrigin(), usedRegisters, callFrameRegister,
-                JSValueRegs(base), JSValueRegs(result), false);
-            
-            MacroAssembler::Label begin = slowPathJIT.label();
-            
-            MacroAssembler::Call call = callOperation(
-                state, usedRegisters, slowPathJIT, operationGetByIdOptimize, result,
-                callFrameRegister, gen.stubInfo(), base, getById.uid());
-            
-            gen.reportSlowPathCall(begin, call);
-            
-            getById.m_slowPathDone = slowPathJIT.jump();
-            getById.m_generator = gen;
-        }
-        
-        for (unsigned i = state.putByIds.size(); i--;) {
-            PutByIdDescriptor& putById = state.putByIds[i];
-            
-            if (Options::verboseCompilation())
-                dataLog("Handling PutById stackmap #", putById.stackmapID(), "\n");
-            
-            StackMaps::RecordMap::iterator iter = recordMap.find(putById.stackmapID());
-            if (iter == recordMap.end()) {
-                // It was optimized out.
-                continue;
-            }
-            
-            StackMaps::Record& record = iter->value;
-            
-            // FIXME: LLVM should tell us which registers are live.
-            RegisterSet usedRegisters = RegisterSet::allRegisters();
-            
-            GPRReg callFrameRegister = record.locations[0].directGPR();
-            GPRReg base = record.locations[1].directGPR();
-            GPRReg value = record.locations[2].directGPR();
-            
-            JITPutByIdGenerator gen(
-                codeBlock, putById.codeOrigin(), usedRegisters, callFrameRegister,
-                JSValueRegs(base), JSValueRegs(value), MacroAssembler::scratchRegister,
-                false, putById.ecmaMode(), putById.putKind());
-            
-            MacroAssembler::Label begin = slowPathJIT.label();
-            
-            MacroAssembler::Call call = callOperation(
-                state, usedRegisters, slowPathJIT, gen.slowPathFunction(), callFrameRegister,
-                gen.stubInfo(), value, base, putById.uid());
-            
-            gen.reportSlowPathCall(begin, call);
-            
-            putById.m_slowPathDone = slowPathJIT.jump();
-            putById.m_generator = gen;
-        }
-        
-        state.finalizer->sideCodeLinkBuffer = adoptPtr(
-            new LinkBuffer(vm, &slowPathJIT, codeBlock, JITCompilationMustSucceed));
-        
-        for (unsigned i = state.getByIds.size(); i--;) {
-            generateICFastPath(
-                state, codeBlock, generatedFunction, recordMap, state.getByIds[i],
-                sizeOfGetById());
-        }
-        for (unsigned i = state.putByIds.size(); i--;) {
-            generateICFastPath(
-                state, codeBlock, generatedFunction, recordMap, state.putByIds[i],
-                sizeOfPutById());
-        }
+    state.graph.m_codeBlock->setCalleeSaveRegisters(WTFMove(registerOffsets));
+    ASSERT(!(state.proc->frameSize() % sizeof(EncodedJSValue)));
+    state.jitCode->common.frameRegisterCount = state.proc->frameSize() / sizeof(EncodedJSValue);
+
+    int localsOffset =
+        state.capturedValue->offsetFromFP() / sizeof(EncodedJSValue) + graph.m_nextMachineLocal;
+    if (shouldDumpDisassembly()) {
+        dataLog(
+            "localsOffset = ", localsOffset, " for stack slot: ",
+            pointerDump(state.capturedValue), " at ", RawPointer(state.capturedValue), "\n");
     }
     
-    RepatchBuffer repatchBuffer(codeBlock);
-    
-    for (unsigned exitIndex = jitCode->osrExit.size(); exitIndex--;) {
-        OSRExitCompilationInfo& info = state.finalizer->osrExit[exitIndex];
-        OSRExit& exit = jitCode->osrExit[exitIndex];
-        StackMaps::RecordMap::iterator iter = recordMap.find(exit.m_stackmapID);
-        if (iter == recordMap.end()) {
-            // This could happen if LLVM optimizes out an OSR exit.
-            continue;
-        }
+    for (unsigned i = graph.m_inlineVariableData.size(); i--;) {
+        InlineCallFrame* inlineCallFrame = graph.m_inlineVariableData[i].inlineCallFrame;
         
-        StackMaps::Record& record = iter->value;
+        if (inlineCallFrame->argumentCountRegister.isValid())
+            inlineCallFrame->argumentCountRegister += localsOffset;
         
-        CodeLocationLabel source = CodeLocationLabel(
-            bitwise_cast<char*>(generatedFunction) + record.instructionOffset);
-        
-        if (info.m_isInvalidationPoint) {
-            jitCode->common.jumpReplacements.append(JumpReplacement(source, info.m_thunkAddress));
-            continue;
+        for (unsigned argument = inlineCallFrame->arguments.size(); argument-- > 1;) {
+            inlineCallFrame->arguments[argument] =
+                inlineCallFrame->arguments[argument].withLocalsOffset(localsOffset);
         }
         
-        repatchBuffer.replaceWithJump(source, info.m_thunkAddress);
-    }
-}
+        if (inlineCallFrame->isClosureCall) {
+            inlineCallFrame->calleeRecovery =
+                inlineCallFrame->calleeRecovery.withLocalsOffset(localsOffset);
+        }
 
-void compile(State& state)
-{
-    char* error = 0;
-    
-    LLVMMCJITCompilerOptions options;
-    llvm->InitializeMCJITCompilerOptions(&options, sizeof(options));
-    options.OptLevel = Options::llvmBackendOptimizationLevel();
-    options.NoFramePointerElim = true;
-    if (Options::useLLVMSmallCodeModel())
-        options.CodeModel = LLVMCodeModelSmall;
-    options.EnableFastISel = Options::enableLLVMFastISel();
-    options.MCJMM = llvm->CreateSimpleMCJITMemoryManager(
-        &state, mmAllocateCodeSection, mmAllocateDataSection, mmApplyPermissions, mmDestroy);
-    
-    LLVMExecutionEngineRef engine;
-    
-    if (llvm->CreateMCJITCompilerForModule(&engine, state.module, &options, sizeof(options), &error)) {
-        dataLog("FATAL: Could not create LLVM execution engine: ", error, "\n");
-        CRASH();
     }
 
-    LLVMPassManagerRef functionPasses = 0;
-    LLVMPassManagerRef modulePasses;
-    
-    if (Options::llvmSimpleOpt()) {
-        modulePasses = llvm->CreatePassManager();
-        llvm->AddTargetData(llvm->GetExecutionEngineTargetData(engine), modulePasses);
-        llvm->AddPromoteMemoryToRegisterPass(modulePasses);
-        llvm->AddConstantPropagationPass(modulePasses);
-        llvm->AddInstructionCombiningPass(modulePasses);
-        llvm->AddBasicAliasAnalysisPass(modulePasses);
-        llvm->AddTypeBasedAliasAnalysisPass(modulePasses);
-        llvm->AddGVNPass(modulePasses);
-        llvm->AddCFGSimplificationPass(modulePasses);
-        llvm->RunPassManager(modulePasses, state.module);
-    } else {
-        LLVMPassManagerBuilderRef passBuilder = llvm->PassManagerBuilderCreate();
-        llvm->PassManagerBuilderSetOptLevel(passBuilder, Options::llvmOptimizationLevel());
-        llvm->PassManagerBuilderSetSizeLevel(passBuilder, Options::llvmSizeLevel());
-        
-        functionPasses = llvm->CreateFunctionPassManagerForModule(state.module);
-        modulePasses = llvm->CreatePassManager();
-        
-        llvm->AddTargetData(llvm->GetExecutionEngineTargetData(engine), modulePasses);
-        
-        llvm->PassManagerBuilderPopulateFunctionPassManager(passBuilder, functionPasses);
-        llvm->PassManagerBuilderPopulateModulePassManager(passBuilder, modulePasses);
-        
-        llvm->PassManagerBuilderDispose(passBuilder);
-        
-        llvm->InitializeFunctionPassManager(functionPasses);
-        for (LValue function = llvm->GetFirstFunction(state.module); function; function = llvm->GetNextFunction(function))
-            llvm->RunFunctionPassManager(functionPasses, function);
-        llvm->FinalizeFunctionPassManager(functionPasses);
-        
-        llvm->RunPassManager(modulePasses, state.module);
+    // Note that the scope register could be invalid here if the original code had CallEval but it
+    // got killed. That's because it takes the CallEval to cause the scope register to be kept alive
+    // unless the debugger is also enabled.
+    if (graph.needsScopeRegister() && codeBlock->scopeRegister().isValid())
+        codeBlock->setScopeRegister(codeBlock->scopeRegister() + localsOffset);
+
+    for (OSRExitDescriptor& descriptor : state.jitCode->osrExitDescriptors) {
+        for (unsigned i = descriptor.m_values.size(); i--;)
+            descriptor.m_values[i] = descriptor.m_values[i].withLocalsOffset(localsOffset);
+        for (ExitTimeObjectMaterialization* materialization : descriptor.m_materializations)
+            materialization->accountForLocalsOffset(localsOffset);
     }
 
-    if (DFG::shouldShowDisassembly() || DFG::verboseCompilationEnabled())
-        state.dumpState("after optimization");
-    
-    // FIXME: Need to add support for the case where JIT memory allocation failed.
-    // https://bugs.webkit.org/show_bug.cgi?id=113620
-    state.generatedFunction = reinterpret_cast<GeneratedFunction>(llvm->GetPointerToGlobal(engine, state.function));
-    if (functionPasses)
-        llvm->DisposePassManager(functionPasses);
-    llvm->DisposePassManager(modulePasses);
-    llvm->DisposeExecutionEngine(engine);
-
-    if (shouldShowDisassembly()) {
-        for (unsigned i = 0; i < state.jitCode->handles().size(); ++i) {
-            ExecutableMemoryHandle* handle = state.jitCode->handles()[i].get();
-            dataLog(
-                "Generated LLVM code for ",
-                CodeBlockWithJITType(state.graph.m_codeBlock, JITCode::DFGJIT),
-                " #", i, ", ", state.codeSectionNames[i], ":\n");
-            disassemble(
-                MacroAssemblerCodePtr(handle->start()), handle->sizeInBytes(),
-                "    ", WTF::dataFile(), LLVMSubset);
-        }
-        
-        for (unsigned i = 0; i < state.jitCode->dataSections().size(); ++i) {
-            const RefCountedArray<LSectionWord>& section = state.jitCode->dataSections()[i];
-            dataLog(
-                "Generated LLVM data section for ",
-                CodeBlockWithJITType(state.graph.m_codeBlock, JITCode::DFGJIT),
-                " #", i, ", ", state.dataSectionNames[i], ":\n");
-            dumpDataSection(section, "    ");
-        }
-    }
-    
-    if (state.stackmapsSection.size()) {
-        if (shouldShowDisassembly()) {
-            dataLog(
-                "Generated LLVM stackmaps section for ",
-                CodeBlockWithJITType(state.graph.m_codeBlock, JITCode::DFGJIT), ":\n");
-            dataLog("    Raw data:\n");
-            dumpDataSection(state.stackmapsSection, "    ");
-        }
-        
-        RefPtr<DataView> stackmapsData = DataView::create(
-            ArrayBuffer::create(state.stackmapsSection.data(), state.stackmapsSection.byteSize()));
-        state.jitCode->stackmaps.parse(stackmapsData.get());
-    
-        if (shouldShowDisassembly()) {
-            dataLog("    Structured data:\n");
-            state.jitCode->stackmaps.dumpMultiline(WTF::dataFile(), "        ");
-        }
-        
-        StackMaps::RecordMap recordMap = state.jitCode->stackmaps.getRecordMap();
-        fixFunctionBasedOnStackMaps(
-            state, state.graph.m_codeBlock, state.jitCode.get(), state.generatedFunction,
-            recordMap);
-        
-        if (shouldShowDisassembly()) {
-            for (unsigned i = 0; i < state.jitCode->handles().size(); ++i) {
-                if (state.codeSectionNames[i] != "__text")
-                    continue;
-                
-                ExecutableMemoryHandle* handle = state.jitCode->handles()[i].get();
-                dataLog(
-                    "Generated LLVM code after stackmap-based fix-up for ",
-                    CodeBlockWithJITType(state.graph.m_codeBlock, JITCode::DFGJIT),
-                    " #", i, ", ", state.codeSectionNames[i], ":\n");
-                disassemble(
-                    MacroAssemblerCodePtr(handle->start()), handle->sizeInBytes(),
-                    "    ", WTF::dataFile(), LLVMSubset);
-            }
-        }
+    // We will add exception handlers while generating.
+    codeBlock->clearExceptionHandlers();
+
+    CCallHelpers jit(&vm, codeBlock);
+    B3::generate(*state.proc, jit);
+
+    // Emit the exception handler.
+    *state.exceptionHandler = jit.label();
+    jit.copyCalleeSavesToVMEntryFrameCalleeSavesBuffer();
+    jit.move(MacroAssembler::TrustedImmPtr(jit.vm()), GPRInfo::argumentGPR0);
+    jit.move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR1);
+    CCallHelpers::Call call = jit.call();
+    jit.jumpToExceptionHandler();
+    jit.addLinkTask(
+        [=] (LinkBuffer& linkBuffer) {
+            linkBuffer.link(call, FunctionPtr(lookupExceptionHandler));
+        });
+
+    state.finalizer->b3CodeLinkBuffer = std::make_unique<LinkBuffer>(
+        vm, jit, codeBlock, JITCompilationCanFail);
+    if (state.finalizer->b3CodeLinkBuffer->didFailToAllocate()) {
+        state.allocationFailed = true;
+        return;
     }
     
-    state.module = 0; // We no longer own the module.
+    B3::PCToOriginMap originMap = state.proc->releasePCToOriginMap();
+    if (vm.shouldBuilderPCToCodeOriginMapping())
+        codeBlock->setPCToCodeOriginMap(std::make_unique<PCToCodeOriginMap>(PCToCodeOriginMapBuilder(vm, WTFMove(originMap)), *state.finalizer->b3CodeLinkBuffer));
+
+    state.generatedFunction = bitwise_cast<GeneratedFunction>(
+        state.finalizer->b3CodeLinkBuffer->entrypoint().executableAddress());
+    state.jitCode->initializeB3Byproducts(state.proc->releaseByproducts());
 }
 
 } } // namespace JSC::FTL
diff --git a/Source/JavaScriptCore/ftl/FTLCompile.h b/Source/JavaScriptCore/ftl/FTLCompile.h
index c963643ed..c3dd83ae7 100644
--- a/Source/JavaScriptCore/ftl/FTLCompile.h
+++ b/Source/JavaScriptCore/ftl/FTLCompile.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2014 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,22 +23,17 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLCompile_h
-#define FTLCompile_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
+#include "DFGSafepoint.h"
 #include "FTLState.h"
 
 namespace JSC { namespace FTL {
 
-void compile(State&);
+void compile(State&, DFG::Safepoint::Result&);
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLCompile_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLDOMJITPatchpointParams.cpp b/Source/JavaScriptCore/ftl/FTLDOMJITPatchpointParams.cpp
new file mode 100644
index 000000000..106e2e561
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLDOMJITPatchpointParams.cpp
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "FTLDOMJITPatchpointParams.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "AllowMacroScratchRegisterUsage.h"
+#include "FTLSlowPathCall.h"
+#include "FTLState.h"
+
+namespace JSC { namespace FTL {
+
+template<typename OperationType, typename ResultType, typename Arguments, size_t... ArgumentsIndex>
+static void dispatch(CCallHelpers& jit, FTL::State* state, const B3::StackmapGenerationParams& params, DFG::Node* node, Box<CCallHelpers::JumpList> exceptions, CCallHelpers::JumpList from, OperationType operation, ResultType result, Arguments arguments, std::index_sequence<ArgumentsIndex...>)
+{
+    CCallHelpers::Label done = jit.label();
+    params.addLatePath([=] (CCallHelpers& jit) {
+        AllowMacroScratchRegisterUsage allowScratch(jit);
+
+        from.link(&jit);
+        callOperation(
+            *state, params.unavailableRegisters(), jit, node->origin.semantic,
+            exceptions.get(), operation, extractResult(result), std::get<ArgumentsIndex>(arguments)...);
+        jit.jump().linkTo(done, &jit);
+    });
+}
+
+#define JSC_DEFINE_CALL_OPERATIONS(OperationType, ResultType, ...) \
+    void DOMJITPatchpointParams::addSlowPathCallImpl(CCallHelpers::JumpList from, CCallHelpers& jit, OperationType operation, ResultType result, std::tuple<__VA_ARGS__> args) \
+    { \
+        dispatch(jit, &m_state, m_params, m_node, m_exceptions, from, operation, result, args, std::make_index_sequence<std::tuple_size<decltype(args)>::value>()); \
+    } \
+
+DOMJIT_SLOW_PATH_CALLS(JSC_DEFINE_CALL_OPERATIONS)
+#undef JSC_DEFINE_CALL_OPERATIONS
+
+} }
+
+#endif
diff --git a/Source/JavaScriptCore/ftl/FTLDOMJITPatchpointParams.h b/Source/JavaScriptCore/ftl/FTLDOMJITPatchpointParams.h
new file mode 100644
index 000000000..3387c9086
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLDOMJITPatchpointParams.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+#include "B3StackmapGenerationParams.h"
+#include "DOMJITPatchpointParams.h"
+
+namespace JSC { namespace FTL {
+
+class State;
+
+class DOMJITPatchpointParams : public DOMJIT::PatchpointParams {
+public:
+    DOMJITPatchpointParams(State& state, const B3::StackmapGenerationParams& params, DFG::Node* node, Box<CCallHelpers::JumpList> exceptions, Vector<DOMJIT::Value>&& regs, Vector<GPRReg>&& gpScratch, Vector<FPRReg>&& fpScratch)
+        : DOMJIT::PatchpointParams(WTFMove(regs), WTFMove(gpScratch), WTFMove(fpScratch))
+        , m_state(state)
+        , m_params(params)
+        , m_node(node)
+        , m_exceptions(exceptions)
+    {
+    }
+
+private:
+#define JSC_DEFINE_CALL_OPERATIONS(OperationType, ResultType, ...) void addSlowPathCallImpl(CCallHelpers::JumpList, CCallHelpers&, OperationType, ResultType, std::tuple<__VA_ARGS__> args) override;
+    DOMJIT_SLOW_PATH_CALLS(JSC_DEFINE_CALL_OPERATIONS)
+#undef JSC_DEFINE_CALL_OPERATIONS
+
+    State& m_state;
+    const B3::StackmapGenerationParams& m_params;
+    DFG::Node* m_node;
+    Box<CCallHelpers::JumpList> m_exceptions;
+};
+
+} }
+
+#endif
diff --git a/Source/JavaScriptCore/ftl/FTLExceptionTarget.cpp b/Source/JavaScriptCore/ftl/FTLExceptionTarget.cpp
new file mode 100644
index 000000000..023e119bf
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLExceptionTarget.cpp
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLExceptionTarget.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "FTLState.h"
+
+namespace JSC { namespace FTL {
+
+ExceptionTarget::~ExceptionTarget()
+{
+}
+
+CodeLocationLabel ExceptionTarget::label(LinkBuffer& linkBuffer)
+{
+    if (m_isDefaultHandler)
+        return linkBuffer.locationOf(*m_defaultHandler);
+    return linkBuffer.locationOf(m_handle->label);
+}
+
+Box<CCallHelpers::JumpList> ExceptionTarget::jumps(CCallHelpers& jit)
+{
+    Box<CCallHelpers::JumpList> result = Box<CCallHelpers::JumpList>::create();
+    if (m_isDefaultHandler) {
+        Box<CCallHelpers::Label> defaultHandler = m_defaultHandler;
+        jit.addLinkTask(
+            [=] (LinkBuffer& linkBuffer) {
+                linkBuffer.link(*result, linkBuffer.locationOf(*defaultHandler));
+            });
+    } else {
+        RefPtr<OSRExitHandle> handle = m_handle;
+        jit.addLinkTask(
+            [=] (LinkBuffer& linkBuffer) {
+                linkBuffer.link(*result, linkBuffer.locationOf(handle->label));
+            });
+    }
+    return result;
+}
+
+ExceptionTarget::ExceptionTarget(
+    bool isDefaultHandler, Box<CCallHelpers::Label> defaultHandler, RefPtr<OSRExitHandle> handle)
+    : m_isDefaultHandler(isDefaultHandler)
+    , m_defaultHandler(defaultHandler)
+    , m_handle(handle)
+{
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLExceptionTarget.h b/Source/JavaScriptCore/ftl/FTLExceptionTarget.h
new file mode 100644
index 000000000..495377433
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLExceptionTarget.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#include "DFGCommon.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "CCallHelpers.h"
+#include "FTLOSRExitHandle.h"
+#include <wtf/Box.h>
+#include <wtf/ThreadSafeRefCounted.h>
+
+namespace JSC { namespace FTL {
+
+class State;
+
+class ExceptionTarget : public ThreadSafeRefCounted<ExceptionTarget> {
+public:
+    ~ExceptionTarget();
+
+    // It's OK to call this during linking, but not any sooner.
+    CodeLocationLabel label(LinkBuffer&);
+
+    // Or, you can get a JumpList at any time. Anything you add to this JumpList will be linked to
+    // the target's label.
+    Box<CCallHelpers::JumpList> jumps(CCallHelpers&);
+    
+private:
+    friend class PatchpointExceptionHandle;
+
+    ExceptionTarget(bool isDefaultHandler, Box<CCallHelpers::Label>, RefPtr<OSRExitHandle>);
+    
+    bool m_isDefaultHandler;
+    Box<CCallHelpers::Label> m_defaultHandler;
+    RefPtr<OSRExitHandle> m_handle;
+};
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLExitArgument.cpp b/Source/JavaScriptCore/ftl/FTLExitArgument.cpp
index cbe0de7fd..381b3d3a4 100644
--- a/Source/JavaScriptCore/ftl/FTLExitArgument.cpp
+++ b/Source/JavaScriptCore/ftl/FTLExitArgument.cpp
@@ -32,7 +32,7 @@ namespace JSC { namespace FTL {
 
 void ExitArgument::dump(PrintStream& out) const
 {
-    out.print("arg", argument(), " as ", format());
+    out.print("#", argument(), " as ", format());
 }
 
 } } // namespace JSC::FTL
diff --git a/Source/JavaScriptCore/ftl/FTLExitArgument.h b/Source/JavaScriptCore/ftl/FTLExitArgument.h
index ae292c69e..833b3b1eb 100644
--- a/Source/JavaScriptCore/ftl/FTLExitArgument.h
+++ b/Source/JavaScriptCore/ftl/FTLExitArgument.h
@@ -23,20 +23,17 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLExitArgument_h
-#define FTLExitArgument_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
-#include "FTLValueFormat.h"
+#include "DataFormat.h"
 #include <wtf/PrintStream.h>
 
 namespace JSC { namespace FTL {
 
 struct ExitArgumentRepresentation {
-    ValueFormat format;
+    DataFormat format;
     unsigned argument;
 };
 
@@ -44,10 +41,10 @@ class ExitArgument {
 public:
     ExitArgument()
     {
-        m_representation.format = InvalidValueFormat;
+        m_representation.format = DataFormatNone;
     }
     
-    ExitArgument(ValueFormat format, unsigned argument)
+    ExitArgument(DataFormat format, unsigned argument)
     {
         m_representation.format = format;
         m_representation.argument = argument;
@@ -58,9 +55,9 @@ public:
         m_representation = representation;
     }
     
-    bool operator!() const { return m_representation.format == InvalidValueFormat; }
+    bool operator!() const { return m_representation.format == DataFormatNone; }
     
-    ValueFormat format() const
+    DataFormat format() const
     {
         ASSERT(*this);
         return m_representation.format;
@@ -72,11 +69,11 @@ public:
         return m_representation.argument;
     }
     
-    ExitArgument withFormat(ValueFormat format)
+    ExitArgument withFormat(DataFormat format)
     {
         return ExitArgument(format, argument());
     }
-    
+
     ExitArgumentRepresentation representation() const { return m_representation; }
     
     void dump(PrintStream&) const;
@@ -88,6 +85,3 @@ private:
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLExitArgument_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLExitArgumentForOperand.cpp b/Source/JavaScriptCore/ftl/FTLExitArgumentForOperand.cpp
index 775abe18f..074e7a69e 100644
--- a/Source/JavaScriptCore/ftl/FTLExitArgumentForOperand.cpp
+++ b/Source/JavaScriptCore/ftl/FTLExitArgumentForOperand.cpp
@@ -32,7 +32,7 @@ namespace JSC { namespace FTL {
 
 void ExitArgumentForOperand::dump(PrintStream& out) const
 {
-    out.print(m_exitArgument, " for r", m_operand);
+    out.print(m_exitArgument, " for ", m_operand);
 }
 
 } } // namespace JSC::FTL
diff --git a/Source/JavaScriptCore/ftl/FTLExitArgumentForOperand.h b/Source/JavaScriptCore/ftl/FTLExitArgumentForOperand.h
index a5ec737c0..2cad043dd 100644
--- a/Source/JavaScriptCore/ftl/FTLExitArgumentForOperand.h
+++ b/Source/JavaScriptCore/ftl/FTLExitArgumentForOperand.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLExitArgumentForOperand_h
-#define FTLExitArgumentForOperand_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -69,6 +66,3 @@ inline bool lesserArgumentIndex(
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLExitArgumentForOperand_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLExitPropertyValue.cpp b/Source/JavaScriptCore/ftl/FTLExitPropertyValue.cpp
new file mode 100644
index 000000000..d57db747a
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLExitPropertyValue.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2014, 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLExitPropertyValue.h"
+
+#if ENABLE(FTL_JIT)
+
+namespace JSC { namespace FTL {
+
+ExitPropertyValue ExitPropertyValue::withLocalsOffset(int offset) const
+{
+    return ExitPropertyValue(m_location, m_value.withLocalsOffset(offset));
+}
+
+void ExitPropertyValue::dump(PrintStream& out) const
+{
+    out.print(m_location, " => ", m_value);
+}
+
+void ExitPropertyValue::validateReferences(const TrackedReferences& trackedReferences) const
+{
+    m_value.validateReferences(trackedReferences);
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLValueFormat.h b/Source/JavaScriptCore/ftl/FTLExitPropertyValue.h
index b031f0de2..228827ab4 100644
--- a/Source/JavaScriptCore/ftl/FTLValueFormat.h
+++ b/Source/JavaScriptCore/ftl/FTLExitPropertyValue.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2014, 2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,47 +23,48 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLValueFormat_h
-#define FTLValueFormat_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
-#include "GPRInfo.h"
-#include <wtf/PrintStream.h>
+#include "DFGPromotedHeapLocation.h"
+#include "FTLExitValue.h"
 
 namespace JSC {
 
-class AssemblyHelpers;
+class TrackedReferences;
 
 namespace FTL {
 
-// Note that this is awkwardly similar to DataFormat in other parts of JSC, except that
-// unlike DataFormat and like ValueRecovery, it distinguishes between UInt32 and Int32.
-
-enum ValueFormat {
-    InvalidValueFormat,
-    ValueFormatInt32,
-    ValueFormatInt52,
-    ValueFormatStrictInt52,
-    ValueFormatBoolean,
-    ValueFormatJSValue,
-    ValueFormatDouble
+class ExitPropertyValue {
+public:
+    ExitPropertyValue()
+    {
+    }
+    
+    ExitPropertyValue(DFG::PromotedLocationDescriptor location, const ExitValue& value)
+        : m_location(location)
+        , m_value(value)
+    {
+        ASSERT(!!location == !!value);
+    }
+    
+    bool operator!() const { return !m_location; }
+    
+    DFG::PromotedLocationDescriptor location() const { return m_location; }
+    const ExitValue& value() const { return m_value; }
+    
+    ExitPropertyValue withLocalsOffset(int offset) const;
+    
+    void dump(PrintStream& out) const;
+    
+    void validateReferences(const TrackedReferences&) const;
+
+private:
+    DFG::PromotedLocationDescriptor m_location;
+    ExitValue m_value;
 };
 
-void reboxAccordingToFormat(
-    ValueFormat, AssemblyHelpers&, GPRReg value, GPRReg scratch1, GPRReg scratch2);
-
 } } // namespace JSC::FTL
 
-namespace WTF {
-
-void printInternal(PrintStream&, JSC::FTL::ValueFormat);
-
-} // namespace WTF
-
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLValueFormat_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLIntrinsicRepository.cpp b/Source/JavaScriptCore/ftl/FTLExitTimeObjectMaterialization.cpp
index dc7d57931..858d1babc 100644
--- a/Source/JavaScriptCore/ftl/FTLIntrinsicRepository.cpp
+++ b/Source/JavaScriptCore/ftl/FTLExitTimeObjectMaterialization.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2014, 2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -24,40 +24,57 @@
  */
 
 #include "config.h"
-#include "FTLIntrinsicRepository.h"
+#include "FTLExitTimeObjectMaterialization.h"
 
 #if ENABLE(FTL_JIT)
 
+#include "DFGGraph.h"
+
 namespace JSC { namespace FTL {
 
-IntrinsicRepository::IntrinsicRepository(LContext context)
-    : CommonValues(context)
-#define INTRINSIC_INITIALIZATION(ourName, llvmName, type) , m_##ourName(0)
-    FOR_EACH_FTL_INTRINSIC(INTRINSIC_INITIALIZATION)
-#undef INTRINSIC_INITIALIZATION
-#define FUNCTION_TYPE_INITIALIZATION(typeName, type) , m_##typeName(0)
-    FOR_EACH_FUNCTION_TYPE(FUNCTION_TYPE_INITIALIZATION)
-#undef FUNCTION_TYPE_INITIALIZATION
+using namespace JSC::DFG;
+
+ExitTimeObjectMaterialization::ExitTimeObjectMaterialization(NodeType type, CodeOrigin codeOrigin)
+    : m_type(type)
+    , m_origin(codeOrigin)
 {
 }
 
-#define INTRINSIC_GETTER_SLOW_DEFINITION(ourName, llvmName, type)       \
-    LValue IntrinsicRepository::ourName##IntrinsicSlow()                \
-    {                                                                   \
-        m_##ourName = addExternFunction(m_module, llvmName, type);      \
-        return m_##ourName;                                             \
-    }
-FOR_EACH_FTL_INTRINSIC(INTRINSIC_GETTER_SLOW_DEFINITION)
-#undef INTRINSIC_GETTER
+ExitTimeObjectMaterialization::~ExitTimeObjectMaterialization()
+{
+}
 
-#define FUNCTION_TYPE_GETTER_SLOW_DEFINITION(typeName, type) \
-    LType IntrinsicRepository::typeName##Slow()              \
-    {                                                        \
-        m_##typeName = type;                                 \
-        return m_##typeName;                                 \
+void ExitTimeObjectMaterialization::add(
+    PromotedLocationDescriptor location, const ExitValue& value)
+{
+    m_properties.append(ExitPropertyValue(location, value));
+}
+
+ExitValue ExitTimeObjectMaterialization::get(PromotedLocationDescriptor location) const
+{
+    for (ExitPropertyValue value : m_properties) {
+        if (value.location() == location)
+            return value.value();
     }
-FOR_EACH_FUNCTION_TYPE(FUNCTION_TYPE_GETTER_SLOW_DEFINITION)
-#undef FUNCTION_TYPE_GETTER_SLOW_DEFINITION
+    return ExitValue();
+}
+
+void ExitTimeObjectMaterialization::accountForLocalsOffset(int offset)
+{
+    for (ExitPropertyValue& property : m_properties)
+        property = property.withLocalsOffset(offset);
+}
+
+void ExitTimeObjectMaterialization::dump(PrintStream& out) const
+{
+    out.print(RawPointer(this), ":", Graph::opName(m_type), "(", listDump(m_properties), ")");
+}
+
+void ExitTimeObjectMaterialization::validateReferences(const TrackedReferences& trackedReferences) const
+{
+    for (ExitPropertyValue value : m_properties)
+        value.validateReferences(trackedReferences);
+}
 
 } } // namespace JSC::FTL
 
diff --git a/Source/JavaScriptCore/ftl/FTLExitTimeObjectMaterialization.h b/Source/JavaScriptCore/ftl/FTLExitTimeObjectMaterialization.h
new file mode 100644
index 000000000..549af1142
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLExitTimeObjectMaterialization.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2014, 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+#include "DFGNodeType.h"
+#include "FTLExitPropertyValue.h"
+#include "FTLExitValue.h"
+#include <wtf/Noncopyable.h>
+
+namespace JSC {
+
+class TrackedReferences;
+
+namespace FTL {
+
+class ExitTimeObjectMaterialization {
+    WTF_MAKE_NONCOPYABLE(ExitTimeObjectMaterialization)
+public:
+    ExitTimeObjectMaterialization(DFG::NodeType, CodeOrigin);
+    ~ExitTimeObjectMaterialization();
+    
+    void add(DFG::PromotedLocationDescriptor, const ExitValue&);
+    
+    DFG::NodeType type() const { return m_type; }
+    CodeOrigin origin() const { return m_origin; }
+    
+    ExitValue get(DFG::PromotedLocationDescriptor) const;
+    const Vector<ExitPropertyValue>& properties() const { return m_properties; }
+    
+    void accountForLocalsOffset(int offset);
+    
+    void dump(PrintStream& out) const;
+    
+    void validateReferences(const TrackedReferences&) const;
+    
+private:
+    DFG::NodeType m_type;
+    CodeOrigin m_origin;
+    Vector<ExitPropertyValue> m_properties;
+};
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLExitValue.cpp b/Source/JavaScriptCore/ftl/FTLExitValue.cpp
index a987c60ce..7004b9bdb 100644
--- a/Source/JavaScriptCore/ftl/FTLExitValue.cpp
+++ b/Source/JavaScriptCore/ftl/FTLExitValue.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -28,10 +28,61 @@
 
 #if ENABLE(FTL_JIT)
 
-#include "Operations.h"
+#include "FTLExitTimeObjectMaterialization.h"
+#include "JSCInlines.h"
+#include "TrackedReferences.h"
 
 namespace JSC { namespace FTL {
 
+ExitValue ExitValue::materializeNewObject(ExitTimeObjectMaterialization* data)
+{
+    ExitValue result;
+    result.m_kind = ExitValueMaterializeNewObject;
+    result.u.newObjectMaterializationData = data;
+    return result;
+}
+
+ExitValue ExitValue::withLocalsOffset(int offset) const
+{
+    if (!isInJSStackSomehow())
+        return *this;
+    if (!virtualRegister().isLocal())
+        return *this;
+    return withVirtualRegister(virtualRegister() + offset);
+}
+
+DataFormat ExitValue::dataFormat() const
+{
+    switch (kind()) {
+    case InvalidExitValue:
+        RELEASE_ASSERT_NOT_REACHED();
+        return DataFormatNone;
+            
+    case ExitValueDead:
+    case ExitValueConstant:
+    case ExitValueInJSStack:
+    case ExitValueMaterializeNewObject:
+        return DataFormatJS;
+            
+    case ExitValueArgument:
+        return exitArgument().format();
+            
+    case ExitValueInJSStackAsInt32:
+        return DataFormatInt32;
+            
+    case ExitValueInJSStackAsInt52:
+        return DataFormatInt52;
+            
+    case ExitValueInJSStackAsDouble:
+        return DataFormatDouble;
+            
+    case ExitValueRecovery:
+        return recoveryFormat();
+    }
+        
+    RELEASE_ASSERT_NOT_REACHED();
+}
+
 void ExitValue::dumpInContext(PrintStream& out, DumpContext* context) const
 {
     switch (kind()) {
@@ -48,16 +99,22 @@ void ExitValue::dumpInContext(PrintStream& out, DumpContext* context) const
         out.print("Constant(", inContext(constant(), context), ")");
         return;
     case ExitValueInJSStack:
-        out.print("InJSStack:r", virtualRegister());
+        out.print("InJSStack:", virtualRegister());
         return;
     case ExitValueInJSStackAsInt32:
-        out.print("InJSStackAsInt32:r", virtualRegister());
+        out.print("InJSStackAsInt32:", virtualRegister());
         return;
     case ExitValueInJSStackAsInt52:
-        out.print("InJSStackAsInt52:r", virtualRegister());
+        out.print("InJSStackAsInt52:", virtualRegister());
         return;
     case ExitValueInJSStackAsDouble:
-        out.print("InJSStackAsDouble:r", virtualRegister());
+        out.print("InJSStackAsDouble:", virtualRegister());
+        return;
+    case ExitValueRecovery:
+        out.print("Recovery(", recoveryOpcode(), ", arg", leftRecoveryArgument(), ", arg", rightRecoveryArgument(), ", ", recoveryFormat(), ")");
+        return;
+    case ExitValueMaterializeNewObject:
+        out.print("Materialize(", WTF::RawPointer(objectMaterialization()), ")");
         return;
     }
     
@@ -69,6 +126,12 @@ void ExitValue::dump(PrintStream& out) const
     dumpInContext(out, 0);
 }
 
+void ExitValue::validateReferences(const TrackedReferences& trackedReferences) const
+{
+    if (isConstant())
+        trackedReferences.check(constant());
+}
+
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLExitValue.h b/Source/JavaScriptCore/ftl/FTLExitValue.h
index 7aaaedd8d..c9946b2e7 100644
--- a/Source/JavaScriptCore/ftl/FTLExitValue.h
+++ b/Source/JavaScriptCore/ftl/FTLExitValue.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,19 +23,21 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLExitValue_h
-#define FTLExitValue_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
 #include "FTLExitArgument.h"
+#include "FTLRecoveryOpcode.h"
 #include "JSCJSValue.h"
 #include "VirtualRegister.h"
 #include <wtf/PrintStream.h>
 
-namespace JSC { namespace FTL {
+namespace JSC {
+
+class TrackedReferences;
+
+namespace FTL {
 
 // This is like ValueRecovery, but respects the way that the FTL does OSR
 // exit: the live non-constant non-flushed values are passed as arguments
@@ -51,9 +53,13 @@ enum ExitValueKind {
     ExitValueInJSStack,
     ExitValueInJSStackAsInt32,
     ExitValueInJSStackAsInt52,
-    ExitValueInJSStackAsDouble
+    ExitValueInJSStackAsDouble,
+    ExitValueRecovery,
+    ExitValueMaterializeNewObject
 };
 
+class ExitTimeObjectMaterialization;
+
 class ExitValue {
 public:
     ExitValue()
@@ -118,6 +124,19 @@ public:
         return result;
     }
     
+    static ExitValue recovery(RecoveryOpcode opcode, unsigned leftArgument, unsigned rightArgument, DataFormat format)
+    {
+        ExitValue result;
+        result.m_kind = ExitValueRecovery;
+        result.u.recovery.opcode = opcode;
+        result.u.recovery.leftArgument = leftArgument;
+        result.u.recovery.rightArgument = rightArgument;
+        result.u.recovery.format = format;
+        return result;
+    }
+    
+    static ExitValue materializeNewObject(ExitTimeObjectMaterialization*);
+    
     ExitValueKind kind() const { return m_kind; }
     
     bool isDead() const { return kind() == ExitValueDead; }
@@ -135,6 +154,9 @@ public:
     }
     bool isConstant() const { return kind() == ExitValueConstant; }
     bool isArgument() const { return kind() == ExitValueArgument; }
+    bool isRecovery() const { return kind() == ExitValueRecovery; }
+    bool isObjectMaterialization() const { return kind() == ExitValueMaterializeNewObject; }
+    bool hasIndexInStackmapLocations() const { return isArgument() || isRecovery(); }
     
     ExitArgument exitArgument() const
     {
@@ -142,6 +164,42 @@ public:
         return ExitArgument(u.argument);
     }
     
+    unsigned leftRecoveryArgument() const
+    {
+        ASSERT(isRecovery());
+        return u.recovery.leftArgument;
+    }
+    
+    unsigned rightRecoveryArgument() const
+    {
+        ASSERT(isRecovery());
+        return u.recovery.rightArgument;
+    }
+
+    void adjustStackmapLocationsIndexByOffset(unsigned offset)
+    {
+        ASSERT(hasIndexInStackmapLocations());
+        if (isArgument())
+            u.argument.argument += offset;
+        else {
+            ASSERT(isRecovery());
+            u.recovery.rightArgument += offset;
+            u.recovery.leftArgument += offset;
+        }
+    }
+    
+    DataFormat recoveryFormat() const
+    {
+        ASSERT(isRecovery());
+        return static_cast<DataFormat>(u.recovery.format);
+    }
+    
+    RecoveryOpcode recoveryOpcode() const
+    {
+        ASSERT(isRecovery());
+        return static_cast<RecoveryOpcode>(u.recovery.opcode);
+    }
+    
     JSValue constant() const
     {
         ASSERT(isConstant());
@@ -153,54 +211,51 @@ public:
         ASSERT(isInJSStackSomehow());
         return VirtualRegister(u.virtualRegister);
     }
+    
+    ExitTimeObjectMaterialization* objectMaterialization() const
+    {
+        ASSERT(isObjectMaterialization());
+        return u.newObjectMaterializationData;
+    }
 
+    ExitValue withVirtualRegister(VirtualRegister virtualRegister) const
+    {
+        ASSERT(isInJSStackSomehow());
+        ExitValue result;
+        result.m_kind = m_kind;
+        result.u.virtualRegister = virtualRegister.offset();
+        return result;
+    }
+    
+    ExitValue withLocalsOffset(int offset) const;
+    
     // If it's in the JSStack somehow, this will tell you what format it's in, in a manner
     // that is compatible with exitArgument().format(). If it's a constant or it's dead, it
     // will claim to be a JSValue. If it's an argument then it will tell you the argument's
     // format.
-    ValueFormat valueFormat() const
-    {
-        switch (kind()) {
-        case InvalidExitValue:
-            RELEASE_ASSERT_NOT_REACHED();
-            return InvalidValueFormat;
-            
-        case ExitValueDead:
-        case ExitValueConstant:
-        case ExitValueInJSStack:
-            return ValueFormatJSValue;
-            
-        case ExitValueArgument:
-            return exitArgument().format();
-            
-        case ExitValueInJSStackAsInt32:
-            return ValueFormatInt32;
-            
-        case ExitValueInJSStackAsInt52:
-            return ValueFormatInt52;
-            
-        case ExitValueInJSStackAsDouble:
-            return ValueFormatDouble;
-        }
-        
-        RELEASE_ASSERT_NOT_REACHED();
-        return InvalidValueFormat;
-    }
+    DataFormat dataFormat() const;
 
     void dump(PrintStream&) const;
     void dumpInContext(PrintStream&, DumpContext*) const;
     
+    void validateReferences(const TrackedReferences&) const;
+    
 private:
     ExitValueKind m_kind;
     union {
         ExitArgumentRepresentation argument;
         EncodedJSValue constant;
         int virtualRegister;
+        struct {
+            uint16_t leftArgument;
+            uint16_t rightArgument;
+            uint16_t opcode;
+            uint16_t format;
+        } recovery;
+        ExitTimeObjectMaterialization* newObjectMaterializationData;
     } u;
 };
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLExitValue_h
diff --git a/Source/JavaScriptCore/ftl/FTLFail.cpp b/Source/JavaScriptCore/ftl/FTLFail.cpp
index 1345c6fa1..5c6426a54 100644
--- a/Source/JavaScriptCore/ftl/FTLFail.cpp
+++ b/Source/JavaScriptCore/ftl/FTLFail.cpp
@@ -30,7 +30,6 @@
 
 #include "DFGFailedFinalizer.h"
 #include "FTLJITCode.h"
-#include "LLVMAPI.h"
 
 namespace JSC { namespace FTL {
 
@@ -38,10 +37,7 @@ using namespace DFG;
 
 void fail(State& state)
 {
-    state.graph.m_plan.finalizer = adoptPtr(new FailedFinalizer(state.graph.m_plan));
-    
-    if (state.module)
-        llvm->DisposeModule(state.module);
+    state.graph.m_plan.finalizer = std::make_unique<FailedFinalizer>(state.graph.m_plan);
 }
 
 } } // namespace JSC::FTL
diff --git a/Source/JavaScriptCore/ftl/FTLFail.h b/Source/JavaScriptCore/ftl/FTLFail.h
index 1d6432cf3..35188a437 100644
--- a/Source/JavaScriptCore/ftl/FTLFail.h
+++ b/Source/JavaScriptCore/ftl/FTLFail.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLFail_h
-#define FTLFail_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -39,6 +36,3 @@ void fail(State&);
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLFail_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLForOSREntryJITCode.cpp b/Source/JavaScriptCore/ftl/FTLForOSREntryJITCode.cpp
index 708bedc38..3080dc345 100644
--- a/Source/JavaScriptCore/ftl/FTLForOSREntryJITCode.cpp
+++ b/Source/JavaScriptCore/ftl/FTLForOSREntryJITCode.cpp
@@ -31,6 +31,8 @@
 namespace JSC { namespace FTL {
 
 ForOSREntryJITCode::ForOSREntryJITCode()
+    : m_bytecodeIndex(UINT_MAX)
+    , m_entryFailureCount(0)
 {
 }
 
@@ -43,9 +45,9 @@ ForOSREntryJITCode* ForOSREntryJITCode::ftlForOSREntry()
     return this;
 }
 
-void ForOSREntryJITCode::initializeEntryBuffer(VM& vm, unsigned numCalleeRegisters)
+void ForOSREntryJITCode::initializeEntryBuffer(VM& vm, unsigned numCalleeLocals)
 {
-    m_entryBuffer = vm.scratchBufferForSize(numCalleeRegisters * sizeof(EncodedJSValue));
+    m_entryBuffer = vm.scratchBufferForSize(numCalleeLocals * sizeof(EncodedJSValue));
 }
 
 } } // namespace JSC::FTL
diff --git a/Source/JavaScriptCore/ftl/FTLForOSREntryJITCode.h b/Source/JavaScriptCore/ftl/FTLForOSREntryJITCode.h
index 8d863a129..06db3dedb 100644
--- a/Source/JavaScriptCore/ftl/FTLForOSREntryJITCode.h
+++ b/Source/JavaScriptCore/ftl/FTLForOSREntryJITCode.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLForOSREntryJITCode_h
-#define FTLForOSREntryJITCode_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -48,7 +45,7 @@ public:
     ForOSREntryJITCode();
     ~ForOSREntryJITCode();
     
-    void initializeEntryBuffer(VM&, unsigned numCalleeRegisters);
+    void initializeEntryBuffer(VM&, unsigned numCalleeLocals);
     ScratchBuffer* entryBuffer() const { return m_entryBuffer; }
     
     void setBytecodeIndex(unsigned value) { m_bytecodeIndex = value; }
@@ -68,6 +65,3 @@ private:
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FLT_JIT)
-
-#endif // FTLForOSREntryJITCode_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLFormattedValue.h b/Source/JavaScriptCore/ftl/FTLFormattedValue.h
index b7ab3616c..ee0a0701f 100644
--- a/Source/JavaScriptCore/ftl/FTLFormattedValue.h
+++ b/Source/JavaScriptCore/ftl/FTLFormattedValue.h
@@ -23,34 +23,28 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLFormattedValue_h
-#define FTLFormattedValue_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
-#include "FTLAbbreviations.h"
-#include "FTLValueFormat.h"
+#include "DataFormat.h"
+#include "FTLAbbreviatedTypes.h"
 
 namespace JSC { namespace FTL {
 
 // This class is mostly used for OSR; it's a way of specifying how a value is formatted
 // in cases where it wouldn't have been obvious from looking at other indicators (like
-// the type of the LLVMValueRef or the type of the DFG::Node). Typically this arises
-// because LLVMValueRef doesn't give us the granularity we need to begin with, and we
-// use this in situations where there is no good way to say what node the value came
-// from.
+// the type of the B3::Value* or the type of the DFG::Node).
 
 class FormattedValue {
 public:
     FormattedValue()
-        : m_format(InvalidValueFormat)
+        : m_format(DataFormatNone)
         , m_value(0)
     {
     }
     
-    FormattedValue(ValueFormat format, LValue value)
+    FormattedValue(DataFormat format, LValue value)
         : m_format(format)
         , m_value(value)
     {
@@ -58,27 +52,24 @@ public:
     
     bool operator!() const
     {
-        ASSERT((m_format == InvalidValueFormat) == !m_value);
-        return m_format == InvalidValueFormat;
+        ASSERT((m_format == DataFormatNone) == !m_value);
+        return m_format == DataFormatNone;
     }
     
-    ValueFormat format() const { return m_format; }
+    DataFormat format() const { return m_format; }
     LValue value() const { return m_value; }
 
 private:
-    ValueFormat m_format;
+    DataFormat m_format;
     LValue m_value;
 };
 
 static inline FormattedValue noValue() { return FormattedValue(); }
-static inline FormattedValue int32Value(LValue value) { return FormattedValue(ValueFormatInt32, value); }
-static inline FormattedValue booleanValue(LValue value) { return FormattedValue(ValueFormatBoolean, value); }
-static inline FormattedValue jsValueValue(LValue value) { return FormattedValue(ValueFormatJSValue, value); }
-static inline FormattedValue doubleValue(LValue value) { return FormattedValue(ValueFormatDouble, value); }
+static inline FormattedValue int32Value(LValue value) { return FormattedValue(DataFormatInt32, value); }
+static inline FormattedValue booleanValue(LValue value) { return FormattedValue(DataFormatBoolean, value); }
+static inline FormattedValue jsValueValue(LValue value) { return FormattedValue(DataFormatJS, value); }
+static inline FormattedValue doubleValue(LValue value) { return FormattedValue(DataFormatDouble, value); }
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLFormattedValue_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLGeneratedFunction.h b/Source/JavaScriptCore/ftl/FTLGeneratedFunction.h
index 8226d0ac3..f6fba2891 100644
--- a/Source/JavaScriptCore/ftl/FTLGeneratedFunction.h
+++ b/Source/JavaScriptCore/ftl/FTLGeneratedFunction.h
@@ -23,8 +23,9 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLGeneratedFunction_h
-#define FTLGeneratedFunction_h
+#pragma once
+
+#if ENABLE(FTL_JIT)
 
 #include "CallFrame.h"
 
@@ -34,4 +35,4 @@ typedef EncodedJSValue (*GeneratedFunction)(ExecState*);
 
 } } // namespace JSC::FTL
 
-#endif // FTLGeneratedFunction_h
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLIntrinsicRepository.h b/Source/JavaScriptCore/ftl/FTLIntrinsicRepository.h
deleted file mode 100644
index 7f560dd95..000000000
--- a/Source/JavaScriptCore/ftl/FTLIntrinsicRepository.h
+++ /dev/null
@@ -1,135 +0,0 @@
-/*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
- */
-
-#ifndef FTLIntrinsicRepository_h
-#define FTLIntrinsicRepository_h
-
-#include <wtf/Platform.h>
-
-#if ENABLE(FTL_JIT)
-
-#include "DFGOperations.h"
-#include "FTLAbbreviations.h"
-#include "FTLCommonValues.h"
-
-namespace JSC { namespace FTL {
-
-#define FOR_EACH_FTL_INTRINSIC(macro) \
-    macro(addWithOverflow32, "llvm.sadd.with.overflow.i32", functionType(structType(m_context, int32, boolean), int32, int32)) \
-    macro(addWithOverflow64, "llvm.sadd.with.overflow.i64", functionType(structType(m_context, int64, boolean), int64, int64)) \
-    macro(doubleAbs, "llvm.fabs.f64", functionType(doubleType, doubleType)) \
-    macro(mulWithOverflow32, "llvm.smul.with.overflow.i32", functionType(structType(m_context, int32, boolean), int32, int32)) \
-    macro(mulWithOverflow64, "llvm.smul.with.overflow.i64", functionType(structType(m_context, int64, boolean), int64, int64)) \
-    macro(patchpointInt64, "llvm.experimental.patchpoint.i64", functionType(int64, int32, int32, ref8, int32, Variadic)) \
-    macro(patchpointVoid, "llvm.experimental.patchpoint.void", functionType(voidType, int32, int32, ref8, int32, Variadic)) \
-    macro(stackmap, "llvm.experimental.stackmap", functionType(voidType, int32, int32, Variadic)) \
-    macro(subWithOverflow32, "llvm.ssub.with.overflow.i32", functionType(structType(m_context, int32, boolean), int32, int32)) \
-    macro(subWithOverflow64, "llvm.ssub.with.overflow.i64", functionType(structType(m_context, int64, boolean), int64, int64)) \
-    macro(trap, "llvm.trap", functionType(voidType)) \
-    macro(x86SSE2CvtTSD2SI, "llvm.x86.sse2.cvttsd2si", functionType(int32, vectorType(doubleType, 2)))
-
-#define FOR_EACH_FUNCTION_TYPE(macro) \
-    macro(C_JITOperation_ESt, functionType(intPtr, intPtr, intPtr)) \
-    macro(I_JITOperation_EJss, functionType(intPtr, intPtr, intPtr)) \
-    macro(J_JITOperation_E, functionType(int64, intPtr)) \
-    macro(J_JITOperation_EAZ, functionType(int64, intPtr, intPtr, int32)) \
-    macro(J_JITOperation_EJJ, functionType(int64, intPtr, int64, int64)) \
-    macro(J_JITOperation_EJssZ, functionType(int64, intPtr, intPtr, int32)) \
-    macro(J_JITOperation_ESsiJI, functionType(int64, intPtr, intPtr, int64, intPtr)) \
-    macro(Jss_JITOperation_EZ, functionType(intPtr, intPtr, int32)) \
-    macro(P_JITOperation_E, functionType(intPtr, intPtr)) \
-    macro(P_JITOperation_EC, functionType(intPtr, intPtr, intPtr)) \
-    macro(P_JITOperation_EO, functionType(intPtr, intPtr, intPtr)) \
-    macro(P_JITOperation_ESt, functionType(intPtr, intPtr, intPtr)) \
-    macro(P_JITOperation_EStPS, functionType(intPtr, intPtr, intPtr, intPtr, intPtr)) \
-    macro(P_JITOperation_EStSS, functionType(intPtr, intPtr, intPtr, intPtr, intPtr)) \
-    macro(P_JITOperation_EStZ, functionType(intPtr, intPtr, intPtr, int32)) \
-    macro(S_JITOperation_EJ, functionType(intPtr, intPtr, int64)) \
-    macro(S_JITOperation_EJJ, functionType(intPtr, intPtr, int64, int64)) \
-    macro(V_JITOperation_EJJJ, functionType(voidType, intPtr, int64, int64, int64)) \
-    macro(V_JITOperation_EOZD, functionType(voidType, intPtr, intPtr, int32, doubleType)) \
-    macro(V_JITOperation_EOZJ, functionType(voidType, intPtr, intPtr, int32, int64)) \
-    macro(V_JITOperation_EC, functionType(voidType, intPtr, intPtr)) \
-    macro(V_JITOperation_EVws, functionType(voidType, intPtr, intPtr)) \
-    macro(Z_JITOperation_D, functionType(int32, doubleType))
-
-class IntrinsicRepository : public CommonValues {
-public:
-    IntrinsicRepository(LContext);
-    
-#define INTRINSIC_GETTER(ourName, llvmName, type) \
-    LValue ourName##Intrinsic() {                 \
-        if (!m_##ourName)                         \
-            return ourName##IntrinsicSlow();      \
-        return m_##ourName;                       \
-    }
-    FOR_EACH_FTL_INTRINSIC(INTRINSIC_GETTER)
-#undef INTRINSIC_GETTER
-
-#define FUNCTION_TYPE_GETTER(typeName, type) \
-    LType typeName()                         \
-    {                                        \
-        if (!m_##typeName)                   \
-            return typeName##Slow();         \
-        return m_##typeName;                 \
-    }
-    FOR_EACH_FUNCTION_TYPE(FUNCTION_TYPE_GETTER)
-#undef FUNCTION_TYPE_GETTER
-    
-#define FUNCTION_TYPE_RESOLVER(typeName, type) \
-    LType operationType(JSC::typeName)         \
-    {                                          \
-        return typeName();                     \
-    }
-    FOR_EACH_FUNCTION_TYPE(FUNCTION_TYPE_RESOLVER)
-#undef FUNCTION_TYPE_RESOLVER
-    
-private:
-#define INTRINSIC_GETTER_SLOW_DECLARATION(ourName, llvmName, type) \
-    LValue ourName##IntrinsicSlow();
-    FOR_EACH_FTL_INTRINSIC(INTRINSIC_GETTER_SLOW_DECLARATION)
-#undef INTRINSIC_GETTER
-
-#define INTRINSIC_FIELD_DECLARATION(ourName, llvmName, type) LValue m_##ourName;
-    FOR_EACH_FTL_INTRINSIC(INTRINSIC_FIELD_DECLARATION)
-#undef INTRINSIC_FIELD_DECLARATION
-
-#define FUNCTION_TYPE_GETTER_SLOW_DECLARATION(typeName, type) \
-    LType typeName##Slow();
-    FOR_EACH_FUNCTION_TYPE(FUNCTION_TYPE_GETTER_SLOW_DECLARATION)
-#undef FUNCTION_TYPE_GETTER_SLOW_DECLARATION
-
-#define FUNCTION_TYPE_FIELD_DECLARATION(typeName, type) \
-    LType m_##typeName;
-    FOR_EACH_FUNCTION_TYPE(FUNCTION_TYPE_FIELD_DECLARATION)
-#undef FUNCTION_TYPE_FIELD_DECLARATION
-};
-
-} } // namespace JSC::FTL
-
-#endif // ENABLE(FTL_JIT)
-
-#endif // FTLIntrinsicRepository_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLJITCode.cpp b/Source/JavaScriptCore/ftl/FTLJITCode.cpp
index cdc7de0c3..1cdb50957 100644
--- a/Source/JavaScriptCore/ftl/FTLJITCode.cpp
+++ b/Source/JavaScriptCore/ftl/FTLJITCode.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2015-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -28,8 +28,12 @@
 
 #if ENABLE(FTL_JIT)
 
+#include "FTLState.h"
+
 namespace JSC { namespace FTL {
 
+using namespace B3;
+
 JITCode::JITCode()
     : JSC::JITCode(FTLJIT)
 {
@@ -37,44 +41,54 @@ JITCode::JITCode()
 
 JITCode::~JITCode()
 {
+    if (FTL::shouldDumpDisassembly()) {
+        dataLog("Destroying FTL JIT code at ");
+        CommaPrinter comma;
+        dataLog(comma, m_b3Code);
+        dataLog(comma, m_arityCheckEntrypoint);
+        dataLog("\n");
+    }
 }
 
-void JITCode::initializeExitThunks(CodeRef exitThunks)
+void JITCode::initializeB3Code(CodeRef b3Code)
 {
-    m_exitThunks = exitThunks;
+    m_b3Code = b3Code;
 }
 
-void JITCode::addHandle(PassRefPtr<ExecutableMemoryHandle> handle)
+void JITCode::initializeB3Byproducts(std::unique_ptr<OpaqueByproducts> byproducts)
 {
-    m_handles.append(handle);
+    m_b3Byproducts = WTFMove(byproducts);
 }
 
-void JITCode::addDataSection(RefCountedArray<LSectionWord> dataSection)
+void JITCode::initializeAddressForCall(CodePtr address)
 {
-    m_dataSections.append(dataSection);
+    m_addressForCall = address;
 }
 
-void JITCode::initializeCode(CodeRef entrypoint)
+void JITCode::initializeArityCheckEntrypoint(CodeRef entrypoint)
 {
-    m_entrypoint = entrypoint;
+    m_arityCheckEntrypoint = entrypoint;
 }
 
-JITCode::CodePtr JITCode::addressForCall()
+JITCode::CodePtr JITCode::addressForCall(ArityCheckMode arityCheck)
 {
-    RELEASE_ASSERT(m_entrypoint);
-    return m_entrypoint.code();
+    switch (arityCheck) {
+    case ArityCheckNotRequired:
+        return m_addressForCall;
+    case MustCheckArity:
+        return m_arityCheckEntrypoint.code();
+    }
+    RELEASE_ASSERT_NOT_REACHED();
+    return CodePtr();
 }
 
 void* JITCode::executableAddressAtOffset(size_t offset)
 {
-    RELEASE_ASSERT(m_entrypoint);
-    return reinterpret_cast<char*>(m_entrypoint.code().executableAddress()) + offset;
+    return reinterpret_cast<char*>(m_addressForCall.executableAddress()) + offset;
 }
 
 void* JITCode::dataAddressAtOffset(size_t)
 {
-    RELEASE_ASSERT(m_entrypoint);
-
     // We can't patch FTL code, yet. Even if we did, it's not clear that we would do so
     // through this API.
     RELEASE_ASSERT_NOT_REACHED();
@@ -83,8 +97,6 @@ void* JITCode::dataAddressAtOffset(size_t)
 
 unsigned JITCode::offsetOf(void*)
 {
-    RELEASE_ASSERT(m_entrypoint);
-
     // We currently don't have visibility into the FTL code.
     RELEASE_ASSERT_NOT_REACHED();
     return 0;
@@ -92,8 +104,6 @@ unsigned JITCode::offsetOf(void*)
 
 size_t JITCode::size()
 {
-    RELEASE_ASSERT(m_entrypoint);
-
     // We don't know the size of FTL code, yet. Make a wild guess. This is mostly used for
     // GC load estimates.
     return 1000;
@@ -101,18 +111,11 @@ size_t JITCode::size()
 
 bool JITCode::contains(void*)
 {
-    RELEASE_ASSERT(m_entrypoint);
-
     // We have no idea what addresses the FTL code contains, yet.
     RELEASE_ASSERT_NOT_REACHED();
     return false;
 }
 
-JITCode::CodePtr JITCode::exitThunks()
-{
-    return m_exitThunks.code();
-}
-
 JITCode* JITCode::ftl()
 {
     return this;
@@ -123,6 +126,45 @@ DFG::CommonData* JITCode::dfgCommon()
     return &common;
 }
 
+void JITCode::validateReferences(const TrackedReferences& trackedReferences)
+{
+    common.validateReferences(trackedReferences);
+    
+    for (OSRExit& exit : osrExit)
+        exit.m_descriptor->validateReferences(trackedReferences);
+}
+
+RegisterSet JITCode::liveRegistersToPreserveAtExceptionHandlingCallSite(CodeBlock*, CallSiteIndex callSiteIndex)
+{
+    for (OSRExit& exit : osrExit) {
+        if (exit.m_exceptionHandlerCallSiteIndex.bits() == callSiteIndex.bits()) {
+            RELEASE_ASSERT(exit.isExceptionHandler());
+            RELEASE_ASSERT(exit.isGenericUnwindHandler());
+            return ValueRep::usedRegisters(exit.m_valueReps);
+        }
+    }
+    return RegisterSet();
+}
+
+std::optional<CodeOrigin> JITCode::findPC(CodeBlock* codeBlock, void* pc)
+{
+    for (OSRExit& exit : osrExit) {
+        if (ExecutableMemoryHandle* handle = exit.m_code.executableMemory()) {
+            if (handle->start() <= pc && pc < handle->end())
+                return std::optional<CodeOrigin>(exit.m_codeOriginForExitProfile);
+        }
+    }
+
+    for (std::unique_ptr<LazySlowPath>& lazySlowPath : lazySlowPaths) {
+        if (ExecutableMemoryHandle* handle = lazySlowPath->stub().executableMemory()) {
+            if (handle->start() <= pc && pc < handle->end())
+                return std::optional<CodeOrigin>(codeBlock->codeOrigin(lazySlowPath->callSiteIndex()));
+        }
+    }
+
+    return std::nullopt;
+}
+
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLJITCode.h b/Source/JavaScriptCore/ftl/FTLJITCode.h
index 3e7213983..2c2809e97 100644
--- a/Source/JavaScriptCore/ftl/FTLJITCode.h
+++ b/Source/JavaScriptCore/ftl/FTLJITCode.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,63 +23,63 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLJITCode_h
-#define FTLJITCode_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
+#include "B3OpaqueByproducts.h"
 #include "DFGCommonData.h"
+#include "FTLLazySlowPath.h"
 #include "FTLOSRExit.h"
-#include "FTLStackMaps.h"
 #include "JITCode.h"
-#include "LLVMAPI.h"
-#include <wtf/RefCountedArray.h>
 
-namespace JSC { namespace FTL {
+namespace JSC {
+
+class TrackedReferences;
 
-typedef int64_t LSectionWord; // We refer to LLVM data sections using LSectionWord*, just to be clear about our intended alignment restrictions.
+namespace FTL {
 
 class JITCode : public JSC::JITCode {
 public:
     JITCode();
     ~JITCode();
+
+    CodePtr addressForCall(ArityCheckMode) override;
+    void* executableAddressAtOffset(size_t offset) override;
+    void* dataAddressAtOffset(size_t offset) override;
+    unsigned offsetOf(void* pointerIntoCode) override;
+    size_t size() override;
+    bool contains(void*) override;
+
+    void initializeB3Code(CodeRef);
+    void initializeB3Byproducts(std::unique_ptr<B3::OpaqueByproducts>);
+    void initializeAddressForCall(CodePtr);
+    void initializeArityCheckEntrypoint(CodeRef);
     
-    CodePtr addressForCall();
-    void* executableAddressAtOffset(size_t offset);
-    void* dataAddressAtOffset(size_t offset);
-    unsigned offsetOf(void* pointerIntoCode);
-    size_t size();
-    bool contains(void*);
-    
-    void initializeExitThunks(CodeRef);
-    void addHandle(PassRefPtr<ExecutableMemoryHandle>);
-    void addDataSection(RefCountedArray<LSectionWord>);
-    void initializeCode(CodeRef entrypoint);
-    
-    const Vector<RefPtr<ExecutableMemoryHandle>>& handles() const { return m_handles; }
-    const Vector<RefCountedArray<LSectionWord>>& dataSections() const { return m_dataSections; }
-    
-    CodePtr exitThunks();
+    void validateReferences(const TrackedReferences&) override;
+
+    RegisterSet liveRegistersToPreserveAtExceptionHandlingCallSite(CodeBlock*, CallSiteIndex) override;
+
+    std::optional<CodeOrigin> findPC(CodeBlock*, void* pc) override;
+
+    CodeRef b3Code() const { return m_b3Code; }
     
-    JITCode* ftl();
-    DFG::CommonData* dfgCommon();
+    JITCode* ftl() override;
+    DFG::CommonData* dfgCommon() override;
+    static ptrdiff_t commonDataOffset() { return OBJECT_OFFSETOF(JITCode, common); }
     
     DFG::CommonData common;
     SegmentedVector<OSRExit, 8> osrExit;
-    StackMaps stackmaps;
+    SegmentedVector<OSRExitDescriptor, 8> osrExitDescriptors;
+    Vector<std::unique_ptr<LazySlowPath>> lazySlowPaths;
     
 private:
-    Vector<RefCountedArray<LSectionWord>> m_dataSections;
-    Vector<RefPtr<ExecutableMemoryHandle>> m_handles;
-    CodeRef m_entrypoint;
-    CodeRef m_exitThunks;
+    CodePtr m_addressForCall;
+    CodeRef m_b3Code;
+    std::unique_ptr<B3::OpaqueByproducts> m_b3Byproducts;
+    CodeRef m_arityCheckEntrypoint;
 };
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FLT_JIT)
-
-#endif // FTLJITCode_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLJITFinalizer.cpp b/Source/JavaScriptCore/ftl/FTLJITFinalizer.cpp
index a8a99b63a..00ea651e1 100644
--- a/Source/JavaScriptCore/ftl/FTLJITFinalizer.cpp
+++ b/Source/JavaScriptCore/ftl/FTLJITFinalizer.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2014, 2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -30,7 +30,10 @@
 
 #include "CodeBlockWithJITType.h"
 #include "DFGPlan.h"
+#include "FTLState.h"
 #include "FTLThunks.h"
+#include "JSCInlines.h"
+#include "ProfilerDatabase.h"
 
 namespace JSC { namespace FTL {
 
@@ -45,6 +48,19 @@ JITFinalizer::~JITFinalizer()
 {
 }
 
+size_t JITFinalizer::codeSize()
+{
+    size_t result = 0;
+
+    if (b3CodeLinkBuffer)
+        result += b3CodeLinkBuffer->size();
+    
+    if (entrypointLinkBuffer)
+        result += entrypointLinkBuffer->size();
+    
+    return result;
+}
+
 bool JITFinalizer::finalize()
 {
     RELEASE_ASSERT_NOT_REACHED();
@@ -53,64 +69,22 @@ bool JITFinalizer::finalize()
 
 bool JITFinalizer::finalizeFunction()
 {
-    for (unsigned i = jitCode->handles().size(); i--;) {
-        MacroAssembler::cacheFlush(
-            jitCode->handles()[i]->start(), jitCode->handles()[i]->sizeInBytes());
-    }
-    
-    if (exitThunksLinkBuffer) {
-        StackMaps::RecordMap recordMap = jitCode->stackmaps.getRecordMap();
-        
-        for (unsigned i = 0; i < osrExit.size(); ++i) {
-            OSRExitCompilationInfo& info = osrExit[i];
-            OSRExit& exit = jitCode->osrExit[i];
-            StackMaps::RecordMap::iterator iter = recordMap.find(exit.m_stackmapID);
-            if (iter == recordMap.end()) {
-                // It's OK, it was optimized out.
-                continue;
-            }
-            
-            exitThunksLinkBuffer->link(
-                info.m_thunkJump,
-                CodeLocationLabel(
-                    m_plan.vm.ftlThunks->getOSRExitGenerationThunk(
-                        m_plan.vm, Location::forStackmaps(
-                            &jitCode->stackmaps, iter->value.locations[0])).code()));
-        }
-        
-        jitCode->initializeExitThunks(
-            FINALIZE_DFG_CODE(
-                *exitThunksLinkBuffer,
-                ("FTL exit thunks for %s", toCString(CodeBlockWithJITType(m_plan.codeBlock.get(), JITCode::FTLJIT)).data())));
-    } // else this function had no OSR exits, so no exit thunks.
-    
-    if (sideCodeLinkBuffer) {
-        // Side code is for special slow paths that we generate ourselves, like for inline
-        // caches.
-        
-        for (unsigned i = slowPathCalls.size(); i--;) {
-            SlowPathCall& call = slowPathCalls[i];
-            sideCodeLinkBuffer->link(
-                call.call(),
-                CodeLocationLabel(m_plan.vm.ftlThunks->getSlowPathCallThunk(m_plan.vm, call.key()).code()));
-        }
-        
-        jitCode->addHandle(FINALIZE_DFG_CODE(
-            *sideCodeLinkBuffer,
-            ("FTL side code for %s",
-                toCString(CodeBlockWithJITType(m_plan.codeBlock.get(), JITCode::FTLJIT)).data()))
-            .executableMemory());
-    }
+    bool dumpDisassembly = shouldDumpDisassembly() || Options::asyncDisassembly();
     
-    MacroAssemblerCodePtr withArityCheck;
-    if (arityCheck.isSet())
-        withArityCheck = entrypointLinkBuffer->locationOf(arityCheck);
-    jitCode->initializeCode(
-        FINALIZE_DFG_CODE(
-            *entrypointLinkBuffer,
-            ("FTL entrypoint thunk for %s with LLVM generated code at %p", toCString(CodeBlockWithJITType(m_plan.codeBlock.get(), JITCode::FTLJIT)).data(), function)));
+    jitCode->initializeB3Code(
+        FINALIZE_CODE_IF(
+            dumpDisassembly, *b3CodeLinkBuffer,
+            ("FTL B3 code for %s", toCString(CodeBlockWithJITType(m_plan.codeBlock, JITCode::FTLJIT)).data())));
+
+    jitCode->initializeArityCheckEntrypoint(
+        FINALIZE_CODE_IF(
+            dumpDisassembly, *entrypointLinkBuffer,
+            ("FTL entrypoint thunk for %s with B3 generated code at %p", toCString(CodeBlockWithJITType(m_plan.codeBlock, JITCode::FTLJIT)).data(), function)));
     
-    m_plan.codeBlock->setJITCode(jitCode, withArityCheck);
+    m_plan.codeBlock->setJITCode(*jitCode);
+
+    if (m_plan.compilation)
+        m_plan.vm->m_perBytecodeProfiler->addCompilation(m_plan.codeBlock, *m_plan.compilation);
     
     return true;
 }
diff --git a/Source/JavaScriptCore/ftl/FTLJITFinalizer.h b/Source/JavaScriptCore/ftl/FTLJITFinalizer.h
index a7ecd9486..630c3b44e 100644
--- a/Source/JavaScriptCore/ftl/FTLJITFinalizer.h
+++ b/Source/JavaScriptCore/ftl/FTLJITFinalizer.h
@@ -23,38 +23,46 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLJITFinalizer_h
-#define FTLJITFinalizer_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
 #include "DFGFinalizer.h"
 #include "FTLGeneratedFunction.h"
 #include "FTLJITCode.h"
-#include "FTLOSRExitCompilationInfo.h"
 #include "FTLSlowPathCall.h"
-#include "LLVMAPI.h"
 #include "LinkBuffer.h"
 #include "MacroAssembler.h"
 
 namespace JSC { namespace FTL {
 
+class OutOfLineCodeInfo {
+public:
+    OutOfLineCodeInfo(std::unique_ptr<LinkBuffer> linkBuffer, const char* codeDescription)
+        : m_linkBuffer(WTFMove(linkBuffer))
+        , m_codeDescription(codeDescription)
+    {
+    }
+
+    std::unique_ptr<LinkBuffer> m_linkBuffer;
+    const char* m_codeDescription;
+};
+
 class JITFinalizer : public DFG::Finalizer {
 public:
     JITFinalizer(DFG::Plan&);
     virtual ~JITFinalizer();
-    
-    bool finalize();
-    bool finalizeFunction();
 
-    OwnPtr<LinkBuffer> exitThunksLinkBuffer;
-    OwnPtr<LinkBuffer> entrypointLinkBuffer;
-    OwnPtr<LinkBuffer> sideCodeLinkBuffer;
-    Vector<SlowPathCall> slowPathCalls; // Calls inside the side code.
-    Vector<OSRExitCompilationInfo> osrExit;
-    MacroAssembler::Label arityCheck;
+    size_t codeSize() override;
+    bool finalize() override;
+    bool finalizeFunction() override;
+
+    std::unique_ptr<LinkBuffer> b3CodeLinkBuffer;
+
+    // Eventually, we can get rid of this with B3.
+    std::unique_ptr<LinkBuffer> entrypointLinkBuffer;
+    
+    Vector<CCallHelpers::Jump> lazySlowPathGeneratorJumps;
     GeneratedFunction function;
     RefPtr<JITCode> jitCode;
 };
@@ -62,6 +70,3 @@ public:
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLJITFinalizer_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLLazySlowPath.cpp b/Source/JavaScriptCore/ftl/FTLLazySlowPath.cpp
new file mode 100644
index 000000000..9bdc06da8
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLLazySlowPath.cpp
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLLazySlowPath.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "FTLSlowPathCall.h"
+#include "LinkBuffer.h"
+
+namespace JSC { namespace FTL {
+
+LazySlowPath::LazySlowPath(
+    CodeLocationJump patchableJump, CodeLocationLabel done,
+    CodeLocationLabel exceptionTarget,
+    const RegisterSet& usedRegisters, CallSiteIndex callSiteIndex, RefPtr<Generator> generator
+    )
+    : m_patchableJump(patchableJump)
+    , m_done(done)
+    , m_exceptionTarget(exceptionTarget)
+    , m_usedRegisters(usedRegisters)
+    , m_callSiteIndex(callSiteIndex)
+    , m_generator(generator)
+{
+}
+
+LazySlowPath::~LazySlowPath()
+{
+}
+
+void LazySlowPath::generate(CodeBlock* codeBlock)
+{
+    RELEASE_ASSERT(!m_stub);
+
+    VM& vm = *codeBlock->vm();
+
+    CCallHelpers jit(&vm, codeBlock);
+    GenerationParams params;
+    CCallHelpers::JumpList exceptionJumps;
+    params.exceptionJumps = m_exceptionTarget ? &exceptionJumps : nullptr;
+    params.lazySlowPath = this;
+
+    m_generator->run(jit, params);
+
+    LinkBuffer linkBuffer(vm, jit, codeBlock, JITCompilationMustSucceed);
+    linkBuffer.link(params.doneJumps, m_done);
+    if (m_exceptionTarget)
+        linkBuffer.link(exceptionJumps, m_exceptionTarget);
+    m_stub = FINALIZE_CODE_FOR(codeBlock, linkBuffer, ("Lazy slow path call stub"));
+
+    MacroAssembler::repatchJump(m_patchableJump, CodeLocationLabel(m_stub.code()));
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLLazySlowPath.h b/Source/JavaScriptCore/ftl/FTLLazySlowPath.h
new file mode 100644
index 000000000..83b5baf0a
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLLazySlowPath.h
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+#include "CCallHelpers.h"
+#include "CodeBlock.h"
+#include "CodeLocation.h"
+#include "GPRInfo.h"
+#include "MacroAssemblerCodeRef.h"
+#include "RegisterSet.h"
+#include "ScratchRegisterAllocator.h"
+#include <wtf/SharedTask.h>
+
+namespace JSC { namespace FTL {
+
+// A LazySlowPath is an object that represents a piece of code that is part of FTL generated code
+// that will be generated lazily. It holds all of the important information needed to generate that
+// code, such as where to link jumps to and which registers are in use. It also has a reference to a
+// SharedTask that will do the actual code generation. That SharedTask may have additional data, like
+// which registers hold the inputs or outputs.
+class LazySlowPath {
+    WTF_MAKE_NONCOPYABLE(LazySlowPath);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    struct GenerationParams {
+        // Extra parameters to the GeneratorFunction are made into fields of this struct, so that if
+        // we add new parameters, we don't have to change all of the users.
+        CCallHelpers::JumpList doneJumps;
+        CCallHelpers::JumpList* exceptionJumps;
+        LazySlowPath* lazySlowPath;
+    };
+
+    typedef void GeneratorFunction(CCallHelpers&, GenerationParams&);
+    typedef SharedTask<GeneratorFunction> Generator;
+
+    template<typename Functor>
+    static RefPtr<Generator> createGenerator(const Functor& functor)
+    {
+        return createSharedTask<GeneratorFunction>(functor);
+    }
+    
+    LazySlowPath(
+        CodeLocationJump patchableJump, CodeLocationLabel done,
+        CodeLocationLabel exceptionTarget, const RegisterSet& usedRegisters,
+        CallSiteIndex, RefPtr<Generator>
+        );
+
+    ~LazySlowPath();
+
+    CodeLocationJump patchableJump() const { return m_patchableJump; }
+    CodeLocationLabel done() const { return m_done; }
+    const RegisterSet& usedRegisters() const { return m_usedRegisters; }
+    CallSiteIndex callSiteIndex() const { return m_callSiteIndex; }
+
+    void generate(CodeBlock*);
+
+    MacroAssemblerCodeRef stub() const { return m_stub; }
+
+private:
+    CodeLocationJump m_patchableJump;
+    CodeLocationLabel m_done;
+    CodeLocationLabel m_exceptionTarget;
+    RegisterSet m_usedRegisters;
+    CallSiteIndex m_callSiteIndex;
+    MacroAssemblerCodeRef m_stub;
+    RefPtr<Generator> m_generator;
+};
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLLazySlowPathCall.h b/Source/JavaScriptCore/ftl/FTLLazySlowPathCall.h
new file mode 100644
index 000000000..29214ac39
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLLazySlowPathCall.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#include "CodeBlock.h"
+#include "CodeLocation.h"
+#include "FTLLazySlowPath.h"
+#include "FTLSlowPathCall.h"
+#include "FTLThunks.h"
+#include "GPRInfo.h"
+#include "MacroAssemblerCodeRef.h"
+#include "RegisterSet.h"
+
+namespace JSC { namespace FTL {
+
+template<typename ResultType, typename... ArgumentTypes>
+RefPtr<LazySlowPath::Generator> createLazyCallGenerator(
+    FunctionPtr function, ResultType result, ArgumentTypes... arguments)
+{
+    return LazySlowPath::createGenerator(
+        [=] (CCallHelpers& jit, LazySlowPath::GenerationParams& params) {
+            callOperation(
+                params.lazySlowPath->usedRegisters(), jit, params.lazySlowPath->callSiteIndex(),
+                params.exceptionJumps, function, result, arguments...);
+            params.doneJumps.append(jit.jump());
+        });
+}
+
+} } // namespace JSC::FTL
diff --git a/Source/JavaScriptCore/ftl/FTLLink.cpp b/Source/JavaScriptCore/ftl/FTLLink.cpp
index 85050d151..d11b2a9b6 100644
--- a/Source/JavaScriptCore/ftl/FTLLink.cpp
+++ b/Source/JavaScriptCore/ftl/FTLLink.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2014 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -29,129 +29,149 @@
 #if ENABLE(FTL_JIT)
 
 #include "CCallHelpers.h"
-#include "CallFrameInlines.h"
 #include "CodeBlockWithJITType.h"
 #include "DFGCommon.h"
 #include "FTLJITCode.h"
 #include "JITOperations.h"
-#include "JITStubs.h"
-#include "LLVMAPI.h"
 #include "LinkBuffer.h"
+#include "JSCInlines.h"
+#include "ProfilerCompilation.h"
 #include "VirtualRegister.h"
 
 namespace JSC { namespace FTL {
 
 using namespace DFG;
 
-static void compileEntry(CCallHelpers& jit)
-{
-    jit.preserveReturnAddressAfterCall(GPRInfo::regT2);
-    jit.emitPutReturnPCToCallFrameHeader(GPRInfo::regT2);
-    jit.emitPutImmediateToCallFrameHeader(jit.codeBlock(), JSStack::CodeBlock);
-}
-
 void link(State& state)
 {
-    CodeBlock* codeBlock = state.graph.m_codeBlock;
+    Graph& graph = state.graph;
+    CodeBlock* codeBlock = graph.m_codeBlock;
+    VM& vm = graph.m_vm;
     
-    // LLVM will create its own jump tables as needed.
+    // B3 will create its own jump tables as needed.
     codeBlock->clearSwitchJumpTables();
+
+    state.jitCode->common.requiredRegisterCountForExit = graph.requiredRegisterCountForExit();
     
-    state.jitCode->common.frameRegisterCount = state.graph.frameRegisterCount();
-    state.jitCode->common.requiredRegisterCountForExit = state.graph.requiredRegisterCountForExit();
-    
-    if (!state.graph.m_inlineCallFrames->isEmpty())
-        state.jitCode->common.inlineCallFrames = std::move(state.graph.m_inlineCallFrames);
+    if (!graph.m_plan.inlineCallFrames->isEmpty())
+        state.jitCode->common.inlineCallFrames = graph.m_plan.inlineCallFrames;
     
+    graph.registerFrozenValues();
+
     // Create the entrypoint. Note that we use this entrypoint totally differently
     // depending on whether we're doing OSR entry or not.
-    // FIXME: Except for OSR entry, this is a total kludge - LLVM should just use our
-    // calling convention.
-    // https://bugs.webkit.org/show_bug.cgi?id=113621
-    CCallHelpers jit(&state.graph.m_vm, codeBlock);
+    CCallHelpers jit(&vm, codeBlock);
     
-    OwnPtr<LinkBuffer> linkBuffer;
-    CCallHelpers::Label arityCheck;
-    switch (state.graph.m_plan.mode) {
-    case FTLMode: {
-        compileEntry(jit);
+    std::unique_ptr<LinkBuffer> linkBuffer;
+
+    CCallHelpers::Address frame = CCallHelpers::Address(
+        CCallHelpers::stackPointerRegister, -static_cast<int32_t>(AssemblyHelpers::prologueStackPointerDelta()));
     
-        // This part is only necessary for functions. We currently only compile functions.
+    if (Profiler::Compilation* compilation = graph.compilation()) {
+        compilation->addDescription(
+            Profiler::OriginStack(),
+            toCString("Generated FTL JIT code for ", CodeBlockWithJITType(codeBlock, JITCode::FTLJIT), ", instruction count = ", graph.m_codeBlock->instructionCount(), ":\n"));
         
-        CCallHelpers::Label fromArityCheck = jit.label();
+        graph.ensureDominators();
+        graph.ensureNaturalLoops();
         
-        // Plant a check that sufficient space is available in the JSStack.
-        // FIXME: https://bugs.webkit.org/show_bug.cgi?id=56291
-        jit.addPtr(
-            CCallHelpers::TrustedImm32(virtualRegisterForLocal(state.jitCode->common.requiredRegisterCountForExit).offset() * sizeof(Register)),
-            GPRInfo::callFrameRegister, GPRInfo::regT1);
-        CCallHelpers::Jump stackCheck = jit.branchPtr(
-            CCallHelpers::Above,
-            CCallHelpers::AbsoluteAddress(state.graph.m_vm.addressOfJSStackLimit()),
-            GPRInfo::regT1);
-        CCallHelpers::Label fromStackCheck = jit.label();
+        const char* prefix = "    ";
         
-        jit.setupArgumentsExecState();
-        jit.move(
-            CCallHelpers::TrustedImmPtr(reinterpret_cast<void*>(state.generatedFunction)),
-            GPRInfo::nonArgGPR0);
-        jit.call(GPRInfo::nonArgGPR0);
-        jit.emitGetReturnPCFromCallFrameHeaderPtr(GPRInfo::regT1);
-        jit.emitGetCallerFrameFromCallFrameHeaderPtr(GPRInfo::callFrameRegister);
-        jit.restoreReturnAddressBeforeReturn(GPRInfo::regT1);
-        jit.ret();
+        DumpContext dumpContext;
+        StringPrintStream out;
+        Node* lastNode = 0;
+        for (size_t blockIndex = 0; blockIndex < graph.numBlocks(); ++blockIndex) {
+            BasicBlock* block = graph.block(blockIndex);
+            if (!block)
+                continue;
+            
+            graph.dumpBlockHeader(out, prefix, block, Graph::DumpLivePhisOnly, &dumpContext);
+            compilation->addDescription(Profiler::OriginStack(), out.toCString());
+            out.reset();
+            
+            for (size_t nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
+                Node* node = block->at(nodeIndex);
+                
+                Profiler::OriginStack stack;
+                
+                if (node->origin.semantic.isSet()) {
+                    stack = Profiler::OriginStack(
+                        *vm.m_perBytecodeProfiler, codeBlock, node->origin.semantic);
+                }
+                
+                if (graph.dumpCodeOrigin(out, prefix, lastNode, node, &dumpContext)) {
+                    compilation->addDescription(stack, out.toCString());
+                    out.reset();
+                }
+                
+                graph.dump(out, prefix, node, &dumpContext);
+                compilation->addDescription(stack, out.toCString());
+                out.reset();
+                
+                if (node->origin.semantic.isSet())
+                    lastNode = node;
+            }
+        }
         
-        stackCheck.link(&jit);
-        jit.move(CCallHelpers::TrustedImmPtr(codeBlock), GPRInfo::argumentGPR1);
-        jit.move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR0);
-        jit.store32(
-            CCallHelpers::TrustedImm32(CallFrame::Location::encodeAsBytecodeOffset(0)),
-            CCallHelpers::tagFor(static_cast<VirtualRegister>(JSStack::ArgumentCount)));
-        jit.storePtr(GPRInfo::callFrameRegister, &state.graph.m_vm.topCallFrame);
-        CCallHelpers::Call callStackCheck = jit.call();
-#if !ASSERT_DISABLED
-        // FIXME: need to make this call register with exception handling somehow. This is
-        // part of a bigger problem: FTL should be able to handle exceptions.
-        // https://bugs.webkit.org/show_bug.cgi?id=113622
-        // Until then, use a JIT ASSERT.
-        jit.load64(state.graph.m_vm.addressOfException(), GPRInfo::regT0);
-        jit.jitAssertIsNull(GPRInfo::regT0);
-#endif
-        jit.jump(fromStackCheck);
+        dumpContext.dump(out, prefix);
+        compilation->addDescription(Profiler::OriginStack(), out.toCString());
+        out.reset();
+
+        out.print("    Disassembly:\n");
+        out.print("        <not implemented yet>\n");
+        compilation->addDescription(Profiler::OriginStack(), out.toCString());
+        out.reset();
         
-        arityCheck = jit.label();
-        compileEntry(jit);
+        state.jitCode->common.compilation = compilation;
+    }
+    
+    switch (graph.m_plan.mode) {
+    case FTLMode: {
+        CCallHelpers::JumpList mainPathJumps;
+    
         jit.load32(
-            CCallHelpers::payloadFor(static_cast<VirtualRegister>(JSStack::ArgumentCount)),
+            frame.withOffset(sizeof(Register) * CallFrameSlot::argumentCount),
             GPRInfo::regT1);
-        jit.branch32(
+        mainPathJumps.append(jit.branch32(
             CCallHelpers::AboveOrEqual, GPRInfo::regT1,
-            CCallHelpers::TrustedImm32(codeBlock->numParameters()))
-            .linkTo(fromArityCheck, &jit);
+            CCallHelpers::TrustedImm32(codeBlock->numParameters())));
+        jit.emitFunctionPrologue();
         jit.move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR0);
-        jit.store32(
-            CCallHelpers::TrustedImm32(CallFrame::Location::encodeAsBytecodeOffset(0)),
-            CCallHelpers::tagFor(static_cast<VirtualRegister>(JSStack::ArgumentCount)));
-        jit.storePtr(GPRInfo::callFrameRegister, &state.graph.m_vm.topCallFrame);
+        jit.storePtr(GPRInfo::callFrameRegister, &vm.topCallFrame);
         CCallHelpers::Call callArityCheck = jit.call();
-#if !ASSERT_DISABLED
-        // FIXME: need to make this call register with exception handling somehow. This is
-        // part of a bigger problem: FTL should be able to handle exceptions.
-        // https://bugs.webkit.org/show_bug.cgi?id=113622
-        // Until then, use a JIT ASSERT.
-        jit.load64(state.graph.m_vm.addressOfException(), GPRInfo::regT1);
-        jit.jitAssertIsNull(GPRInfo::regT1);
-#endif
-        if (GPRInfo::returnValueGPR != GPRInfo::regT0)
-            jit.move(GPRInfo::returnValueGPR, GPRInfo::regT0);
-        jit.branchTest32(CCallHelpers::Zero, GPRInfo::regT0).linkTo(fromArityCheck, &jit);
+
+        auto noException = jit.branch32(CCallHelpers::GreaterThanOrEqual, GPRInfo::returnValueGPR, CCallHelpers::TrustedImm32(0));
+        jit.copyCalleeSavesToVMEntryFrameCalleeSavesBuffer();
+        jit.move(CCallHelpers::TrustedImmPtr(jit.vm()), GPRInfo::argumentGPR0);
+        jit.move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR1);
+        CCallHelpers::Call callLookupExceptionHandlerFromCallerFrame = jit.call();
+        jit.jumpToExceptionHandler();
+        noException.link(&jit);
+
+        if (!ASSERT_DISABLED) {
+            jit.load64(vm.addressOfException(), GPRInfo::regT1);
+            jit.jitAssertIsNull(GPRInfo::regT1);
+        }
+
+        jit.move(GPRInfo::returnValueGPR, GPRInfo::argumentGPR0);
+        jit.emitFunctionEpilogue();
+        mainPathJumps.append(jit.branchTest32(CCallHelpers::Zero, GPRInfo::argumentGPR0));
+        jit.emitFunctionPrologue();
         CCallHelpers::Call callArityFixup = jit.call();
-        jit.jump(fromArityCheck);
-        
-        linkBuffer = adoptPtr(new LinkBuffer(state.graph.m_vm, &jit, codeBlock, JITCompilationMustSucceed));
-        linkBuffer->link(callStackCheck, operationStackCheck);
+        jit.emitFunctionEpilogue();
+        mainPathJumps.append(jit.jump());
+
+        linkBuffer = std::make_unique<LinkBuffer>(vm, jit, codeBlock, JITCompilationCanFail);
+        if (linkBuffer->didFailToAllocate()) {
+            state.allocationFailed = true;
+            return;
+        }
         linkBuffer->link(callArityCheck, codeBlock->m_isConstructor ? operationConstructArityCheck : operationCallArityCheck);
-        linkBuffer->link(callArityFixup, FunctionPtr((state.graph.m_vm.getCTIStub(arityFixup)).code().executableAddress()));
+        linkBuffer->link(callLookupExceptionHandlerFromCallerFrame, lookupExceptionHandlerFromCallerFrame);
+        linkBuffer->link(callArityFixup, FunctionPtr((vm.getCTIStub(arityFixupGenerator)).code().executableAddress()));
+        linkBuffer->link(mainPathJumps, CodeLocationLabel(bitwise_cast<void*>(state.generatedFunction)));
+
+        state.jitCode->initializeAddressForCall(MacroAssemblerCodePtr(bitwise_cast<void*>(state.generatedFunction)));
         break;
     }
         
@@ -159,19 +179,19 @@ void link(State& state)
         // We jump to here straight from DFG code, after having boxed up all of the
         // values into the scratch buffer. Everything should be good to go - at this
         // point we've even done the stack check. Basically we just have to make the
-        // call to the LLVM-generated code.
-        jit.setupArgumentsExecState();
-        jit.move(
-            CCallHelpers::TrustedImmPtr(reinterpret_cast<void*>(state.generatedFunction)),
-            GPRInfo::nonArgGPR0);
-        jit.call(GPRInfo::nonArgGPR0);
-        jit.emitGetReturnPCFromCallFrameHeaderPtr(GPRInfo::regT1);
-        jit.emitGetCallerFrameFromCallFrameHeaderPtr(GPRInfo::callFrameRegister);
-        jit.restoreReturnAddressBeforeReturn(GPRInfo::regT1);
-        jit.ret();
+        // call to the B3-generated code.
+        CCallHelpers::Label start = jit.label();
+        jit.emitFunctionEpilogue();
+        CCallHelpers::Jump mainPathJump = jit.jump();
         
-        linkBuffer = adoptPtr(new LinkBuffer(
-            state.graph.m_vm, &jit, codeBlock, JITCompilationMustSucceed));
+        linkBuffer = std::make_unique<LinkBuffer>(vm, jit, codeBlock, JITCompilationCanFail);
+        if (linkBuffer->didFailToAllocate()) {
+            state.allocationFailed = true;
+            return;
+        }
+        linkBuffer->link(mainPathJump, CodeLocationLabel(bitwise_cast<void*>(state.generatedFunction)));
+
+        state.jitCode->initializeAddressForCall(linkBuffer->locationOf(start));
         break;
     }
         
@@ -180,9 +200,8 @@ void link(State& state)
         break;
     }
     
-    state.finalizer->entrypointLinkBuffer = linkBuffer.release();
+    state.finalizer->entrypointLinkBuffer = WTFMove(linkBuffer);
     state.finalizer->function = state.generatedFunction;
-    state.finalizer->arityCheck = arityCheck;
     state.finalizer->jitCode = state.jitCode;
 }
 
diff --git a/Source/JavaScriptCore/ftl/FTLLink.h b/Source/JavaScriptCore/ftl/FTLLink.h
index d49e169fc..d3805737c 100644
--- a/Source/JavaScriptCore/ftl/FTLLink.h
+++ b/Source/JavaScriptCore/ftl/FTLLink.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLLink_h
-#define FTLLink_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -39,6 +36,3 @@ void link(State&);
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLLink_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLLocation.cpp b/Source/JavaScriptCore/ftl/FTLLocation.cpp
new file mode 100644
index 000000000..ac8f23ef8
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLLocation.cpp
@@ -0,0 +1,195 @@
+/*
+ * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLLocation.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "B3ValueRep.h"
+#include "FTLSaveRestore.h"
+#include "RegisterSet.h"
+#include <wtf/CommaPrinter.h>
+#include <wtf/DataLog.h>
+#include <wtf/ListDump.h>
+
+namespace JSC { namespace FTL {
+
+using namespace B3;
+
+Location Location::forValueRep(const ValueRep& rep)
+{
+    switch (rep.kind()) {
+    case ValueRep::Register:
+        return forRegister(rep.reg(), 0);
+    case ValueRep::Stack:
+        return forIndirect(GPRInfo::callFrameRegister, rep.offsetFromFP());
+    case ValueRep::Constant:
+        return forConstant(rep.value());
+    default:
+        RELEASE_ASSERT_NOT_REACHED();
+        return Location();
+    }
+}
+
+void Location::dump(PrintStream& out) const
+{
+    out.print("(", kind());
+    if (hasReg())
+        out.print(", ", reg());
+    if (hasOffset())
+        out.print(", ", offset());
+    if (hasAddend())
+        out.print(", ", addend());
+    if (hasConstant())
+        out.print(", ", constant());
+    out.print(")");
+}
+
+bool Location::involvesGPR() const
+{
+    return isGPR() || kind() == Indirect;
+}
+
+bool Location::isGPR() const
+{
+    return kind() == Register && reg().isGPR();
+}
+
+GPRReg Location::gpr() const
+{
+    return reg().gpr();
+}
+
+bool Location::isFPR() const
+{
+    return kind() == Register && reg().isFPR();
+}
+
+FPRReg Location::fpr() const
+{
+    return reg().fpr();
+}
+
+void Location::restoreInto(MacroAssembler& jit, char* savedRegisters, GPRReg result, unsigned numFramesToPop) const
+{
+    if (involvesGPR() && RegisterSet::stackRegisters().get(gpr())) {
+        // Make the result GPR contain the appropriate stack register.
+        if (numFramesToPop) {
+            jit.move(MacroAssembler::framePointerRegister, result);
+            
+            for (unsigned i = numFramesToPop - 1; i--;)
+                jit.loadPtr(result, result);
+            
+            if (gpr() == MacroAssembler::framePointerRegister)
+                jit.loadPtr(result, result);
+            else
+                jit.addPtr(MacroAssembler::TrustedImmPtr(sizeof(void*) * 2), result);
+        } else
+            jit.move(gpr(), result);
+    }
+    
+    if (isGPR()) {
+        if (RegisterSet::stackRegisters().get(gpr())) {
+            // Already restored into result.
+        } else
+            jit.load64(savedRegisters + offsetOfGPR(gpr()), result);
+        
+        if (addend())
+            jit.add64(MacroAssembler::TrustedImm32(addend()), result);
+        return;
+    }
+    
+    if (isFPR()) {
+        jit.load64(savedRegisters + offsetOfFPR(fpr()), result);
+        ASSERT(!addend());
+        return;
+    }
+    
+    switch (kind()) {
+    case Register:
+        // B3 used some register that we don't know about!
+        dataLog("Unrecognized location: ", *this, "\n");
+        RELEASE_ASSERT_NOT_REACHED();
+        return;
+        
+    case Indirect:
+        if (RegisterSet::stackRegisters().get(gpr())) {
+            // The stack register is already recovered into result.
+            jit.load64(MacroAssembler::Address(result, offset()), result);
+            return;
+        }
+        
+        jit.load64(savedRegisters + offsetOfGPR(gpr()), result);
+        jit.load64(MacroAssembler::Address(result, offset()), result);
+        return;
+        
+    case Constant:
+        jit.move(MacroAssembler::TrustedImm64(constant()), result);
+        return;
+        
+    case Unprocessed:
+        RELEASE_ASSERT_NOT_REACHED();
+        return;
+    }
+    
+    RELEASE_ASSERT_NOT_REACHED();
+}
+
+GPRReg Location::directGPR() const
+{
+    RELEASE_ASSERT(!addend());
+    return gpr();
+}
+
+} } // namespace JSC::FTL
+
+namespace WTF {
+
+using namespace JSC::FTL;
+
+void printInternal(PrintStream& out, JSC::FTL::Location::Kind kind)
+{
+    switch (kind) {
+    case Location::Unprocessed:
+        out.print("Unprocessed");
+        return;
+    case Location::Register:
+        out.print("Register");
+        return;
+    case Location::Indirect:
+        out.print("Indirect");
+        return;
+    case Location::Constant:
+        out.print("Constant");
+        return;
+    }
+    RELEASE_ASSERT_NOT_REACHED();
+}
+
+} // namespace WTF
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLLocation.h b/Source/JavaScriptCore/ftl/FTLLocation.h
new file mode 100644
index 000000000..46772b9f5
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLLocation.h
@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+#include "DFGCommon.h"
+#include "FPRInfo.h"
+#include "GPRInfo.h"
+#include "Reg.h"
+#include <wtf/HashMap.h>
+
+namespace JSC {
+
+namespace B3 {
+class ValueRep;
+} // namespace B3
+
+namespace FTL {
+
+class Location {
+public:
+    enum Kind {
+        Unprocessed,
+        Register,
+        Indirect,
+        Constant
+    };
+    
+    Location()
+        : m_kind(Unprocessed)
+    {
+        u.constant = 0;
+    }
+    
+    Location(WTF::HashTableDeletedValueType)
+        : m_kind(Unprocessed)
+    {
+        u.constant = 1;
+    }
+
+    static Location forRegister(Reg reg, int32_t addend)
+    {
+        Location result;
+        result.m_kind = Register;
+        result.u.variable.regIndex = reg.index();
+        result.u.variable.offset = addend;
+        return result;
+    }
+    
+    static Location forIndirect(Reg reg, int32_t offset)
+    {
+        Location result;
+        result.m_kind = Indirect;
+        result.u.variable.regIndex = reg.index();
+        result.u.variable.offset = offset;
+        return result;
+    }
+    
+    static Location forConstant(int64_t constant)
+    {
+        Location result;
+        result.m_kind = Constant;
+        result.u.constant = constant;
+        return result;
+    }
+
+    static Location forValueRep(const B3::ValueRep&);
+
+    Kind kind() const { return m_kind; }
+
+    bool hasReg() const { return kind() == Register || kind() == Indirect; }
+    Reg reg() const
+    {
+        ASSERT(hasReg());
+        return Reg::fromIndex(u.variable.regIndex);
+    }
+    
+    bool hasOffset() const { return kind() == Indirect; }
+    int32_t offset() const
+    {
+        ASSERT(hasOffset());
+        return u.variable.offset;
+    }
+    
+    bool hasAddend() const { return kind() == Register; }
+    int32_t addend() const
+    {
+        ASSERT(hasAddend());
+        return u.variable.offset;
+    }
+    
+    bool hasConstant() const { return kind() == Constant; }
+    int64_t constant() const
+    {
+        ASSERT(hasConstant());
+        return u.constant;
+    }
+    
+    explicit operator bool() const { return kind() != Unprocessed || u.variable.offset; }
+
+    bool operator!() const { return !static_cast<bool>(*this); }
+    
+    bool isHashTableDeletedValue() const { return kind() == Unprocessed && u.variable.offset; }
+    
+    bool operator==(const Location& other) const
+    {
+        return m_kind == other.m_kind
+            && u.constant == other.u.constant;
+    }
+    
+    unsigned hash() const
+    {
+        unsigned result = m_kind;
+        
+        switch (kind()) {
+        case Unprocessed:
+            result ^= u.variable.offset;
+            break;
+
+        case Register:
+            result ^= u.variable.regIndex;
+            break;
+            
+        case Indirect:
+            result ^= u.variable.regIndex;
+            result ^= u.variable.offset;
+            break;
+            
+        case Constant:
+            result ^= WTF::IntHash<int64_t>::hash(u.constant);
+            break;
+        }
+        
+        return WTF::IntHash<unsigned>::hash(result);
+    }
+    
+    void dump(PrintStream&) const;
+    
+    bool isGPR() const;
+    bool involvesGPR() const;
+    GPRReg gpr() const;
+    GPRReg directGPR() const; // Get the GPR and assert that there is no addend.
+    
+    bool isFPR() const;
+    FPRReg fpr() const;
+    
+    // Assuming that all registers are saved to the savedRegisters buffer according
+    // to FTLSaveRestore convention, this loads the value into the given register.
+    // The code that this generates isn't exactly super fast. This assumes that FP
+    // and SP contain the same values that they would have contained in the original
+    // frame, or that you've done one or more canonically formed calls (i.e. can
+    // restore the FP by following the call frame linked list numFramesToPop times,
+    // and SP can be recovered by popping FP numFramesToPop-1 times and adding 16).
+    void restoreInto(MacroAssembler&, char* savedRegisters, GPRReg result, unsigned numFramesToPop = 0) const;
+    
+private:
+    Kind m_kind;
+    union {
+        int64_t constant;
+        struct {
+            unsigned regIndex;
+            int32_t offset;
+        } variable;
+    } u;
+};
+
+struct LocationHash {
+    static unsigned hash(const Location& key) { return key.hash(); }
+    static bool equal(const Location& a, const Location& b) { return a == b; }
+    static const bool safeToCompareToEmptyOrDeleted = true;
+};
+
+} } // namespace JSC::FTL
+
+namespace WTF {
+
+void printInternal(PrintStream&, JSC::FTL::Location::Kind);
+
+template<typename T> struct DefaultHash;
+template<> struct DefaultHash<JSC::FTL::Location> {
+    typedef JSC::FTL::LocationHash Hash;
+};
+
+template<typename T> struct HashTraits;
+template<> struct HashTraits<JSC::FTL::Location> : SimpleClassHashTraits<JSC::FTL::Location> { };
+
+} // namespace WTF
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp b/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp
new file mode 100644
index 000000000..399c85127
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp
@@ -0,0 +1,13970 @@
+/*
+ * Copyright (C) 2013-2017 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLLowerDFGToB3.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "AirGenerationContext.h"
+#include "AllowMacroScratchRegisterUsage.h"
+#include "B3CheckValue.h"
+#include "B3FenceValue.h"
+#include "B3PatchpointValue.h"
+#include "B3SlotBaseValue.h"
+#include "B3StackmapGenerationParams.h"
+#include "B3ValueInlines.h"
+#include "CallFrameShuffler.h"
+#include "CodeBlockWithJITType.h"
+#include "DFGAbstractInterpreterInlines.h"
+#include "DFGCapabilities.h"
+#include "DFGDominators.h"
+#include "DFGInPlaceAbstractState.h"
+#include "DFGOSRAvailabilityAnalysisPhase.h"
+#include "DFGOSRExitFuzz.h"
+#include "DOMJITPatchpoint.h"
+#include "DirectArguments.h"
+#include "FTLAbstractHeapRepository.h"
+#include "FTLAvailableRecovery.h"
+#include "FTLDOMJITPatchpointParams.h"
+#include "FTLExceptionTarget.h"
+#include "FTLForOSREntryJITCode.h"
+#include "FTLFormattedValue.h"
+#include "FTLLazySlowPathCall.h"
+#include "FTLLoweredNodeValue.h"
+#include "FTLOperations.h"
+#include "FTLOutput.h"
+#include "FTLPatchpointExceptionHandle.h"
+#include "FTLThunks.h"
+#include "FTLWeightedTarget.h"
+#include "JITAddGenerator.h"
+#include "JITBitAndGenerator.h"
+#include "JITBitOrGenerator.h"
+#include "JITBitXorGenerator.h"
+#include "JITDivGenerator.h"
+#include "JITInlineCacheGenerator.h"
+#include "JITLeftShiftGenerator.h"
+#include "JITMathIC.h"
+#include "JITMulGenerator.h"
+#include "JITRightShiftGenerator.h"
+#include "JITSubGenerator.h"
+#include "JSCInlines.h"
+#include "JSGeneratorFunction.h"
+#include "JSLexicalEnvironment.h"
+#include "JSMap.h"
+#include "OperandsInlines.h"
+#include "ScopedArguments.h"
+#include "ScopedArgumentsTable.h"
+#include "ScratchRegisterAllocator.h"
+#include "SetupVarargsFrame.h"
+#include "ShadowChicken.h"
+#include "StructureStubInfo.h"
+#include "VirtualRegister.h"
+#include "Watchdog.h"
+#include <atomic>
+#if !OS(WINDOWS)
+#include <dlfcn.h>
+#endif
+#include <unordered_set>
+#include <wtf/Box.h>
+#include <wtf/ProcessID.h>
+
+namespace JSC { namespace FTL {
+
+using namespace B3;
+using namespace DFG;
+
+namespace {
+
+std::atomic<int> compileCounter;
+
+#if !ASSERT_DISABLED
+NO_RETURN_DUE_TO_CRASH static void ftlUnreachable(
+    CodeBlock* codeBlock, BlockIndex blockIndex, unsigned nodeIndex)
+{
+    dataLog("Crashing in thought-to-be-unreachable FTL-generated code for ", pointerDump(codeBlock), " at basic block #", blockIndex);
+    if (nodeIndex != UINT_MAX)
+        dataLog(", node @", nodeIndex);
+    dataLog(".\n");
+    CRASH();
+}
+#endif
+
+// Using this instead of typeCheck() helps to reduce the load on B3, by creating
+// significantly less dead code.
+#define FTL_TYPE_CHECK_WITH_EXIT_KIND(exitKind, lowValue, highValue, typesPassedThrough, failCondition) do { \
+        FormattedValue _ftc_lowValue = (lowValue);                      \
+        Edge _ftc_highValue = (highValue);                              \
+        SpeculatedType _ftc_typesPassedThrough = (typesPassedThrough);  \
+        if (!m_interpreter.needsTypeCheck(_ftc_highValue, _ftc_typesPassedThrough)) \
+            break;                                                      \
+        typeCheck(_ftc_lowValue, _ftc_highValue, _ftc_typesPassedThrough, (failCondition), exitKind); \
+    } while (false)
+
+#define FTL_TYPE_CHECK(lowValue, highValue, typesPassedThrough, failCondition) \
+    FTL_TYPE_CHECK_WITH_EXIT_KIND(BadType, lowValue, highValue, typesPassedThrough, failCondition)
+
+class LowerDFGToB3 {
+    WTF_MAKE_NONCOPYABLE(LowerDFGToB3);
+public:
+    LowerDFGToB3(State& state)
+        : m_graph(state.graph)
+        , m_ftlState(state)
+        , m_out(state)
+        , m_proc(*state.proc)
+        , m_availabilityCalculator(m_graph)
+        , m_state(state.graph)
+        , m_interpreter(state.graph, m_state)
+    {
+    }
+    
+    void lower()
+    {
+        State* state = &m_ftlState;
+        
+        CString name;
+        if (verboseCompilationEnabled()) {
+            name = toCString(
+                "jsBody_", ++compileCounter, "_", codeBlock()->inferredName(),
+                "_", codeBlock()->hash());
+        } else
+            name = "jsBody";
+        
+        m_graph.ensureDominators();
+
+        if (verboseCompilationEnabled())
+            dataLog("Function ready, beginning lowering.\n");
+
+        m_out.initialize(m_heaps);
+
+        // We use prologue frequency for all of the initialization code.
+        m_out.setFrequency(1);
+        
+        m_prologue = m_out.newBlock();
+        m_handleExceptions = m_out.newBlock();
+
+        for (BlockIndex blockIndex = 0; blockIndex < m_graph.numBlocks(); ++blockIndex) {
+            m_highBlock = m_graph.block(blockIndex);
+            if (!m_highBlock)
+                continue;
+            m_out.setFrequency(m_highBlock->executionCount);
+            m_blocks.add(m_highBlock, m_out.newBlock());
+        }
+
+        // Back to prologue frequency for any bocks that get sneakily created in the initialization code.
+        m_out.setFrequency(1);
+        
+        m_out.appendTo(m_prologue, m_handleExceptions);
+        m_out.initializeConstants(m_proc, m_prologue);
+        createPhiVariables();
+
+        size_t sizeOfCaptured = sizeof(JSValue) * m_graph.m_nextMachineLocal;
+        B3::SlotBaseValue* capturedBase = m_out.lockedStackSlot(sizeOfCaptured);
+        m_captured = m_out.add(capturedBase, m_out.constIntPtr(sizeOfCaptured));
+        state->capturedValue = capturedBase->slot();
+
+        auto preOrder = m_graph.blocksInPreOrder();
+
+        m_callFrame = m_out.framePointer();
+        m_tagTypeNumber = m_out.constInt64(TagTypeNumber);
+        m_tagMask = m_out.constInt64(TagMask);
+
+        // Make sure that B3 knows that we really care about the mask registers. This forces the
+        // constants to be materialized in registers.
+        m_proc.addFastConstant(m_tagTypeNumber->key());
+        m_proc.addFastConstant(m_tagMask->key());
+        
+        // We don't want the CodeBlock to have a weak pointer to itself because
+        // that would cause it to always get collected.
+        m_out.storePtr(m_out.constIntPtr(bitwise_cast<intptr_t>(codeBlock())), addressFor(CallFrameSlot::codeBlock));
+
+        // Stack Overflow Check.
+        unsigned exitFrameSize = m_graph.requiredRegisterCountForExit() * sizeof(Register);
+        MacroAssembler::AbsoluteAddress addressOfStackLimit(vm().addressOfSoftStackLimit());
+        PatchpointValue* stackOverflowHandler = m_out.patchpoint(Void);
+        CallSiteIndex callSiteIndex = callSiteIndexForCodeOrigin(m_ftlState, CodeOrigin(0));
+        stackOverflowHandler->appendSomeRegister(m_callFrame);
+        stackOverflowHandler->clobber(RegisterSet::macroScratchRegisters());
+        stackOverflowHandler->numGPScratchRegisters = 1;
+        stackOverflowHandler->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+                GPRReg fp = params[0].gpr();
+                GPRReg scratch = params.gpScratch(0);
+
+                unsigned ftlFrameSize = params.proc().frameSize();
+
+                jit.addPtr(MacroAssembler::TrustedImm32(-std::max(exitFrameSize, ftlFrameSize)), fp, scratch);
+                MacroAssembler::Jump stackOverflow = jit.branchPtr(MacroAssembler::Above, addressOfStackLimit, scratch);
+
+                params.addLatePath([=] (CCallHelpers& jit) {
+                    AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                    stackOverflow.link(&jit);
+                    jit.store32(
+                        MacroAssembler::TrustedImm32(callSiteIndex.bits()),
+                        CCallHelpers::tagFor(VirtualRegister(CallFrameSlot::argumentCount)));
+                    jit.copyCalleeSavesToVMEntryFrameCalleeSavesBuffer();
+
+                    jit.move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR0);
+                    jit.move(CCallHelpers::TrustedImmPtr(jit.codeBlock()), GPRInfo::argumentGPR1);
+                    CCallHelpers::Call throwCall = jit.call();
+
+                    jit.move(CCallHelpers::TrustedImmPtr(jit.vm()), GPRInfo::argumentGPR0);
+                    jit.move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR1);
+                    CCallHelpers::Call lookupExceptionHandlerCall = jit.call();
+                    jit.jumpToExceptionHandler();
+
+                    jit.addLinkTask(
+                        [=] (LinkBuffer& linkBuffer) {
+                            linkBuffer.link(throwCall, FunctionPtr(operationThrowStackOverflowError));
+                            linkBuffer.link(lookupExceptionHandlerCall, FunctionPtr(lookupExceptionHandlerFromCallerFrame));
+                    });
+                });
+            });
+
+        LBasicBlock firstDFGBasicBlock = lowBlock(m_graph.block(0));
+        // Check Arguments.
+        availabilityMap().clear();
+        availabilityMap().m_locals = Operands<Availability>(codeBlock()->numParameters(), 0);
+        for (unsigned i = codeBlock()->numParameters(); i--;) {
+            availabilityMap().m_locals.argument(i) =
+                Availability(FlushedAt(FlushedJSValue, virtualRegisterForArgument(i)));
+        }
+        m_node = nullptr;
+        m_origin = NodeOrigin(CodeOrigin(0), CodeOrigin(0), true);
+        for (unsigned i = codeBlock()->numParameters(); i--;) {
+            Node* node = m_graph.m_arguments[i];
+            VirtualRegister operand = virtualRegisterForArgument(i);
+            
+            LValue jsValue = m_out.load64(addressFor(operand));
+            
+            if (node) {
+                DFG_ASSERT(m_graph, node, operand == node->stackAccessData()->machineLocal);
+                
+                // This is a hack, but it's an effective one. It allows us to do CSE on the
+                // primordial load of arguments. This assumes that the GetLocal that got put in
+                // place of the original SetArgument doesn't have any effects before it. This
+                // should hold true.
+                m_loadedArgumentValues.add(node, jsValue);
+            }
+            
+            switch (m_graph.m_argumentFormats[i]) {
+            case FlushedInt32:
+                speculate(BadType, jsValueValue(jsValue), node, isNotInt32(jsValue));
+                break;
+            case FlushedBoolean:
+                speculate(BadType, jsValueValue(jsValue), node, isNotBoolean(jsValue));
+                break;
+            case FlushedCell:
+                speculate(BadType, jsValueValue(jsValue), node, isNotCell(jsValue));
+                break;
+            case FlushedJSValue:
+                break;
+            default:
+                DFG_CRASH(m_graph, node, "Bad flush format for argument");
+                break;
+            }
+        }
+        m_out.jump(firstDFGBasicBlock);
+
+        m_out.appendTo(m_handleExceptions, firstDFGBasicBlock);
+        Box<CCallHelpers::Label> exceptionHandler = state->exceptionHandler;
+        m_out.patchpoint(Void)->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams&) {
+                CCallHelpers::Jump jump = jit.jump();
+                jit.addLinkTask(
+                    [=] (LinkBuffer& linkBuffer) {
+                        linkBuffer.link(jump, linkBuffer.locationOf(*exceptionHandler));
+                    });
+            });
+        m_out.unreachable();
+
+        for (DFG::BasicBlock* block : preOrder)
+            compileBlock(block);
+
+        // Make sure everything is decorated. This does a bunch of deferred decorating. This has
+        // to happen last because our abstract heaps are generated lazily. They have to be
+        // generated lazily because we have an infiniten number of numbered, indexed, and
+        // absolute heaps. We only become aware of the ones we actually mention while lowering.
+        m_heaps.computeRangesAndDecorateInstructions();
+
+        // We create all Phi's up front, but we may then decide not to compile the basic block
+        // that would have contained one of them. So this creates orphans, which triggers B3
+        // validation failures. Calling this fixes the issue.
+        //
+        // Note that you should avoid the temptation to make this call conditional upon
+        // validation being enabled. B3 makes no guarantees of any kind of correctness when
+        // dealing with IR that would have failed validation. For example, it would be valid to
+        // write a B3 phase that so aggressively assumes the lack of orphans that it would crash
+        // if any orphans were around. We might even have such phases already.
+        m_proc.deleteOrphans();
+
+        // We put the blocks into the B3 procedure in a super weird order. Now we reorder them.
+        m_out.applyBlockOrder();
+    }
+
+private:
+    
+    void createPhiVariables()
+    {
+        for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
+            DFG::BasicBlock* block = m_graph.block(blockIndex);
+            if (!block)
+                continue;
+            for (unsigned nodeIndex = block->size(); nodeIndex--;) {
+                Node* node = block->at(nodeIndex);
+                if (node->op() != DFG::Phi)
+                    continue;
+                LType type;
+                switch (node->flags() & NodeResultMask) {
+                case NodeResultDouble:
+                    type = Double;
+                    break;
+                case NodeResultInt32:
+                    type = Int32;
+                    break;
+                case NodeResultInt52:
+                    type = Int64;
+                    break;
+                case NodeResultBoolean:
+                    type = Int32;
+                    break;
+                case NodeResultJS:
+                    type = Int64;
+                    break;
+                default:
+                    DFG_CRASH(m_graph, node, "Bad Phi node result type");
+                    break;
+                }
+                m_phis.add(node, m_proc.add<Value>(B3::Phi, type, Origin(node)));
+            }
+        }
+    }
+    
+    void compileBlock(DFG::BasicBlock* block)
+    {
+        if (!block)
+            return;
+        
+        if (verboseCompilationEnabled())
+            dataLog("Compiling block ", *block, "\n");
+        
+        m_highBlock = block;
+        
+        // Make sure that any blocks created while lowering code in the high block have the frequency of
+        // the high block. This is appropriate because B3 doesn't need precise frequencies. It just needs
+        // something roughly approximate for things like register allocation.
+        m_out.setFrequency(m_highBlock->executionCount);
+        
+        LBasicBlock lowBlock = m_blocks.get(m_highBlock);
+        
+        m_nextHighBlock = 0;
+        for (BlockIndex nextBlockIndex = m_highBlock->index + 1; nextBlockIndex < m_graph.numBlocks(); ++nextBlockIndex) {
+            m_nextHighBlock = m_graph.block(nextBlockIndex);
+            if (m_nextHighBlock)
+                break;
+        }
+        m_nextLowBlock = m_nextHighBlock ? m_blocks.get(m_nextHighBlock) : 0;
+        
+        // All of this effort to find the next block gives us the ability to keep the
+        // generated IR in roughly program order. This ought not affect the performance
+        // of the generated code (since we expect B3 to reorder things) but it will
+        // make IR dumps easier to read.
+        m_out.appendTo(lowBlock, m_nextLowBlock);
+        
+        if (Options::ftlCrashes())
+            m_out.trap();
+        
+        if (!m_highBlock->cfaHasVisited) {
+            if (verboseCompilationEnabled())
+                dataLog("Bailing because CFA didn't reach.\n");
+            crash(m_highBlock, nullptr);
+            return;
+        }
+        
+        m_availabilityCalculator.beginBlock(m_highBlock);
+        
+        m_state.reset();
+        m_state.beginBasicBlock(m_highBlock);
+        
+        for (m_nodeIndex = 0; m_nodeIndex < m_highBlock->size(); ++m_nodeIndex) {
+            if (!compileNode(m_nodeIndex))
+                break;
+        }
+    }
+
+    void safelyInvalidateAfterTermination()
+    {
+        if (verboseCompilationEnabled())
+            dataLog("Bailing.\n");
+        crash();
+
+        // Invalidate dominated blocks. Under normal circumstances we would expect
+        // them to be invalidated already. But you can have the CFA become more
+        // precise over time because the structures of objects change on the main
+        // thread. Failing to do this would result in weird crashes due to a value
+        // being used but not defined. Race conditions FTW!
+        for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
+            DFG::BasicBlock* target = m_graph.block(blockIndex);
+            if (!target)
+                continue;
+            if (m_graph.m_dominators->dominates(m_highBlock, target)) {
+                if (verboseCompilationEnabled())
+                    dataLog("Block ", *target, " will bail also.\n");
+                target->cfaHasVisited = false;
+            }
+        }
+    }
+
+    bool compileNode(unsigned nodeIndex)
+    {
+        if (!m_state.isValid()) {
+            safelyInvalidateAfterTermination();
+            return false;
+        }
+        
+        m_node = m_highBlock->at(nodeIndex);
+        m_origin = m_node->origin;
+        m_out.setOrigin(m_node);
+        
+        if (verboseCompilationEnabled())
+            dataLog("Lowering ", m_node, "\n");
+        
+        m_availableRecoveries.resize(0);
+        
+        m_interpreter.startExecuting();
+        m_interpreter.executeKnownEdgeTypes(m_node);
+        
+        switch (m_node->op()) {
+        case DFG::Upsilon:
+            compileUpsilon();
+            break;
+        case DFG::Phi:
+            compilePhi();
+            break;
+        case JSConstant:
+            break;
+        case DoubleConstant:
+            compileDoubleConstant();
+            break;
+        case Int52Constant:
+            compileInt52Constant();
+            break;
+        case LazyJSConstant:
+            compileLazyJSConstant();
+            break;
+        case DoubleRep:
+            compileDoubleRep();
+            break;
+        case DoubleAsInt32:
+            compileDoubleAsInt32();
+            break;
+        case DFG::ValueRep:
+            compileValueRep();
+            break;
+        case Int52Rep:
+            compileInt52Rep();
+            break;
+        case ValueToInt32:
+            compileValueToInt32();
+            break;
+        case BooleanToNumber:
+            compileBooleanToNumber();
+            break;
+        case ExtractOSREntryLocal:
+            compileExtractOSREntryLocal();
+            break;
+        case GetStack:
+            compileGetStack();
+            break;
+        case PutStack:
+            compilePutStack();
+            break;
+        case DFG::Check:
+            compileNoOp();
+            break;
+        case CallObjectConstructor:
+            compileCallObjectConstructor();
+            break;
+        case ToThis:
+            compileToThis();
+            break;
+        case ValueAdd:
+            compileValueAdd();
+            break;
+        case StrCat:
+            compileStrCat();
+            break;
+        case ArithAdd:
+        case ArithSub:
+            compileArithAddOrSub();
+            break;
+        case ArithClz32:
+            compileArithClz32();
+            break;
+        case ArithMul:
+            compileArithMul();
+            break;
+        case ArithDiv:
+            compileArithDiv();
+            break;
+        case ArithMod:
+            compileArithMod();
+            break;
+        case ArithMin:
+        case ArithMax:
+            compileArithMinOrMax();
+            break;
+        case ArithAbs:
+            compileArithAbs();
+            break;
+        case ArithSin:
+            compileArithSin();
+            break;
+        case ArithCos:
+            compileArithCos();
+            break;
+        case ArithTan:
+            compileArithTan();
+            break;
+        case ArithPow:
+            compileArithPow();
+            break;
+        case ArithRandom:
+            compileArithRandom();
+            break;
+        case ArithRound:
+            compileArithRound();
+            break;
+        case ArithFloor:
+            compileArithFloor();
+            break;
+        case ArithCeil:
+            compileArithCeil();
+            break;
+        case ArithTrunc:
+            compileArithTrunc();
+            break;
+        case ArithSqrt:
+            compileArithSqrt();
+            break;
+        case ArithLog:
+            compileArithLog();
+            break;
+        case ArithFRound:
+            compileArithFRound();
+            break;
+        case ArithNegate:
+            compileArithNegate();
+            break;
+        case DFG::BitAnd:
+            compileBitAnd();
+            break;
+        case DFG::BitOr:
+            compileBitOr();
+            break;
+        case DFG::BitXor:
+            compileBitXor();
+            break;
+        case BitRShift:
+            compileBitRShift();
+            break;
+        case BitLShift:
+            compileBitLShift();
+            break;
+        case BitURShift:
+            compileBitURShift();
+            break;
+        case UInt32ToNumber:
+            compileUInt32ToNumber();
+            break;
+        case CheckStructure:
+            compileCheckStructure();
+            break;
+        case CheckCell:
+            compileCheckCell();
+            break;
+        case CheckNotEmpty:
+            compileCheckNotEmpty();
+            break;
+        case CheckBadCell:
+            compileCheckBadCell();
+            break;
+        case CheckStringIdent:
+            compileCheckStringIdent();
+            break;
+        case GetExecutable:
+            compileGetExecutable();
+            break;
+        case ArrayifyToStructure:
+            compileArrayifyToStructure();
+            break;
+        case PutStructure:
+            compilePutStructure();
+            break;
+        case TryGetById:
+            compileGetById(AccessType::TryGet);
+            break;
+        case GetById:
+        case GetByIdFlush:
+            compileGetById(AccessType::Get);
+            break;
+        case GetByIdWithThis:
+            compileGetByIdWithThis();
+            break;
+        case In:
+            compileIn();
+            break;
+        case HasOwnProperty:
+            compileHasOwnProperty();
+            break;
+        case PutById:
+        case PutByIdDirect:
+        case PutByIdFlush:
+            compilePutById();
+            break;
+        case PutByIdWithThis:
+            compilePutByIdWithThis();
+            break;
+        case PutGetterById:
+        case PutSetterById:
+            compilePutAccessorById();
+            break;
+        case PutGetterSetterById:
+            compilePutGetterSetterById();
+            break;
+        case PutGetterByVal:
+        case PutSetterByVal:
+            compilePutAccessorByVal();
+            break;
+        case GetButterfly:
+            compileGetButterfly();
+            break;
+        case ConstantStoragePointer:
+            compileConstantStoragePointer();
+            break;
+        case GetIndexedPropertyStorage:
+            compileGetIndexedPropertyStorage();
+            break;
+        case CheckArray:
+            compileCheckArray();
+            break;
+        case GetArrayLength:
+            compileGetArrayLength();
+            break;
+        case CheckInBounds:
+            compileCheckInBounds();
+            break;
+        case GetByVal:
+            compileGetByVal();
+            break;
+        case GetMyArgumentByVal:
+        case GetMyArgumentByValOutOfBounds:
+            compileGetMyArgumentByVal();
+            break;
+        case GetByValWithThis:
+            compileGetByValWithThis();
+            break;
+        case PutByVal:
+        case PutByValAlias:
+        case PutByValDirect:
+            compilePutByVal();
+            break;
+        case PutByValWithThis:
+            compilePutByValWithThis();
+            break;
+        case DefineDataProperty:
+            compileDefineDataProperty();
+            break;
+        case DefineAccessorProperty:
+            compileDefineAccessorProperty();
+            break;
+        case ArrayPush:
+            compileArrayPush();
+            break;
+        case ArrayPop:
+            compileArrayPop();
+            break;
+        case ArraySlice:
+            compileArraySlice();
+            break;
+        case CreateActivation:
+            compileCreateActivation();
+            break;
+        case NewFunction:
+        case NewGeneratorFunction:
+        case NewAsyncFunction:
+            compileNewFunction();
+            break;
+        case CreateDirectArguments:
+            compileCreateDirectArguments();
+            break;
+        case CreateScopedArguments:
+            compileCreateScopedArguments();
+            break;
+        case CreateClonedArguments:
+            compileCreateClonedArguments();
+            break;
+        case NewObject:
+            compileNewObject();
+            break;
+        case NewArray:
+            compileNewArray();
+            break;
+        case NewArrayWithSpread:
+            compileNewArrayWithSpread();
+            break;
+        case Spread:
+            compileSpread();
+            break;
+        case NewArrayBuffer:
+            compileNewArrayBuffer();
+            break;
+        case NewArrayWithSize:
+            compileNewArrayWithSize();
+            break;
+        case NewTypedArray:
+            compileNewTypedArray();
+            break;
+        case GetTypedArrayByteOffset:
+            compileGetTypedArrayByteOffset();
+            break;
+        case AllocatePropertyStorage:
+            compileAllocatePropertyStorage();
+            break;
+        case ReallocatePropertyStorage:
+            compileReallocatePropertyStorage();
+            break;
+        case NukeStructureAndSetButterfly:
+            compileNukeStructureAndSetButterfly();
+            break;
+        case ToNumber:
+            compileToNumber();
+            break;
+        case ToString:
+        case CallStringConstructor:
+            compileToStringOrCallStringConstructor();
+            break;
+        case ToPrimitive:
+            compileToPrimitive();
+            break;
+        case MakeRope:
+            compileMakeRope();
+            break;
+        case StringCharAt:
+            compileStringCharAt();
+            break;
+        case StringCharCodeAt:
+            compileStringCharCodeAt();
+            break;
+        case StringFromCharCode:
+            compileStringFromCharCode();
+            break;
+        case GetByOffset:
+        case GetGetterSetterByOffset:
+            compileGetByOffset();
+            break;
+        case GetGetter:
+            compileGetGetter();
+            break;
+        case GetSetter:
+            compileGetSetter();
+            break;
+        case MultiGetByOffset:
+            compileMultiGetByOffset();
+            break;
+        case PutByOffset:
+            compilePutByOffset();
+            break;
+        case MultiPutByOffset:
+            compileMultiPutByOffset();
+            break;
+        case GetGlobalVar:
+        case GetGlobalLexicalVariable:
+            compileGetGlobalVariable();
+            break;
+        case PutGlobalVariable:
+            compilePutGlobalVariable();
+            break;
+        case NotifyWrite:
+            compileNotifyWrite();
+            break;
+        case GetCallee:
+            compileGetCallee();
+            break;
+        case GetArgumentCountIncludingThis:
+            compileGetArgumentCountIncludingThis();
+            break;
+        case GetScope:
+            compileGetScope();
+            break;
+        case SkipScope:
+            compileSkipScope();
+            break;
+        case GetGlobalObject:
+            compileGetGlobalObject();
+            break;
+        case GetClosureVar:
+            compileGetClosureVar();
+            break;
+        case PutClosureVar:
+            compilePutClosureVar();
+            break;
+        case GetFromArguments:
+            compileGetFromArguments();
+            break;
+        case PutToArguments:
+            compilePutToArguments();
+            break;
+        case GetArgument:
+            compileGetArgument();
+            break;
+        case CompareEq:
+            compileCompareEq();
+            break;
+        case CompareStrictEq:
+            compileCompareStrictEq();
+            break;
+        case CompareLess:
+            compileCompareLess();
+            break;
+        case CompareLessEq:
+            compileCompareLessEq();
+            break;
+        case CompareGreater:
+            compileCompareGreater();
+            break;
+        case CompareGreaterEq:
+            compileCompareGreaterEq();
+            break;
+        case CompareEqPtr:
+            compileCompareEqPtr();
+            break;
+        case LogicalNot:
+            compileLogicalNot();
+            break;
+        case Call:
+        case TailCallInlinedCaller:
+        case Construct:
+            compileCallOrConstruct();
+            break;
+        case DirectCall:
+        case DirectTailCallInlinedCaller:
+        case DirectConstruct:
+        case DirectTailCall:
+            compileDirectCallOrConstruct();
+            break;
+        case TailCall:
+            compileTailCall();
+            break;
+        case CallVarargs:
+        case CallForwardVarargs:
+        case TailCallVarargs:
+        case TailCallVarargsInlinedCaller:
+        case TailCallForwardVarargs:
+        case TailCallForwardVarargsInlinedCaller:
+        case ConstructVarargs:
+        case ConstructForwardVarargs:
+            compileCallOrConstructVarargs();
+            break;
+        case CallEval:
+            compileCallEval();
+            break;
+        case LoadVarargs:
+            compileLoadVarargs();
+            break;
+        case ForwardVarargs:
+            compileForwardVarargs();
+            break;
+        case DFG::Jump:
+            compileJump();
+            break;
+        case DFG::Branch:
+            compileBranch();
+            break;
+        case DFG::Switch:
+            compileSwitch();
+            break;
+        case DFG::Return:
+            compileReturn();
+            break;
+        case ForceOSRExit:
+            compileForceOSRExit();
+            break;
+        case Throw:
+        case ThrowStaticError:
+            compileThrow();
+            break;
+        case InvalidationPoint:
+            compileInvalidationPoint();
+            break;
+        case IsEmpty:
+            compileIsEmpty();
+            break;
+        case IsUndefined:
+            compileIsUndefined();
+            break;
+        case IsBoolean:
+            compileIsBoolean();
+            break;
+        case IsNumber:
+            compileIsNumber();
+            break;
+        case IsCellWithType:
+            compileIsCellWithType();
+            break;
+        case MapHash:
+            compileMapHash();
+            break;
+        case GetMapBucket:
+            compileGetMapBucket();
+            break;
+        case LoadFromJSMapBucket:
+            compileLoadFromJSMapBucket();
+            break;
+        case IsNonEmptyMapBucket:
+            compileIsNonEmptyMapBucket();
+            break;
+        case IsObject:
+            compileIsObject();
+            break;
+        case IsObjectOrNull:
+            compileIsObjectOrNull();
+            break;
+        case IsFunction:
+            compileIsFunction();
+            break;
+        case IsTypedArrayView:
+            compileIsTypedArrayView();
+            break;
+        case ParseInt:
+            compileParseInt();
+            break;
+        case TypeOf:
+            compileTypeOf();
+            break;
+        case CheckTypeInfoFlags:
+            compileCheckTypeInfoFlags();
+            break;
+        case OverridesHasInstance:
+            compileOverridesHasInstance();
+            break;
+        case InstanceOf:
+            compileInstanceOf();
+            break;
+        case InstanceOfCustom:
+            compileInstanceOfCustom();
+            break;
+        case CountExecution:
+            compileCountExecution();
+            break;
+        case StoreBarrier:
+        case FencedStoreBarrier:
+            compileStoreBarrier();
+            break;
+        case HasIndexedProperty:
+            compileHasIndexedProperty();
+            break;
+        case HasGenericProperty:
+            compileHasGenericProperty();
+            break;
+        case HasStructureProperty:
+            compileHasStructureProperty();
+            break;
+        case GetDirectPname:
+            compileGetDirectPname();
+            break;
+        case GetEnumerableLength:
+            compileGetEnumerableLength();
+            break;
+        case GetPropertyEnumerator:
+            compileGetPropertyEnumerator();
+            break;
+        case GetEnumeratorStructurePname:
+            compileGetEnumeratorStructurePname();
+            break;
+        case GetEnumeratorGenericPname:
+            compileGetEnumeratorGenericPname();
+            break;
+        case ToIndexString:
+            compileToIndexString();
+            break;
+        case CheckStructureImmediate:
+            compileCheckStructureImmediate();
+            break;
+        case MaterializeNewObject:
+            compileMaterializeNewObject();
+            break;
+        case MaterializeCreateActivation:
+            compileMaterializeCreateActivation();
+            break;
+        case CheckWatchdogTimer:
+            compileCheckWatchdogTimer();
+            break;
+        case CreateRest:
+            compileCreateRest();
+            break;
+        case GetRestLength:
+            compileGetRestLength();
+            break;
+        case RegExpExec:
+            compileRegExpExec();
+            break;
+        case RegExpTest:
+            compileRegExpTest();
+            break;
+        case NewRegexp:
+            compileNewRegexp();
+            break;
+        case SetFunctionName:
+            compileSetFunctionName();
+            break;
+        case StringReplace:
+        case StringReplaceRegExp:
+            compileStringReplace();
+            break;
+        case GetRegExpObjectLastIndex:
+            compileGetRegExpObjectLastIndex();
+            break;
+        case SetRegExpObjectLastIndex:
+            compileSetRegExpObjectLastIndex();
+            break;
+        case LogShadowChickenPrologue:
+            compileLogShadowChickenPrologue();
+            break;
+        case LogShadowChickenTail:
+            compileLogShadowChickenTail();
+            break;
+        case RecordRegExpCachedResult:
+            compileRecordRegExpCachedResult();
+            break;
+        case ResolveScope:
+            compileResolveScope();
+            break;
+        case GetDynamicVar:
+            compileGetDynamicVar();
+            break;
+        case PutDynamicVar:
+            compilePutDynamicVar();
+            break;
+        case Unreachable:
+            compileUnreachable();
+            break;
+        case ToLowerCase:
+            compileToLowerCase();
+            break;
+        case NumberToStringWithRadix:
+            compileNumberToStringWithRadix();
+            break;
+        case CheckDOM:
+            compileCheckDOM();
+            break;
+        case CallDOM:
+            compileCallDOM();
+            break;
+        case CallDOMGetter:
+            compileCallDOMGetter();
+            break;
+
+        case PhantomLocal:
+        case LoopHint:
+        case MovHint:
+        case ZombieHint:
+        case ExitOK:
+        case PhantomNewObject:
+        case PhantomNewFunction:
+        case PhantomNewGeneratorFunction:
+        case PhantomNewAsyncFunction:
+        case PhantomCreateActivation:
+        case PhantomDirectArguments:
+        case PhantomCreateRest:
+        case PhantomSpread:
+        case PhantomNewArrayWithSpread:
+        case PhantomClonedArguments:
+        case PutHint:
+        case BottomValue:
+        case KillStack:
+            break;
+        default:
+            DFG_CRASH(m_graph, m_node, "Unrecognized node in FTL backend");
+            break;
+        }
+        
+        if (m_node->isTerminal())
+            return false;
+        
+        if (!m_state.isValid()) {
+            safelyInvalidateAfterTermination();
+            return false;
+        }
+
+        m_availabilityCalculator.executeNode(m_node);
+        m_interpreter.executeEffects(nodeIndex);
+        
+        return true;
+    }
+
+    void compileUpsilon()
+    {
+        LValue upsilonValue = nullptr;
+        switch (m_node->child1().useKind()) {
+        case DoubleRepUse:
+            upsilonValue = lowDouble(m_node->child1());
+            break;
+        case Int32Use:
+        case KnownInt32Use:
+            upsilonValue = lowInt32(m_node->child1());
+            break;
+        case Int52RepUse:
+            upsilonValue = lowInt52(m_node->child1());
+            break;
+        case BooleanUse:
+        case KnownBooleanUse:
+            upsilonValue = lowBoolean(m_node->child1());
+            break;
+        case CellUse:
+        case KnownCellUse:
+            upsilonValue = lowCell(m_node->child1());
+            break;
+        case UntypedUse:
+            upsilonValue = lowJSValue(m_node->child1());
+            break;
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            break;
+        }
+        ValueFromBlock upsilon = m_out.anchor(upsilonValue);
+        LValue phiNode = m_phis.get(m_node->phi());
+        m_out.addIncomingToPhi(phiNode, upsilon);
+    }
+    
+    void compilePhi()
+    {
+        LValue phi = m_phis.get(m_node);
+        m_out.m_block->append(phi);
+
+        switch (m_node->flags() & NodeResultMask) {
+        case NodeResultDouble:
+            setDouble(phi);
+            break;
+        case NodeResultInt32:
+            setInt32(phi);
+            break;
+        case NodeResultInt52:
+            setInt52(phi);
+            break;
+        case NodeResultBoolean:
+            setBoolean(phi);
+            break;
+        case NodeResultJS:
+            setJSValue(phi);
+            break;
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            break;
+        }
+    }
+    
+    void compileDoubleConstant()
+    {
+        setDouble(m_out.constDouble(m_node->asNumber()));
+    }
+    
+    void compileInt52Constant()
+    {
+        int64_t value = m_node->asAnyInt();
+        
+        setInt52(m_out.constInt64(value << JSValue::int52ShiftAmount));
+        setStrictInt52(m_out.constInt64(value));
+    }
+
+    void compileLazyJSConstant()
+    {
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+        LazyJSValue value = m_node->lazyJSValue();
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                value.emit(jit, JSValueRegs(params[0].gpr()));
+            });
+        patchpoint->effects = Effects::none();
+        setJSValue(patchpoint);
+    }
+
+    void compileDoubleRep()
+    {
+        switch (m_node->child1().useKind()) {
+        case RealNumberUse: {
+            LValue value = lowJSValue(m_node->child1(), ManualOperandSpeculation);
+            
+            LValue doubleValue = unboxDouble(value);
+            
+            LBasicBlock intCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            ValueFromBlock fastResult = m_out.anchor(doubleValue);
+            m_out.branch(
+                m_out.doubleEqual(doubleValue, doubleValue),
+                usually(continuation), rarely(intCase));
+            
+            LBasicBlock lastNext = m_out.appendTo(intCase, continuation);
+
+            FTL_TYPE_CHECK(
+                jsValueValue(value), m_node->child1(), SpecBytecodeRealNumber,
+                isNotInt32(value, provenType(m_node->child1()) & ~SpecDoubleReal));
+            ValueFromBlock slowResult = m_out.anchor(m_out.intToDouble(unboxInt32(value)));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            
+            setDouble(m_out.phi(Double, fastResult, slowResult));
+            return;
+        }
+            
+        case NotCellUse:
+        case NumberUse: {
+            bool shouldConvertNonNumber = m_node->child1().useKind() == NotCellUse;
+            
+            LValue value = lowJSValue(m_node->child1(), ManualOperandSpeculation);
+
+            LBasicBlock intCase = m_out.newBlock();
+            LBasicBlock doubleTesting = m_out.newBlock();
+            LBasicBlock doubleCase = m_out.newBlock();
+            LBasicBlock nonDoubleCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            m_out.branch(
+                isNotInt32(value, provenType(m_node->child1())),
+                unsure(doubleTesting), unsure(intCase));
+            
+            LBasicBlock lastNext = m_out.appendTo(intCase, doubleTesting);
+            
+            ValueFromBlock intToDouble = m_out.anchor(
+                m_out.intToDouble(unboxInt32(value)));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(doubleTesting, doubleCase);
+            LValue valueIsNumber = isNumber(value, provenType(m_node->child1()));
+            m_out.branch(valueIsNumber, usually(doubleCase), rarely(nonDoubleCase));
+
+            m_out.appendTo(doubleCase, nonDoubleCase);
+            ValueFromBlock unboxedDouble = m_out.anchor(unboxDouble(value));
+            m_out.jump(continuation);
+
+            if (shouldConvertNonNumber) {
+                LBasicBlock undefinedCase = m_out.newBlock();
+                LBasicBlock testNullCase = m_out.newBlock();
+                LBasicBlock nullCase = m_out.newBlock();
+                LBasicBlock testBooleanTrueCase = m_out.newBlock();
+                LBasicBlock convertBooleanTrueCase = m_out.newBlock();
+                LBasicBlock convertBooleanFalseCase = m_out.newBlock();
+
+                m_out.appendTo(nonDoubleCase, undefinedCase);
+                LValue valueIsUndefined = m_out.equal(value, m_out.constInt64(ValueUndefined));
+                m_out.branch(valueIsUndefined, unsure(undefinedCase), unsure(testNullCase));
+
+                m_out.appendTo(undefinedCase, testNullCase);
+                ValueFromBlock convertedUndefined = m_out.anchor(m_out.constDouble(PNaN));
+                m_out.jump(continuation);
+
+                m_out.appendTo(testNullCase, nullCase);
+                LValue valueIsNull = m_out.equal(value, m_out.constInt64(ValueNull));
+                m_out.branch(valueIsNull, unsure(nullCase), unsure(testBooleanTrueCase));
+
+                m_out.appendTo(nullCase, testBooleanTrueCase);
+                ValueFromBlock convertedNull = m_out.anchor(m_out.constDouble(0));
+                m_out.jump(continuation);
+
+                m_out.appendTo(testBooleanTrueCase, convertBooleanTrueCase);
+                LValue valueIsBooleanTrue = m_out.equal(value, m_out.constInt64(ValueTrue));
+                m_out.branch(valueIsBooleanTrue, unsure(convertBooleanTrueCase), unsure(convertBooleanFalseCase));
+
+                m_out.appendTo(convertBooleanTrueCase, convertBooleanFalseCase);
+                ValueFromBlock convertedTrue = m_out.anchor(m_out.constDouble(1));
+                m_out.jump(continuation);
+
+                m_out.appendTo(convertBooleanFalseCase, continuation);
+
+                LValue valueIsNotBooleanFalse = m_out.notEqual(value, m_out.constInt64(ValueFalse));
+                FTL_TYPE_CHECK(jsValueValue(value), m_node->child1(), ~SpecCell, valueIsNotBooleanFalse);
+                ValueFromBlock convertedFalse = m_out.anchor(m_out.constDouble(0));
+                m_out.jump(continuation);
+
+                m_out.appendTo(continuation, lastNext);
+                setDouble(m_out.phi(Double, intToDouble, unboxedDouble, convertedUndefined, convertedNull, convertedTrue, convertedFalse));
+                return;
+            }
+            m_out.appendTo(nonDoubleCase, continuation);
+            FTL_TYPE_CHECK(jsValueValue(value), m_node->child1(), SpecBytecodeNumber, m_out.booleanTrue);
+            m_out.unreachable();
+
+            m_out.appendTo(continuation, lastNext);
+
+            setDouble(m_out.phi(Double, intToDouble, unboxedDouble));
+            return;
+        }
+            
+        case Int52RepUse: {
+            setDouble(strictInt52ToDouble(lowStrictInt52(m_node->child1())));
+            return;
+        }
+            
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+        }
+    }
+
+    void compileDoubleAsInt32()
+    {
+        LValue integerValue = convertDoubleToInt32(lowDouble(m_node->child1()), shouldCheckNegativeZero(m_node->arithMode()));
+        setInt32(integerValue);
+    }
+
+    void compileValueRep()
+    {
+        switch (m_node->child1().useKind()) {
+        case DoubleRepUse: {
+            LValue value = lowDouble(m_node->child1());
+            
+            if (m_interpreter.needsTypeCheck(m_node->child1(), ~SpecDoubleImpureNaN)) {
+                value = m_out.select(
+                    m_out.doubleEqual(value, value), value, m_out.constDouble(PNaN));
+            }
+            
+            setJSValue(boxDouble(value));
+            return;
+        }
+            
+        case Int52RepUse: {
+            setJSValue(strictInt52ToJSValue(lowStrictInt52(m_node->child1())));
+            return;
+        }
+            
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+        }
+    }
+    
+    void compileInt52Rep()
+    {
+        switch (m_node->child1().useKind()) {
+        case Int32Use:
+            setStrictInt52(m_out.signExt32To64(lowInt32(m_node->child1())));
+            return;
+            
+        case AnyIntUse:
+            setStrictInt52(
+                jsValueToStrictInt52(
+                    m_node->child1(), lowJSValue(m_node->child1(), ManualOperandSpeculation)));
+            return;
+            
+        case DoubleRepAnyIntUse:
+            setStrictInt52(
+                doubleToStrictInt52(
+                    m_node->child1(), lowDouble(m_node->child1())));
+            return;
+            
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+        }
+    }
+    
+    void compileValueToInt32()
+    {
+        switch (m_node->child1().useKind()) {
+        case Int52RepUse:
+            setInt32(m_out.castToInt32(lowStrictInt52(m_node->child1())));
+            break;
+            
+        case DoubleRepUse:
+            setInt32(doubleToInt32(lowDouble(m_node->child1())));
+            break;
+            
+        case NumberUse:
+        case NotCellUse: {
+            LoweredNodeValue value = m_int32Values.get(m_node->child1().node());
+            if (isValid(value)) {
+                setInt32(value.value());
+                break;
+            }
+            
+            value = m_jsValueValues.get(m_node->child1().node());
+            if (isValid(value)) {
+                setInt32(numberOrNotCellToInt32(m_node->child1(), value.value()));
+                break;
+            }
+            
+            // We'll basically just get here for constants. But it's good to have this
+            // catch-all since we often add new representations into the mix.
+            setInt32(
+                numberOrNotCellToInt32(
+                    m_node->child1(),
+                    lowJSValue(m_node->child1(), ManualOperandSpeculation)));
+            break;
+        }
+            
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            break;
+        }
+    }
+    
+    void compileBooleanToNumber()
+    {
+        switch (m_node->child1().useKind()) {
+        case BooleanUse: {
+            setInt32(m_out.zeroExt(lowBoolean(m_node->child1()), Int32));
+            return;
+        }
+            
+        case UntypedUse: {
+            LValue value = lowJSValue(m_node->child1());
+            
+            if (!m_interpreter.needsTypeCheck(m_node->child1(), SpecBoolInt32 | SpecBoolean)) {
+                setInt32(m_out.bitAnd(m_out.castToInt32(value), m_out.int32One));
+                return;
+            }
+            
+            LBasicBlock booleanCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            ValueFromBlock notBooleanResult = m_out.anchor(value);
+            m_out.branch(
+                isBoolean(value, provenType(m_node->child1())),
+                unsure(booleanCase), unsure(continuation));
+            
+            LBasicBlock lastNext = m_out.appendTo(booleanCase, continuation);
+            ValueFromBlock booleanResult = m_out.anchor(m_out.bitOr(
+                m_out.zeroExt(unboxBoolean(value), Int64), m_tagTypeNumber));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(Int64, booleanResult, notBooleanResult));
+            return;
+        }
+            
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+            return;
+        }
+    }
+
+    void compileExtractOSREntryLocal()
+    {
+        EncodedJSValue* buffer = static_cast<EncodedJSValue*>(
+            m_ftlState.jitCode->ftlForOSREntry()->entryBuffer()->dataBuffer());
+        setJSValue(m_out.load64(m_out.absolute(buffer + m_node->unlinkedLocal().toLocal())));
+    }
+    
+    void compileGetStack()
+    {
+        // GetLocals arise only for captured variables and arguments. For arguments, we might have
+        // already loaded it.
+        if (LValue value = m_loadedArgumentValues.get(m_node)) {
+            setJSValue(value);
+            return;
+        }
+        
+        StackAccessData* data = m_node->stackAccessData();
+        AbstractValue& value = m_state.variables().operand(data->local);
+        
+        DFG_ASSERT(m_graph, m_node, isConcrete(data->format));
+        DFG_ASSERT(m_graph, m_node, data->format != FlushedDouble); // This just happens to not arise for GetStacks, right now. It would be trivial to support.
+        
+        if (isInt32Speculation(value.m_type))
+            setInt32(m_out.load32(payloadFor(data->machineLocal)));
+        else
+            setJSValue(m_out.load64(addressFor(data->machineLocal)));
+    }
+    
+    void compilePutStack()
+    {
+        StackAccessData* data = m_node->stackAccessData();
+        switch (data->format) {
+        case FlushedJSValue: {
+            LValue value = lowJSValue(m_node->child1());
+            m_out.store64(value, addressFor(data->machineLocal));
+            break;
+        }
+            
+        case FlushedDouble: {
+            LValue value = lowDouble(m_node->child1());
+            m_out.storeDouble(value, addressFor(data->machineLocal));
+            break;
+        }
+            
+        case FlushedInt32: {
+            LValue value = lowInt32(m_node->child1());
+            m_out.store32(value, payloadFor(data->machineLocal));
+            break;
+        }
+            
+        case FlushedInt52: {
+            LValue value = lowInt52(m_node->child1());
+            m_out.store64(value, addressFor(data->machineLocal));
+            break;
+        }
+            
+        case FlushedCell: {
+            LValue value = lowCell(m_node->child1());
+            m_out.store64(value, addressFor(data->machineLocal));
+            break;
+        }
+            
+        case FlushedBoolean: {
+            speculateBoolean(m_node->child1());
+            m_out.store64(
+                lowJSValue(m_node->child1(), ManualOperandSpeculation),
+                addressFor(data->machineLocal));
+            break;
+        }
+            
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad flush format");
+            break;
+        }
+    }
+    
+    void compileNoOp()
+    {
+        DFG_NODE_DO_TO_CHILDREN(m_graph, m_node, speculate);
+    }
+
+    void compileCallObjectConstructor()
+    {
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+        LValue value = lowJSValue(m_node->child1());
+
+        LBasicBlock isCellCase = m_out.newBlock();
+        LBasicBlock slowCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(isCell(value, provenType(m_node->child1())), usually(isCellCase), rarely(slowCase));
+
+        LBasicBlock lastNext = m_out.appendTo(isCellCase, slowCase);
+        ValueFromBlock fastResult = m_out.anchor(value);
+        m_out.branch(isObject(value), usually(continuation), rarely(slowCase));
+
+        m_out.appendTo(slowCase, continuation);
+        ValueFromBlock slowResult = m_out.anchor(vmCall(Int64, m_out.operation(operationObjectConstructor), m_callFrame, weakPointer(globalObject), value));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, fastResult, slowResult));
+    }
+    
+    void compileToThis()
+    {
+        LValue value = lowJSValue(m_node->child1());
+        
+        LBasicBlock isCellCase = m_out.newBlock();
+        LBasicBlock slowCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        m_out.branch(
+            isCell(value, provenType(m_node->child1())), usually(isCellCase), rarely(slowCase));
+        
+        LBasicBlock lastNext = m_out.appendTo(isCellCase, slowCase);
+        ValueFromBlock fastResult = m_out.anchor(value);
+        m_out.branch(
+            m_out.testIsZero32(
+                m_out.load8ZeroExt32(value, m_heaps.JSCell_typeInfoFlags),
+                m_out.constInt32(OverridesToThis)),
+            usually(continuation), rarely(slowCase));
+        
+        m_out.appendTo(slowCase, continuation);
+        J_JITOperation_EJ function;
+        if (m_graph.isStrictModeFor(m_node->origin.semantic))
+            function = operationToThisStrict;
+        else
+            function = operationToThis;
+        ValueFromBlock slowResult = m_out.anchor(
+            vmCall(Int64, m_out.operation(function), m_callFrame, value));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, fastResult, slowResult));
+    }
+
+    void compileValueAdd()
+    {
+        ArithProfile* arithProfile = m_ftlState.graph.baselineCodeBlockFor(m_node->origin.semantic)->arithProfileForBytecodeOffset(m_node->origin.semantic.bytecodeIndex);
+        JITAddIC* addIC = codeBlock()->addJITAddIC(arithProfile);
+        auto repatchingFunction = operationValueAddOptimize;
+        auto nonRepatchingFunction = operationValueAdd;
+        compileMathIC(addIC, repatchingFunction, nonRepatchingFunction);
+    }
+
+    template <typename Generator>
+    void compileMathIC(JITUnaryMathIC<Generator>* mathIC, FunctionPtr repatchingFunction, FunctionPtr nonRepatchingFunction)
+    {
+        Node* node = m_node;
+
+        LValue operand = lowJSValue(node->child1());
+
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+        patchpoint->appendSomeRegister(operand);
+        patchpoint->append(m_tagMask, ValueRep::lateReg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::lateReg(GPRInfo::tagTypeNumberRegister));
+        RefPtr<PatchpointExceptionHandle> exceptionHandle = preparePatchpointForExceptions(patchpoint);
+        patchpoint->numGPScratchRegisters = 1;
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                Box<CCallHelpers::JumpList> exceptions =
+                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+
+#if ENABLE(MATH_IC_STATS)
+                auto inlineStart = jit.label();
+#endif
+
+                Box<MathICGenerationState> mathICGenerationState = Box<MathICGenerationState>::create();
+                mathIC->m_generator = Generator(JSValueRegs(params[0].gpr()), JSValueRegs(params[1].gpr()), params.gpScratch(0));
+
+                bool shouldEmitProfiling = false;
+                bool generatedInline = mathIC->generateInline(jit, *mathICGenerationState, shouldEmitProfiling);
+
+                if (generatedInline) {
+                    ASSERT(!mathICGenerationState->slowPathJumps.empty());
+                    auto done = jit.label();
+                    params.addLatePath([=] (CCallHelpers& jit) {
+                        AllowMacroScratchRegisterUsage allowScratch(jit);
+                        mathICGenerationState->slowPathJumps.link(&jit);
+                        mathICGenerationState->slowPathStart = jit.label();
+#if ENABLE(MATH_IC_STATS)
+                        auto slowPathStart = jit.label();
+#endif
+
+                        if (mathICGenerationState->shouldSlowPathRepatch) {
+                            SlowPathCall call = callOperation(*state, params.unavailableRegisters(), jit, node->origin.semantic, exceptions.get(),
+                                repatchingFunction, params[0].gpr(), params[1].gpr(), CCallHelpers::TrustedImmPtr(mathIC));
+                            mathICGenerationState->slowPathCall = call.call();
+                        } else {
+                            SlowPathCall call = callOperation(*state, params.unavailableRegisters(), jit, node->origin.semantic,
+                                exceptions.get(), nonRepatchingFunction, params[0].gpr(), params[1].gpr());
+                            mathICGenerationState->slowPathCall = call.call();
+                        }
+                        jit.jump().linkTo(done, &jit);
+
+                        jit.addLinkTask([=] (LinkBuffer& linkBuffer) {
+                            mathIC->finalizeInlineCode(*mathICGenerationState, linkBuffer);
+                        });
+
+#if ENABLE(MATH_IC_STATS)
+                        auto slowPathEnd = jit.label();
+                        jit.addLinkTask([=] (LinkBuffer& linkBuffer) {
+                            size_t size = static_cast<char*>(linkBuffer.locationOf(slowPathEnd).executableAddress()) - static_cast<char*>(linkBuffer.locationOf(slowPathStart).executableAddress());
+                            mathIC->m_generatedCodeSize += size;
+                        });
+#endif
+                    });
+                } else {
+                    callOperation(
+                        *state, params.unavailableRegisters(), jit, node->origin.semantic, exceptions.get(),
+                        nonRepatchingFunction, params[0].gpr(), params[1].gpr());
+                }
+
+#if ENABLE(MATH_IC_STATS)
+                auto inlineEnd = jit.label();
+                jit.addLinkTask([=] (LinkBuffer& linkBuffer) {
+                    size_t size = static_cast<char*>(linkBuffer.locationOf(inlineEnd).executableAddress()) - static_cast<char*>(linkBuffer.locationOf(inlineStart).executableAddress());
+                    mathIC->m_generatedCodeSize += size;
+                });
+#endif
+            });
+
+        setJSValue(patchpoint);
+    }
+
+    template <typename Generator>
+    void compileMathIC(JITBinaryMathIC<Generator>* mathIC, FunctionPtr repatchingFunction, FunctionPtr nonRepatchingFunction)
+    {
+        Node* node = m_node;
+        
+        LValue left = lowJSValue(node->child1());
+        LValue right = lowJSValue(node->child2());
+
+        SnippetOperand leftOperand(m_state.forNode(node->child1()).resultType());
+        SnippetOperand rightOperand(m_state.forNode(node->child2()).resultType());
+            
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+        patchpoint->appendSomeRegister(left);
+        patchpoint->appendSomeRegister(right);
+        patchpoint->append(m_tagMask, ValueRep::lateReg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::lateReg(GPRInfo::tagTypeNumberRegister));
+        RefPtr<PatchpointExceptionHandle> exceptionHandle =
+            preparePatchpointForExceptions(patchpoint);
+        patchpoint->numGPScratchRegisters = 1;
+        patchpoint->numFPScratchRegisters = 2;
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                Box<CCallHelpers::JumpList> exceptions =
+                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+
+#if ENABLE(MATH_IC_STATS)
+                auto inlineStart = jit.label();
+#endif
+
+                Box<MathICGenerationState> mathICGenerationState = Box<MathICGenerationState>::create();
+                mathIC->m_generator = Generator(leftOperand, rightOperand, JSValueRegs(params[0].gpr()),
+                    JSValueRegs(params[1].gpr()), JSValueRegs(params[2].gpr()), params.fpScratch(0),
+                    params.fpScratch(1), params.gpScratch(0), InvalidFPRReg);
+
+                bool shouldEmitProfiling = false;
+                bool generatedInline = mathIC->generateInline(jit, *mathICGenerationState, shouldEmitProfiling);
+
+                if (generatedInline) {
+                    ASSERT(!mathICGenerationState->slowPathJumps.empty());
+                    auto done = jit.label();
+                    params.addLatePath([=] (CCallHelpers& jit) {
+                        AllowMacroScratchRegisterUsage allowScratch(jit);
+                        mathICGenerationState->slowPathJumps.link(&jit);
+                        mathICGenerationState->slowPathStart = jit.label();
+#if ENABLE(MATH_IC_STATS)
+                        auto slowPathStart = jit.label();
+#endif
+
+                        if (mathICGenerationState->shouldSlowPathRepatch) {
+                            SlowPathCall call = callOperation(*state, params.unavailableRegisters(), jit, node->origin.semantic, exceptions.get(),
+                                repatchingFunction, params[0].gpr(), params[1].gpr(), params[2].gpr(), CCallHelpers::TrustedImmPtr(mathIC));
+                            mathICGenerationState->slowPathCall = call.call();
+                        } else {
+                            SlowPathCall call = callOperation(*state, params.unavailableRegisters(), jit, node->origin.semantic,
+                                exceptions.get(), nonRepatchingFunction, params[0].gpr(), params[1].gpr(), params[2].gpr());
+                            mathICGenerationState->slowPathCall = call.call();
+                        }
+                        jit.jump().linkTo(done, &jit);
+
+                        jit.addLinkTask([=] (LinkBuffer& linkBuffer) {
+                            mathIC->finalizeInlineCode(*mathICGenerationState, linkBuffer);
+                        });
+
+#if ENABLE(MATH_IC_STATS)
+                        auto slowPathEnd = jit.label();
+                        jit.addLinkTask([=] (LinkBuffer& linkBuffer) {
+                            size_t size = static_cast<char*>(linkBuffer.locationOf(slowPathEnd).executableAddress()) - static_cast<char*>(linkBuffer.locationOf(slowPathStart).executableAddress());
+                            mathIC->m_generatedCodeSize += size;
+                        });
+#endif
+                    });
+                } else {
+                    callOperation(
+                        *state, params.unavailableRegisters(), jit, node->origin.semantic, exceptions.get(),
+                        nonRepatchingFunction, params[0].gpr(), params[1].gpr(), params[2].gpr());
+                }
+
+#if ENABLE(MATH_IC_STATS)
+                auto inlineEnd = jit.label();
+                jit.addLinkTask([=] (LinkBuffer& linkBuffer) {
+                    size_t size = static_cast<char*>(linkBuffer.locationOf(inlineEnd).executableAddress()) - static_cast<char*>(linkBuffer.locationOf(inlineStart).executableAddress());
+                    mathIC->m_generatedCodeSize += size;
+                });
+#endif
+            });
+
+        setJSValue(patchpoint);
+    }
+    
+    void compileStrCat()
+    {
+        LValue result;
+        if (m_node->child3()) {
+            result = vmCall(
+                Int64, m_out.operation(operationStrCat3), m_callFrame,
+                lowJSValue(m_node->child1(), ManualOperandSpeculation),
+                lowJSValue(m_node->child2(), ManualOperandSpeculation),
+                lowJSValue(m_node->child3(), ManualOperandSpeculation));
+        } else {
+            result = vmCall(
+                Int64, m_out.operation(operationStrCat2), m_callFrame,
+                lowJSValue(m_node->child1(), ManualOperandSpeculation),
+                lowJSValue(m_node->child2(), ManualOperandSpeculation));
+        }
+        setJSValue(result);
+    }
+    
+    void compileArithAddOrSub()
+    {
+        bool isSub =  m_node->op() == ArithSub;
+        switch (m_node->binaryUseKind()) {
+        case Int32Use: {
+            LValue left = lowInt32(m_node->child1());
+            LValue right = lowInt32(m_node->child2());
+
+            if (!shouldCheckOverflow(m_node->arithMode())) {
+                setInt32(isSub ? m_out.sub(left, right) : m_out.add(left, right));
+                break;
+            }
+
+            CheckValue* result =
+                isSub ? m_out.speculateSub(left, right) : m_out.speculateAdd(left, right);
+            blessSpeculation(result, Overflow, noValue(), nullptr, m_origin);
+            setInt32(result);
+            break;
+        }
+            
+        case Int52RepUse: {
+            if (!abstractValue(m_node->child1()).couldBeType(SpecInt52Only)
+                && !abstractValue(m_node->child2()).couldBeType(SpecInt52Only)) {
+                Int52Kind kind;
+                LValue left = lowWhicheverInt52(m_node->child1(), kind);
+                LValue right = lowInt52(m_node->child2(), kind);
+                setInt52(isSub ? m_out.sub(left, right) : m_out.add(left, right), kind);
+                break;
+            }
+
+            LValue left = lowInt52(m_node->child1());
+            LValue right = lowInt52(m_node->child2());
+            CheckValue* result =
+                isSub ? m_out.speculateSub(left, right) : m_out.speculateAdd(left, right);
+            blessSpeculation(result, Overflow, noValue(), nullptr, m_origin);
+            setInt52(result);
+            break;
+        }
+            
+        case DoubleRepUse: {
+            LValue C1 = lowDouble(m_node->child1());
+            LValue C2 = lowDouble(m_node->child2());
+
+            setDouble(isSub ? m_out.doubleSub(C1, C2) : m_out.doubleAdd(C1, C2));
+            break;
+        }
+
+        case UntypedUse: {
+            if (!isSub) {
+                DFG_CRASH(m_graph, m_node, "Bad use kind");
+                break;
+            }
+
+            ArithProfile* arithProfile = m_ftlState.graph.baselineCodeBlockFor(m_node->origin.semantic)->arithProfileForBytecodeOffset(m_node->origin.semantic.bytecodeIndex);
+            JITSubIC* subIC = codeBlock()->addJITSubIC(arithProfile);
+            auto repatchingFunction = operationValueSubOptimize;
+            auto nonRepatchingFunction = operationValueSub;
+            compileMathIC(subIC, repatchingFunction, nonRepatchingFunction);
+            break;
+        }
+
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            break;
+        }
+    }
+
+    void compileArithClz32()
+    {
+        if (m_node->child1().useKind() == Int32Use || m_node->child1().useKind() == KnownInt32Use) {
+            LValue operand = lowInt32(m_node->child1());
+            setInt32(m_out.ctlz32(operand));
+            return;
+        }
+        DFG_ASSERT(m_graph, m_node, m_node->child1().useKind() == UntypedUse);
+        LValue argument = lowJSValue(m_node->child1());
+        LValue result = vmCall(Int32, m_out.operation(operationArithClz32), m_callFrame, argument);
+        setInt32(result);
+    }
+    
+    void compileArithMul()
+    {
+        switch (m_node->binaryUseKind()) {
+        case Int32Use: {
+            LValue left = lowInt32(m_node->child1());
+            LValue right = lowInt32(m_node->child2());
+            
+            LValue result;
+
+            if (!shouldCheckOverflow(m_node->arithMode()))
+                result = m_out.mul(left, right);
+            else {
+                CheckValue* speculation = m_out.speculateMul(left, right);
+                blessSpeculation(speculation, Overflow, noValue(), nullptr, m_origin);
+                result = speculation;
+            }
+            
+            if (shouldCheckNegativeZero(m_node->arithMode())) {
+                LBasicBlock slowCase = m_out.newBlock();
+                LBasicBlock continuation = m_out.newBlock();
+                
+                m_out.branch(
+                    m_out.notZero32(result), usually(continuation), rarely(slowCase));
+                
+                LBasicBlock lastNext = m_out.appendTo(slowCase, continuation);
+                speculate(NegativeZero, noValue(), nullptr, m_out.lessThan(left, m_out.int32Zero));
+                speculate(NegativeZero, noValue(), nullptr, m_out.lessThan(right, m_out.int32Zero));
+                m_out.jump(continuation);
+                m_out.appendTo(continuation, lastNext);
+            }
+            
+            setInt32(result);
+            break;
+        }
+            
+        case Int52RepUse: {
+            Int52Kind kind;
+            LValue left = lowWhicheverInt52(m_node->child1(), kind);
+            LValue right = lowInt52(m_node->child2(), opposite(kind));
+
+            CheckValue* result = m_out.speculateMul(left, right);
+            blessSpeculation(result, Overflow, noValue(), nullptr, m_origin);
+
+            if (shouldCheckNegativeZero(m_node->arithMode())) {
+                LBasicBlock slowCase = m_out.newBlock();
+                LBasicBlock continuation = m_out.newBlock();
+                
+                m_out.branch(
+                    m_out.notZero64(result), usually(continuation), rarely(slowCase));
+                
+                LBasicBlock lastNext = m_out.appendTo(slowCase, continuation);
+                speculate(NegativeZero, noValue(), nullptr, m_out.lessThan(left, m_out.int64Zero));
+                speculate(NegativeZero, noValue(), nullptr, m_out.lessThan(right, m_out.int64Zero));
+                m_out.jump(continuation);
+                m_out.appendTo(continuation, lastNext);
+            }
+            
+            setInt52(result);
+            break;
+        }
+            
+        case DoubleRepUse: {
+            setDouble(
+                m_out.doubleMul(lowDouble(m_node->child1()), lowDouble(m_node->child2())));
+            break;
+        }
+
+        case UntypedUse: {
+            ArithProfile* arithProfile = m_ftlState.graph.baselineCodeBlockFor(m_node->origin.semantic)->arithProfileForBytecodeOffset(m_node->origin.semantic.bytecodeIndex);
+            JITMulIC* mulIC = codeBlock()->addJITMulIC(arithProfile);
+            auto repatchingFunction = operationValueMulOptimize;
+            auto nonRepatchingFunction = operationValueMul;
+            compileMathIC(mulIC, repatchingFunction, nonRepatchingFunction);
+            break;
+        }
+
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            break;
+        }
+    }
+
+    void compileArithDiv()
+    {
+        switch (m_node->binaryUseKind()) {
+        case Int32Use: {
+            LValue numerator = lowInt32(m_node->child1());
+            LValue denominator = lowInt32(m_node->child2());
+
+            if (shouldCheckNegativeZero(m_node->arithMode())) {
+                LBasicBlock zeroNumerator = m_out.newBlock();
+                LBasicBlock numeratorContinuation = m_out.newBlock();
+
+                m_out.branch(
+                    m_out.isZero32(numerator),
+                    rarely(zeroNumerator), usually(numeratorContinuation));
+
+                LBasicBlock innerLastNext = m_out.appendTo(zeroNumerator, numeratorContinuation);
+
+                speculate(
+                    NegativeZero, noValue(), 0, m_out.lessThan(denominator, m_out.int32Zero));
+
+                m_out.jump(numeratorContinuation);
+
+                m_out.appendTo(numeratorContinuation, innerLastNext);
+            }
+            
+            if (shouldCheckOverflow(m_node->arithMode())) {
+                LBasicBlock unsafeDenominator = m_out.newBlock();
+                LBasicBlock continuation = m_out.newBlock();
+
+                LValue adjustedDenominator = m_out.add(denominator, m_out.int32One);
+                m_out.branch(
+                    m_out.above(adjustedDenominator, m_out.int32One),
+                    usually(continuation), rarely(unsafeDenominator));
+
+                LBasicBlock lastNext = m_out.appendTo(unsafeDenominator, continuation);
+                LValue neg2ToThe31 = m_out.constInt32(-2147483647-1);
+                speculate(Overflow, noValue(), nullptr, m_out.isZero32(denominator));
+                speculate(Overflow, noValue(), nullptr, m_out.equal(numerator, neg2ToThe31));
+                m_out.jump(continuation);
+
+                m_out.appendTo(continuation, lastNext);
+                LValue result = m_out.div(numerator, denominator);
+                speculate(
+                    Overflow, noValue(), 0,
+                    m_out.notEqual(m_out.mul(result, denominator), numerator));
+                setInt32(result);
+            } else
+                setInt32(m_out.chillDiv(numerator, denominator));
+
+            break;
+        }
+            
+        case DoubleRepUse: {
+            setDouble(m_out.doubleDiv(
+                lowDouble(m_node->child1()), lowDouble(m_node->child2())));
+            break;
+        }
+
+        case UntypedUse: {
+            emitBinarySnippet<JITDivGenerator, NeedScratchFPR>(operationValueDiv);
+            break;
+        }
+
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            break;
+        }
+    }
+    
+    void compileArithMod()
+    {
+        switch (m_node->binaryUseKind()) {
+        case Int32Use: {
+            LValue numerator = lowInt32(m_node->child1());
+            LValue denominator = lowInt32(m_node->child2());
+
+            LValue remainder;
+            if (shouldCheckOverflow(m_node->arithMode())) {
+                LBasicBlock unsafeDenominator = m_out.newBlock();
+                LBasicBlock continuation = m_out.newBlock();
+
+                LValue adjustedDenominator = m_out.add(denominator, m_out.int32One);
+                m_out.branch(
+                    m_out.above(adjustedDenominator, m_out.int32One),
+                    usually(continuation), rarely(unsafeDenominator));
+
+                LBasicBlock lastNext = m_out.appendTo(unsafeDenominator, continuation);
+                LValue neg2ToThe31 = m_out.constInt32(-2147483647-1);
+                speculate(Overflow, noValue(), nullptr, m_out.isZero32(denominator));
+                speculate(Overflow, noValue(), nullptr, m_out.equal(numerator, neg2ToThe31));
+                m_out.jump(continuation);
+
+                m_out.appendTo(continuation, lastNext);
+                LValue result = m_out.mod(numerator, denominator);
+                remainder = result;
+            } else
+                remainder = m_out.chillMod(numerator, denominator);
+
+            if (shouldCheckNegativeZero(m_node->arithMode())) {
+                LBasicBlock negativeNumerator = m_out.newBlock();
+                LBasicBlock numeratorContinuation = m_out.newBlock();
+
+                m_out.branch(
+                    m_out.lessThan(numerator, m_out.int32Zero),
+                    unsure(negativeNumerator), unsure(numeratorContinuation));
+
+                LBasicBlock innerLastNext = m_out.appendTo(negativeNumerator, numeratorContinuation);
+
+                speculate(NegativeZero, noValue(), 0, m_out.isZero32(remainder));
+
+                m_out.jump(numeratorContinuation);
+
+                m_out.appendTo(numeratorContinuation, innerLastNext);
+            }
+
+            setInt32(remainder);
+            break;
+        }
+            
+        case DoubleRepUse: {
+            setDouble(
+                m_out.doubleMod(lowDouble(m_node->child1()), lowDouble(m_node->child2())));
+            break;
+        }
+            
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            break;
+        }
+    }
+
+    void compileArithMinOrMax()
+    {
+        switch (m_node->binaryUseKind()) {
+        case Int32Use: {
+            LValue left = lowInt32(m_node->child1());
+            LValue right = lowInt32(m_node->child2());
+            
+            setInt32(
+                m_out.select(
+                    m_node->op() == ArithMin
+                        ? m_out.lessThan(left, right)
+                        : m_out.lessThan(right, left),
+                    left, right));
+            break;
+        }
+            
+        case DoubleRepUse: {
+            LValue left = lowDouble(m_node->child1());
+            LValue right = lowDouble(m_node->child2());
+            
+            LBasicBlock notLessThan = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            Vector<ValueFromBlock, 2> results;
+            
+            results.append(m_out.anchor(left));
+            m_out.branch(
+                m_node->op() == ArithMin
+                    ? m_out.doubleLessThan(left, right)
+                    : m_out.doubleGreaterThan(left, right),
+                unsure(continuation), unsure(notLessThan));
+            
+            LBasicBlock lastNext = m_out.appendTo(notLessThan, continuation);
+            results.append(m_out.anchor(m_out.select(
+                m_node->op() == ArithMin
+                    ? m_out.doubleGreaterThanOrEqual(left, right)
+                    : m_out.doubleLessThanOrEqual(left, right),
+                right, m_out.constDouble(PNaN))));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setDouble(m_out.phi(Double, results));
+            break;
+        }
+            
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            break;
+        }
+    }
+    
+    void compileArithAbs()
+    {
+        switch (m_node->child1().useKind()) {
+        case Int32Use: {
+            LValue value = lowInt32(m_node->child1());
+
+            LValue mask = m_out.aShr(value, m_out.constInt32(31));
+            LValue result = m_out.bitXor(mask, m_out.add(mask, value));
+
+            if (shouldCheckOverflow(m_node->arithMode()))
+                speculate(Overflow, noValue(), 0, m_out.lessThan(result, m_out.int32Zero));
+
+            setInt32(result);
+            break;
+        }
+            
+        case DoubleRepUse: {
+            setDouble(m_out.doubleAbs(lowDouble(m_node->child1())));
+            break;
+        }
+            
+        default: {
+            DFG_ASSERT(m_graph, m_node, m_node->child1().useKind() == UntypedUse);
+            LValue argument = lowJSValue(m_node->child1());
+            LValue result = vmCall(Double, m_out.operation(operationArithAbs), m_callFrame, argument);
+            setDouble(result);
+            break;
+        }
+        }
+    }
+
+    void compileArithSin()
+    {
+        if (m_node->child1().useKind() == DoubleRepUse) {
+            setDouble(m_out.doubleSin(lowDouble(m_node->child1())));
+            return;
+        }
+        LValue argument = lowJSValue(m_node->child1());
+        LValue result = vmCall(Double, m_out.operation(operationArithSin), m_callFrame, argument);
+        setDouble(result);
+    }
+
+    void compileArithCos()
+    {
+        if (m_node->child1().useKind() == DoubleRepUse) {
+            setDouble(m_out.doubleCos(lowDouble(m_node->child1())));
+            return;
+        }
+        LValue argument = lowJSValue(m_node->child1());
+        LValue result = vmCall(Double, m_out.operation(operationArithCos), m_callFrame, argument);
+        setDouble(result);
+    }
+
+    void compileArithTan()
+    {
+        if (m_node->child1().useKind() == DoubleRepUse) {
+            setDouble(m_out.doubleTan(lowDouble(m_node->child1())));
+            return;
+        }
+        LValue argument = lowJSValue(m_node->child1());
+        LValue result = vmCall(Double, m_out.operation(operationArithTan), m_callFrame, argument);
+        setDouble(result);
+    }
+
+    void compileArithPow()
+    {
+        if (m_node->child2().useKind() == Int32Use)
+            setDouble(m_out.doublePowi(lowDouble(m_node->child1()), lowInt32(m_node->child2())));
+        else {
+            LValue base = lowDouble(m_node->child1());
+            LValue exponent = lowDouble(m_node->child2());
+
+            LBasicBlock integerExponentIsSmallBlock = m_out.newBlock();
+            LBasicBlock integerExponentPowBlock = m_out.newBlock();
+            LBasicBlock doubleExponentPowBlockEntry = m_out.newBlock();
+            LBasicBlock nanExceptionBaseIsOne = m_out.newBlock();
+            LBasicBlock nanExceptionExponentIsInfinity = m_out.newBlock();
+            LBasicBlock testExponentIsOneHalf = m_out.newBlock();
+            LBasicBlock handleBaseZeroExponentIsOneHalf = m_out.newBlock();
+            LBasicBlock handleInfinityForExponentIsOneHalf = m_out.newBlock();
+            LBasicBlock exponentIsOneHalfNormal = m_out.newBlock();
+            LBasicBlock exponentIsOneHalfInfinity = m_out.newBlock();
+            LBasicBlock testExponentIsNegativeOneHalf = m_out.newBlock();
+            LBasicBlock testBaseZeroExponentIsNegativeOneHalf = m_out.newBlock();
+            LBasicBlock handleBaseZeroExponentIsNegativeOneHalf = m_out.newBlock();
+            LBasicBlock handleInfinityForExponentIsNegativeOneHalf = m_out.newBlock();
+            LBasicBlock exponentIsNegativeOneHalfNormal = m_out.newBlock();
+            LBasicBlock exponentIsNegativeOneHalfInfinity = m_out.newBlock();
+            LBasicBlock powBlock = m_out.newBlock();
+            LBasicBlock nanExceptionResultIsNaN = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            LValue integerExponent = m_out.doubleToInt(exponent);
+            LValue integerExponentConvertedToDouble = m_out.intToDouble(integerExponent);
+            LValue exponentIsInteger = m_out.doubleEqual(exponent, integerExponentConvertedToDouble);
+            m_out.branch(exponentIsInteger, unsure(integerExponentIsSmallBlock), unsure(doubleExponentPowBlockEntry));
+
+            LBasicBlock lastNext = m_out.appendTo(integerExponentIsSmallBlock, integerExponentPowBlock);
+            LValue integerExponentBelowMax = m_out.belowOrEqual(integerExponent, m_out.constInt32(maxExponentForIntegerMathPow));
+            m_out.branch(integerExponentBelowMax, usually(integerExponentPowBlock), rarely(doubleExponentPowBlockEntry));
+
+            m_out.appendTo(integerExponentPowBlock, doubleExponentPowBlockEntry);
+            ValueFromBlock powDoubleIntResult = m_out.anchor(m_out.doublePowi(base, integerExponent));
+            m_out.jump(continuation);
+
+            // If y is NaN, the result is NaN.
+            m_out.appendTo(doubleExponentPowBlockEntry, nanExceptionBaseIsOne);
+            LValue exponentIsNaN;
+            if (provenType(m_node->child2()) & SpecDoubleNaN)
+                exponentIsNaN = m_out.doubleNotEqualOrUnordered(exponent, exponent);
+            else
+                exponentIsNaN = m_out.booleanFalse;
+            m_out.branch(exponentIsNaN, rarely(nanExceptionResultIsNaN), usually(nanExceptionBaseIsOne));
+
+            // If abs(x) is 1 and y is +infinity, the result is NaN.
+            // If abs(x) is 1 and y is -infinity, the result is NaN.
+
+            //     Test if base == 1.
+            m_out.appendTo(nanExceptionBaseIsOne, nanExceptionExponentIsInfinity);
+            LValue absoluteBase = m_out.doubleAbs(base);
+            LValue absoluteBaseIsOne = m_out.doubleEqual(absoluteBase, m_out.constDouble(1));
+            m_out.branch(absoluteBaseIsOne, rarely(nanExceptionExponentIsInfinity), usually(testExponentIsOneHalf));
+
+            //     Test if abs(y) == Infinity.
+            m_out.appendTo(nanExceptionExponentIsInfinity, testExponentIsOneHalf);
+            LValue absoluteExponent = m_out.doubleAbs(exponent);
+            LValue absoluteExponentIsInfinity = m_out.doubleEqual(absoluteExponent, m_out.constDouble(std::numeric_limits<double>::infinity()));
+            m_out.branch(absoluteExponentIsInfinity, rarely(nanExceptionResultIsNaN), usually(testExponentIsOneHalf));
+
+            // If y == 0.5 or y == -0.5, handle it through SQRT.
+            // We have be carefuly with -0 and -Infinity.
+
+            //     Test if y == 0.5
+            m_out.appendTo(testExponentIsOneHalf, handleBaseZeroExponentIsOneHalf);
+            LValue exponentIsOneHalf = m_out.doubleEqual(exponent, m_out.constDouble(0.5));
+            m_out.branch(exponentIsOneHalf, rarely(handleBaseZeroExponentIsOneHalf), usually(testExponentIsNegativeOneHalf));
+
+            //     Handle x == -0.
+            m_out.appendTo(handleBaseZeroExponentIsOneHalf, handleInfinityForExponentIsOneHalf);
+            LValue baseIsZeroExponentIsOneHalf = m_out.doubleEqual(base, m_out.doubleZero);
+            ValueFromBlock zeroResultExponentIsOneHalf = m_out.anchor(m_out.doubleZero);
+            m_out.branch(baseIsZeroExponentIsOneHalf, rarely(continuation), usually(handleInfinityForExponentIsOneHalf));
+
+            //     Test if abs(x) == Infinity.
+            m_out.appendTo(handleInfinityForExponentIsOneHalf, exponentIsOneHalfNormal);
+            LValue absoluteBaseIsInfinityOneHalf = m_out.doubleEqual(absoluteBase, m_out.constDouble(std::numeric_limits<double>::infinity()));
+            m_out.branch(absoluteBaseIsInfinityOneHalf, rarely(exponentIsOneHalfInfinity), usually(exponentIsOneHalfNormal));
+
+            //     The exponent is 0.5, the base is finite or NaN, we can use SQRT.
+            m_out.appendTo(exponentIsOneHalfNormal, exponentIsOneHalfInfinity);
+            ValueFromBlock sqrtResult = m_out.anchor(m_out.doubleSqrt(base));
+            m_out.jump(continuation);
+
+            //     The exponent is 0.5, the base is infinite, the result is always infinite.
+            m_out.appendTo(exponentIsOneHalfInfinity, testExponentIsNegativeOneHalf);
+            ValueFromBlock sqrtInfinityResult = m_out.anchor(m_out.constDouble(std::numeric_limits<double>::infinity()));
+            m_out.jump(continuation);
+
+            //     Test if y == -0.5
+            m_out.appendTo(testExponentIsNegativeOneHalf, testBaseZeroExponentIsNegativeOneHalf);
+            LValue exponentIsNegativeOneHalf = m_out.doubleEqual(exponent, m_out.constDouble(-0.5));
+            m_out.branch(exponentIsNegativeOneHalf, rarely(testBaseZeroExponentIsNegativeOneHalf), usually(powBlock));
+
+            //     Handle x == -0.
+            m_out.appendTo(testBaseZeroExponentIsNegativeOneHalf, handleBaseZeroExponentIsNegativeOneHalf);
+            LValue baseIsZeroExponentIsNegativeOneHalf = m_out.doubleEqual(base, m_out.doubleZero);
+            m_out.branch(baseIsZeroExponentIsNegativeOneHalf, rarely(handleBaseZeroExponentIsNegativeOneHalf), usually(handleInfinityForExponentIsNegativeOneHalf));
+
+            m_out.appendTo(handleBaseZeroExponentIsNegativeOneHalf, handleInfinityForExponentIsNegativeOneHalf);
+            ValueFromBlock oneOverSqrtZeroResult = m_out.anchor(m_out.constDouble(std::numeric_limits<double>::infinity()));
+            m_out.jump(continuation);
+
+            //     Test if abs(x) == Infinity.
+            m_out.appendTo(handleInfinityForExponentIsNegativeOneHalf, exponentIsNegativeOneHalfNormal);
+            LValue absoluteBaseIsInfinityNegativeOneHalf = m_out.doubleEqual(absoluteBase, m_out.constDouble(std::numeric_limits<double>::infinity()));
+            m_out.branch(absoluteBaseIsInfinityNegativeOneHalf, rarely(exponentIsNegativeOneHalfInfinity), usually(exponentIsNegativeOneHalfNormal));
+
+            //     The exponent is -0.5, the base is finite or NaN, we can use 1/SQRT.
+            m_out.appendTo(exponentIsNegativeOneHalfNormal, exponentIsNegativeOneHalfInfinity);
+            LValue sqrtBase = m_out.doubleSqrt(base);
+            ValueFromBlock oneOverSqrtResult = m_out.anchor(m_out.div(m_out.constDouble(1.), sqrtBase));
+            m_out.jump(continuation);
+
+            //     The exponent is -0.5, the base is infinite, the result is always zero.
+            m_out.appendTo(exponentIsNegativeOneHalfInfinity, powBlock);
+            ValueFromBlock oneOverSqrtInfinityResult = m_out.anchor(m_out.doubleZero);
+            m_out.jump(continuation);
+
+            m_out.appendTo(powBlock, nanExceptionResultIsNaN);
+            ValueFromBlock powResult = m_out.anchor(m_out.doublePow(base, exponent));
+            m_out.jump(continuation);
+
+            m_out.appendTo(nanExceptionResultIsNaN, continuation);
+            ValueFromBlock pureNan = m_out.anchor(m_out.constDouble(PNaN));
+            m_out.jump(continuation);
+
+            m_out.appendTo(continuation, lastNext);
+            setDouble(m_out.phi(Double, powDoubleIntResult, zeroResultExponentIsOneHalf, sqrtResult, sqrtInfinityResult, oneOverSqrtZeroResult, oneOverSqrtResult, oneOverSqrtInfinityResult, powResult, pureNan));
+        }
+    }
+
+    void compileArithRandom()
+    {
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+
+        // Inlined WeakRandom::advance().
+        // uint64_t x = m_low;
+        void* lowAddress = reinterpret_cast<uint8_t*>(globalObject) + JSGlobalObject::weakRandomOffset() + WeakRandom::lowOffset();
+        LValue low = m_out.load64(m_out.absolute(lowAddress));
+        // uint64_t y = m_high;
+        void* highAddress = reinterpret_cast<uint8_t*>(globalObject) + JSGlobalObject::weakRandomOffset() + WeakRandom::highOffset();
+        LValue high = m_out.load64(m_out.absolute(highAddress));
+        // m_low = y;
+        m_out.store64(high, m_out.absolute(lowAddress));
+
+        // x ^= x << 23;
+        LValue phase1 = m_out.bitXor(m_out.shl(low, m_out.constInt64(23)), low);
+
+        // x ^= x >> 17;
+        LValue phase2 = m_out.bitXor(m_out.lShr(phase1, m_out.constInt64(17)), phase1);
+
+        // x ^= y ^ (y >> 26);
+        LValue phase3 = m_out.bitXor(m_out.bitXor(high, m_out.lShr(high, m_out.constInt64(26))), phase2);
+
+        // m_high = x;
+        m_out.store64(phase3, m_out.absolute(highAddress));
+
+        // return x + y;
+        LValue random64 = m_out.add(phase3, high);
+
+        // Extract random 53bit. [0, 53] bit is safe integer number ranges in double representation.
+        LValue random53 = m_out.bitAnd(random64, m_out.constInt64((1ULL << 53) - 1));
+
+        LValue double53Integer = m_out.intToDouble(random53);
+
+        // Convert `(53bit double integer value) / (1 << 53)` to `(53bit double integer value) * (1.0 / (1 << 53))`.
+        // In latter case, `1.0 / (1 << 53)` will become a double value represented as (mantissa = 0 & exp = 970, it means 1e-(2**54)).
+        static const double scale = 1.0 / (1ULL << 53);
+
+        // Multiplying 1e-(2**54) with the double integer does not change anything of the mantissa part of the double integer.
+        // It just reduces the exp part of the given 53bit double integer.
+        // (Except for 0.0. This is specially handled and in this case, exp just becomes 0.)
+        // Now we get 53bit precision random double value in [0, 1).
+        LValue result = m_out.doubleMul(double53Integer, m_out.constDouble(scale));
+
+        setDouble(result);
+    }
+
+    void compileArithRound()
+    {
+        if (m_node->child1().useKind() == DoubleRepUse) {
+            LValue result = nullptr;
+            if (producesInteger(m_node->arithRoundingMode()) && !shouldCheckNegativeZero(m_node->arithRoundingMode())) {
+                LValue value = lowDouble(m_node->child1());
+                result = m_out.doubleFloor(m_out.doubleAdd(value, m_out.constDouble(0.5)));
+            } else {
+                LBasicBlock realPartIsMoreThanHalf = m_out.newBlock();
+                LBasicBlock continuation = m_out.newBlock();
+
+                LValue value = lowDouble(m_node->child1());
+                LValue integerValue = m_out.doubleCeil(value);
+                ValueFromBlock integerValueResult = m_out.anchor(integerValue);
+
+                LValue realPart = m_out.doubleSub(integerValue, value);
+
+                m_out.branch(m_out.doubleGreaterThanOrUnordered(realPart, m_out.constDouble(0.5)), unsure(realPartIsMoreThanHalf), unsure(continuation));
+
+                LBasicBlock lastNext = m_out.appendTo(realPartIsMoreThanHalf, continuation);
+                LValue integerValueRoundedDown = m_out.doubleSub(integerValue, m_out.constDouble(1));
+                ValueFromBlock integerValueRoundedDownResult = m_out.anchor(integerValueRoundedDown);
+                m_out.jump(continuation);
+                m_out.appendTo(continuation, lastNext);
+
+                result = m_out.phi(Double, integerValueResult, integerValueRoundedDownResult);
+            }
+
+            if (producesInteger(m_node->arithRoundingMode())) {
+                LValue integerValue = convertDoubleToInt32(result, shouldCheckNegativeZero(m_node->arithRoundingMode()));
+                setInt32(integerValue);
+            } else
+                setDouble(result);
+            return;
+        }
+
+        DFG_ASSERT(m_graph, m_node, m_node->child1().useKind() == UntypedUse);
+        LValue argument = lowJSValue(m_node->child1());
+        setJSValue(vmCall(Int64, m_out.operation(operationArithRound), m_callFrame, argument));
+    }
+
+    void compileArithFloor()
+    {
+        if (m_node->child1().useKind() == DoubleRepUse) {
+            LValue value = lowDouble(m_node->child1());
+            LValue integerValue = m_out.doubleFloor(value);
+            if (producesInteger(m_node->arithRoundingMode()))
+                setInt32(convertDoubleToInt32(integerValue, shouldCheckNegativeZero(m_node->arithRoundingMode())));
+            else
+                setDouble(integerValue);
+            return;
+        }
+        DFG_ASSERT(m_graph, m_node, m_node->child1().useKind() == UntypedUse);
+        LValue argument = lowJSValue(m_node->child1());
+        setJSValue(vmCall(Int64, m_out.operation(operationArithFloor), m_callFrame, argument));
+    }
+
+    void compileArithCeil()
+    {
+        if (m_node->child1().useKind() == DoubleRepUse) {
+            LValue value = lowDouble(m_node->child1());
+            LValue integerValue = m_out.doubleCeil(value);
+            if (producesInteger(m_node->arithRoundingMode()))
+                setInt32(convertDoubleToInt32(integerValue, shouldCheckNegativeZero(m_node->arithRoundingMode())));
+            else
+                setDouble(integerValue);
+            return;
+        }
+        DFG_ASSERT(m_graph, m_node, m_node->child1().useKind() == UntypedUse);
+        LValue argument = lowJSValue(m_node->child1());
+        setJSValue(vmCall(Int64, m_out.operation(operationArithCeil), m_callFrame, argument));
+    }
+
+    void compileArithTrunc()
+    {
+        if (m_node->child1().useKind() == DoubleRepUse) {
+            LValue value = lowDouble(m_node->child1());
+            LValue result = m_out.doubleTrunc(value);
+            if (producesInteger(m_node->arithRoundingMode()))
+                setInt32(convertDoubleToInt32(result, shouldCheckNegativeZero(m_node->arithRoundingMode())));
+            else
+                setDouble(result);
+            return;
+        }
+        DFG_ASSERT(m_graph, m_node, m_node->child1().useKind() == UntypedUse);
+        LValue argument = lowJSValue(m_node->child1());
+        setJSValue(vmCall(Int64, m_out.operation(operationArithTrunc), m_callFrame, argument));
+    }
+
+    void compileArithSqrt()
+    {
+        if (m_node->child1().useKind() == DoubleRepUse) {
+            setDouble(m_out.doubleSqrt(lowDouble(m_node->child1())));
+            return;
+        }
+        LValue argument = lowJSValue(m_node->child1());
+        LValue result = vmCall(Double, m_out.operation(operationArithSqrt), m_callFrame, argument);
+        setDouble(result);
+    }
+
+    void compileArithLog()
+    {
+        if (m_node->child1().useKind() == DoubleRepUse) {
+            setDouble(m_out.doubleLog(lowDouble(m_node->child1())));
+            return;
+        }
+        LValue argument = lowJSValue(m_node->child1());
+        LValue result = vmCall(Double, m_out.operation(operationArithLog), m_callFrame, argument);
+        setDouble(result);
+    }
+    
+    void compileArithFRound()
+    {
+        if (m_node->child1().useKind() == DoubleRepUse) {
+            setDouble(m_out.fround(lowDouble(m_node->child1())));
+            return;
+        }
+        LValue argument = lowJSValue(m_node->child1());
+        LValue result = vmCall(Double, m_out.operation(operationArithFRound), m_callFrame, argument);
+        setDouble(result);
+    }
+    
+    void compileArithNegate()
+    {
+        switch (m_node->child1().useKind()) {
+        case Int32Use: {
+            LValue value = lowInt32(m_node->child1());
+            
+            LValue result;
+            if (!shouldCheckOverflow(m_node->arithMode()))
+                result = m_out.neg(value);
+            else if (!shouldCheckNegativeZero(m_node->arithMode())) {
+                CheckValue* check = m_out.speculateSub(m_out.int32Zero, value);
+                blessSpeculation(check, Overflow, noValue(), nullptr, m_origin);
+                result = check;
+            } else {
+                speculate(Overflow, noValue(), 0, m_out.testIsZero32(value, m_out.constInt32(0x7fffffff)));
+                result = m_out.neg(value);
+            }
+
+            setInt32(result);
+            break;
+        }
+            
+        case Int52RepUse: {
+            if (!abstractValue(m_node->child1()).couldBeType(SpecInt52Only)) {
+                Int52Kind kind;
+                LValue value = lowWhicheverInt52(m_node->child1(), kind);
+                LValue result = m_out.neg(value);
+                if (shouldCheckNegativeZero(m_node->arithMode()))
+                    speculate(NegativeZero, noValue(), 0, m_out.isZero64(result));
+                setInt52(result, kind);
+                break;
+            }
+            
+            LValue value = lowInt52(m_node->child1());
+            CheckValue* result = m_out.speculateSub(m_out.int64Zero, value);
+            blessSpeculation(result, Int52Overflow, noValue(), nullptr, m_origin);
+            if (shouldCheckNegativeZero(m_node->arithMode()))
+                speculate(NegativeZero, noValue(), 0, m_out.isZero64(result));
+            setInt52(result);
+            break;
+        }
+            
+        case DoubleRepUse: {
+            setDouble(m_out.doubleNeg(lowDouble(m_node->child1())));
+            break;
+        }
+            
+        default:
+            DFG_ASSERT(m_graph, m_node, m_node->child1().useKind() == UntypedUse);
+            ArithProfile* arithProfile = m_ftlState.graph.baselineCodeBlockFor(m_node->origin.semantic)->arithProfileForBytecodeOffset(m_node->origin.semantic.bytecodeIndex);
+            JITNegIC* negIC = codeBlock()->addJITNegIC(arithProfile);
+            auto repatchingFunction = operationArithNegateOptimize;
+            auto nonRepatchingFunction = operationArithNegate;
+            compileMathIC(negIC, repatchingFunction, nonRepatchingFunction);
+            break;
+        }
+    }
+    
+    void compileBitAnd()
+    {
+        if (m_node->isBinaryUseKind(UntypedUse)) {
+            emitBinaryBitOpSnippet<JITBitAndGenerator>(operationValueBitAnd);
+            return;
+        }
+        setInt32(m_out.bitAnd(lowInt32(m_node->child1()), lowInt32(m_node->child2())));
+    }
+    
+    void compileBitOr()
+    {
+        if (m_node->isBinaryUseKind(UntypedUse)) {
+            emitBinaryBitOpSnippet<JITBitOrGenerator>(operationValueBitOr);
+            return;
+        }
+        setInt32(m_out.bitOr(lowInt32(m_node->child1()), lowInt32(m_node->child2())));
+    }
+    
+    void compileBitXor()
+    {
+        if (m_node->isBinaryUseKind(UntypedUse)) {
+            emitBinaryBitOpSnippet<JITBitXorGenerator>(operationValueBitXor);
+            return;
+        }
+        setInt32(m_out.bitXor(lowInt32(m_node->child1()), lowInt32(m_node->child2())));
+    }
+    
+    void compileBitRShift()
+    {
+        if (m_node->isBinaryUseKind(UntypedUse)) {
+            emitRightShiftSnippet(JITRightShiftGenerator::SignedShift);
+            return;
+        }
+        setInt32(m_out.aShr(
+            lowInt32(m_node->child1()),
+            m_out.bitAnd(lowInt32(m_node->child2()), m_out.constInt32(31))));
+    }
+    
+    void compileBitLShift()
+    {
+        if (m_node->isBinaryUseKind(UntypedUse)) {
+            emitBinaryBitOpSnippet<JITLeftShiftGenerator>(operationValueBitLShift);
+            return;
+        }
+        setInt32(m_out.shl(
+            lowInt32(m_node->child1()),
+            m_out.bitAnd(lowInt32(m_node->child2()), m_out.constInt32(31))));
+    }
+    
+    void compileBitURShift()
+    {
+        if (m_node->isBinaryUseKind(UntypedUse)) {
+            emitRightShiftSnippet(JITRightShiftGenerator::UnsignedShift);
+            return;
+        }
+        setInt32(m_out.lShr(
+            lowInt32(m_node->child1()),
+            m_out.bitAnd(lowInt32(m_node->child2()), m_out.constInt32(31))));
+    }
+    
+    void compileUInt32ToNumber()
+    {
+        LValue value = lowInt32(m_node->child1());
+
+        if (doesOverflow(m_node->arithMode())) {
+            setStrictInt52(m_out.zeroExtPtr(value));
+            return;
+        }
+
+        speculate(Overflow, noValue(), 0, m_out.lessThan(value, m_out.int32Zero));
+        setInt32(value);
+    }
+    
+    void compileCheckStructure()
+    {
+        ExitKind exitKind;
+        if (m_node->child1()->hasConstant())
+            exitKind = BadConstantCache;
+        else
+            exitKind = BadCache;
+
+        switch (m_node->child1().useKind()) {
+        case CellUse:
+        case KnownCellUse: {
+            LValue cell = lowCell(m_node->child1());
+            
+            checkStructure(
+                m_out.load32(cell, m_heaps.JSCell_structureID), jsValueValue(cell),
+                exitKind, m_node->structureSet(),
+                [&] (RegisteredStructure structure) {
+                    return weakStructureID(structure);
+                });
+            return;
+        }
+
+        case CellOrOtherUse: {
+            LValue value = lowJSValue(m_node->child1(), ManualOperandSpeculation);
+
+            LBasicBlock cellCase = m_out.newBlock();
+            LBasicBlock notCellCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            m_out.branch(
+                isCell(value, provenType(m_node->child1())), unsure(cellCase), unsure(notCellCase));
+
+            LBasicBlock lastNext = m_out.appendTo(cellCase, notCellCase);
+            checkStructure(
+                m_out.load32(value, m_heaps.JSCell_structureID), jsValueValue(value),
+                exitKind, m_node->structureSet(),
+                [&] (RegisteredStructure structure) {
+                    return weakStructureID(structure);
+                });
+            m_out.jump(continuation);
+
+            m_out.appendTo(notCellCase, continuation);
+            FTL_TYPE_CHECK(jsValueValue(value), m_node->child1(), SpecCell | SpecOther, isNotOther(value));
+            m_out.jump(continuation);
+
+            m_out.appendTo(continuation, lastNext);
+            return;
+        }
+
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            return;
+        }
+    }
+    
+    void compileCheckCell()
+    {
+        LValue cell = lowCell(m_node->child1());
+        
+        speculate(
+            BadCell, jsValueValue(cell), m_node->child1().node(),
+            m_out.notEqual(cell, weakPointer(m_node->cellOperand()->cell())));
+    }
+    
+    void compileCheckBadCell()
+    {
+        terminate(BadCell);
+    }
+
+    void compileCheckNotEmpty()
+    {
+        speculate(TDZFailure, noValue(), nullptr, m_out.isZero64(lowJSValue(m_node->child1())));
+    }
+
+    void compileCheckStringIdent()
+    {
+        UniquedStringImpl* uid = m_node->uidOperand();
+        LValue stringImpl = lowStringIdent(m_node->child1());
+        speculate(BadIdent, noValue(), nullptr, m_out.notEqual(stringImpl, m_out.constIntPtr(uid)));
+    }
+
+    void compileGetExecutable()
+    {
+        LValue cell = lowCell(m_node->child1());
+        speculateFunction(m_node->child1(), cell);
+        setJSValue(m_out.loadPtr(cell, m_heaps.JSFunction_executable));
+    }
+    
+    void compileArrayifyToStructure()
+    {
+        LValue cell = lowCell(m_node->child1());
+        LValue property = !!m_node->child2() ? lowInt32(m_node->child2()) : 0;
+        
+        LBasicBlock unexpectedStructure = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LValue structureID = m_out.load32(cell, m_heaps.JSCell_structureID);
+        
+        m_out.branch(
+            m_out.notEqual(structureID, weakStructureID(m_node->structure())),
+            rarely(unexpectedStructure), usually(continuation));
+        
+        LBasicBlock lastNext = m_out.appendTo(unexpectedStructure, continuation);
+        
+        if (property) {
+            switch (m_node->arrayMode().type()) {
+            case Array::Int32:
+            case Array::Double:
+            case Array::Contiguous:
+                speculate(
+                    Uncountable, noValue(), 0,
+                    m_out.aboveOrEqual(property, m_out.constInt32(MIN_SPARSE_ARRAY_INDEX)));
+                break;
+            default:
+                break;
+            }
+        }
+        
+        switch (m_node->arrayMode().type()) {
+        case Array::Int32:
+            vmCall(Void, m_out.operation(operationEnsureInt32), m_callFrame, cell);
+            break;
+        case Array::Double:
+            vmCall(Void, m_out.operation(operationEnsureDouble), m_callFrame, cell);
+            break;
+        case Array::Contiguous:
+            vmCall(Void, m_out.operation(operationEnsureContiguous), m_callFrame, cell);
+            break;
+        case Array::ArrayStorage:
+        case Array::SlowPutArrayStorage:
+            vmCall(Void, m_out.operation(operationEnsureArrayStorage), m_callFrame, cell);
+            break;
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad array type");
+            break;
+        }
+        
+        structureID = m_out.load32(cell, m_heaps.JSCell_structureID);
+        speculate(
+            BadIndexingType, jsValueValue(cell), 0,
+            m_out.notEqual(structureID, weakStructureID(m_node->structure())));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    void compilePutStructure()
+    {
+        m_ftlState.jitCode->common.notifyCompilingStructureTransition(m_graph.m_plan, codeBlock(), m_node);
+        
+        RegisteredStructure oldStructure = m_node->transition()->previous;
+        RegisteredStructure newStructure = m_node->transition()->next;
+        ASSERT_UNUSED(oldStructure, oldStructure->indexingType() == newStructure->indexingType());
+        ASSERT(oldStructure->typeInfo().inlineTypeFlags() == newStructure->typeInfo().inlineTypeFlags());
+        ASSERT(oldStructure->typeInfo().type() == newStructure->typeInfo().type());
+
+        LValue cell = lowCell(m_node->child1()); 
+        m_out.store32(
+            weakStructureID(newStructure),
+            cell, m_heaps.JSCell_structureID);
+    }
+    
+    void compileGetById(AccessType type)
+    {
+        ASSERT(type == AccessType::Get || type == AccessType::TryGet);
+        switch (m_node->child1().useKind()) {
+        case CellUse: {
+            setJSValue(getById(lowCell(m_node->child1()), type));
+            return;
+        }
+            
+        case UntypedUse: {
+            // This is pretty weird, since we duplicate the slow path both here and in the
+            // code generated by the IC. We should investigate making this less bad.
+            // https://bugs.webkit.org/show_bug.cgi?id=127830
+            LValue value = lowJSValue(m_node->child1());
+            
+            LBasicBlock cellCase = m_out.newBlock();
+            LBasicBlock notCellCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            m_out.branch(
+                isCell(value, provenType(m_node->child1())), unsure(cellCase), unsure(notCellCase));
+            
+            LBasicBlock lastNext = m_out.appendTo(cellCase, notCellCase);
+            ValueFromBlock cellResult = m_out.anchor(getById(value, type));
+            m_out.jump(continuation);
+
+            J_JITOperation_EJI getByIdFunction;
+            if (type == AccessType::Get)
+                getByIdFunction = operationGetByIdGeneric;
+            else
+                getByIdFunction = operationTryGetByIdGeneric;
+
+            m_out.appendTo(notCellCase, continuation);
+            ValueFromBlock notCellResult = m_out.anchor(vmCall(
+                Int64, m_out.operation(getByIdFunction),
+                m_callFrame, value,
+                m_out.constIntPtr(m_graph.identifiers()[m_node->identifierNumber()])));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(Int64, cellResult, notCellResult));
+            return;
+        }
+            
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            return;
+        }
+    }
+
+    void compileGetByIdWithThis()
+    {
+        LValue base = lowJSValue(m_node->child1());
+        LValue thisValue = lowJSValue(m_node->child2());
+        LValue result = vmCall(Int64, m_out.operation(operationGetByIdWithThis), m_callFrame, base, thisValue, m_out.constIntPtr(m_graph.identifiers()[m_node->identifierNumber()]));
+        setJSValue(result);
+    }
+
+    void compileGetByValWithThis()
+    {
+        LValue base = lowJSValue(m_node->child1());
+        LValue thisValue = lowJSValue(m_node->child2());
+        LValue subscript = lowJSValue(m_node->child3());
+
+        LValue result = vmCall(Int64, m_out.operation(operationGetByValWithThis), m_callFrame, base, thisValue, subscript);
+        setJSValue(result);
+    }
+
+    void compilePutByIdWithThis()
+    {
+        LValue base = lowJSValue(m_node->child1());
+        LValue thisValue = lowJSValue(m_node->child2());
+        LValue value = lowJSValue(m_node->child3());
+
+        vmCall(Void, m_out.operation(m_graph.isStrictModeFor(m_node->origin.semantic) ? operationPutByIdWithThisStrict : operationPutByIdWithThis),
+            m_callFrame, base, thisValue, value, m_out.constIntPtr(m_graph.identifiers()[m_node->identifierNumber()]));
+    }
+
+    void compilePutByValWithThis()
+    {
+        LValue base = lowJSValue(m_graph.varArgChild(m_node, 0));
+        LValue thisValue = lowJSValue(m_graph.varArgChild(m_node, 1));
+        LValue property = lowJSValue(m_graph.varArgChild(m_node, 2));
+        LValue value = lowJSValue(m_graph.varArgChild(m_node, 3));
+
+        vmCall(Void, m_out.operation(m_graph.isStrictModeFor(m_node->origin.semantic) ? operationPutByValWithThisStrict : operationPutByValWithThis),
+            m_callFrame, base, thisValue, property, value);
+    }
+
+    void compileDefineDataProperty()
+    {
+        LValue base = lowCell(m_graph.varArgChild(m_node, 0));
+        LValue value  = lowJSValue(m_graph.varArgChild(m_node, 2));
+        LValue attributes = lowInt32(m_graph.varArgChild(m_node, 3));
+        Edge& propertyEdge = m_graph.varArgChild(m_node, 1);
+        switch (propertyEdge.useKind()) {
+        case StringUse: {
+            LValue property = lowString(propertyEdge);
+            vmCall(Void, m_out.operation(operationDefineDataPropertyString), m_callFrame, base, property, value, attributes);
+            break;
+        }
+        case StringIdentUse: {
+            LValue property = lowStringIdent(propertyEdge);
+            vmCall(Void, m_out.operation(operationDefineDataPropertyStringIdent), m_callFrame, base, property, value, attributes);
+            break;
+        }
+        case SymbolUse: {
+            LValue property = lowSymbol(propertyEdge);
+            vmCall(Void, m_out.operation(operationDefineDataPropertySymbol), m_callFrame, base, property, value, attributes);
+            break;
+        }
+        case UntypedUse: {
+            LValue property = lowJSValue(propertyEdge);
+            vmCall(Void, m_out.operation(operationDefineDataProperty), m_callFrame, base, property, value, attributes);
+            break;
+        }
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+        }
+    }
+
+    void compileDefineAccessorProperty()
+    {
+        LValue base = lowCell(m_graph.varArgChild(m_node, 0));
+        LValue getter = lowCell(m_graph.varArgChild(m_node, 2));
+        LValue setter = lowCell(m_graph.varArgChild(m_node, 3));
+        LValue attributes = lowInt32(m_graph.varArgChild(m_node, 4));
+        Edge& propertyEdge = m_graph.varArgChild(m_node, 1);
+        switch (propertyEdge.useKind()) {
+        case StringUse: {
+            LValue property = lowString(propertyEdge);
+            vmCall(Void, m_out.operation(operationDefineAccessorPropertyString), m_callFrame, base, property, getter, setter, attributes);
+            break;
+        }
+        case StringIdentUse: {
+            LValue property = lowStringIdent(propertyEdge);
+            vmCall(Void, m_out.operation(operationDefineAccessorPropertyStringIdent), m_callFrame, base, property, getter, setter, attributes);
+            break;
+        }
+        case SymbolUse: {
+            LValue property = lowSymbol(propertyEdge);
+            vmCall(Void, m_out.operation(operationDefineAccessorPropertySymbol), m_callFrame, base, property, getter, setter, attributes);
+            break;
+        }
+        case UntypedUse: {
+            LValue property = lowJSValue(propertyEdge);
+            vmCall(Void, m_out.operation(operationDefineAccessorProperty), m_callFrame, base, property, getter, setter, attributes);
+            break;
+        }
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+        }
+    }
+    
+    void compilePutById()
+    {
+        DFG_ASSERT(m_graph, m_node, m_node->child1().useKind() == CellUse);
+
+        Node* node = m_node;
+        LValue base = lowCell(node->child1());
+        LValue value = lowJSValue(node->child2());
+        auto uid = m_graph.identifiers()[node->identifierNumber()];
+
+        B3::PatchpointValue* patchpoint = m_out.patchpoint(Void);
+        patchpoint->appendSomeRegister(base);
+        patchpoint->appendSomeRegister(value);
+        patchpoint->append(m_tagMask, ValueRep::reg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::reg(GPRInfo::tagTypeNumberRegister));
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+
+        // FIXME: If this is a PutByIdFlush, we might want to late-clobber volatile registers.
+        // https://bugs.webkit.org/show_bug.cgi?id=152848
+
+        RefPtr<PatchpointExceptionHandle> exceptionHandle =
+            preparePatchpointForExceptions(patchpoint);
+
+        State* state = &m_ftlState;
+        ECMAMode ecmaMode = m_graph.executableFor(node->origin.semantic)->ecmaMode();
+        
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                CallSiteIndex callSiteIndex =
+                    state->jitCode->common.addUniqueCallSiteIndex(node->origin.semantic);
+
+                Box<CCallHelpers::JumpList> exceptions =
+                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+
+                // JS setter call ICs generated by the PutById IC will need this.
+                exceptionHandle->scheduleExitCreationForUnwind(params, callSiteIndex);
+
+                auto generator = Box<JITPutByIdGenerator>::create(
+                    jit.codeBlock(), node->origin.semantic, callSiteIndex,
+                    params.unavailableRegisters(), JSValueRegs(params[0].gpr()),
+                    JSValueRegs(params[1].gpr()), GPRInfo::patchpointScratchRegister, ecmaMode,
+                    node->op() == PutByIdDirect ? Direct : NotDirect);
+
+                generator->generateFastPath(jit);
+                CCallHelpers::Label done = jit.label();
+
+                params.addLatePath(
+                    [=] (CCallHelpers& jit) {
+                        AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                        generator->slowPathJump().link(&jit);
+                        CCallHelpers::Label slowPathBegin = jit.label();
+                        CCallHelpers::Call slowPathCall = callOperation(
+                            *state, params.unavailableRegisters(), jit, node->origin.semantic,
+                            exceptions.get(), generator->slowPathFunction(), InvalidGPRReg,
+                            CCallHelpers::TrustedImmPtr(generator->stubInfo()), params[1].gpr(),
+                            params[0].gpr(), CCallHelpers::TrustedImmPtr(uid)).call();
+                        jit.jump().linkTo(done, &jit);
+
+                        generator->reportSlowPathCall(slowPathBegin, slowPathCall);
+
+                        jit.addLinkTask(
+                            [=] (LinkBuffer& linkBuffer) {
+                                generator->finalize(linkBuffer);
+                            });
+                    });
+            });
+    }
+    
+    void compileGetButterfly()
+    {
+        setStorage(m_out.loadPtr(lowCell(m_node->child1()), m_heaps.JSObject_butterfly));
+    }
+
+    void compileConstantStoragePointer()
+    {
+        setStorage(m_out.constIntPtr(m_node->storagePointer()));
+    }
+    
+    void compileGetIndexedPropertyStorage()
+    {
+        LValue cell = lowCell(m_node->child1());
+        
+        if (m_node->arrayMode().type() == Array::String) {
+            LBasicBlock slowPath = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            LValue fastResultValue = m_out.loadPtr(cell, m_heaps.JSString_value);
+            ValueFromBlock fastResult = m_out.anchor(fastResultValue);
+            
+            m_out.branch(
+                m_out.notNull(fastResultValue), usually(continuation), rarely(slowPath));
+            
+            LBasicBlock lastNext = m_out.appendTo(slowPath, continuation);
+            
+            ValueFromBlock slowResult = m_out.anchor(
+                vmCall(pointerType(), m_out.operation(operationResolveRope), m_callFrame, cell));
+            
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            
+            setStorage(m_out.loadPtr(m_out.phi(pointerType(), fastResult, slowResult), m_heaps.StringImpl_data));
+            return;
+        }
+
+        DFG_ASSERT(m_graph, m_node, isTypedView(m_node->arrayMode().typedArrayType()));
+        setStorage(m_out.loadPtr(cell, m_heaps.JSArrayBufferView_vector));
+    }
+    
+    void compileCheckArray()
+    {
+        Edge edge = m_node->child1();
+        LValue cell = lowCell(edge);
+        
+        if (m_node->arrayMode().alreadyChecked(m_graph, m_node, abstractValue(edge)))
+            return;
+        
+        speculate(
+            BadIndexingType, jsValueValue(cell), 0,
+            m_out.logicalNot(isArrayType(cell, m_node->arrayMode())));
+    }
+
+    void compileGetTypedArrayByteOffset()
+    {
+        LValue basePtr = lowCell(m_node->child1());    
+
+        LBasicBlock simpleCase = m_out.newBlock();
+        LBasicBlock wastefulCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LValue mode = m_out.load32(basePtr, m_heaps.JSArrayBufferView_mode);
+        m_out.branch(
+            m_out.notEqual(mode, m_out.constInt32(WastefulTypedArray)),
+            unsure(simpleCase), unsure(wastefulCase));
+
+        LBasicBlock lastNext = m_out.appendTo(simpleCase, wastefulCase);
+
+        ValueFromBlock simpleOut = m_out.anchor(m_out.constIntPtr(0));
+
+        m_out.jump(continuation);
+
+        m_out.appendTo(wastefulCase, continuation);
+
+        LValue vectorPtr = m_out.loadPtr(basePtr, m_heaps.JSArrayBufferView_vector);
+        LValue butterflyPtr = m_out.loadPtr(basePtr, m_heaps.JSObject_butterfly);
+        LValue arrayBufferPtr = m_out.loadPtr(butterflyPtr, m_heaps.Butterfly_arrayBuffer);
+        LValue dataPtr = m_out.loadPtr(arrayBufferPtr, m_heaps.ArrayBuffer_data);
+
+        ValueFromBlock wastefulOut = m_out.anchor(m_out.sub(vectorPtr, dataPtr));
+
+        m_out.jump(continuation);
+        m_out.appendTo(continuation, lastNext);
+
+        setInt32(m_out.castToInt32(m_out.phi(pointerType(), simpleOut, wastefulOut)));
+    }
+    
+    void compileGetArrayLength()
+    {
+        switch (m_node->arrayMode().type()) {
+        case Array::Undecided:
+        case Array::Int32:
+        case Array::Double:
+        case Array::Contiguous: {
+            setInt32(m_out.load32NonNegative(lowStorage(m_node->child2()), m_heaps.Butterfly_publicLength));
+            return;
+        }
+            
+        case Array::String: {
+            LValue string = lowCell(m_node->child1());
+            setInt32(m_out.load32NonNegative(string, m_heaps.JSString_length));
+            return;
+        }
+            
+        case Array::DirectArguments: {
+            LValue arguments = lowCell(m_node->child1());
+            speculate(
+                ExoticObjectMode, noValue(), nullptr,
+                m_out.notNull(m_out.loadPtr(arguments, m_heaps.DirectArguments_mappedArguments)));
+            setInt32(m_out.load32NonNegative(arguments, m_heaps.DirectArguments_length));
+            return;
+        }
+            
+        case Array::ScopedArguments: {
+            LValue arguments = lowCell(m_node->child1());
+            speculate(
+                ExoticObjectMode, noValue(), nullptr,
+                m_out.notZero32(m_out.load8ZeroExt32(arguments, m_heaps.ScopedArguments_overrodeThings)));
+            setInt32(m_out.load32NonNegative(arguments, m_heaps.ScopedArguments_totalLength));
+            return;
+        }
+            
+        default:
+            if (m_node->arrayMode().isSomeTypedArrayView()) {
+                setInt32(
+                    m_out.load32NonNegative(lowCell(m_node->child1()), m_heaps.JSArrayBufferView_length));
+                return;
+            }
+            
+            DFG_CRASH(m_graph, m_node, "Bad array type");
+            return;
+        }
+    }
+    
+    void compileCheckInBounds()
+    {
+        speculate(
+            OutOfBounds, noValue(), 0,
+            m_out.aboveOrEqual(lowInt32(m_node->child1()), lowInt32(m_node->child2())));
+    }
+    
+    void compileGetByVal()
+    {
+        switch (m_node->arrayMode().type()) {
+        case Array::Int32:
+        case Array::Contiguous: {
+            LValue index = lowInt32(m_node->child2());
+            LValue storage = lowStorage(m_node->child3());
+            
+            IndexedAbstractHeap& heap = m_node->arrayMode().type() == Array::Int32 ?
+                m_heaps.indexedInt32Properties : m_heaps.indexedContiguousProperties;
+            
+            if (m_node->arrayMode().isInBounds()) {
+                LValue result = m_out.load64(baseIndex(heap, storage, index, m_node->child2()));
+                LValue isHole = m_out.isZero64(result);
+                if (m_node->arrayMode().isSaneChain()) {
+                    DFG_ASSERT(
+                        m_graph, m_node, m_node->arrayMode().type() == Array::Contiguous);
+                    result = m_out.select(
+                        isHole, m_out.constInt64(JSValue::encode(jsUndefined())), result);
+                } else
+                    speculate(LoadFromHole, noValue(), 0, isHole);
+                setJSValue(result);
+                return;
+            }
+            
+            LValue base = lowCell(m_node->child1());
+            
+            LBasicBlock fastCase = m_out.newBlock();
+            LBasicBlock slowCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            m_out.branch(
+                m_out.aboveOrEqual(
+                    index, m_out.load32NonNegative(storage, m_heaps.Butterfly_publicLength)),
+                rarely(slowCase), usually(fastCase));
+            
+            LBasicBlock lastNext = m_out.appendTo(fastCase, slowCase);
+
+            LValue fastResultValue = m_out.load64(baseIndex(heap, storage, index, m_node->child2()));
+            ValueFromBlock fastResult = m_out.anchor(fastResultValue);
+            m_out.branch(
+                m_out.isZero64(fastResultValue), rarely(slowCase), usually(continuation));
+            
+            m_out.appendTo(slowCase, continuation);
+            ValueFromBlock slowResult = m_out.anchor(
+                vmCall(Int64, m_out.operation(operationGetByValArrayInt), m_callFrame, base, index));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(Int64, fastResult, slowResult));
+            return;
+        }
+            
+        case Array::Double: {
+            LValue index = lowInt32(m_node->child2());
+            LValue storage = lowStorage(m_node->child3());
+            
+            IndexedAbstractHeap& heap = m_heaps.indexedDoubleProperties;
+            
+            if (m_node->arrayMode().isInBounds()) {
+                LValue result = m_out.loadDouble(
+                    baseIndex(heap, storage, index, m_node->child2()));
+                
+                if (!m_node->arrayMode().isSaneChain()) {
+                    speculate(
+                        LoadFromHole, noValue(), 0,
+                        m_out.doubleNotEqualOrUnordered(result, result));
+                }
+                setDouble(result);
+                break;
+            }
+            
+            LValue base = lowCell(m_node->child1());
+            
+            LBasicBlock inBounds = m_out.newBlock();
+            LBasicBlock boxPath = m_out.newBlock();
+            LBasicBlock slowCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            m_out.branch(
+                m_out.aboveOrEqual(
+                    index, m_out.load32NonNegative(storage, m_heaps.Butterfly_publicLength)),
+                rarely(slowCase), usually(inBounds));
+            
+            LBasicBlock lastNext = m_out.appendTo(inBounds, boxPath);
+            LValue doubleValue = m_out.loadDouble(
+                baseIndex(heap, storage, index, m_node->child2()));
+            m_out.branch(
+                m_out.doubleNotEqualOrUnordered(doubleValue, doubleValue),
+                rarely(slowCase), usually(boxPath));
+            
+            m_out.appendTo(boxPath, slowCase);
+            ValueFromBlock fastResult = m_out.anchor(boxDouble(doubleValue));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(slowCase, continuation);
+            ValueFromBlock slowResult = m_out.anchor(
+                vmCall(Int64, m_out.operation(operationGetByValArrayInt), m_callFrame, base, index));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(Int64, fastResult, slowResult));
+            return;
+        }
+
+        case Array::Undecided: {
+            LValue index = lowInt32(m_node->child2());
+
+            speculate(OutOfBounds, noValue(), m_node, m_out.lessThan(index, m_out.int32Zero));
+            setJSValue(m_out.constInt64(ValueUndefined));
+            return;
+        }
+            
+        case Array::DirectArguments: {
+            LValue base = lowCell(m_node->child1());
+            LValue index = lowInt32(m_node->child2());
+            
+            speculate(
+                ExoticObjectMode, noValue(), nullptr,
+                m_out.notNull(m_out.loadPtr(base, m_heaps.DirectArguments_mappedArguments)));
+            speculate(
+                ExoticObjectMode, noValue(), nullptr,
+                m_out.aboveOrEqual(
+                    index,
+                    m_out.load32NonNegative(base, m_heaps.DirectArguments_length)));
+
+            TypedPointer address = m_out.baseIndex(
+                m_heaps.DirectArguments_storage, base, m_out.zeroExtPtr(index));
+            setJSValue(m_out.load64(address));
+            return;
+        }
+            
+        case Array::ScopedArguments: {
+            LValue base = lowCell(m_node->child1());
+            LValue index = lowInt32(m_node->child2());
+            
+            speculate(
+                ExoticObjectMode, noValue(), nullptr,
+                m_out.aboveOrEqual(
+                    index,
+                    m_out.load32NonNegative(base, m_heaps.ScopedArguments_totalLength)));
+            
+            LValue table = m_out.loadPtr(base, m_heaps.ScopedArguments_table);
+            LValue namedLength = m_out.load32(table, m_heaps.ScopedArgumentsTable_length);
+            
+            LBasicBlock namedCase = m_out.newBlock();
+            LBasicBlock overflowCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            m_out.branch(
+                m_out.aboveOrEqual(index, namedLength), unsure(overflowCase), unsure(namedCase));
+            
+            LBasicBlock lastNext = m_out.appendTo(namedCase, overflowCase);
+            
+            LValue scope = m_out.loadPtr(base, m_heaps.ScopedArguments_scope);
+            LValue arguments = m_out.loadPtr(table, m_heaps.ScopedArgumentsTable_arguments);
+            
+            TypedPointer address = m_out.baseIndex(
+                m_heaps.scopedArgumentsTableArguments, arguments, m_out.zeroExtPtr(index));
+            LValue scopeOffset = m_out.load32(address);
+            
+            speculate(
+                ExoticObjectMode, noValue(), nullptr,
+                m_out.equal(scopeOffset, m_out.constInt32(ScopeOffset::invalidOffset)));
+            
+            address = m_out.baseIndex(
+                m_heaps.JSEnvironmentRecord_variables, scope, m_out.zeroExtPtr(scopeOffset));
+            ValueFromBlock namedResult = m_out.anchor(m_out.load64(address));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(overflowCase, continuation);
+            
+            address = m_out.baseIndex(
+                m_heaps.ScopedArguments_overflowStorage, base,
+                m_out.zeroExtPtr(m_out.sub(index, namedLength)));
+            LValue overflowValue = m_out.load64(address);
+            speculate(ExoticObjectMode, noValue(), nullptr, m_out.isZero64(overflowValue));
+            ValueFromBlock overflowResult = m_out.anchor(overflowValue);
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(Int64, namedResult, overflowResult));
+            return;
+        }
+            
+        case Array::Generic: {
+            setJSValue(vmCall(
+                Int64, m_out.operation(operationGetByVal), m_callFrame,
+                lowJSValue(m_node->child1()), lowJSValue(m_node->child2())));
+            return;
+        }
+            
+        case Array::String: {
+            compileStringCharAt();
+            return;
+        }
+            
+        default: {
+            LValue index = lowInt32(m_node->child2());
+            LValue storage = lowStorage(m_node->child3());
+            
+            TypedArrayType type = m_node->arrayMode().typedArrayType();
+            
+            if (isTypedView(type)) {
+                TypedPointer pointer = TypedPointer(
+                    m_heaps.typedArrayProperties,
+                    m_out.add(
+                        storage,
+                        m_out.shl(
+                            m_out.zeroExtPtr(index),
+                            m_out.constIntPtr(logElementSize(type)))));
+                
+                if (isInt(type)) {
+                    LValue result;
+                    switch (elementSize(type)) {
+                    case 1:
+                        result = isSigned(type) ? m_out.load8SignExt32(pointer) :  m_out.load8ZeroExt32(pointer);
+                        break;
+                    case 2:
+                        result = isSigned(type) ? m_out.load16SignExt32(pointer) :  m_out.load16ZeroExt32(pointer);
+                        break;
+                    case 4:
+                        result = m_out.load32(pointer);
+                        break;
+                    default:
+                        DFG_CRASH(m_graph, m_node, "Bad element size");
+                    }
+                    
+                    if (elementSize(type) < 4 || isSigned(type)) {
+                        setInt32(result);
+                        return;
+                    }
+
+                    if (m_node->shouldSpeculateInt32()) {
+                        speculate(
+                            Overflow, noValue(), 0, m_out.lessThan(result, m_out.int32Zero));
+                        setInt32(result);
+                        return;
+                    }
+                    
+                    if (m_node->shouldSpeculateAnyInt()) {
+                        setStrictInt52(m_out.zeroExt(result, Int64));
+                        return;
+                    }
+                    
+                    setDouble(m_out.unsignedToDouble(result));
+                    return;
+                }
+            
+                ASSERT(isFloat(type));
+                
+                LValue result;
+                switch (type) {
+                case TypeFloat32:
+                    result = m_out.floatToDouble(m_out.loadFloat(pointer));
+                    break;
+                case TypeFloat64:
+                    result = m_out.loadDouble(pointer);
+                    break;
+                default:
+                    DFG_CRASH(m_graph, m_node, "Bad typed array type");
+                }
+                
+                setDouble(result);
+                return;
+            }
+            
+            DFG_CRASH(m_graph, m_node, "Bad array type");
+            return;
+        } }
+    }
+    
+    void compileGetMyArgumentByVal()
+    {
+        InlineCallFrame* inlineCallFrame = m_node->child1()->origin.semantic.inlineCallFrame;
+        
+        LValue index = lowInt32(m_node->child2());
+        if (m_node->numberOfArgumentsToSkip())
+            index = m_out.add(index, m_out.constInt32(m_node->numberOfArgumentsToSkip()));
+        
+        LValue limit;
+        if (inlineCallFrame && !inlineCallFrame->isVarargs())
+            limit = m_out.constInt32(inlineCallFrame->arguments.size() - 1);
+        else {
+            VirtualRegister argumentCountRegister = AssemblyHelpers::argumentCount(inlineCallFrame);
+            limit = m_out.sub(m_out.load32(payloadFor(argumentCountRegister)), m_out.int32One);
+        }
+        
+        LValue isOutOfBounds = m_out.aboveOrEqual(index, limit);
+        LBasicBlock continuation = nullptr;
+        LBasicBlock lastNext = nullptr;
+        ValueFromBlock slowResult;
+        if (m_node->op() == GetMyArgumentByValOutOfBounds) {
+            LBasicBlock normalCase = m_out.newBlock();
+            continuation = m_out.newBlock();
+            
+            slowResult = m_out.anchor(m_out.constInt64(JSValue::encode(jsUndefined())));
+            m_out.branch(isOutOfBounds, unsure(continuation), unsure(normalCase));
+            
+            lastNext = m_out.appendTo(normalCase, continuation);
+        } else
+            speculate(ExoticObjectMode, noValue(), 0, isOutOfBounds);
+        
+        TypedPointer base;
+        if (inlineCallFrame) {
+            if (inlineCallFrame->arguments.size() > 1)
+                base = addressFor(inlineCallFrame->arguments[1].virtualRegister());
+        } else
+            base = addressFor(virtualRegisterForArgument(1));
+        
+        LValue result;
+        if (base) {
+            LValue pointer = m_out.baseIndex(
+                base.value(), m_out.zeroExt(index, pointerType()), ScaleEight);
+            result = m_out.load64(TypedPointer(m_heaps.variables.atAnyIndex(), pointer));
+        } else
+            result = m_out.constInt64(JSValue::encode(jsUndefined()));
+        
+        if (m_node->op() == GetMyArgumentByValOutOfBounds) {
+            ValueFromBlock normalResult = m_out.anchor(result);
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            result = m_out.phi(Int64, slowResult, normalResult);
+        }
+        
+        setJSValue(result);
+    }
+    
+    void compilePutByVal()
+    {
+        Edge child1 = m_graph.varArgChild(m_node, 0);
+        Edge child2 = m_graph.varArgChild(m_node, 1);
+        Edge child3 = m_graph.varArgChild(m_node, 2);
+        Edge child4 = m_graph.varArgChild(m_node, 3);
+        Edge child5 = m_graph.varArgChild(m_node, 4);
+        
+        switch (m_node->arrayMode().type()) {
+        case Array::Generic: {
+            V_JITOperation_EJJJ operation;
+            if (m_node->op() == PutByValDirect) {
+                if (m_graph.isStrictModeFor(m_node->origin.semantic))
+                    operation = operationPutByValDirectStrict;
+                else
+                    operation = operationPutByValDirectNonStrict;
+            } else {
+                if (m_graph.isStrictModeFor(m_node->origin.semantic))
+                    operation = operationPutByValStrict;
+                else
+                    operation = operationPutByValNonStrict;
+            }
+                
+            vmCall(
+                Void, m_out.operation(operation), m_callFrame,
+                lowJSValue(child1), lowJSValue(child2), lowJSValue(child3));
+            return;
+        }
+            
+        default:
+            break;
+        }
+
+        LValue base = lowCell(child1);
+        LValue index = lowInt32(child2);
+        LValue storage = lowStorage(child4);
+        
+        switch (m_node->arrayMode().type()) {
+        case Array::Int32:
+        case Array::Double:
+        case Array::Contiguous: {
+            LBasicBlock continuation = m_out.newBlock();
+            LBasicBlock outerLastNext = m_out.appendTo(m_out.m_block, continuation);
+            
+            switch (m_node->arrayMode().type()) {
+            case Array::Int32:
+            case Array::Contiguous: {
+                LValue value = lowJSValue(child3, ManualOperandSpeculation);
+                
+                if (m_node->arrayMode().type() == Array::Int32)
+                    FTL_TYPE_CHECK(jsValueValue(value), child3, SpecInt32Only, isNotInt32(value));
+                
+                TypedPointer elementPointer = m_out.baseIndex(
+                    m_node->arrayMode().type() == Array::Int32 ?
+                    m_heaps.indexedInt32Properties : m_heaps.indexedContiguousProperties,
+                    storage, m_out.zeroExtPtr(index), provenValue(child2));
+                
+                if (m_node->op() == PutByValAlias) {
+                    m_out.store64(value, elementPointer);
+                    break;
+                }
+                
+                contiguousPutByValOutOfBounds(
+                    codeBlock()->isStrictMode()
+                    ? operationPutByValBeyondArrayBoundsStrict
+                    : operationPutByValBeyondArrayBoundsNonStrict,
+                    base, storage, index, value, continuation);
+                
+                m_out.store64(value, elementPointer);
+                break;
+            }
+                
+            case Array::Double: {
+                LValue value = lowDouble(child3);
+                
+                FTL_TYPE_CHECK(
+                    doubleValue(value), child3, SpecDoubleReal,
+                    m_out.doubleNotEqualOrUnordered(value, value));
+                
+                TypedPointer elementPointer = m_out.baseIndex(
+                    m_heaps.indexedDoubleProperties, storage, m_out.zeroExtPtr(index),
+                    provenValue(child2));
+                
+                if (m_node->op() == PutByValAlias) {
+                    m_out.storeDouble(value, elementPointer);
+                    break;
+                }
+                
+                contiguousPutByValOutOfBounds(
+                    codeBlock()->isStrictMode()
+                    ? operationPutDoubleByValBeyondArrayBoundsStrict
+                    : operationPutDoubleByValBeyondArrayBoundsNonStrict,
+                    base, storage, index, value, continuation);
+                
+                m_out.storeDouble(value, elementPointer);
+                break;
+            }
+                
+            default:
+                DFG_CRASH(m_graph, m_node, "Bad array type");
+            }
+
+            m_out.jump(continuation);
+            m_out.appendTo(continuation, outerLastNext);
+            return;
+        }
+            
+        default:
+            TypedArrayType type = m_node->arrayMode().typedArrayType();
+            
+            if (isTypedView(type)) {
+                TypedPointer pointer = TypedPointer(
+                    m_heaps.typedArrayProperties,
+                    m_out.add(
+                        storage,
+                        m_out.shl(
+                            m_out.zeroExt(index, pointerType()),
+                            m_out.constIntPtr(logElementSize(type)))));
+                
+                Output::StoreType storeType;
+                LValue valueToStore;
+                
+                if (isInt(type)) {
+                    LValue intValue;
+                    switch (child3.useKind()) {
+                    case Int52RepUse:
+                    case Int32Use: {
+                        if (child3.useKind() == Int32Use)
+                            intValue = lowInt32(child3);
+                        else
+                            intValue = m_out.castToInt32(lowStrictInt52(child3));
+
+                        if (isClamped(type)) {
+                            ASSERT(elementSize(type) == 1);
+                            
+                            LBasicBlock atLeastZero = m_out.newBlock();
+                            LBasicBlock continuation = m_out.newBlock();
+                            
+                            Vector<ValueFromBlock, 2> intValues;
+                            intValues.append(m_out.anchor(m_out.int32Zero));
+                            m_out.branch(
+                                m_out.lessThan(intValue, m_out.int32Zero),
+                                unsure(continuation), unsure(atLeastZero));
+                            
+                            LBasicBlock lastNext = m_out.appendTo(atLeastZero, continuation);
+                            
+                            intValues.append(m_out.anchor(m_out.select(
+                                m_out.greaterThan(intValue, m_out.constInt32(255)),
+                                m_out.constInt32(255),
+                                intValue)));
+                            m_out.jump(continuation);
+                            
+                            m_out.appendTo(continuation, lastNext);
+                            intValue = m_out.phi(Int32, intValues);
+                        }
+                        break;
+                    }
+                        
+                    case DoubleRepUse: {
+                        LValue doubleValue = lowDouble(child3);
+                        
+                        if (isClamped(type)) {
+                            ASSERT(elementSize(type) == 1);
+                            
+                            LBasicBlock atLeastZero = m_out.newBlock();
+                            LBasicBlock withinRange = m_out.newBlock();
+                            LBasicBlock continuation = m_out.newBlock();
+                            
+                            Vector<ValueFromBlock, 3> intValues;
+                            intValues.append(m_out.anchor(m_out.int32Zero));
+                            m_out.branch(
+                                m_out.doubleLessThanOrUnordered(doubleValue, m_out.doubleZero),
+                                unsure(continuation), unsure(atLeastZero));
+                            
+                            LBasicBlock lastNext = m_out.appendTo(atLeastZero, withinRange);
+                            intValues.append(m_out.anchor(m_out.constInt32(255)));
+                            m_out.branch(
+                                m_out.doubleGreaterThan(doubleValue, m_out.constDouble(255)),
+                                unsure(continuation), unsure(withinRange));
+                            
+                            m_out.appendTo(withinRange, continuation);
+                            intValues.append(m_out.anchor(m_out.doubleToInt(doubleValue)));
+                            m_out.jump(continuation);
+                            
+                            m_out.appendTo(continuation, lastNext);
+                            intValue = m_out.phi(Int32, intValues);
+                        } else
+                            intValue = doubleToInt32(doubleValue);
+                        break;
+                    }
+                        
+                    default:
+                        DFG_CRASH(m_graph, m_node, "Bad use kind");
+                    }
+
+                    valueToStore = intValue;
+                    switch (elementSize(type)) {
+                    case 1:
+                        storeType = Output::Store32As8;
+                        break;
+                    case 2:
+                        storeType = Output::Store32As16;
+                        break;
+                    case 4:
+                        storeType = Output::Store32;
+                        break;
+                    default:
+                        DFG_CRASH(m_graph, m_node, "Bad element size");
+                    }
+                } else /* !isInt(type) */ {
+                    LValue value = lowDouble(child3);
+                    switch (type) {
+                    case TypeFloat32:
+                        valueToStore = m_out.doubleToFloat(value);
+                        storeType = Output::StoreFloat;
+                        break;
+                    case TypeFloat64:
+                        valueToStore = value;
+                        storeType = Output::StoreDouble;
+                        break;
+                    default:
+                        DFG_CRASH(m_graph, m_node, "Bad typed array type");
+                    }
+                }
+
+                if (m_node->arrayMode().isInBounds() || m_node->op() == PutByValAlias)
+                    m_out.store(valueToStore, pointer, storeType);
+                else {
+                    LBasicBlock isInBounds = m_out.newBlock();
+                    LBasicBlock isOutOfBounds = m_out.newBlock();
+                    LBasicBlock continuation = m_out.newBlock();
+                    
+                    m_out.branch(
+                        m_out.aboveOrEqual(index, lowInt32(child5)),
+                        unsure(isOutOfBounds), unsure(isInBounds));
+                    
+                    LBasicBlock lastNext = m_out.appendTo(isInBounds, isOutOfBounds);
+                    m_out.store(valueToStore, pointer, storeType);
+                    m_out.jump(continuation);
+
+                    m_out.appendTo(isOutOfBounds, continuation);
+                    speculateTypedArrayIsNotNeutered(base);
+                    m_out.jump(continuation);
+                    
+                    m_out.appendTo(continuation, lastNext);
+                }
+                
+                return;
+            }
+
+            DFG_CRASH(m_graph, m_node, "Bad array type");
+            break;
+        }
+    }
+
+    void compilePutAccessorById()
+    {
+        LValue base = lowCell(m_node->child1());
+        LValue accessor = lowCell(m_node->child2());
+        auto uid = m_graph.identifiers()[m_node->identifierNumber()];
+        vmCall(
+            Void,
+            m_out.operation(m_node->op() == PutGetterById ? operationPutGetterById : operationPutSetterById),
+            m_callFrame, base, m_out.constIntPtr(uid), m_out.constInt32(m_node->accessorAttributes()), accessor);
+    }
+
+    void compilePutGetterSetterById()
+    {
+        LValue base = lowCell(m_node->child1());
+        LValue getter = lowJSValue(m_node->child2());
+        LValue setter = lowJSValue(m_node->child3());
+        auto uid = m_graph.identifiers()[m_node->identifierNumber()];
+        vmCall(
+            Void, m_out.operation(operationPutGetterSetter),
+            m_callFrame, base, m_out.constIntPtr(uid), m_out.constInt32(m_node->accessorAttributes()), getter, setter);
+
+    }
+
+    void compilePutAccessorByVal()
+    {
+        LValue base = lowCell(m_node->child1());
+        LValue subscript = lowJSValue(m_node->child2());
+        LValue accessor = lowCell(m_node->child3());
+        vmCall(
+            Void,
+            m_out.operation(m_node->op() == PutGetterByVal ? operationPutGetterByVal : operationPutSetterByVal),
+            m_callFrame, base, subscript, m_out.constInt32(m_node->accessorAttributes()), accessor);
+    }
+    
+    void compileArrayPush()
+    {
+        LValue base = lowCell(m_node->child1());
+        LValue storage = lowStorage(m_node->child3());
+        
+        switch (m_node->arrayMode().type()) {
+        case Array::Int32:
+        case Array::Contiguous:
+        case Array::Double: {
+            LValue value;
+            Output::StoreType storeType;
+            
+            if (m_node->arrayMode().type() != Array::Double) {
+                value = lowJSValue(m_node->child2(), ManualOperandSpeculation);
+                if (m_node->arrayMode().type() == Array::Int32) {
+                    FTL_TYPE_CHECK(
+                        jsValueValue(value), m_node->child2(), SpecInt32Only, isNotInt32(value));
+                }
+                storeType = Output::Store64;
+            } else {
+                value = lowDouble(m_node->child2());
+                FTL_TYPE_CHECK(
+                    doubleValue(value), m_node->child2(), SpecDoubleReal,
+                    m_out.doubleNotEqualOrUnordered(value, value));
+                storeType = Output::StoreDouble;
+            }
+            
+            IndexedAbstractHeap& heap = m_heaps.forArrayType(m_node->arrayMode().type());
+
+            LValue prevLength = m_out.load32(storage, m_heaps.Butterfly_publicLength);
+            
+            LBasicBlock fastPath = m_out.newBlock();
+            LBasicBlock slowPath = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            m_out.branch(
+                m_out.aboveOrEqual(
+                    prevLength, m_out.load32(storage, m_heaps.Butterfly_vectorLength)),
+                unsure(slowPath), unsure(fastPath));
+            
+            LBasicBlock lastNext = m_out.appendTo(fastPath, slowPath);
+            m_out.store(
+                value, m_out.baseIndex(heap, storage, m_out.zeroExtPtr(prevLength)), storeType);
+            LValue newLength = m_out.add(prevLength, m_out.int32One);
+            m_out.store32(newLength, storage, m_heaps.Butterfly_publicLength);
+            
+            ValueFromBlock fastResult = m_out.anchor(boxInt32(newLength));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(slowPath, continuation);
+            LValue operation;
+            if (m_node->arrayMode().type() != Array::Double)
+                operation = m_out.operation(operationArrayPush);
+            else
+                operation = m_out.operation(operationArrayPushDouble);
+            ValueFromBlock slowResult = m_out.anchor(
+                vmCall(Int64, operation, m_callFrame, value, base));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(Int64, fastResult, slowResult));
+            return;
+        }
+            
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad array type");
+            return;
+        }
+    }
+
+    void compileArraySlice()
+    {
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+
+        LValue sourceStorage = lowStorage(m_node->numChildren() == 3 ? m_graph.varArgChild(m_node, 2) : m_graph.varArgChild(m_node, 3));
+        LValue inputLength = m_out.load32(sourceStorage, m_heaps.Butterfly_publicLength);
+
+        LValue endBoundary;
+        if (m_node->numChildren() == 3)
+            endBoundary = m_out.load32(sourceStorage, m_heaps.Butterfly_publicLength);
+        else {
+            endBoundary = lowInt32(m_graph.varArgChild(m_node, 2));
+            endBoundary = m_out.select(m_out.greaterThanOrEqual(endBoundary, m_out.constInt32(0)),
+                m_out.select(m_out.above(endBoundary, inputLength), inputLength, endBoundary),
+                m_out.select(m_out.lessThan(m_out.add(inputLength, endBoundary), m_out.constInt32(0)), m_out.constInt32(0), m_out.add(inputLength, endBoundary)));
+        }
+
+        LValue startIndex = lowInt32(m_graph.varArgChild(m_node, 1));
+        startIndex = m_out.select(m_out.greaterThanOrEqual(startIndex, m_out.constInt32(0)),
+            m_out.select(m_out.above(startIndex, inputLength), inputLength, startIndex),
+            m_out.select(m_out.lessThan(m_out.add(inputLength, startIndex), m_out.constInt32(0)), m_out.constInt32(0), m_out.add(inputLength, startIndex)));
+
+        LValue resultLength = m_out.select(m_out.below(startIndex, endBoundary),
+            m_out.sub(endBoundary, startIndex),
+            m_out.constInt32(0));
+
+        ArrayValues arrayResult;
+        {
+            LValue indexingType = m_out.load8ZeroExt32(lowCell(m_graph.varArgChild(m_node, 0)), m_heaps.JSCell_indexingTypeAndMisc);
+            indexingType = m_out.bitAnd(indexingType, m_out.constInt32(AllArrayTypesAndHistory));
+            // When we emit an ArraySlice, we dominate the use of the array by a CheckStructure
+            // to ensure the incoming array is one to be one of the original array structures
+            // with one of the following indexing shapes: Int32, Contiguous, Double.
+            LValue structure = m_out.select(
+                m_out.equal(indexingType, m_out.constInt32(ArrayWithInt32)),
+                weakStructure(m_graph.registerStructure(globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithInt32))),
+                m_out.select(m_out.equal(indexingType, m_out.constInt32(ArrayWithContiguous)),
+                    weakStructure(m_graph.registerStructure(globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithContiguous))),
+                    weakStructure(m_graph.registerStructure(globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithDouble)))));
+            arrayResult = allocateJSArray(resultLength, structure, indexingType, false, false);
+        }
+
+        LBasicBlock loop = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        resultLength = m_out.zeroExtPtr(resultLength);
+        ValueFromBlock startLoadIndex = m_out.anchor(m_out.zeroExtPtr(startIndex));
+        ValueFromBlock startStoreIndex = m_out.anchor(m_out.constIntPtr(0));
+
+        m_out.branch(
+            m_out.below(m_out.constIntPtr(0), resultLength), unsure(loop), unsure(continuation));
+
+        LBasicBlock lastNext = m_out.appendTo(loop, continuation);
+        LValue storeIndex = m_out.phi(pointerType(), startStoreIndex);
+        LValue loadIndex = m_out.phi(pointerType(), startLoadIndex);
+        LValue value = m_out.load64(m_out.baseIndex(m_heaps.root, sourceStorage, loadIndex, ScaleEight));
+        m_out.store64(value, m_out.baseIndex(m_heaps.root, arrayResult.butterfly, storeIndex, ScaleEight));
+        LValue nextStoreIndex = m_out.add(storeIndex, m_out.constIntPtr(1));
+        m_out.addIncomingToPhi(storeIndex, m_out.anchor(nextStoreIndex));
+        m_out.addIncomingToPhi(loadIndex, m_out.anchor(m_out.add(loadIndex, m_out.constIntPtr(1))));
+        m_out.branch(
+            m_out.below(nextStoreIndex, resultLength), unsure(loop), unsure(continuation));
+
+        m_out.appendTo(continuation, lastNext);
+
+        mutatorFence();
+        setJSValue(arrayResult.array);
+    }
+    
+    void compileArrayPop()
+    {
+        LValue base = lowCell(m_node->child1());
+        LValue storage = lowStorage(m_node->child2());
+        
+        switch (m_node->arrayMode().type()) {
+        case Array::Int32:
+        case Array::Double:
+        case Array::Contiguous: {
+            IndexedAbstractHeap& heap = m_heaps.forArrayType(m_node->arrayMode().type());
+            
+            LBasicBlock fastCase = m_out.newBlock();
+            LBasicBlock slowCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            LValue prevLength = m_out.load32(storage, m_heaps.Butterfly_publicLength);
+            
+            Vector<ValueFromBlock, 3> results;
+            results.append(m_out.anchor(m_out.constInt64(JSValue::encode(jsUndefined()))));
+            m_out.branch(
+                m_out.isZero32(prevLength), rarely(continuation), usually(fastCase));
+            
+            LBasicBlock lastNext = m_out.appendTo(fastCase, slowCase);
+            LValue newLength = m_out.sub(prevLength, m_out.int32One);
+            m_out.store32(newLength, storage, m_heaps.Butterfly_publicLength);
+            TypedPointer pointer = m_out.baseIndex(heap, storage, m_out.zeroExtPtr(newLength));
+            if (m_node->arrayMode().type() != Array::Double) {
+                LValue result = m_out.load64(pointer);
+                m_out.store64(m_out.int64Zero, pointer);
+                results.append(m_out.anchor(result));
+                m_out.branch(
+                    m_out.notZero64(result), usually(continuation), rarely(slowCase));
+            } else {
+                LValue result = m_out.loadDouble(pointer);
+                m_out.store64(m_out.constInt64(bitwise_cast<int64_t>(PNaN)), pointer);
+                results.append(m_out.anchor(boxDouble(result)));
+                m_out.branch(
+                    m_out.doubleEqual(result, result),
+                    usually(continuation), rarely(slowCase));
+            }
+            
+            m_out.appendTo(slowCase, continuation);
+            results.append(m_out.anchor(vmCall(
+                Int64, m_out.operation(operationArrayPopAndRecoverLength), m_callFrame, base)));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(Int64, results));
+            return;
+        }
+
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad array type");
+            return;
+        }
+    }
+    
+    void compileCreateActivation()
+    {
+        LValue scope = lowCell(m_node->child1());
+        SymbolTable* table = m_node->castOperand<SymbolTable*>();
+        RegisteredStructure structure = m_graph.registerStructure(m_graph.globalObjectFor(m_node->origin.semantic)->activationStructure());
+        JSValue initializationValue = m_node->initializationValueForActivation();
+        ASSERT(initializationValue.isUndefined() || initializationValue == jsTDZValue());
+        if (table->singletonScope()->isStillValid()) {
+            LValue callResult = vmCall(
+                Int64,
+                m_out.operation(operationCreateActivationDirect), m_callFrame, weakStructure(structure),
+                scope, weakPointer(table), m_out.constInt64(JSValue::encode(initializationValue)));
+            setJSValue(callResult);
+            return;
+        }
+        
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
+        
+        LValue fastObject = allocateObject<JSLexicalEnvironment>(
+            JSLexicalEnvironment::allocationSize(table), structure, m_out.intPtrZero, slowPath);
+        
+        // We don't need memory barriers since we just fast-created the activation, so the
+        // activation must be young.
+        m_out.storePtr(scope, fastObject, m_heaps.JSScope_next);
+        m_out.storePtr(weakPointer(table), fastObject, m_heaps.JSSymbolTableObject_symbolTable);
+        
+        for (unsigned i = 0; i < table->scopeSize(); ++i) {
+            m_out.store64(
+                m_out.constInt64(JSValue::encode(initializationValue)),
+                fastObject, m_heaps.JSEnvironmentRecord_variables[i]);
+        }
+        
+        mutatorFence();
+        
+        ValueFromBlock fastResult = m_out.anchor(fastObject);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(slowPath, continuation);
+        LValue callResult = lazySlowPath(
+            [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                return createLazyCallGenerator(
+                    operationCreateActivationDirect, locations[0].directGPR(),
+                    CCallHelpers::TrustedImmPtr(structure.get()), locations[1].directGPR(),
+                    CCallHelpers::TrustedImmPtr(table),
+                    CCallHelpers::TrustedImm64(JSValue::encode(initializationValue)));
+            },
+            scope);
+        ValueFromBlock slowResult = m_out.anchor(callResult);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(pointerType(), fastResult, slowResult));
+    }
+    
+    void compileNewFunction()
+    {
+        ASSERT(m_node->op() == NewFunction || m_node->op() == NewGeneratorFunction || m_node->op() == NewAsyncFunction);
+        bool isGeneratorFunction = m_node->op() == NewGeneratorFunction;
+        bool isAsyncFunction = m_node->op() == NewAsyncFunction;
+        
+        LValue scope = lowCell(m_node->child1());
+        
+        FunctionExecutable* executable = m_node->castOperand<FunctionExecutable*>();
+        if (executable->singletonFunction()->isStillValid()) {
+            LValue callResult =
+                isGeneratorFunction ? vmCall(Int64, m_out.operation(operationNewGeneratorFunction), m_callFrame, scope, weakPointer(executable)) :
+                isAsyncFunction ? vmCall(Int64, m_out.operation(operationNewAsyncFunction), m_callFrame, scope, weakPointer(executable)) :
+                vmCall(Int64, m_out.operation(operationNewFunction), m_callFrame, scope, weakPointer(executable));
+            setJSValue(callResult);
+            return;
+        }
+        
+        RegisteredStructure structure = m_graph.registerStructure(
+            isGeneratorFunction ? m_graph.globalObjectFor(m_node->origin.semantic)->generatorFunctionStructure() :
+            isAsyncFunction ? m_graph.globalObjectFor(m_node->origin.semantic)->asyncFunctionStructure() :
+            m_graph.globalObjectFor(m_node->origin.semantic)->functionStructure());
+        
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
+        
+        LValue fastObject =
+            isGeneratorFunction ? allocateObject<JSGeneratorFunction>(structure, m_out.intPtrZero, slowPath) :
+            allocateObject<JSFunction>(structure, m_out.intPtrZero, slowPath);
+        
+        
+        // We don't need memory barriers since we just fast-created the function, so it
+        // must be young.
+        m_out.storePtr(scope, fastObject, m_heaps.JSFunction_scope);
+        m_out.storePtr(weakPointer(executable), fastObject, m_heaps.JSFunction_executable);
+        m_out.storePtr(m_out.intPtrZero, fastObject, m_heaps.JSFunction_rareData);
+        
+        mutatorFence();
+        
+        ValueFromBlock fastResult = m_out.anchor(fastObject);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(slowPath, continuation);
+
+        Vector<LValue> slowPathArguments;
+        slowPathArguments.append(scope);
+        LValue callResult = lazySlowPath(
+            [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                if (isGeneratorFunction) {
+                    return createLazyCallGenerator(
+                        operationNewGeneratorFunctionWithInvalidatedReallocationWatchpoint,
+                        locations[0].directGPR(), locations[1].directGPR(),
+                        CCallHelpers::TrustedImmPtr(executable));
+                }
+                if (isAsyncFunction) {
+                    return createLazyCallGenerator(
+                        operationNewAsyncFunctionWithInvalidatedReallocationWatchpoint,
+                        locations[0].directGPR(), locations[1].directGPR(),
+                        CCallHelpers::TrustedImmPtr(executable));
+                }
+                return createLazyCallGenerator(
+                    operationNewFunctionWithInvalidatedReallocationWatchpoint,
+                    locations[0].directGPR(), locations[1].directGPR(),
+                    CCallHelpers::TrustedImmPtr(executable));
+            },
+            slowPathArguments);
+        ValueFromBlock slowResult = m_out.anchor(callResult);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(pointerType(), fastResult, slowResult));
+    }
+    
+    void compileCreateDirectArguments()
+    {
+        // FIXME: A more effective way of dealing with the argument count and callee is to have
+        // them be explicit arguments to this node.
+        // https://bugs.webkit.org/show_bug.cgi?id=142207
+        
+        RegisteredStructure structure =
+            m_graph.registerStructure(m_graph.globalObjectFor(m_node->origin.semantic)->directArgumentsStructure());
+        
+        unsigned minCapacity = m_graph.baselineCodeBlockFor(m_node->origin.semantic)->numParameters() - 1;
+        
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
+        
+        ArgumentsLength length = getArgumentsLength();
+        
+        LValue fastObject;
+        if (length.isKnown) {
+            fastObject = allocateObject<DirectArguments>(
+                DirectArguments::allocationSize(std::max(length.known, minCapacity)), structure,
+                m_out.intPtrZero, slowPath);
+        } else {
+            LValue size = m_out.add(
+                m_out.shl(length.value, m_out.constInt32(3)),
+                m_out.constInt32(DirectArguments::storageOffset()));
+            
+            size = m_out.select(
+                m_out.aboveOrEqual(length.value, m_out.constInt32(minCapacity)),
+                size, m_out.constInt32(DirectArguments::allocationSize(minCapacity)));
+            
+            fastObject = allocateVariableSizedObject<DirectArguments>(
+                m_out.zeroExtPtr(size), structure, m_out.intPtrZero, slowPath);
+        }
+        
+        m_out.store32(length.value, fastObject, m_heaps.DirectArguments_length);
+        m_out.store32(m_out.constInt32(minCapacity), fastObject, m_heaps.DirectArguments_minCapacity);
+        m_out.storePtr(m_out.intPtrZero, fastObject, m_heaps.DirectArguments_mappedArguments);
+        m_out.storePtr(m_out.intPtrZero, fastObject, m_heaps.DirectArguments_modifiedArgumentsDescriptor);
+        
+        ValueFromBlock fastResult = m_out.anchor(fastObject);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(slowPath, continuation);
+        LValue callResult = lazySlowPath(
+            [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                return createLazyCallGenerator(
+                    operationCreateDirectArguments, locations[0].directGPR(),
+                    CCallHelpers::TrustedImmPtr(structure.get()), locations[1].directGPR(),
+                    CCallHelpers::TrustedImm32(minCapacity));
+            }, length.value);
+        ValueFromBlock slowResult = m_out.anchor(callResult);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        LValue result = m_out.phi(pointerType(), fastResult, slowResult);
+
+        m_out.storePtr(getCurrentCallee(), result, m_heaps.DirectArguments_callee);
+        
+        if (length.isKnown) {
+            VirtualRegister start = AssemblyHelpers::argumentsStart(m_node->origin.semantic);
+            for (unsigned i = 0; i < std::max(length.known, minCapacity); ++i) {
+                m_out.store64(
+                    m_out.load64(addressFor(start + i)),
+                    result, m_heaps.DirectArguments_storage[i]);
+            }
+        } else {
+            LValue stackBase = getArgumentsStart();
+            
+            LBasicBlock loop = m_out.newBlock();
+            LBasicBlock end = m_out.newBlock();
+
+            ValueFromBlock originalLength;
+            if (minCapacity) {
+                LValue capacity = m_out.select(
+                    m_out.aboveOrEqual(length.value, m_out.constInt32(minCapacity)),
+                    length.value,
+                    m_out.constInt32(minCapacity));
+                LValue originalLengthValue = m_out.zeroExtPtr(capacity);
+                originalLength = m_out.anchor(originalLengthValue);
+                m_out.jump(loop);
+            } else {
+                LValue originalLengthValue = m_out.zeroExtPtr(length.value);
+                originalLength = m_out.anchor(originalLengthValue);
+                m_out.branch(m_out.isNull(originalLengthValue), unsure(end), unsure(loop));
+            }
+            
+            lastNext = m_out.appendTo(loop, end);
+            LValue previousIndex = m_out.phi(pointerType(), originalLength);
+            LValue index = m_out.sub(previousIndex, m_out.intPtrOne);
+            m_out.store64(
+                m_out.load64(m_out.baseIndex(m_heaps.variables, stackBase, index)),
+                m_out.baseIndex(m_heaps.DirectArguments_storage, result, index));
+            ValueFromBlock nextIndex = m_out.anchor(index);
+            m_out.addIncomingToPhi(previousIndex, nextIndex);
+            m_out.branch(m_out.isNull(index), unsure(end), unsure(loop));
+            
+            m_out.appendTo(end, lastNext);
+        }
+        
+        mutatorFence();
+        
+        setJSValue(result);
+    }
+    
+    void compileCreateScopedArguments()
+    {
+        LValue scope = lowCell(m_node->child1());
+        
+        LValue result = vmCall(
+            Int64, m_out.operation(operationCreateScopedArguments), m_callFrame,
+            weakPointer(
+                m_graph.globalObjectFor(m_node->origin.semantic)->scopedArgumentsStructure()),
+            getArgumentsStart(), getArgumentsLength().value, getCurrentCallee(), scope);
+        
+        setJSValue(result);
+    }
+    
+    void compileCreateClonedArguments()
+    {
+        LValue result = vmCall(
+            Int64, m_out.operation(operationCreateClonedArguments), m_callFrame,
+            weakPointer(
+                m_graph.globalObjectFor(m_node->origin.semantic)->clonedArgumentsStructure()),
+            getArgumentsStart(), getArgumentsLength().value, getCurrentCallee());
+        
+        setJSValue(result);
+    }
+
+    void compileCreateRest()
+    {
+        if (m_graph.isWatchingHavingABadTimeWatchpoint(m_node)) {
+            LBasicBlock continuation = m_out.newBlock();
+            LValue arrayLength = lowInt32(m_node->child1());
+            LBasicBlock loopStart = m_out.newBlock();
+            JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+            RegisteredStructure structure = m_graph.registerStructure(globalObject->restParameterStructure());
+            ArrayValues arrayValues = allocateUninitializedContiguousJSArray(arrayLength, structure);
+            LValue array = arrayValues.array;
+            LValue butterfly = arrayValues.butterfly;
+            ValueFromBlock startLength = m_out.anchor(arrayLength);
+            LValue argumentRegion = m_out.add(getArgumentsStart(), m_out.constInt64(sizeof(Register) * m_node->numberOfArgumentsToSkip()));
+            m_out.branch(m_out.equal(arrayLength, m_out.constInt32(0)),
+                unsure(continuation), unsure(loopStart));
+
+            LBasicBlock lastNext = m_out.appendTo(loopStart, continuation);
+            LValue phiOffset = m_out.phi(Int32, startLength);
+            LValue currentOffset = m_out.sub(phiOffset, m_out.int32One);
+            m_out.addIncomingToPhi(phiOffset, m_out.anchor(currentOffset));
+            LValue loadedValue = m_out.load64(m_out.baseIndex(m_heaps.variables, argumentRegion, m_out.zeroExtPtr(currentOffset)));
+            IndexedAbstractHeap& heap = m_heaps.indexedContiguousProperties;
+            m_out.store64(loadedValue, m_out.baseIndex(heap, butterfly, m_out.zeroExtPtr(currentOffset)));
+            m_out.branch(m_out.equal(currentOffset, m_out.constInt32(0)), unsure(continuation), unsure(loopStart));
+
+            m_out.appendTo(continuation, lastNext);
+            mutatorFence();
+            setJSValue(array);
+            return;
+        }
+
+        LValue arrayLength = lowInt32(m_node->child1());
+        LValue argumentStart = getArgumentsStart();
+        LValue numberOfArgumentsToSkip = m_out.constInt32(m_node->numberOfArgumentsToSkip());
+        setJSValue(vmCall(
+            Int64, m_out.operation(operationCreateRest), m_callFrame, argumentStart, numberOfArgumentsToSkip, arrayLength));
+    }
+
+    void compileGetRestLength()
+    {
+        LBasicBlock nonZeroLength = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        ValueFromBlock zeroLengthResult = m_out.anchor(m_out.constInt32(0));
+
+        LValue numberOfArgumentsToSkip = m_out.constInt32(m_node->numberOfArgumentsToSkip());
+        LValue argumentsLength = getArgumentsLength().value;
+        m_out.branch(m_out.above(argumentsLength, numberOfArgumentsToSkip),
+            unsure(nonZeroLength), unsure(continuation));
+        
+        LBasicBlock lastNext = m_out.appendTo(nonZeroLength, continuation);
+        ValueFromBlock nonZeroLengthResult = m_out.anchor(m_out.sub(argumentsLength, numberOfArgumentsToSkip));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setInt32(m_out.phi(Int32, zeroLengthResult, nonZeroLengthResult));
+    }
+    
+    void compileNewObject()
+    {
+        setJSValue(allocateObject(m_node->structure()));
+        mutatorFence();
+    }
+    
+    void compileNewArray()
+    {
+        // First speculate appropriately on all of the children. Do this unconditionally up here
+        // because some of the slow paths may otherwise forget to do it. It's sort of arguable
+        // that doing the speculations up here might be unprofitable for RA - so we can consider
+        // sinking this to below the allocation fast path if we find that this has a lot of
+        // register pressure.
+        for (unsigned operandIndex = 0; operandIndex < m_node->numChildren(); ++operandIndex)
+            speculate(m_graph.varArgChild(m_node, operandIndex));
+        
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+        RegisteredStructure structure = m_graph.registerStructure(globalObject->arrayStructureForIndexingTypeDuringAllocation(
+            m_node->indexingType()));
+
+        if (!globalObject->isHavingABadTime() && !hasAnyArrayStorage(m_node->indexingType())) {
+            unsigned numElements = m_node->numChildren();
+            
+            ArrayValues arrayValues =
+                allocateUninitializedContiguousJSArray(m_out.constInt32(numElements), structure);
+            
+            for (unsigned operandIndex = 0; operandIndex < m_node->numChildren(); ++operandIndex) {
+                Edge edge = m_graph.varArgChild(m_node, operandIndex);
+                
+                switch (m_node->indexingType()) {
+                case ALL_BLANK_INDEXING_TYPES:
+                case ALL_UNDECIDED_INDEXING_TYPES:
+                    DFG_CRASH(m_graph, m_node, "Bad indexing type");
+                    break;
+                    
+                case ALL_DOUBLE_INDEXING_TYPES:
+                    m_out.storeDouble(
+                        lowDouble(edge),
+                        arrayValues.butterfly, m_heaps.indexedDoubleProperties[operandIndex]);
+                    break;
+                    
+                case ALL_INT32_INDEXING_TYPES:
+                case ALL_CONTIGUOUS_INDEXING_TYPES:
+                    m_out.store64(
+                        lowJSValue(edge, ManualOperandSpeculation),
+                        arrayValues.butterfly,
+                        m_heaps.forIndexingType(m_node->indexingType())->at(operandIndex));
+                    break;
+                    
+                default:
+                    DFG_CRASH(m_graph, m_node, "Corrupt indexing type");
+                    break;
+                }
+            }
+            
+            setJSValue(arrayValues.array);
+            mutatorFence();
+            return;
+        }
+        
+        if (!m_node->numChildren()) {
+            setJSValue(vmCall(
+                Int64, m_out.operation(operationNewEmptyArray), m_callFrame,
+                weakStructure(structure)));
+            return;
+        }
+        
+        size_t scratchSize = sizeof(EncodedJSValue) * m_node->numChildren();
+        ASSERT(scratchSize);
+        ScratchBuffer* scratchBuffer = vm().scratchBufferForSize(scratchSize);
+        EncodedJSValue* buffer = static_cast<EncodedJSValue*>(scratchBuffer->dataBuffer());
+        
+        for (unsigned operandIndex = 0; operandIndex < m_node->numChildren(); ++operandIndex) {
+            Edge edge = m_graph.varArgChild(m_node, operandIndex);
+            m_out.store64(
+                lowJSValue(edge, ManualOperandSpeculation),
+                m_out.absolute(buffer + operandIndex));
+        }
+        
+        m_out.storePtr(
+            m_out.constIntPtr(scratchSize), m_out.absolute(scratchBuffer->activeLengthPtr()));
+        
+        LValue result = vmCall(
+            Int64, m_out.operation(operationNewArray), m_callFrame,
+            weakStructure(structure), m_out.constIntPtr(buffer),
+            m_out.constIntPtr(m_node->numChildren()));
+        
+        m_out.storePtr(m_out.intPtrZero, m_out.absolute(scratchBuffer->activeLengthPtr()));
+        
+        setJSValue(result);
+    }
+
+    void compileNewArrayWithSpread()
+    {
+        if (m_graph.isWatchingHavingABadTimeWatchpoint(m_node)) {
+            unsigned startLength = 0;
+            BitVector* bitVector = m_node->bitVector();
+            HashMap<InlineCallFrame*, LValue, WTF::DefaultHash<InlineCallFrame*>::Hash, WTF::NullableHashTraits<InlineCallFrame*>> cachedSpreadLengths;
+
+            for (unsigned i = 0; i < m_node->numChildren(); ++i) {
+                if (!bitVector->get(i))
+                    ++startLength;
+            }
+
+            LValue length = m_out.constInt32(startLength);
+
+            for (unsigned i = 0; i < m_node->numChildren(); ++i) {
+                if (bitVector->get(i)) {
+                    Edge use = m_graph.varArgChild(m_node, i);
+                    CheckValue* lengthCheck = nullptr;
+                    if (use->op() == PhantomSpread) {
+                        RELEASE_ASSERT(use->child1()->op() == PhantomCreateRest);
+                        InlineCallFrame* inlineCallFrame = use->child1()->origin.semantic.inlineCallFrame;
+                        unsigned numberOfArgumentsToSkip = use->child1()->numberOfArgumentsToSkip();
+                        LValue spreadLength = cachedSpreadLengths.ensure(inlineCallFrame, [&] () {
+                            return getSpreadLengthFromInlineCallFrame(inlineCallFrame, numberOfArgumentsToSkip);
+                        }).iterator->value;
+                        lengthCheck = m_out.speculateAdd(length, spreadLength);
+                    } else {
+                        LValue fixedArray = lowCell(use);
+                        lengthCheck = m_out.speculateAdd(length, m_out.load32(fixedArray, m_heaps.JSFixedArray_size));
+                    }
+                    blessSpeculation(lengthCheck, Overflow, noValue(), nullptr, m_origin);
+                    length = lengthCheck;
+                }
+            }
+
+            RegisteredStructure structure = m_graph.registerStructure(m_graph.globalObjectFor(m_node->origin.semantic)->originalArrayStructureForIndexingType(ArrayWithContiguous));
+            ArrayValues arrayValues = allocateUninitializedContiguousJSArray(length, structure);
+            LValue result = arrayValues.array;
+            LValue storage = arrayValues.butterfly;
+            LValue index = m_out.constIntPtr(0);
+
+            for (unsigned i = 0; i < m_node->numChildren(); ++i) {
+                Edge use = m_graph.varArgChild(m_node, i);
+                if (bitVector->get(i)) {
+                    if (use->op() == PhantomSpread) {
+                        RELEASE_ASSERT(use->child1()->op() == PhantomCreateRest);
+                        InlineCallFrame* inlineCallFrame = use->child1()->origin.semantic.inlineCallFrame;
+                        unsigned numberOfArgumentsToSkip = use->child1()->numberOfArgumentsToSkip();
+
+                        LValue length = m_out.zeroExtPtr(cachedSpreadLengths.get(inlineCallFrame));
+                        LValue sourceStart = getArgumentsStart(inlineCallFrame, numberOfArgumentsToSkip);
+
+                        LBasicBlock loopStart = m_out.newBlock();
+                        LBasicBlock continuation = m_out.newBlock();
+
+                        ValueFromBlock loadIndexStart = m_out.anchor(m_out.constIntPtr(0));
+                        ValueFromBlock arrayIndexStart = m_out.anchor(index);
+                        ValueFromBlock arrayIndexStartForFinish = m_out.anchor(index);
+
+                        m_out.branch(
+                            m_out.isZero64(length),
+                            unsure(continuation), unsure(loopStart));
+
+                        LBasicBlock lastNext = m_out.appendTo(loopStart, continuation);
+
+                        LValue arrayIndex = m_out.phi(pointerType(), arrayIndexStart);
+                        LValue loadIndex = m_out.phi(pointerType(), loadIndexStart);
+
+                        LValue item = m_out.load64(m_out.baseIndex(m_heaps.variables, sourceStart, loadIndex));
+                        m_out.store64(item, m_out.baseIndex(m_heaps.indexedContiguousProperties, storage, arrayIndex));
+
+                        LValue nextArrayIndex = m_out.add(arrayIndex, m_out.constIntPtr(1));
+                        LValue nextLoadIndex = m_out.add(loadIndex, m_out.constIntPtr(1));
+                        ValueFromBlock arrayIndexLoopForFinish = m_out.anchor(nextArrayIndex);
+
+                        m_out.addIncomingToPhi(loadIndex, m_out.anchor(nextLoadIndex));
+                        m_out.addIncomingToPhi(arrayIndex, m_out.anchor(nextArrayIndex));
+
+                        m_out.branch(
+                            m_out.below(nextLoadIndex, length),
+                            unsure(loopStart), unsure(continuation));
+
+                        m_out.appendTo(continuation, lastNext);
+                        index = m_out.phi(pointerType(), arrayIndexStartForFinish, arrayIndexLoopForFinish);
+                    } else {
+                        LBasicBlock loopStart = m_out.newBlock();
+                        LBasicBlock continuation = m_out.newBlock();
+
+                        LValue fixedArray = lowCell(use);
+
+                        ValueFromBlock fixedIndexStart = m_out.anchor(m_out.constIntPtr(0));
+                        ValueFromBlock arrayIndexStart = m_out.anchor(index);
+                        ValueFromBlock arrayIndexStartForFinish = m_out.anchor(index);
+
+                        LValue fixedArraySize = m_out.zeroExtPtr(m_out.load32(fixedArray, m_heaps.JSFixedArray_size));
+
+                        m_out.branch(
+                            m_out.isZero64(fixedArraySize),
+                            unsure(continuation), unsure(loopStart));
+
+                        LBasicBlock lastNext = m_out.appendTo(loopStart, continuation);
+
+                        LValue arrayIndex = m_out.phi(pointerType(), arrayIndexStart);
+                        LValue fixedArrayIndex = m_out.phi(pointerType(), fixedIndexStart);
+
+                        LValue item = m_out.load64(m_out.baseIndex(m_heaps.JSFixedArray_buffer, fixedArray, fixedArrayIndex));
+                        m_out.store64(item, m_out.baseIndex(m_heaps.indexedContiguousProperties, storage, arrayIndex));
+
+                        LValue nextArrayIndex = m_out.add(arrayIndex, m_out.constIntPtr(1));
+                        LValue nextFixedArrayIndex = m_out.add(fixedArrayIndex, m_out.constIntPtr(1));
+                        ValueFromBlock arrayIndexLoopForFinish = m_out.anchor(nextArrayIndex);
+
+                        m_out.addIncomingToPhi(fixedArrayIndex, m_out.anchor(nextFixedArrayIndex));
+                        m_out.addIncomingToPhi(arrayIndex, m_out.anchor(nextArrayIndex));
+
+                        m_out.branch(
+                            m_out.below(nextFixedArrayIndex, fixedArraySize),
+                            unsure(loopStart), unsure(continuation));
+
+                        m_out.appendTo(continuation, lastNext);
+                        index = m_out.phi(pointerType(), arrayIndexStartForFinish, arrayIndexLoopForFinish);
+                    }
+                } else {
+                    IndexedAbstractHeap& heap = m_heaps.indexedContiguousProperties;
+                    LValue item = lowJSValue(use);
+                    m_out.store64(item, m_out.baseIndex(heap, storage, index));
+                    index = m_out.add(index, m_out.constIntPtr(1));
+                }
+            }
+
+            mutatorFence();
+            setJSValue(result);
+            return;
+        }
+
+        ASSERT(m_node->numChildren());
+        size_t scratchSize = sizeof(EncodedJSValue) * m_node->numChildren();
+        ScratchBuffer* scratchBuffer = vm().scratchBufferForSize(scratchSize);
+        EncodedJSValue* buffer = static_cast<EncodedJSValue*>(scratchBuffer->dataBuffer());
+        BitVector* bitVector = m_node->bitVector();
+        for (unsigned i = 0; i < m_node->numChildren(); ++i) {
+            Edge use = m_graph.m_varArgChildren[m_node->firstChild() + i];
+            LValue value;
+            if (bitVector->get(i))
+                value = lowCell(use);
+            else
+                value = lowJSValue(use);
+            m_out.store64(value, m_out.absolute(&buffer[i]));
+        }
+
+        m_out.storePtr(m_out.constIntPtr(scratchSize), m_out.absolute(scratchBuffer->activeLengthPtr()));
+        LValue result = vmCall(Int64, m_out.operation(operationNewArrayWithSpreadSlow), m_callFrame, m_out.constIntPtr(buffer), m_out.constInt32(m_node->numChildren()));
+        m_out.storePtr(m_out.constIntPtr(0), m_out.absolute(scratchBuffer->activeLengthPtr()));
+
+        setJSValue(result);
+    }
+
+    void compileSpread()
+    {
+        // It would be trivial to support this, but for now, we never create
+        // IR that would necessitate this. The reason is that Spread is only
+        // consumed by NewArrayWithSpread and never anything else. Also, any
+        // Spread(PhantomCreateRest) will turn into PhantomSpread(PhantomCreateRest).
+        RELEASE_ASSERT(m_node->child1()->op() != PhantomCreateRest); 
+
+        LValue argument = lowCell(m_node->child1());
+
+        LValue result;
+        if (m_node->child1().useKind() == ArrayUse) {
+            speculateArray(m_node->child1());
+
+            LBasicBlock preLoop = m_out.newBlock();
+            LBasicBlock loopSelection = m_out.newBlock();
+            LBasicBlock contiguousLoopStart = m_out.newBlock();
+            LBasicBlock doubleLoopStart = m_out.newBlock();
+            LBasicBlock slowPath = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            LValue indexingShape = m_out.load8ZeroExt32(argument, m_heaps.JSCell_indexingTypeAndMisc);
+            indexingShape = m_out.bitAnd(indexingShape, m_out.constInt32(IndexingShapeMask));
+            LValue isOKIndexingType = m_out.belowOrEqual(
+                m_out.sub(indexingShape, m_out.constInt32(Int32Shape)),
+                m_out.constInt32(ContiguousShape - Int32Shape));
+
+            m_out.branch(isOKIndexingType, unsure(preLoop), unsure(slowPath));
+            LBasicBlock lastNext = m_out.appendTo(preLoop, loopSelection);
+
+            LValue butterfly = m_out.loadPtr(argument, m_heaps.JSObject_butterfly);
+            LValue length = m_out.load32NonNegative(butterfly, m_heaps.Butterfly_publicLength);
+            static_assert(sizeof(JSValue) == 8 && 1 << 3 == 8, "Assumed in the code below.");
+            LValue size = m_out.add(
+                m_out.shl(m_out.zeroExtPtr(length), m_out.constInt32(3)),
+                m_out.constIntPtr(JSFixedArray::offsetOfData()));
+
+            LValue fastAllocation = allocateVariableSizedCell<JSFixedArray>(size, m_graph.m_vm.fixedArrayStructure.get(), slowPath);
+            ValueFromBlock fastResult = m_out.anchor(fastAllocation);
+            m_out.store32(length, fastAllocation, m_heaps.JSFixedArray_size);
+
+            ValueFromBlock startIndexForContiguous = m_out.anchor(m_out.constIntPtr(0));
+            ValueFromBlock startIndexForDouble = m_out.anchor(m_out.constIntPtr(0));
+
+            m_out.branch(m_out.isZero32(length), unsure(continuation), unsure(loopSelection));
+
+            m_out.appendTo(loopSelection, contiguousLoopStart);
+            m_out.branch(m_out.equal(indexingShape, m_out.constInt32(DoubleShape)),
+                unsure(doubleLoopStart), unsure(contiguousLoopStart));
+
+            {
+                m_out.appendTo(contiguousLoopStart, doubleLoopStart);
+                LValue index = m_out.phi(pointerType(), startIndexForContiguous);
+
+                TypedPointer loadSite = m_out.baseIndex(m_heaps.root, butterfly, index, ScaleEight); // We read TOP here since we can be reading either int32 or contiguous properties.
+                LValue value = m_out.load64(loadSite);
+                value = m_out.select(m_out.isZero64(value), m_out.constInt64(JSValue::encode(jsUndefined())), value);
+                m_out.store64(value, m_out.baseIndex(m_heaps.JSFixedArray_buffer, fastAllocation, index));
+
+                LValue nextIndex = m_out.add(index, m_out.constIntPtr(1));
+                m_out.addIncomingToPhi(index, m_out.anchor(nextIndex));
+
+                m_out.branch(m_out.below(nextIndex, m_out.zeroExtPtr(length)),
+                    unsure(contiguousLoopStart), unsure(continuation));
+            }
+
+            {
+                m_out.appendTo(doubleLoopStart, slowPath);
+                LValue index = m_out.phi(pointerType(), startIndexForDouble);
+
+                LValue value = m_out.loadDouble(m_out.baseIndex(m_heaps.indexedDoubleProperties, butterfly, index));
+                LValue isNaN = m_out.doubleNotEqualOrUnordered(value, value);
+                LValue holeResult = m_out.constInt64(JSValue::encode(jsUndefined()));
+                LValue normalResult = boxDouble(value);
+                value = m_out.select(isNaN, holeResult, normalResult);
+                m_out.store64(value, m_out.baseIndex(m_heaps.JSFixedArray_buffer, fastAllocation, index));
+
+                LValue nextIndex = m_out.add(index, m_out.constIntPtr(1));
+                m_out.addIncomingToPhi(index, m_out.anchor(nextIndex));
+
+                m_out.branch(m_out.below(nextIndex, m_out.zeroExtPtr(length)),
+                    unsure(doubleLoopStart), unsure(continuation));
+            }
+
+            m_out.appendTo(slowPath, continuation);
+            ValueFromBlock slowResult = m_out.anchor(vmCall(Int64, m_out.operation(operationSpreadFastArray), m_callFrame, argument));
+            m_out.jump(continuation);
+
+            m_out.appendTo(continuation, lastNext);
+            result = m_out.phi(Int64, fastResult, slowResult);
+            mutatorFence();
+        } else
+            result = vmCall(Int64, m_out.operation(operationSpreadGeneric), m_callFrame, argument);
+
+        setJSValue(result);
+    }
+    
+    void compileNewArrayBuffer()
+    {
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+        RegisteredStructure structure = m_graph.registerStructure(globalObject->arrayStructureForIndexingTypeDuringAllocation(
+            m_node->indexingType()));
+        
+        if (!globalObject->isHavingABadTime() && !hasAnyArrayStorage(m_node->indexingType())) {
+            unsigned numElements = m_node->numConstants();
+            
+            ArrayValues arrayValues =
+                allocateUninitializedContiguousJSArray(m_out.constInt32(numElements), structure);
+            
+            JSValue* data = codeBlock()->constantBuffer(m_node->startConstant());
+            for (unsigned index = 0; index < m_node->numConstants(); ++index) {
+                int64_t value;
+                if (hasDouble(m_node->indexingType()))
+                    value = bitwise_cast<int64_t>(data[index].asNumber());
+                else
+                    value = JSValue::encode(data[index]);
+                
+                m_out.store64(
+                    m_out.constInt64(value),
+                    arrayValues.butterfly,
+                    m_heaps.forIndexingType(m_node->indexingType())->at(index));
+            }
+            
+            mutatorFence();
+            setJSValue(arrayValues.array);
+            return;
+        }
+        
+        setJSValue(vmCall(
+            Int64, m_out.operation(operationNewArrayBuffer), m_callFrame,
+            weakStructure(structure), m_out.constIntPtr(m_node->startConstant()),
+            m_out.constIntPtr(m_node->numConstants())));
+    }
+
+    void compileNewArrayWithSize()
+    {
+        LValue publicLength = lowInt32(m_node->child1());
+        
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+        RegisteredStructure structure = m_graph.registerStructure(globalObject->arrayStructureForIndexingTypeDuringAllocation(
+            m_node->indexingType()));
+        
+        if (!globalObject->isHavingABadTime() && !hasAnyArrayStorage(m_node->indexingType())) {
+            IndexingType indexingType = m_node->indexingType();
+            setJSValue(
+                allocateJSArray(
+                    publicLength, weakPointer(globalObject->arrayStructureForIndexingTypeDuringAllocation(indexingType)), m_out.constInt32(indexingType)).array);
+            mutatorFence();
+            return;
+        }
+        
+        LValue structureValue = m_out.select(
+            m_out.aboveOrEqual(publicLength, m_out.constInt32(MIN_ARRAY_STORAGE_CONSTRUCTION_LENGTH)),
+            weakStructure(m_graph.registerStructure(globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithArrayStorage))),
+            weakStructure(structure));
+        setJSValue(vmCall(Int64, m_out.operation(operationNewArrayWithSize), m_callFrame, structureValue, publicLength, m_out.intPtrZero));
+    }
+
+    void compileNewTypedArray()
+    {
+        TypedArrayType type = m_node->typedArrayType();
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+        
+        switch (m_node->child1().useKind()) {
+        case Int32Use: {
+            RegisteredStructure structure = m_graph.registerStructure(globalObject->typedArrayStructureConcurrently(type));
+
+            LValue size = lowInt32(m_node->child1());
+
+            LBasicBlock smallEnoughCase = m_out.newBlock();
+            LBasicBlock nonZeroCase = m_out.newBlock();
+            LBasicBlock slowCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            ValueFromBlock noStorage = m_out.anchor(m_out.intPtrZero);
+
+            m_out.branch(
+                m_out.above(size, m_out.constInt32(JSArrayBufferView::fastSizeLimit)),
+                rarely(slowCase), usually(smallEnoughCase));
+
+            LBasicBlock lastNext = m_out.appendTo(smallEnoughCase, nonZeroCase);
+
+            m_out.branch(m_out.notZero32(size), usually(nonZeroCase), rarely(slowCase));
+
+            m_out.appendTo(nonZeroCase, slowCase);
+
+            LValue byteSize =
+                m_out.shl(m_out.zeroExtPtr(size), m_out.constInt32(logElementSize(type)));
+            if (elementSize(type) < 8) {
+                byteSize = m_out.bitAnd(
+                    m_out.add(byteSize, m_out.constIntPtr(7)),
+                    m_out.constIntPtr(~static_cast<intptr_t>(7)));
+            }
+        
+            LValue allocator = allocatorForSize(vm().auxiliarySpace, byteSize, slowCase);
+            LValue storage = allocateHeapCell(allocator, slowCase);
+            
+            splatWords(
+                storage,
+                m_out.int32Zero,
+                m_out.castToInt32(m_out.lShr(byteSize, m_out.constIntPtr(3))),
+                m_out.int64Zero,
+                m_heaps.typedArrayProperties);
+
+            ValueFromBlock haveStorage = m_out.anchor(storage);
+
+            LValue fastResultValue =
+                allocateObject<JSArrayBufferView>(structure, m_out.intPtrZero, slowCase);
+
+            m_out.storePtr(storage, fastResultValue, m_heaps.JSArrayBufferView_vector);
+            m_out.store32(size, fastResultValue, m_heaps.JSArrayBufferView_length);
+            m_out.store32(m_out.constInt32(FastTypedArray), fastResultValue, m_heaps.JSArrayBufferView_mode);
+            
+            mutatorFence();
+            ValueFromBlock fastResult = m_out.anchor(fastResultValue);
+            m_out.jump(continuation);
+
+            m_out.appendTo(slowCase, continuation);
+            LValue storageValue = m_out.phi(pointerType(), noStorage, haveStorage);
+
+            LValue slowResultValue = lazySlowPath(
+                [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                    return createLazyCallGenerator(
+                        operationNewTypedArrayWithSizeForType(type), locations[0].directGPR(),
+                        CCallHelpers::TrustedImmPtr(structure.get()), locations[1].directGPR(),
+                        locations[2].directGPR());
+                },
+                size, storageValue);
+            ValueFromBlock slowResult = m_out.anchor(slowResultValue);
+            m_out.jump(continuation);
+
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(pointerType(), fastResult, slowResult));
+            return;
+        }
+
+        case UntypedUse: {
+            LValue argument = lowJSValue(m_node->child1());
+
+            LValue result = vmCall(
+                pointerType(), m_out.operation(operationNewTypedArrayWithOneArgumentForType(type)),
+                m_callFrame, weakPointer(globalObject->typedArrayStructureConcurrently(type)), argument);
+
+            setJSValue(result);
+            return;
+        }
+
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            return;
+        }
+    }
+    
+    void compileAllocatePropertyStorage()
+    {
+        LValue object = lowCell(m_node->child1());
+        setStorage(allocatePropertyStorage(object, m_node->transition()->previous.get()));
+    }
+
+    void compileReallocatePropertyStorage()
+    {
+        Transition* transition = m_node->transition();
+        LValue object = lowCell(m_node->child1());
+        LValue oldStorage = lowStorage(m_node->child2());
+        
+        setStorage(
+            reallocatePropertyStorage(
+                object, oldStorage, transition->previous.get(), transition->next.get()));
+    }
+    
+    void compileNukeStructureAndSetButterfly()
+    {
+        nukeStructureAndSetButterfly(lowStorage(m_node->child2()), lowCell(m_node->child1()));
+    }
+
+    void compileToNumber()
+    {
+        LValue value = lowJSValue(m_node->child1());
+
+        if (!(abstractValue(m_node->child1()).m_type & SpecBytecodeNumber))
+            setJSValue(vmCall(Int64, m_out.operation(operationToNumber), m_callFrame, value));
+        else {
+            LBasicBlock notNumber = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            ValueFromBlock fastResult = m_out.anchor(value);
+            m_out.branch(isNumber(value, provenType(m_node->child1())), unsure(continuation), unsure(notNumber));
+
+            // notNumber case.
+            LBasicBlock lastNext = m_out.appendTo(notNumber, continuation);
+            // We have several attempts to remove ToNumber. But ToNumber still exists.
+            // It means that converting non-numbers to numbers by this ToNumber is not rare.
+            // Instead of the lazy slow path generator, we call the operation here.
+            ValueFromBlock slowResult = m_out.anchor(vmCall(Int64, m_out.operation(operationToNumber), m_callFrame, value));
+            m_out.jump(continuation);
+
+            // continuation case.
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(Int64, fastResult, slowResult));
+        }
+    }
+    
+    void compileToStringOrCallStringConstructor()
+    {
+        switch (m_node->child1().useKind()) {
+        case StringObjectUse: {
+            LValue cell = lowCell(m_node->child1());
+            speculateStringObjectForCell(m_node->child1(), cell);
+            m_interpreter.filter(m_node->child1(), SpecStringObject);
+            
+            setJSValue(m_out.loadPtr(cell, m_heaps.JSWrapperObject_internalValue));
+            return;
+        }
+            
+        case StringOrStringObjectUse: {
+            LValue cell = lowCell(m_node->child1());
+            LValue structureID = m_out.load32(cell, m_heaps.JSCell_structureID);
+            
+            LBasicBlock notString = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            ValueFromBlock simpleResult = m_out.anchor(cell);
+            m_out.branch(
+                m_out.equal(structureID, m_out.constInt32(vm().stringStructure->id())),
+                unsure(continuation), unsure(notString));
+            
+            LBasicBlock lastNext = m_out.appendTo(notString, continuation);
+            speculateStringObjectForStructureID(m_node->child1(), structureID);
+            ValueFromBlock unboxedResult = m_out.anchor(
+                m_out.loadPtr(cell, m_heaps.JSWrapperObject_internalValue));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(Int64, simpleResult, unboxedResult));
+            
+            m_interpreter.filter(m_node->child1(), SpecString | SpecStringObject);
+            return;
+        }
+            
+        case CellUse:
+        case NotCellUse:
+        case UntypedUse: {
+            LValue value;
+            if (m_node->child1().useKind() == CellUse)
+                value = lowCell(m_node->child1());
+            else if (m_node->child1().useKind() == NotCellUse)
+                value = lowNotCell(m_node->child1());
+            else
+                value = lowJSValue(m_node->child1());
+            
+            LBasicBlock isCell = m_out.newBlock();
+            LBasicBlock notString = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            LValue isCellPredicate;
+            if (m_node->child1().useKind() == CellUse)
+                isCellPredicate = m_out.booleanTrue;
+            else if (m_node->child1().useKind() == NotCellUse)
+                isCellPredicate = m_out.booleanFalse;
+            else
+                isCellPredicate = this->isCell(value, provenType(m_node->child1()));
+            m_out.branch(isCellPredicate, unsure(isCell), unsure(notString));
+            
+            LBasicBlock lastNext = m_out.appendTo(isCell, notString);
+            ValueFromBlock simpleResult = m_out.anchor(value);
+            LValue isStringPredicate;
+            if (m_node->child1()->prediction() & SpecString) {
+                isStringPredicate = isString(value, provenType(m_node->child1()));
+            } else
+                isStringPredicate = m_out.booleanFalse;
+            m_out.branch(isStringPredicate, unsure(continuation), unsure(notString));
+            
+            m_out.appendTo(notString, continuation);
+            LValue operation;
+            if (m_node->child1().useKind() == CellUse)
+                operation = m_out.operation(m_node->op() == ToString ? operationToStringOnCell : operationCallStringConstructorOnCell);
+            else
+                operation = m_out.operation(m_node->op() == ToString ? operationToString : operationCallStringConstructor);
+            ValueFromBlock convertedResult = m_out.anchor(vmCall(Int64, operation, m_callFrame, value));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setJSValue(m_out.phi(Int64, simpleResult, convertedResult));
+            return;
+        }
+
+        case Int32Use:
+            setJSValue(vmCall(Int64, m_out.operation(operationInt32ToStringWithValidRadix), m_callFrame, lowInt32(m_node->child1()), m_out.constInt32(10)));
+            return;
+
+        case Int52RepUse:
+            setJSValue(vmCall(Int64, m_out.operation(operationInt52ToStringWithValidRadix), m_callFrame, lowStrictInt52(m_node->child1()), m_out.constInt32(10)));
+            return;
+
+        case DoubleRepUse:
+            setJSValue(vmCall(Int64, m_out.operation(operationDoubleToStringWithValidRadix), m_callFrame, lowDouble(m_node->child1()), m_out.constInt32(10)));
+            return;
+            
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            break;
+        }
+    }
+    
+    void compileToPrimitive()
+    {
+        LValue value = lowJSValue(m_node->child1());
+        
+        LBasicBlock isCellCase = m_out.newBlock();
+        LBasicBlock isObjectCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        Vector<ValueFromBlock, 3> results;
+        
+        results.append(m_out.anchor(value));
+        m_out.branch(
+            isCell(value, provenType(m_node->child1())), unsure(isCellCase), unsure(continuation));
+        
+        LBasicBlock lastNext = m_out.appendTo(isCellCase, isObjectCase);
+        results.append(m_out.anchor(value));
+        m_out.branch(
+            isObject(value, provenType(m_node->child1())),
+            unsure(isObjectCase), unsure(continuation));
+        
+        m_out.appendTo(isObjectCase, continuation);
+        results.append(m_out.anchor(vmCall(
+            Int64, m_out.operation(operationToPrimitive), m_callFrame, value)));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, results));
+    }
+    
+    void compileMakeRope()
+    {
+        LValue kids[3];
+        unsigned numKids;
+        kids[0] = lowCell(m_node->child1());
+        kids[1] = lowCell(m_node->child2());
+        if (m_node->child3()) {
+            kids[2] = lowCell(m_node->child3());
+            numKids = 3;
+        } else {
+            kids[2] = 0;
+            numKids = 2;
+        }
+        
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
+        
+        MarkedAllocator* allocator = subspaceFor<JSRopeString>(vm())->allocatorFor(sizeof(JSRopeString));
+        DFG_ASSERT(m_graph, m_node, allocator);
+        
+        LValue result = allocateCell(
+            m_out.constIntPtr(allocator), vm().stringStructure.get(), slowPath);
+        
+        m_out.storePtr(m_out.intPtrZero, result, m_heaps.JSString_value);
+        for (unsigned i = 0; i < numKids; ++i)
+            m_out.storePtr(kids[i], result, m_heaps.JSRopeString_fibers[i]);
+        for (unsigned i = numKids; i < JSRopeString::s_maxInternalRopeLength; ++i)
+            m_out.storePtr(m_out.intPtrZero, result, m_heaps.JSRopeString_fibers[i]);
+        LValue flags = m_out.load32(kids[0], m_heaps.JSString_flags);
+        LValue length = m_out.load32(kids[0], m_heaps.JSString_length);
+        for (unsigned i = 1; i < numKids; ++i) {
+            flags = m_out.bitAnd(flags, m_out.load32(kids[i], m_heaps.JSString_flags));
+            CheckValue* lengthCheck = m_out.speculateAdd(
+                length, m_out.load32(kids[i], m_heaps.JSString_length));
+            blessSpeculation(lengthCheck, Uncountable, noValue(), nullptr, m_origin);
+            length = lengthCheck;
+        }
+        m_out.store32(
+            m_out.bitAnd(m_out.constInt32(JSString::Is8Bit), flags),
+            result, m_heaps.JSString_flags);
+        m_out.store32(length, result, m_heaps.JSString_length);
+        
+        mutatorFence();
+        ValueFromBlock fastResult = m_out.anchor(result);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(slowPath, continuation);
+        LValue slowResultValue;
+        switch (numKids) {
+        case 2:
+            slowResultValue = lazySlowPath(
+                [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                    return createLazyCallGenerator(
+                        operationMakeRope2, locations[0].directGPR(), locations[1].directGPR(),
+                        locations[2].directGPR());
+                }, kids[0], kids[1]);
+            break;
+        case 3:
+            slowResultValue = lazySlowPath(
+                [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                    return createLazyCallGenerator(
+                        operationMakeRope3, locations[0].directGPR(), locations[1].directGPR(),
+                        locations[2].directGPR(), locations[3].directGPR());
+                }, kids[0], kids[1], kids[2]);
+            break;
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad number of children");
+            break;
+        }
+        ValueFromBlock slowResult = m_out.anchor(slowResultValue);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, fastResult, slowResult));
+    }
+    
+    void compileStringCharAt()
+    {
+        LValue base = lowCell(m_node->child1());
+        LValue index = lowInt32(m_node->child2());
+        LValue storage = lowStorage(m_node->child3());
+            
+        LBasicBlock fastPath = m_out.newBlock();
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+            
+        m_out.branch(
+            m_out.aboveOrEqual(
+                index, m_out.load32NonNegative(base, m_heaps.JSString_length)),
+            rarely(slowPath), usually(fastPath));
+            
+        LBasicBlock lastNext = m_out.appendTo(fastPath, slowPath);
+            
+        LValue stringImpl = m_out.loadPtr(base, m_heaps.JSString_value);
+            
+        LBasicBlock is8Bit = m_out.newBlock();
+        LBasicBlock is16Bit = m_out.newBlock();
+        LBasicBlock bitsContinuation = m_out.newBlock();
+        LBasicBlock bigCharacter = m_out.newBlock();
+            
+        m_out.branch(
+            m_out.testIsZero32(
+                m_out.load32(stringImpl, m_heaps.StringImpl_hashAndFlags),
+                m_out.constInt32(StringImpl::flagIs8Bit())),
+            unsure(is16Bit), unsure(is8Bit));
+            
+        m_out.appendTo(is8Bit, is16Bit);
+            
+        ValueFromBlock char8Bit = m_out.anchor(
+            m_out.load8ZeroExt32(m_out.baseIndex(
+                m_heaps.characters8, storage, m_out.zeroExtPtr(index),
+                provenValue(m_node->child2()))));
+        m_out.jump(bitsContinuation);
+            
+        m_out.appendTo(is16Bit, bigCharacter);
+
+        LValue char16BitValue = m_out.load16ZeroExt32(
+            m_out.baseIndex(
+                m_heaps.characters16, storage, m_out.zeroExtPtr(index),
+                provenValue(m_node->child2())));
+        ValueFromBlock char16Bit = m_out.anchor(char16BitValue);
+        m_out.branch(
+            m_out.aboveOrEqual(char16BitValue, m_out.constInt32(0x100)),
+            rarely(bigCharacter), usually(bitsContinuation));
+            
+        m_out.appendTo(bigCharacter, bitsContinuation);
+            
+        Vector<ValueFromBlock, 4> results;
+        results.append(m_out.anchor(vmCall(
+            Int64, m_out.operation(operationSingleCharacterString),
+            m_callFrame, char16BitValue)));
+        m_out.jump(continuation);
+            
+        m_out.appendTo(bitsContinuation, slowPath);
+            
+        LValue character = m_out.phi(Int32, char8Bit, char16Bit);
+            
+        LValue smallStrings = m_out.constIntPtr(vm().smallStrings.singleCharacterStrings());
+            
+        results.append(m_out.anchor(m_out.loadPtr(m_out.baseIndex(
+            m_heaps.singleCharacterStrings, smallStrings, m_out.zeroExtPtr(character)))));
+        m_out.jump(continuation);
+            
+        m_out.appendTo(slowPath, continuation);
+            
+        if (m_node->arrayMode().isInBounds()) {
+            speculate(OutOfBounds, noValue(), 0, m_out.booleanTrue);
+            results.append(m_out.anchor(m_out.intPtrZero));
+        } else {
+            JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+            
+            bool prototypeChainIsSane = false;
+            if (globalObject->stringPrototypeChainIsSane()) {
+                // FIXME: This could be captured using a Speculation mode that means
+                // "out-of-bounds loads return a trivial value", something like
+                // SaneChainOutOfBounds.
+                // https://bugs.webkit.org/show_bug.cgi?id=144668
+                
+                m_graph.watchpoints().addLazily(globalObject->stringPrototype()->structure()->transitionWatchpointSet());
+                m_graph.watchpoints().addLazily(globalObject->objectPrototype()->structure()->transitionWatchpointSet());
+                
+                prototypeChainIsSane = globalObject->stringPrototypeChainIsSane();
+            }
+            if (prototypeChainIsSane) {
+                LBasicBlock negativeIndex = m_out.newBlock();
+                    
+                results.append(m_out.anchor(m_out.constInt64(JSValue::encode(jsUndefined()))));
+                m_out.branch(
+                    m_out.lessThan(index, m_out.int32Zero),
+                    rarely(negativeIndex), usually(continuation));
+                    
+                m_out.appendTo(negativeIndex, continuation);
+            }
+                
+            results.append(m_out.anchor(vmCall(
+                Int64, m_out.operation(operationGetByValStringInt), m_callFrame, base, index)));
+        }
+            
+        m_out.jump(continuation);
+            
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, results));
+    }
+    
+    void compileStringCharCodeAt()
+    {
+        LBasicBlock is8Bit = m_out.newBlock();
+        LBasicBlock is16Bit = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        LValue base = lowCell(m_node->child1());
+        LValue index = lowInt32(m_node->child2());
+        LValue storage = lowStorage(m_node->child3());
+        
+        speculate(
+            Uncountable, noValue(), 0,
+            m_out.aboveOrEqual(
+                index, m_out.load32NonNegative(base, m_heaps.JSString_length)));
+        
+        LValue stringImpl = m_out.loadPtr(base, m_heaps.JSString_value);
+        
+        m_out.branch(
+            m_out.testIsZero32(
+                m_out.load32(stringImpl, m_heaps.StringImpl_hashAndFlags),
+                m_out.constInt32(StringImpl::flagIs8Bit())),
+            unsure(is16Bit), unsure(is8Bit));
+            
+        LBasicBlock lastNext = m_out.appendTo(is8Bit, is16Bit);
+            
+        ValueFromBlock char8Bit = m_out.anchor(
+            m_out.load8ZeroExt32(m_out.baseIndex(
+                m_heaps.characters8, storage, m_out.zeroExtPtr(index),
+                provenValue(m_node->child2()))));
+        m_out.jump(continuation);
+            
+        m_out.appendTo(is16Bit, continuation);
+            
+        ValueFromBlock char16Bit = m_out.anchor(
+            m_out.load16ZeroExt32(m_out.baseIndex(
+                m_heaps.characters16, storage, m_out.zeroExtPtr(index),
+                provenValue(m_node->child2()))));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        
+        setInt32(m_out.phi(Int32, char8Bit, char16Bit));
+    }
+
+    void compileStringFromCharCode()
+    {
+        Edge childEdge = m_node->child1();
+        
+        if (childEdge.useKind() == UntypedUse) {
+            LValue result = vmCall(
+                Int64, m_out.operation(operationStringFromCharCodeUntyped), m_callFrame,
+                lowJSValue(childEdge));
+            setJSValue(result);
+            return;
+        }
+
+        DFG_ASSERT(m_graph, m_node, childEdge.useKind() == Int32Use);
+
+        LValue value = lowInt32(childEdge);
+        
+        LBasicBlock smallIntCase = m_out.newBlock();
+        LBasicBlock slowCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(
+            m_out.aboveOrEqual(value, m_out.constInt32(0xff)),
+            rarely(slowCase), usually(smallIntCase));
+
+        LBasicBlock lastNext = m_out.appendTo(smallIntCase, slowCase);
+
+        LValue smallStrings = m_out.constIntPtr(vm().smallStrings.singleCharacterStrings());
+        LValue fastResultValue = m_out.loadPtr(
+            m_out.baseIndex(m_heaps.singleCharacterStrings, smallStrings, m_out.zeroExtPtr(value)));
+        ValueFromBlock fastResult = m_out.anchor(fastResultValue);
+        m_out.jump(continuation);
+
+        m_out.appendTo(slowCase, continuation);
+
+        LValue slowResultValue = vmCall(
+            pointerType(), m_out.operation(operationStringFromCharCode), m_callFrame, value);
+        ValueFromBlock slowResult = m_out.anchor(slowResultValue);
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+
+        setJSValue(m_out.phi(Int64, fastResult, slowResult));
+    }
+    
+    void compileGetByOffset()
+    {
+        StorageAccessData& data = m_node->storageAccessData();
+        
+        setJSValue(loadProperty(
+            lowStorage(m_node->child1()), data.identifierNumber, data.offset));
+    }
+    
+    void compileGetGetter()
+    {
+        setJSValue(m_out.loadPtr(lowCell(m_node->child1()), m_heaps.GetterSetter_getter));
+    }
+    
+    void compileGetSetter()
+    {
+        setJSValue(m_out.loadPtr(lowCell(m_node->child1()), m_heaps.GetterSetter_setter));
+    }
+    
+    void compileMultiGetByOffset()
+    {
+        LValue base = lowCell(m_node->child1());
+        
+        MultiGetByOffsetData& data = m_node->multiGetByOffsetData();
+
+        if (data.cases.isEmpty()) {
+            // Protect against creating a Phi function with zero inputs. LLVM didn't like that.
+            // It's not clear if this is needed anymore.
+            // FIXME: https://bugs.webkit.org/show_bug.cgi?id=154382
+            terminate(BadCache);
+            return;
+        }
+        
+        Vector<LBasicBlock, 2> blocks(data.cases.size());
+        for (unsigned i = data.cases.size(); i--;)
+            blocks[i] = m_out.newBlock();
+        LBasicBlock exit = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        Vector<SwitchCase, 2> cases;
+        RegisteredStructureSet baseSet;
+        for (unsigned i = data.cases.size(); i--;) {
+            MultiGetByOffsetCase getCase = data.cases[i];
+            for (unsigned j = getCase.set().size(); j--;) {
+                RegisteredStructure structure = getCase.set()[j];
+                baseSet.add(structure);
+                cases.append(SwitchCase(weakStructureID(structure), blocks[i], Weight(1)));
+            }
+        }
+        m_out.switchInstruction(
+            m_out.load32(base, m_heaps.JSCell_structureID), cases, exit, Weight(0));
+        
+        LBasicBlock lastNext = m_out.m_nextBlock;
+        
+        Vector<ValueFromBlock, 2> results;
+        for (unsigned i = data.cases.size(); i--;) {
+            MultiGetByOffsetCase getCase = data.cases[i];
+            GetByOffsetMethod method = getCase.method();
+            
+            m_out.appendTo(blocks[i], i + 1 < data.cases.size() ? blocks[i + 1] : exit);
+            
+            LValue result;
+            
+            switch (method.kind()) {
+            case GetByOffsetMethod::Invalid:
+                RELEASE_ASSERT_NOT_REACHED();
+                break;
+                
+            case GetByOffsetMethod::Constant:
+                result = m_out.constInt64(JSValue::encode(method.constant()->value()));
+                break;
+                
+            case GetByOffsetMethod::Load:
+            case GetByOffsetMethod::LoadFromPrototype: {
+                LValue propertyBase;
+                if (method.kind() == GetByOffsetMethod::Load)
+                    propertyBase = base;
+                else
+                    propertyBase = weakPointer(method.prototype()->value().asCell());
+                if (!isInlineOffset(method.offset()))
+                    propertyBase = m_out.loadPtr(propertyBase, m_heaps.JSObject_butterfly);
+                result = loadProperty(
+                    propertyBase, data.identifierNumber, method.offset());
+                break;
+            } }
+            
+            results.append(m_out.anchor(result));
+            m_out.jump(continuation);
+        }
+        
+        m_out.appendTo(exit, continuation);
+        if (!m_interpreter.forNode(m_node->child1()).m_structure.isSubsetOf(baseSet))
+            speculate(BadCache, noValue(), nullptr, m_out.booleanTrue);
+        m_out.unreachable();
+        
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, results));
+    }
+    
+    void compilePutByOffset()
+    {
+        StorageAccessData& data = m_node->storageAccessData();
+        
+        storeProperty(
+            lowJSValue(m_node->child3()),
+            lowStorage(m_node->child1()), data.identifierNumber, data.offset);
+    }
+    
+    void compileMultiPutByOffset()
+    {
+        LValue base = lowCell(m_node->child1());
+        LValue value = lowJSValue(m_node->child2());
+        
+        MultiPutByOffsetData& data = m_node->multiPutByOffsetData();
+        
+        Vector<LBasicBlock, 2> blocks(data.variants.size());
+        for (unsigned i = data.variants.size(); i--;)
+            blocks[i] = m_out.newBlock();
+        LBasicBlock exit = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        Vector<SwitchCase, 2> cases;
+        RegisteredStructureSet baseSet;
+        for (unsigned i = data.variants.size(); i--;) {
+            PutByIdVariant variant = data.variants[i];
+            for (unsigned j = variant.oldStructure().size(); j--;) {
+                RegisteredStructure structure = m_graph.registerStructure(variant.oldStructure()[j]);
+                baseSet.add(structure);
+                cases.append(SwitchCase(weakStructureID(structure), blocks[i], Weight(1)));
+            }
+        }
+        m_out.switchInstruction(
+            m_out.load32(base, m_heaps.JSCell_structureID), cases, exit, Weight(0));
+        
+        LBasicBlock lastNext = m_out.m_nextBlock;
+        
+        for (unsigned i = data.variants.size(); i--;) {
+            m_out.appendTo(blocks[i], i + 1 < data.variants.size() ? blocks[i + 1] : exit);
+            
+            PutByIdVariant variant = data.variants[i];
+
+            checkInferredType(m_node->child2(), value, variant.requiredType());
+            
+            LValue storage;
+            if (variant.kind() == PutByIdVariant::Replace) {
+                if (isInlineOffset(variant.offset()))
+                    storage = base;
+                else
+                    storage = m_out.loadPtr(base, m_heaps.JSObject_butterfly);
+            } else {
+                DFG_ASSERT(m_graph, m_node, variant.kind() == PutByIdVariant::Transition);
+                m_graph.m_plan.transitions.addLazily(
+                    codeBlock(), m_node->origin.semantic.codeOriginOwner(),
+                    variant.oldStructureForTransition(), variant.newStructure());
+                
+                storage = storageForTransition(
+                    base, variant.offset(),
+                    variant.oldStructureForTransition(), variant.newStructure());
+            }
+            
+            storeProperty(value, storage, data.identifierNumber, variant.offset());
+            
+            if (variant.kind() == PutByIdVariant::Transition) {
+                ASSERT(variant.oldStructureForTransition()->indexingType() == variant.newStructure()->indexingType());
+                ASSERT(variant.oldStructureForTransition()->typeInfo().inlineTypeFlags() == variant.newStructure()->typeInfo().inlineTypeFlags());
+                ASSERT(variant.oldStructureForTransition()->typeInfo().type() == variant.newStructure()->typeInfo().type());
+                m_out.store32(
+                    weakStructureID(m_graph.registerStructure(variant.newStructure())), base, m_heaps.JSCell_structureID);
+            }
+            
+            m_out.jump(continuation);
+        }
+        
+        m_out.appendTo(exit, continuation);
+        if (!m_interpreter.forNode(m_node->child1()).m_structure.isSubsetOf(baseSet))
+            speculate(BadCache, noValue(), nullptr, m_out.booleanTrue);
+        m_out.unreachable();
+        
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    void compileGetGlobalVariable()
+    {
+        setJSValue(m_out.load64(m_out.absolute(m_node->variablePointer())));
+    }
+    
+    void compilePutGlobalVariable()
+    {
+        m_out.store64(
+            lowJSValue(m_node->child2()), m_out.absolute(m_node->variablePointer()));
+    }
+    
+    void compileNotifyWrite()
+    {
+        WatchpointSet* set = m_node->watchpointSet();
+        
+        LBasicBlock isNotInvalidated = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LValue state = m_out.load8ZeroExt32(m_out.absolute(set->addressOfState()));
+        m_out.branch(
+            m_out.equal(state, m_out.constInt32(IsInvalidated)),
+            usually(continuation), rarely(isNotInvalidated));
+        
+        LBasicBlock lastNext = m_out.appendTo(isNotInvalidated, continuation);
+
+        lazySlowPath(
+            [=] (const Vector<Location>&) -> RefPtr<LazySlowPath::Generator> {
+                return createLazyCallGenerator(
+                    operationNotifyWrite, InvalidGPRReg, CCallHelpers::TrustedImmPtr(set));
+            });
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    void compileGetCallee()
+    {
+        setJSValue(m_out.loadPtr(addressFor(CallFrameSlot::callee)));
+    }
+    
+    void compileGetArgumentCountIncludingThis()
+    {
+        setInt32(m_out.load32(payloadFor(CallFrameSlot::argumentCount)));
+    }
+    
+    void compileGetScope()
+    {
+        setJSValue(m_out.loadPtr(lowCell(m_node->child1()), m_heaps.JSFunction_scope));
+    }
+    
+    void compileSkipScope()
+    {
+        setJSValue(m_out.loadPtr(lowCell(m_node->child1()), m_heaps.JSScope_next));
+    }
+
+    void compileGetGlobalObject()
+    {
+        LValue structure = loadStructure(lowCell(m_node->child1()));
+        setJSValue(m_out.loadPtr(structure, m_heaps.Structure_globalObject));
+    }
+    
+    void compileGetClosureVar()
+    {
+        setJSValue(
+            m_out.load64(
+                lowCell(m_node->child1()),
+                m_heaps.JSEnvironmentRecord_variables[m_node->scopeOffset().offset()]));
+    }
+    
+    void compilePutClosureVar()
+    {
+        m_out.store64(
+            lowJSValue(m_node->child2()),
+            lowCell(m_node->child1()),
+            m_heaps.JSEnvironmentRecord_variables[m_node->scopeOffset().offset()]);
+    }
+    
+    void compileGetFromArguments()
+    {
+        setJSValue(
+            m_out.load64(
+                lowCell(m_node->child1()),
+                m_heaps.DirectArguments_storage[m_node->capturedArgumentsOffset().offset()]));
+    }
+    
+    void compilePutToArguments()
+    {
+        m_out.store64(
+            lowJSValue(m_node->child2()),
+            lowCell(m_node->child1()),
+            m_heaps.DirectArguments_storage[m_node->capturedArgumentsOffset().offset()]);
+    }
+
+    void compileGetArgument()
+    {
+        LValue argumentCount = m_out.load32(payloadFor(AssemblyHelpers::argumentCount(m_node->origin.semantic)));
+
+        LBasicBlock inBounds = m_out.newBlock();
+        LBasicBlock outOfBounds = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(m_out.lessThanOrEqual(argumentCount, m_out.constInt32(m_node->argumentIndex())), unsure(outOfBounds), unsure(inBounds));
+
+        LBasicBlock lastNext = m_out.appendTo(inBounds, outOfBounds);
+        VirtualRegister arg = AssemblyHelpers::argumentsStart(m_node->origin.semantic) + m_node->argumentIndex() - 1;
+        ValueFromBlock inBoundsResult = m_out.anchor(m_out.load64(addressFor(arg)));
+        m_out.jump(continuation);
+
+        m_out.appendTo(outOfBounds, continuation);
+        ValueFromBlock outOfBoundsResult = m_out.anchor(m_out.constInt64(ValueUndefined));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, inBoundsResult, outOfBoundsResult));
+    }
+    
+    void compileCompareEq()
+    {
+        if (m_node->isBinaryUseKind(Int32Use)
+            || m_node->isBinaryUseKind(Int52RepUse)
+            || m_node->isBinaryUseKind(DoubleRepUse)
+            || m_node->isBinaryUseKind(ObjectUse)
+            || m_node->isBinaryUseKind(BooleanUse)
+            || m_node->isBinaryUseKind(SymbolUse)
+            || m_node->isBinaryUseKind(StringIdentUse)
+            || m_node->isBinaryUseKind(StringUse)) {
+            compileCompareStrictEq();
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(ObjectUse, ObjectOrOtherUse)) {
+            compareEqObjectOrOtherToObject(m_node->child2(), m_node->child1());
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(ObjectOrOtherUse, ObjectUse)) {
+            compareEqObjectOrOtherToObject(m_node->child1(), m_node->child2());
+            return;
+        }
+
+        if (m_node->child1().useKind() == OtherUse) {
+            ASSERT(!m_interpreter.needsTypeCheck(m_node->child1(), SpecOther));
+            setBoolean(equalNullOrUndefined(m_node->child2(), AllCellsAreFalse, EqualNullOrUndefined, ManualOperandSpeculation));
+            return;
+        }
+
+        if (m_node->child2().useKind() == OtherUse) {
+            ASSERT(!m_interpreter.needsTypeCheck(m_node->child2(), SpecOther));
+            setBoolean(equalNullOrUndefined(m_node->child1(), AllCellsAreFalse, EqualNullOrUndefined, ManualOperandSpeculation));
+            return;
+        }
+
+        DFG_ASSERT(m_graph, m_node, m_node->isBinaryUseKind(UntypedUse));
+        nonSpeculativeCompare(
+            [&] (LValue left, LValue right) {
+                return m_out.equal(left, right);
+            },
+            operationCompareEq);
+    }
+    
+    void compileCompareStrictEq()
+    {
+        if (m_node->isBinaryUseKind(Int32Use)) {
+            setBoolean(
+                m_out.equal(lowInt32(m_node->child1()), lowInt32(m_node->child2())));
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(Int52RepUse)) {
+            Int52Kind kind;
+            LValue left = lowWhicheverInt52(m_node->child1(), kind);
+            LValue right = lowInt52(m_node->child2(), kind);
+            setBoolean(m_out.equal(left, right));
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(DoubleRepUse)) {
+            setBoolean(
+                m_out.doubleEqual(lowDouble(m_node->child1()), lowDouble(m_node->child2())));
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(StringIdentUse)) {
+            setBoolean(
+                m_out.equal(lowStringIdent(m_node->child1()), lowStringIdent(m_node->child2())));
+            return;
+        }
+
+        if (m_node->isBinaryUseKind(StringUse)) {
+            LValue left = lowCell(m_node->child1());
+            LValue right = lowCell(m_node->child2());
+
+            LBasicBlock notTriviallyEqualCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            speculateString(m_node->child1(), left);
+
+            ValueFromBlock fastResult = m_out.anchor(m_out.booleanTrue);
+            m_out.branch(
+                m_out.equal(left, right), unsure(continuation), unsure(notTriviallyEqualCase));
+
+            LBasicBlock lastNext = m_out.appendTo(notTriviallyEqualCase, continuation);
+
+            speculateString(m_node->child2(), right);
+            
+            ValueFromBlock slowResult = m_out.anchor(stringsEqual(left, right));
+            m_out.jump(continuation);
+
+            m_out.appendTo(continuation, lastNext);
+            setBoolean(m_out.phi(Int32, fastResult, slowResult));
+            return;
+        }
+
+        if (m_node->isBinaryUseKind(ObjectUse, UntypedUse)) {
+            setBoolean(
+                m_out.equal(
+                    lowNonNullObject(m_node->child1()),
+                    lowJSValue(m_node->child2())));
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(UntypedUse, ObjectUse)) {
+            setBoolean(
+                m_out.equal(
+                    lowNonNullObject(m_node->child2()),
+                    lowJSValue(m_node->child1())));
+            return;
+        }
+
+        if (m_node->isBinaryUseKind(ObjectUse)) {
+            setBoolean(
+                m_out.equal(
+                    lowNonNullObject(m_node->child1()),
+                    lowNonNullObject(m_node->child2())));
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(BooleanUse)) {
+            setBoolean(
+                m_out.equal(lowBoolean(m_node->child1()), lowBoolean(m_node->child2())));
+            return;
+        }
+
+        if (m_node->isBinaryUseKind(SymbolUse)) {
+            LValue leftSymbol = lowSymbol(m_node->child1());
+            LValue rightSymbol = lowSymbol(m_node->child2());
+            setBoolean(m_out.equal(leftSymbol, rightSymbol));
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(SymbolUse, UntypedUse)
+            || m_node->isBinaryUseKind(UntypedUse, SymbolUse)) {
+            Edge symbolEdge = m_node->child1();
+            Edge untypedEdge = m_node->child2();
+            if (symbolEdge.useKind() != SymbolUse)
+                std::swap(symbolEdge, untypedEdge);
+            
+            LValue leftSymbol = lowSymbol(symbolEdge);
+            LValue untypedValue = lowJSValue(untypedEdge);
+
+            setBoolean(m_out.equal(leftSymbol, untypedValue));
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(MiscUse, UntypedUse)
+            || m_node->isBinaryUseKind(UntypedUse, MiscUse)) {
+            speculate(m_node->child1());
+            speculate(m_node->child2());
+            LValue left = lowJSValue(m_node->child1(), ManualOperandSpeculation);
+            LValue right = lowJSValue(m_node->child2(), ManualOperandSpeculation);
+            setBoolean(m_out.equal(left, right));
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(StringIdentUse, NotStringVarUse)
+            || m_node->isBinaryUseKind(NotStringVarUse, StringIdentUse)) {
+            Edge leftEdge = m_node->childFor(StringIdentUse);
+            Edge rightEdge = m_node->childFor(NotStringVarUse);
+            
+            LValue left = lowStringIdent(leftEdge);
+            LValue rightValue = lowJSValue(rightEdge, ManualOperandSpeculation);
+            
+            LBasicBlock isCellCase = m_out.newBlock();
+            LBasicBlock isStringCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            ValueFromBlock notCellResult = m_out.anchor(m_out.booleanFalse);
+            m_out.branch(
+                isCell(rightValue, provenType(rightEdge)),
+                unsure(isCellCase), unsure(continuation));
+            
+            LBasicBlock lastNext = m_out.appendTo(isCellCase, isStringCase);
+            ValueFromBlock notStringResult = m_out.anchor(m_out.booleanFalse);
+            m_out.branch(
+                isString(rightValue, provenType(rightEdge)),
+                unsure(isStringCase), unsure(continuation));
+            
+            m_out.appendTo(isStringCase, continuation);
+            LValue right = m_out.loadPtr(rightValue, m_heaps.JSString_value);
+            speculateStringIdent(rightEdge, rightValue, right);
+            ValueFromBlock isStringResult = m_out.anchor(m_out.equal(left, right));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setBoolean(m_out.phi(Int32, notCellResult, notStringResult, isStringResult));
+            return;
+        }
+
+        if (m_node->isBinaryUseKind(StringUse, UntypedUse)) {
+            compileStringToUntypedStrictEquality(m_node->child1(), m_node->child2());
+            return;
+        }
+        if (m_node->isBinaryUseKind(UntypedUse, StringUse)) {
+            compileStringToUntypedStrictEquality(m_node->child2(), m_node->child1());
+            return;
+        }
+
+        DFG_ASSERT(m_graph, m_node, m_node->isBinaryUseKind(UntypedUse));
+        nonSpeculativeCompare(
+            [&] (LValue left, LValue right) {
+                return m_out.equal(left, right);
+            },
+            operationCompareStrictEq);
+    }
+
+    void compileStringToUntypedStrictEquality(Edge stringEdge, Edge untypedEdge)
+    {
+        ASSERT(stringEdge.useKind() == StringUse);
+        ASSERT(untypedEdge.useKind() == UntypedUse);
+
+        LValue leftString = lowCell(stringEdge);
+        LValue rightValue = lowJSValue(untypedEdge);
+        SpeculatedType rightValueType = provenType(untypedEdge);
+
+        // Verify left is string.
+        speculateString(stringEdge, leftString);
+
+        LBasicBlock testUntypedEdgeIsCell = m_out.newBlock();
+        LBasicBlock testUntypedEdgeIsString = m_out.newBlock();
+        LBasicBlock testStringEquality = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        // Given left is string. If the value are strictly equal, rightValue has to be the same string.
+        ValueFromBlock fastTrue = m_out.anchor(m_out.booleanTrue);
+        m_out.branch(m_out.equal(leftString, rightValue), unsure(continuation), unsure(testUntypedEdgeIsCell));
+
+        LBasicBlock lastNext = m_out.appendTo(testUntypedEdgeIsCell, testUntypedEdgeIsString);
+        ValueFromBlock fastFalse = m_out.anchor(m_out.booleanFalse);
+        m_out.branch(isNotCell(rightValue, rightValueType), unsure(continuation), unsure(testUntypedEdgeIsString));
+
+        // Check if the untyped edge is a string.
+        m_out.appendTo(testUntypedEdgeIsString, testStringEquality);
+        m_out.branch(isNotString(rightValue, rightValueType), unsure(continuation), unsure(testStringEquality));
+
+        // Full String compare.
+        m_out.appendTo(testStringEquality, continuation);
+        ValueFromBlock slowResult = m_out.anchor(stringsEqual(leftString, rightValue));
+        m_out.jump(continuation);
+
+        // Continuation.
+        m_out.appendTo(continuation, lastNext);
+        setBoolean(m_out.phi(Int32, fastTrue, fastFalse, slowResult));
+    }
+
+    void compileCompareEqPtr()
+    {
+        setBoolean(
+            m_out.equal(
+                lowJSValue(m_node->child1()),
+                weakPointer(m_node->cellOperand()->cell())));
+    }
+    
+    void compileCompareLess()
+    {
+        compare(
+            [&] (LValue left, LValue right) {
+                return m_out.lessThan(left, right);
+            },
+            [&] (LValue left, LValue right) {
+                return m_out.doubleLessThan(left, right);
+            },
+            operationCompareStringImplLess,
+            operationCompareStringLess,
+            operationCompareLess);
+    }
+    
+    void compileCompareLessEq()
+    {
+        compare(
+            [&] (LValue left, LValue right) {
+                return m_out.lessThanOrEqual(left, right);
+            },
+            [&] (LValue left, LValue right) {
+                return m_out.doubleLessThanOrEqual(left, right);
+            },
+            operationCompareStringImplLessEq,
+            operationCompareStringLessEq,
+            operationCompareLessEq);
+    }
+    
+    void compileCompareGreater()
+    {
+        compare(
+            [&] (LValue left, LValue right) {
+                return m_out.greaterThan(left, right);
+            },
+            [&] (LValue left, LValue right) {
+                return m_out.doubleGreaterThan(left, right);
+            },
+            operationCompareStringImplGreater,
+            operationCompareStringGreater,
+            operationCompareGreater);
+    }
+    
+    void compileCompareGreaterEq()
+    {
+        compare(
+            [&] (LValue left, LValue right) {
+                return m_out.greaterThanOrEqual(left, right);
+            },
+            [&] (LValue left, LValue right) {
+                return m_out.doubleGreaterThanOrEqual(left, right);
+            },
+            operationCompareStringImplGreaterEq,
+            operationCompareStringGreaterEq,
+            operationCompareGreaterEq);
+    }
+    
+    void compileLogicalNot()
+    {
+        setBoolean(m_out.logicalNot(boolify(m_node->child1())));
+    }
+
+    void compileCallOrConstruct()
+    {
+        Node* node = m_node;
+        unsigned numArgs = node->numChildren() - 1;
+
+        LValue jsCallee = lowJSValue(m_graph.varArgChild(node, 0));
+
+        unsigned frameSize = (CallFrame::headerSizeInRegisters + numArgs) * sizeof(EncodedJSValue);
+        unsigned alignedFrameSize = WTF::roundUpToMultipleOf(stackAlignmentBytes(), frameSize);
+
+        // JS->JS calling convention requires that the caller allows this much space on top of stack to
+        // get trashed by the callee, even if not all of that space is used to pass arguments. We tell
+        // B3 this explicitly for two reasons:
+        //
+        // - We will only pass frameSize worth of stuff.
+        // - The trashed stack guarantee is logically separate from the act of passing arguments, so we
+        //   shouldn't rely on Air to infer the trashed stack property based on the arguments it ends
+        //   up seeing.
+        m_proc.requestCallArgAreaSizeInBytes(alignedFrameSize);
+
+        // Collect the arguments, since this can generate code and we want to generate it before we emit
+        // the call.
+        Vector<ConstrainedValue> arguments;
+
+        // Make sure that the callee goes into GPR0 because that's where the slow path thunks expect the
+        // callee to be.
+        arguments.append(ConstrainedValue(jsCallee, ValueRep::reg(GPRInfo::regT0)));
+
+        auto addArgument = [&] (LValue value, VirtualRegister reg, int offset) {
+            intptr_t offsetFromSP =
+                (reg.offset() - CallerFrameAndPC::sizeInRegisters) * sizeof(EncodedJSValue) + offset;
+            arguments.append(ConstrainedValue(value, ValueRep::stackArgument(offsetFromSP)));
+        };
+
+        addArgument(jsCallee, VirtualRegister(CallFrameSlot::callee), 0);
+        addArgument(m_out.constInt32(numArgs), VirtualRegister(CallFrameSlot::argumentCount), PayloadOffset);
+        for (unsigned i = 0; i < numArgs; ++i)
+            addArgument(lowJSValue(m_graph.varArgChild(node, 1 + i)), virtualRegisterForArgument(i), 0);
+
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+        patchpoint->appendVector(arguments);
+
+        RefPtr<PatchpointExceptionHandle> exceptionHandle =
+            preparePatchpointForExceptions(patchpoint);
+        
+        patchpoint->append(m_tagMask, ValueRep::reg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::reg(GPRInfo::tagTypeNumberRegister));
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        patchpoint->clobberLate(RegisterSet::volatileRegistersForJSCall());
+        patchpoint->resultConstraint = ValueRep::reg(GPRInfo::returnValueGPR);
+
+        CodeOrigin codeOrigin = codeOriginDescriptionOfCallSite();
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+                CallSiteIndex callSiteIndex = state->jitCode->common.addUniqueCallSiteIndex(codeOrigin);
+
+                exceptionHandle->scheduleExitCreationForUnwind(params, callSiteIndex);
+
+                jit.store32(
+                    CCallHelpers::TrustedImm32(callSiteIndex.bits()),
+                    CCallHelpers::tagFor(VirtualRegister(CallFrameSlot::argumentCount)));
+
+                CallLinkInfo* callLinkInfo = jit.codeBlock()->addCallLinkInfo();
+
+                CCallHelpers::DataLabelPtr targetToCheck;
+                CCallHelpers::Jump slowPath = jit.branchPtrWithPatch(
+                    CCallHelpers::NotEqual, GPRInfo::regT0, targetToCheck,
+                    CCallHelpers::TrustedImmPtr(0));
+
+                CCallHelpers::Call fastCall = jit.nearCall();
+                CCallHelpers::Jump done = jit.jump();
+
+                slowPath.link(&jit);
+
+                jit.move(CCallHelpers::TrustedImmPtr(callLinkInfo), GPRInfo::regT2);
+                CCallHelpers::Call slowCall = jit.nearCall();
+                done.link(&jit);
+
+                callLinkInfo->setUpCall(
+                    node->op() == Construct ? CallLinkInfo::Construct : CallLinkInfo::Call,
+                    node->origin.semantic, GPRInfo::regT0);
+
+                jit.addPtr(
+                    CCallHelpers::TrustedImm32(-params.proc().frameSize()),
+                    GPRInfo::callFrameRegister, CCallHelpers::stackPointerRegister);
+
+                jit.addLinkTask(
+                    [=] (LinkBuffer& linkBuffer) {
+                        MacroAssemblerCodePtr linkCall =
+                            linkBuffer.vm().getCTIStub(linkCallThunkGenerator).code();
+                        linkBuffer.link(slowCall, FunctionPtr(linkCall.executableAddress()));
+
+                        callLinkInfo->setCallLocations(
+                            CodeLocationLabel(linkBuffer.locationOfNearCall(slowCall)),
+                            CodeLocationLabel(linkBuffer.locationOf(targetToCheck)),
+                            linkBuffer.locationOfNearCall(fastCall));
+                    });
+            });
+
+        setJSValue(patchpoint);
+    }
+    
+    void compileDirectCallOrConstruct()
+    {
+        Node* node = m_node;
+        bool isTail = node->op() == DirectTailCall;
+        bool isConstruct = node->op() == DirectConstruct;
+        
+        ExecutableBase* executable = node->castOperand<ExecutableBase*>();
+        FunctionExecutable* functionExecutable = jsDynamicCast<FunctionExecutable*>(vm(), executable);
+        
+        unsigned numPassedArgs = node->numChildren() - 1;
+        unsigned numAllocatedArgs = numPassedArgs;
+        
+        if (functionExecutable) {
+            numAllocatedArgs = std::max(
+                numAllocatedArgs,
+                std::min(
+                    static_cast<unsigned>(functionExecutable->parameterCount()) + 1,
+                    Options::maximumDirectCallStackSize()));
+        }
+        
+        LValue jsCallee = lowJSValue(m_graph.varArgChild(node, 0));
+        
+        if (!isTail) {
+            unsigned frameSize = (CallFrame::headerSizeInRegisters + numAllocatedArgs) * sizeof(EncodedJSValue);
+            unsigned alignedFrameSize = WTF::roundUpToMultipleOf(stackAlignmentBytes(), frameSize);
+            
+            m_proc.requestCallArgAreaSizeInBytes(alignedFrameSize);
+        }
+        
+        Vector<ConstrainedValue> arguments;
+        
+        arguments.append(ConstrainedValue(jsCallee, ValueRep::SomeRegister));
+        if (!isTail) {
+            auto addArgument = [&] (LValue value, VirtualRegister reg, int offset) {
+                intptr_t offsetFromSP =
+                    (reg.offset() - CallerFrameAndPC::sizeInRegisters) * sizeof(EncodedJSValue) + offset;
+                arguments.append(ConstrainedValue(value, ValueRep::stackArgument(offsetFromSP)));
+            };
+            
+            addArgument(jsCallee, VirtualRegister(CallFrameSlot::callee), 0);
+            addArgument(m_out.constInt32(numPassedArgs), VirtualRegister(CallFrameSlot::argumentCount), PayloadOffset);
+            for (unsigned i = 0; i < numPassedArgs; ++i)
+                addArgument(lowJSValue(m_graph.varArgChild(node, 1 + i)), virtualRegisterForArgument(i), 0);
+            for (unsigned i = numPassedArgs; i < numAllocatedArgs; ++i)
+                addArgument(m_out.constInt64(JSValue::encode(jsUndefined())), virtualRegisterForArgument(i), 0);
+        } else {
+            for (unsigned i = 0; i < numPassedArgs; ++i)
+                arguments.append(ConstrainedValue(lowJSValue(m_graph.varArgChild(node, 1 + i)), ValueRep::WarmAny));
+        }
+        
+        PatchpointValue* patchpoint = m_out.patchpoint(isTail ? Void : Int64);
+        patchpoint->appendVector(arguments);
+        
+        RefPtr<PatchpointExceptionHandle> exceptionHandle = preparePatchpointForExceptions(patchpoint);
+        
+        if (isTail) {
+            // The shuffler needs tags.
+            patchpoint->append(m_tagMask, ValueRep::reg(GPRInfo::tagMaskRegister));
+            patchpoint->append(m_tagTypeNumber, ValueRep::reg(GPRInfo::tagTypeNumberRegister));
+        }
+        
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        if (!isTail) {
+            patchpoint->clobberLate(RegisterSet::volatileRegistersForJSCall());
+            patchpoint->resultConstraint = ValueRep::reg(GPRInfo::returnValueGPR);
+        }
+        
+        CodeOrigin codeOrigin = codeOriginDescriptionOfCallSite();
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+                CallSiteIndex callSiteIndex = state->jitCode->common.addUniqueCallSiteIndex(codeOrigin);
+                
+                GPRReg calleeGPR = params[!isTail].gpr();
+
+                exceptionHandle->scheduleExitCreationForUnwind(params, callSiteIndex);
+                
+                Box<CCallHelpers::JumpList> exceptions =
+                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+                
+                if (isTail) {
+                    CallFrameShuffleData shuffleData;
+                    shuffleData.numLocals = state->jitCode->common.frameRegisterCount;
+                    
+                    RegisterSet toSave = params.unavailableRegisters();
+                    shuffleData.callee = ValueRecovery::inGPR(calleeGPR, DataFormatCell);
+                    toSave.set(calleeGPR);
+                    for (unsigned i = 0; i < numPassedArgs; ++i) {
+                        ValueRecovery recovery = params[1 + i].recoveryForJSValue();
+                        shuffleData.args.append(recovery);
+                        recovery.forEachReg(
+                            [&] (Reg reg) {
+                                toSave.set(reg);
+                            });
+                    }
+                    for (unsigned i = numPassedArgs; i < numAllocatedArgs; ++i)
+                        shuffleData.args.append(ValueRecovery::constant(jsUndefined()));
+                    shuffleData.numPassedArgs = numPassedArgs;
+                    shuffleData.setupCalleeSaveRegisters(jit.codeBlock());
+                    
+                    CallLinkInfo* callLinkInfo = jit.codeBlock()->addCallLinkInfo();
+                    
+                    CCallHelpers::PatchableJump patchableJump = jit.patchableJump();
+                    CCallHelpers::Label mainPath = jit.label();
+                    
+                    jit.store32(
+                        CCallHelpers::TrustedImm32(callSiteIndex.bits()),
+                        CCallHelpers::tagFor(VirtualRegister(CallFrameSlot::argumentCount)));
+                
+                    callLinkInfo->setFrameShuffleData(shuffleData);
+                    CallFrameShuffler(jit, shuffleData).prepareForTailCall();
+                    
+                    CCallHelpers::Call call = jit.nearTailCall();
+                    
+                    jit.abortWithReason(JITDidReturnFromTailCall);
+                    
+                    CCallHelpers::Label slowPath = jit.label();
+                    patchableJump.m_jump.linkTo(slowPath, &jit);
+                    callOperation(
+                        *state, toSave, jit,
+                        node->origin.semantic, exceptions.get(), operationLinkDirectCall,
+                        InvalidGPRReg, CCallHelpers::TrustedImmPtr(callLinkInfo), calleeGPR).call();
+                    jit.jump().linkTo(mainPath, &jit);
+                    
+                    callLinkInfo->setUpCall(
+                        CallLinkInfo::DirectTailCall, node->origin.semantic, InvalidGPRReg);
+                    callLinkInfo->setExecutableDuringCompilation(executable);
+                    if (numAllocatedArgs > numPassedArgs)
+                        callLinkInfo->setMaxNumArguments(numAllocatedArgs);
+                    
+                    jit.addLinkTask(
+                        [=] (LinkBuffer& linkBuffer) {
+                            CodeLocationLabel patchableJumpLocation = linkBuffer.locationOf(patchableJump);
+                            CodeLocationNearCall callLocation = linkBuffer.locationOfNearCall(call);
+                            CodeLocationLabel slowPathLocation = linkBuffer.locationOf(slowPath);
+                            
+                            callLinkInfo->setCallLocations(
+                                patchableJumpLocation,
+                                slowPathLocation,
+                                callLocation);
+                        });
+                    return;
+                }
+                
+                CallLinkInfo* callLinkInfo = jit.codeBlock()->addCallLinkInfo();
+                
+                CCallHelpers::Label mainPath = jit.label();
+
+                jit.store32(
+                    CCallHelpers::TrustedImm32(callSiteIndex.bits()),
+                    CCallHelpers::tagFor(VirtualRegister(CallFrameSlot::argumentCount)));
+                
+                CCallHelpers::Call call = jit.nearCall();
+                jit.addPtr(
+                    CCallHelpers::TrustedImm32(-params.proc().frameSize()),
+                    GPRInfo::callFrameRegister, CCallHelpers::stackPointerRegister);
+                
+                callLinkInfo->setUpCall(
+                    isConstruct ? CallLinkInfo::DirectConstruct : CallLinkInfo::DirectCall,
+                    node->origin.semantic, InvalidGPRReg);
+                callLinkInfo->setExecutableDuringCompilation(executable);
+                if (numAllocatedArgs > numPassedArgs)
+                    callLinkInfo->setMaxNumArguments(numAllocatedArgs);
+                
+                params.addLatePath(
+                    [=] (CCallHelpers& jit) {
+                        AllowMacroScratchRegisterUsage allowScratch(jit);
+                        
+                        CCallHelpers::Label slowPath = jit.label();
+                        if (isX86())
+                            jit.pop(CCallHelpers::selectScratchGPR(calleeGPR));
+                        
+                        callOperation(
+                            *state, params.unavailableRegisters(), jit,
+                            node->origin.semantic, exceptions.get(), operationLinkDirectCall,
+                            InvalidGPRReg, CCallHelpers::TrustedImmPtr(callLinkInfo),
+                            calleeGPR).call();
+                        jit.jump().linkTo(mainPath, &jit);
+                        
+                        jit.addLinkTask(
+                            [=] (LinkBuffer& linkBuffer) {
+                                CodeLocationNearCall callLocation = linkBuffer.locationOfNearCall(call);
+                                CodeLocationLabel slowPathLocation = linkBuffer.locationOf(slowPath);
+                                
+                                linkBuffer.link(call, slowPathLocation);
+                                
+                                callLinkInfo->setCallLocations(
+                                    CodeLocationLabel(),
+                                    slowPathLocation,
+                                    callLocation);
+                            });
+                    });
+            });
+        
+        if (isTail)
+            patchpoint->effects.terminal = true;
+        else
+            setJSValue(patchpoint);
+    }
+
+    void compileTailCall()
+    {
+        Node* node = m_node;
+        unsigned numArgs = node->numChildren() - 1;
+
+        LValue jsCallee = lowJSValue(m_graph.varArgChild(node, 0));
+        
+        // We want B3 to give us all of the arguments using whatever mechanism it thinks is
+        // convenient. The generator then shuffles those arguments into our own call frame,
+        // destroying our frame in the process.
+
+        // Note that we don't have to do anything special for exceptions. A tail call is only a
+        // tail call if it is not inside a try block.
+
+        Vector<ConstrainedValue> arguments;
+
+        arguments.append(ConstrainedValue(jsCallee, ValueRep::reg(GPRInfo::regT0)));
+
+        for (unsigned i = 0; i < numArgs; ++i) {
+            // Note: we could let the shuffler do boxing for us, but it's not super clear that this
+            // would be better. Also, if we wanted to do that, then we'd have to teach the shuffler
+            // that 32-bit values could land at 4-byte alignment but not 8-byte alignment.
+            
+            ConstrainedValue constrainedValue(
+                lowJSValue(m_graph.varArgChild(node, 1 + i)),
+                ValueRep::WarmAny);
+            arguments.append(constrainedValue);
+        }
+
+        PatchpointValue* patchpoint = m_out.patchpoint(Void);
+        patchpoint->appendVector(arguments);
+
+        patchpoint->append(m_tagMask, ValueRep::reg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::reg(GPRInfo::tagTypeNumberRegister));
+
+        // Prevent any of the arguments from using the scratch register.
+        patchpoint->clobberEarly(RegisterSet::macroScratchRegisters());
+        
+        patchpoint->effects.terminal = true;
+
+        // We don't have to tell the patchpoint that we will clobber registers, since we won't return
+        // anyway.
+
+        CodeOrigin codeOrigin = codeOriginDescriptionOfCallSite();
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+                CallSiteIndex callSiteIndex = state->jitCode->common.addUniqueCallSiteIndex(codeOrigin);
+
+                // Yes, this is really necessary. You could throw an exception in a host call on the
+                // slow path. That'll route us to lookupExceptionHandler(), which unwinds starting
+                // with the call site index of our frame. Bad things happen if it's not set.
+                jit.store32(
+                    CCallHelpers::TrustedImm32(callSiteIndex.bits()),
+                    CCallHelpers::tagFor(VirtualRegister(CallFrameSlot::argumentCount)));
+
+                CallFrameShuffleData shuffleData;
+                shuffleData.numLocals = state->jitCode->common.frameRegisterCount;
+                shuffleData.callee = ValueRecovery::inGPR(GPRInfo::regT0, DataFormatJS);
+
+                for (unsigned i = 0; i < numArgs; ++i)
+                    shuffleData.args.append(params[1 + i].recoveryForJSValue());
+
+                shuffleData.numPassedArgs = numArgs;
+                
+                shuffleData.setupCalleeSaveRegisters(jit.codeBlock());
+
+                CallLinkInfo* callLinkInfo = jit.codeBlock()->addCallLinkInfo();
+
+                CCallHelpers::DataLabelPtr targetToCheck;
+                CCallHelpers::Jump slowPath = jit.branchPtrWithPatch(
+                    CCallHelpers::NotEqual, GPRInfo::regT0, targetToCheck,
+                    CCallHelpers::TrustedImmPtr(0));
+
+                callLinkInfo->setFrameShuffleData(shuffleData);
+                CallFrameShuffler(jit, shuffleData).prepareForTailCall();
+
+                CCallHelpers::Call fastCall = jit.nearTailCall();
+
+                slowPath.link(&jit);
+
+                CallFrameShuffler slowPathShuffler(jit, shuffleData);
+                slowPathShuffler.setCalleeJSValueRegs(JSValueRegs(GPRInfo::regT0));
+                slowPathShuffler.prepareForSlowPath();
+
+                jit.move(CCallHelpers::TrustedImmPtr(callLinkInfo), GPRInfo::regT2);
+                CCallHelpers::Call slowCall = jit.nearCall();
+
+                jit.abortWithReason(JITDidReturnFromTailCall);
+
+                callLinkInfo->setUpCall(CallLinkInfo::TailCall, codeOrigin, GPRInfo::regT0);
+
+                jit.addLinkTask(
+                    [=] (LinkBuffer& linkBuffer) {
+                        MacroAssemblerCodePtr linkCall =
+                            linkBuffer.vm().getCTIStub(linkCallThunkGenerator).code();
+                        linkBuffer.link(slowCall, FunctionPtr(linkCall.executableAddress()));
+
+                        callLinkInfo->setCallLocations(
+                            CodeLocationLabel(linkBuffer.locationOfNearCall(slowCall)),
+                            CodeLocationLabel(linkBuffer.locationOf(targetToCheck)),
+                            linkBuffer.locationOfNearCall(fastCall));
+                    });
+            });
+    }
+    
+    void compileCallOrConstructVarargsSpread()
+    {
+        Node* node = m_node;
+        LValue jsCallee = lowJSValue(m_node->child1());
+        LValue thisArg = lowJSValue(m_node->child2());
+
+        RELEASE_ASSERT(node->child3()->op() == PhantomNewArrayWithSpread);
+        Node* arrayWithSpread = node->child3().node();
+        BitVector* bitVector = arrayWithSpread->bitVector();
+        unsigned numNonSpreadParameters = 0;
+        Vector<LValue, 2> spreadLengths;
+        Vector<LValue, 8> patchpointArguments;
+        HashMap<InlineCallFrame*, LValue, WTF::DefaultHash<InlineCallFrame*>::Hash, WTF::NullableHashTraits<InlineCallFrame*>> cachedSpreadLengths;
+
+        for (unsigned i = 0; i < arrayWithSpread->numChildren(); i++) {
+            if (bitVector->get(i)) {
+                Node* spread = m_graph.varArgChild(arrayWithSpread, i).node();
+                RELEASE_ASSERT(spread->op() == PhantomSpread);
+                RELEASE_ASSERT(spread->child1()->op() == PhantomCreateRest);
+                InlineCallFrame* inlineCallFrame = spread->child1()->origin.semantic.inlineCallFrame;
+                unsigned numberOfArgumentsToSkip = spread->child1()->numberOfArgumentsToSkip();
+                LValue length = cachedSpreadLengths.ensure(inlineCallFrame, [&] () {
+                    return m_out.zeroExtPtr(getSpreadLengthFromInlineCallFrame(inlineCallFrame, numberOfArgumentsToSkip));
+                }).iterator->value;
+                patchpointArguments.append(length);
+                spreadLengths.append(length);
+            } else {
+                ++numNonSpreadParameters;
+                LValue argument = lowJSValue(m_graph.varArgChild(arrayWithSpread, i));
+                patchpointArguments.append(argument);
+            }
+        }
+
+        LValue argumentCountIncludingThis = m_out.constIntPtr(numNonSpreadParameters + 1);
+        for (LValue length : spreadLengths)
+            argumentCountIncludingThis = m_out.add(length, argumentCountIncludingThis);
+        
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+
+        patchpoint->append(jsCallee, ValueRep::reg(GPRInfo::regT0));
+        patchpoint->append(thisArg, ValueRep::WarmAny);
+        patchpoint->append(argumentCountIncludingThis, ValueRep::WarmAny);
+        patchpoint->appendVectorWithRep(patchpointArguments, ValueRep::WarmAny);
+        patchpoint->append(m_tagMask, ValueRep::reg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::reg(GPRInfo::tagTypeNumberRegister));
+
+        RefPtr<PatchpointExceptionHandle> exceptionHandle = preparePatchpointForExceptions(patchpoint);
+
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        patchpoint->clobber(RegisterSet::volatileRegistersForJSCall()); // No inputs will be in a volatile register.
+        patchpoint->resultConstraint = ValueRep::reg(GPRInfo::returnValueGPR);
+
+        patchpoint->numGPScratchRegisters = 0;
+
+        // This is the minimum amount of call arg area stack space that all JS->JS calls always have.
+        unsigned minimumJSCallAreaSize =
+            sizeof(CallerFrameAndPC) +
+            WTF::roundUpToMultipleOf(stackAlignmentBytes(), 5 * sizeof(EncodedJSValue));
+
+        m_proc.requestCallArgAreaSizeInBytes(minimumJSCallAreaSize);
+        
+        CodeOrigin codeOrigin = codeOriginDescriptionOfCallSite();
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+                CallSiteIndex callSiteIndex =
+                    state->jitCode->common.addUniqueCallSiteIndex(codeOrigin);
+
+                Box<CCallHelpers::JumpList> exceptions =
+                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+
+                exceptionHandle->scheduleExitCreationForUnwind(params, callSiteIndex);
+
+                jit.store32(
+                    CCallHelpers::TrustedImm32(callSiteIndex.bits()),
+                    CCallHelpers::tagFor(VirtualRegister(CallFrameSlot::argumentCount)));
+
+                CallLinkInfo* callLinkInfo = jit.codeBlock()->addCallLinkInfo();
+
+                RegisterSet usedRegisters = RegisterSet::allRegisters();
+                usedRegisters.exclude(RegisterSet::volatileRegistersForJSCall());
+                GPRReg calleeGPR = params[1].gpr();
+                usedRegisters.set(calleeGPR);
+
+                ScratchRegisterAllocator allocator(usedRegisters);
+                GPRReg scratchGPR1 = allocator.allocateScratchGPR();
+                GPRReg scratchGPR2 = allocator.allocateScratchGPR();
+                GPRReg scratchGPR3 = allocator.allocateScratchGPR();
+                GPRReg scratchGPR4 = allocator.allocateScratchGPR();
+                RELEASE_ASSERT(!allocator.numberOfReusedRegisters());
+
+                auto getValueFromRep = [&] (B3::ValueRep rep, GPRReg result) {
+                    ASSERT(!usedRegisters.get(result));
+
+                    if (rep.isConstant()) {
+                        jit.move(CCallHelpers::Imm64(rep.value()), result);
+                        return;
+                    }
+
+                    // Note: in this function, we only request 64 bit values.
+                    if (rep.isStack()) {
+                        jit.load64(
+                            CCallHelpers::Address(GPRInfo::callFrameRegister, rep.offsetFromFP()),
+                            result);
+                        return;
+                    }
+
+                    RELEASE_ASSERT(rep.isGPR());
+                    ASSERT(usedRegisters.get(rep.gpr()));
+                    jit.move(rep.gpr(), result);
+                };
+
+                auto callWithExceptionCheck = [&] (void* callee) {
+                    jit.move(CCallHelpers::TrustedImmPtr(callee), GPRInfo::nonPreservedNonArgumentGPR);
+                    jit.call(GPRInfo::nonPreservedNonArgumentGPR);
+                    exceptions->append(jit.emitExceptionCheck(AssemblyHelpers::NormalExceptionCheck, AssemblyHelpers::FarJumpWidth));
+                };
+
+                CCallHelpers::JumpList slowCase;
+                unsigned originalStackHeight = params.proc().frameSize();
+
+                {
+                    unsigned numUsedSlots = WTF::roundUpToMultipleOf(stackAlignmentRegisters(), originalStackHeight / sizeof(EncodedJSValue));
+                    B3::ValueRep argumentCountIncludingThisRep = params[3];
+                    getValueFromRep(argumentCountIncludingThisRep, scratchGPR2);
+                    slowCase.append(jit.branch32(CCallHelpers::Above, scratchGPR2, CCallHelpers::TrustedImm32(JSC::maxArguments + 1)));
+                    
+                    jit.move(scratchGPR2, scratchGPR1);
+                    jit.addPtr(CCallHelpers::TrustedImmPtr(static_cast<size_t>(numUsedSlots + CallFrame::headerSizeInRegisters)), scratchGPR1);
+                    // scratchGPR1 now has the required frame size in Register units
+                    // Round scratchGPR1 to next multiple of stackAlignmentRegisters()
+                    jit.addPtr(CCallHelpers::TrustedImm32(stackAlignmentRegisters() - 1), scratchGPR1);
+                    jit.andPtr(CCallHelpers::TrustedImm32(~(stackAlignmentRegisters() - 1)), scratchGPR1);
+                    jit.negPtr(scratchGPR1);
+                    jit.lshiftPtr(CCallHelpers::Imm32(3), scratchGPR1);
+                    jit.addPtr(GPRInfo::callFrameRegister, scratchGPR1);
+
+                    // Before touching stack values, we should update the stack pointer to protect them from signal stack.
+                    jit.addPtr(CCallHelpers::TrustedImm32(sizeof(CallerFrameAndPC)), scratchGPR1, CCallHelpers::stackPointerRegister);
+
+                    jit.store32(scratchGPR2, CCallHelpers::Address(scratchGPR1, CallFrameSlot::argumentCount * static_cast<int>(sizeof(Register)) + PayloadOffset));
+
+                    int storeOffset = CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register));
+
+                    for (unsigned i = arrayWithSpread->numChildren(); i--; ) {
+                        unsigned paramsOffset = 4;
+
+                        if (bitVector->get(i)) {
+                            Node* spread = state->graph.varArgChild(arrayWithSpread, i).node();
+                            RELEASE_ASSERT(spread->op() == PhantomSpread);
+                            RELEASE_ASSERT(spread->child1()->op() == PhantomCreateRest);
+                            InlineCallFrame* inlineCallFrame = spread->child1()->origin.semantic.inlineCallFrame;
+
+                            unsigned numberOfArgumentsToSkip = spread->child1()->numberOfArgumentsToSkip();
+
+                            B3::ValueRep numArgumentsToCopy = params[paramsOffset + i];
+                            getValueFromRep(numArgumentsToCopy, scratchGPR3);
+                            int loadOffset = (AssemblyHelpers::argumentsStart(inlineCallFrame).offset() + numberOfArgumentsToSkip) * static_cast<int>(sizeof(Register));
+
+                            auto done = jit.branchTestPtr(MacroAssembler::Zero, scratchGPR3);
+                            auto loopStart = jit.label();
+                            jit.subPtr(CCallHelpers::TrustedImmPtr(static_cast<size_t>(1)), scratchGPR3);
+                            jit.subPtr(CCallHelpers::TrustedImmPtr(static_cast<size_t>(1)), scratchGPR2);
+                            jit.load64(CCallHelpers::BaseIndex(GPRInfo::callFrameRegister, scratchGPR3, CCallHelpers::TimesEight, loadOffset), scratchGPR4);
+                            jit.store64(scratchGPR4,
+                                CCallHelpers::BaseIndex(scratchGPR1, scratchGPR2, CCallHelpers::TimesEight, storeOffset));
+                            jit.branchTestPtr(CCallHelpers::NonZero, scratchGPR3).linkTo(loopStart, &jit);
+                            done.link(&jit);
+                        } else {
+                            jit.subPtr(CCallHelpers::TrustedImmPtr(static_cast<size_t>(1)), scratchGPR2);
+                            getValueFromRep(params[paramsOffset + i], scratchGPR3);
+                            jit.store64(scratchGPR3,
+                                CCallHelpers::BaseIndex(scratchGPR1, scratchGPR2, CCallHelpers::TimesEight, storeOffset));
+                        }
+                    }
+                }
+
+                {
+                    CCallHelpers::Jump dontThrow = jit.jump();
+                    slowCase.link(&jit);
+                    jit.setupArgumentsExecState();
+                    callWithExceptionCheck(bitwise_cast<void*>(operationThrowStackOverflowForVarargs));
+                    jit.abortWithReason(DFGVarargsThrowingPathDidNotThrow);
+                    
+                    dontThrow.link(&jit);
+                }
+                
+                ASSERT(calleeGPR == GPRInfo::regT0);
+                jit.store64(calleeGPR, CCallHelpers::calleeFrameSlot(CallFrameSlot::callee));
+                getValueFromRep(params[2], scratchGPR3);
+                jit.store64(scratchGPR3, CCallHelpers::calleeArgumentSlot(0));
+                
+                CallLinkInfo::CallType callType;
+                if (node->op() == ConstructVarargs || node->op() == ConstructForwardVarargs)
+                    callType = CallLinkInfo::ConstructVarargs;
+                else if (node->op() == TailCallVarargs || node->op() == TailCallForwardVarargs)
+                    callType = CallLinkInfo::TailCallVarargs;
+                else
+                    callType = CallLinkInfo::CallVarargs;
+                
+                bool isTailCall = CallLinkInfo::callModeFor(callType) == CallMode::Tail;
+                
+                CCallHelpers::DataLabelPtr targetToCheck;
+                CCallHelpers::Jump slowPath = jit.branchPtrWithPatch(
+                    CCallHelpers::NotEqual, GPRInfo::regT0, targetToCheck,
+                    CCallHelpers::TrustedImmPtr(nullptr));
+                
+                CCallHelpers::Call fastCall;
+                CCallHelpers::Jump done;
+                
+                if (isTailCall) {
+                    jit.emitRestoreCalleeSaves();
+                    jit.prepareForTailCallSlow();
+                    fastCall = jit.nearTailCall();
+                } else {
+                    fastCall = jit.nearCall();
+                    done = jit.jump();
+                }
+                
+                slowPath.link(&jit);
+
+                if (isTailCall)
+                    jit.emitRestoreCalleeSaves();
+                ASSERT(!usedRegisters.get(GPRInfo::regT2));
+                jit.move(CCallHelpers::TrustedImmPtr(callLinkInfo), GPRInfo::regT2);
+                CCallHelpers::Call slowCall = jit.nearCall();
+                
+                if (isTailCall)
+                    jit.abortWithReason(JITDidReturnFromTailCall);
+                else
+                    done.link(&jit);
+                
+                callLinkInfo->setUpCall(callType, node->origin.semantic, GPRInfo::regT0);
+
+                jit.addPtr(
+                    CCallHelpers::TrustedImm32(-originalStackHeight),
+                    GPRInfo::callFrameRegister, CCallHelpers::stackPointerRegister);
+                
+                jit.addLinkTask(
+                    [=] (LinkBuffer& linkBuffer) {
+                        MacroAssemblerCodePtr linkCall =
+                            linkBuffer.vm().getCTIStub(linkCallThunkGenerator).code();
+                        linkBuffer.link(slowCall, FunctionPtr(linkCall.executableAddress()));
+                        
+                        callLinkInfo->setCallLocations(
+                            CodeLocationLabel(linkBuffer.locationOfNearCall(slowCall)),
+                            CodeLocationLabel(linkBuffer.locationOf(targetToCheck)),
+                            linkBuffer.locationOfNearCall(fastCall));
+                    });
+            });
+
+        switch (node->op()) {
+        case TailCallForwardVarargs:
+            m_out.unreachable();
+            break;
+
+        default:
+            setJSValue(patchpoint);
+            break;
+        }
+    }
+
+    void compileCallOrConstructVarargs()
+    {
+        Node* node = m_node;
+        LValue jsCallee = lowJSValue(m_node->child1());
+        LValue thisArg = lowJSValue(m_node->child2());
+        
+        LValue jsArguments = nullptr;
+        bool forwarding = false;
+        
+        switch (node->op()) {
+        case CallVarargs:
+        case TailCallVarargs:
+        case TailCallVarargsInlinedCaller:
+        case ConstructVarargs:
+            jsArguments = lowJSValue(node->child3());
+            break;
+        case CallForwardVarargs:
+        case TailCallForwardVarargs:
+        case TailCallForwardVarargsInlinedCaller:
+        case ConstructForwardVarargs:
+            forwarding = true;
+            break;
+        default:
+            DFG_CRASH(m_graph, node, "bad node type");
+            break;
+        }
+
+        if (forwarding && m_node->child3() && m_node->child3()->op() == PhantomNewArrayWithSpread) {
+            compileCallOrConstructVarargsSpread();
+            return;
+        }
+
+        
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+
+        // Append the forms of the arguments that we will use before any clobbering happens.
+        patchpoint->append(jsCallee, ValueRep::reg(GPRInfo::regT0));
+        if (jsArguments)
+            patchpoint->appendSomeRegister(jsArguments);
+        patchpoint->appendSomeRegister(thisArg);
+
+        if (!forwarding) {
+            // Now append them again for after clobbering. Note that the compiler may ask us to use a
+            // different register for the late for the post-clobbering version of the value. This gives
+            // the compiler a chance to spill these values without having to burn any callee-saves.
+            patchpoint->append(jsCallee, ValueRep::LateColdAny);
+            patchpoint->append(jsArguments, ValueRep::LateColdAny);
+            patchpoint->append(thisArg, ValueRep::LateColdAny);
+        }
+
+        RefPtr<PatchpointExceptionHandle> exceptionHandle =
+            preparePatchpointForExceptions(patchpoint);
+        
+        patchpoint->append(m_tagMask, ValueRep::reg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::reg(GPRInfo::tagTypeNumberRegister));
+
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        patchpoint->clobberLate(RegisterSet::volatileRegistersForJSCall());
+        patchpoint->resultConstraint = ValueRep::reg(GPRInfo::returnValueGPR);
+
+        // This is the minimum amount of call arg area stack space that all JS->JS calls always have.
+        unsigned minimumJSCallAreaSize =
+            sizeof(CallerFrameAndPC) +
+            WTF::roundUpToMultipleOf(stackAlignmentBytes(), 5 * sizeof(EncodedJSValue));
+
+        m_proc.requestCallArgAreaSizeInBytes(minimumJSCallAreaSize);
+        
+        CodeOrigin codeOrigin = codeOriginDescriptionOfCallSite();
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+                CallSiteIndex callSiteIndex =
+                    state->jitCode->common.addUniqueCallSiteIndex(codeOrigin);
+
+                Box<CCallHelpers::JumpList> exceptions =
+                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+
+                exceptionHandle->scheduleExitCreationForUnwind(params, callSiteIndex);
+
+                jit.store32(
+                    CCallHelpers::TrustedImm32(callSiteIndex.bits()),
+                    CCallHelpers::tagFor(VirtualRegister(CallFrameSlot::argumentCount)));
+
+                CallLinkInfo* callLinkInfo = jit.codeBlock()->addCallLinkInfo();
+                CallVarargsData* data = node->callVarargsData();
+
+                unsigned argIndex = 1;
+                GPRReg calleeGPR = params[argIndex++].gpr();
+                ASSERT(calleeGPR == GPRInfo::regT0);
+                GPRReg argumentsGPR = jsArguments ? params[argIndex++].gpr() : InvalidGPRReg;
+                GPRReg thisGPR = params[argIndex++].gpr();
+
+                B3::ValueRep calleeLateRep;
+                B3::ValueRep argumentsLateRep;
+                B3::ValueRep thisLateRep;
+                if (!forwarding) {
+                    // If we're not forwarding then we'll need callee, arguments, and this after we
+                    // have potentially clobbered calleeGPR, argumentsGPR, and thisGPR. Our technique
+                    // for this is to supply all of those operands as late uses in addition to
+                    // specifying them as early uses. It's possible that the late use uses a spill
+                    // while the early use uses a register, and it's possible for the late and early
+                    // uses to use different registers. We do know that the late uses interfere with
+                    // all volatile registers and so won't use those, but the early uses may use
+                    // volatile registers and in the case of calleeGPR, it's pinned to regT0 so it
+                    // definitely will.
+                    //
+                    // Note that we have to be super careful with these. It's possible that these
+                    // use a shuffling of the registers used for calleeGPR, argumentsGPR, and
+                    // thisGPR. If that happens and we do for example:
+                    //
+                    //     calleeLateRep.emitRestore(jit, calleeGPR);
+                    //     argumentsLateRep.emitRestore(jit, calleeGPR);
+                    //
+                    // Then we might end up with garbage if calleeLateRep.gpr() == argumentsGPR and
+                    // argumentsLateRep.gpr() == calleeGPR.
+                    //
+                    // We do a variety of things to prevent this from happening. For example, we use
+                    // argumentsLateRep before needing the other two and after we've already stopped
+                    // using the *GPRs. Also, we pin calleeGPR to regT0, and rely on the fact that
+                    // the *LateReps cannot use volatile registers (so they cannot be regT0, so
+                    // calleeGPR != argumentsLateRep.gpr() and calleeGPR != thisLateRep.gpr()).
+                    //
+                    // An alternative would have been to just use early uses and early-clobber all
+                    // volatile registers. But that would force callee, arguments, and this into
+                    // callee-save registers even if we have to spill them. We don't want spilling to
+                    // use up three callee-saves.
+                    //
+                    // TL;DR: The way we use LateReps here is dangerous and barely works but achieves
+                    // some desirable performance properties, so don't mistake the cleverness for
+                    // elegance.
+                    calleeLateRep = params[argIndex++];
+                    argumentsLateRep = params[argIndex++];
+                    thisLateRep = params[argIndex++];
+                }
+
+                // Get some scratch registers.
+                RegisterSet usedRegisters;
+                usedRegisters.merge(RegisterSet::stackRegisters());
+                usedRegisters.merge(RegisterSet::reservedHardwareRegisters());
+                usedRegisters.merge(RegisterSet::calleeSaveRegisters());
+                usedRegisters.set(calleeGPR);
+                if (argumentsGPR != InvalidGPRReg)
+                    usedRegisters.set(argumentsGPR);
+                usedRegisters.set(thisGPR);
+                if (calleeLateRep.isReg())
+                    usedRegisters.set(calleeLateRep.reg());
+                if (argumentsLateRep.isReg())
+                    usedRegisters.set(argumentsLateRep.reg());
+                if (thisLateRep.isReg())
+                    usedRegisters.set(thisLateRep.reg());
+                ScratchRegisterAllocator allocator(usedRegisters);
+                GPRReg scratchGPR1 = allocator.allocateScratchGPR();
+                GPRReg scratchGPR2 = allocator.allocateScratchGPR();
+                GPRReg scratchGPR3 = forwarding ? allocator.allocateScratchGPR() : InvalidGPRReg;
+                RELEASE_ASSERT(!allocator.numberOfReusedRegisters());
+
+                auto callWithExceptionCheck = [&] (void* callee) {
+                    jit.move(CCallHelpers::TrustedImmPtr(callee), GPRInfo::nonPreservedNonArgumentGPR);
+                    jit.call(GPRInfo::nonPreservedNonArgumentGPR);
+                    exceptions->append(jit.emitExceptionCheck(AssemblyHelpers::NormalExceptionCheck, AssemblyHelpers::FarJumpWidth));
+                };
+
+                unsigned originalStackHeight = params.proc().frameSize();
+
+                if (forwarding) {
+                    jit.move(CCallHelpers::TrustedImm32(originalStackHeight / sizeof(EncodedJSValue)), scratchGPR2);
+                    
+                    CCallHelpers::JumpList slowCase;
+                    InlineCallFrame* inlineCallFrame;
+                    if (node->child3())
+                        inlineCallFrame = node->child3()->origin.semantic.inlineCallFrame;
+                    else
+                        inlineCallFrame = node->origin.semantic.inlineCallFrame;
+
+                    // emitSetupVarargsFrameFastCase modifies the stack pointer if it succeeds.
+                    emitSetupVarargsFrameFastCase(jit, scratchGPR2, scratchGPR1, scratchGPR2, scratchGPR3, inlineCallFrame, data->firstVarArgOffset, slowCase);
+
+                    CCallHelpers::Jump done = jit.jump();
+                    slowCase.link(&jit);
+                    jit.setupArgumentsExecState();
+                    callWithExceptionCheck(bitwise_cast<void*>(operationThrowStackOverflowForVarargs));
+                    jit.abortWithReason(DFGVarargsThrowingPathDidNotThrow);
+                    
+                    done.link(&jit);
+                } else {
+                    jit.move(CCallHelpers::TrustedImm32(originalStackHeight / sizeof(EncodedJSValue)), scratchGPR1);
+                    jit.setupArgumentsWithExecState(argumentsGPR, scratchGPR1, CCallHelpers::TrustedImm32(data->firstVarArgOffset));
+                    callWithExceptionCheck(bitwise_cast<void*>(operationSizeFrameForVarargs));
+
+                    jit.move(GPRInfo::returnValueGPR, scratchGPR1);
+                    jit.move(CCallHelpers::TrustedImm32(originalStackHeight / sizeof(EncodedJSValue)), scratchGPR2);
+                    argumentsLateRep.emitRestore(jit, argumentsGPR);
+                    emitSetVarargsFrame(jit, scratchGPR1, false, scratchGPR2, scratchGPR2);
+                    jit.addPtr(CCallHelpers::TrustedImm32(-minimumJSCallAreaSize), scratchGPR2, CCallHelpers::stackPointerRegister);
+                    jit.setupArgumentsWithExecState(scratchGPR2, argumentsGPR, CCallHelpers::TrustedImm32(data->firstVarArgOffset), scratchGPR1);
+                    callWithExceptionCheck(bitwise_cast<void*>(operationSetupVarargsFrame));
+                    
+                    jit.addPtr(CCallHelpers::TrustedImm32(sizeof(CallerFrameAndPC)), GPRInfo::returnValueGPR, CCallHelpers::stackPointerRegister);
+
+                    calleeLateRep.emitRestore(jit, GPRInfo::regT0);
+
+                    // This may not emit code if thisGPR got a callee-save. Also, we're guaranteed
+                    // that thisGPR != GPRInfo::regT0 because regT0 interferes with it.
+                    thisLateRep.emitRestore(jit, thisGPR);
+                }
+                
+                jit.store64(GPRInfo::regT0, CCallHelpers::calleeFrameSlot(CallFrameSlot::callee));
+                jit.store64(thisGPR, CCallHelpers::calleeArgumentSlot(0));
+                
+                CallLinkInfo::CallType callType;
+                if (node->op() == ConstructVarargs || node->op() == ConstructForwardVarargs)
+                    callType = CallLinkInfo::ConstructVarargs;
+                else if (node->op() == TailCallVarargs || node->op() == TailCallForwardVarargs)
+                    callType = CallLinkInfo::TailCallVarargs;
+                else
+                    callType = CallLinkInfo::CallVarargs;
+                
+                bool isTailCall = CallLinkInfo::callModeFor(callType) == CallMode::Tail;
+                
+                CCallHelpers::DataLabelPtr targetToCheck;
+                CCallHelpers::Jump slowPath = jit.branchPtrWithPatch(
+                    CCallHelpers::NotEqual, GPRInfo::regT0, targetToCheck,
+                    CCallHelpers::TrustedImmPtr(0));
+                
+                CCallHelpers::Call fastCall;
+                CCallHelpers::Jump done;
+                
+                if (isTailCall) {
+                    jit.emitRestoreCalleeSaves();
+                    jit.prepareForTailCallSlow();
+                    fastCall = jit.nearTailCall();
+                } else {
+                    fastCall = jit.nearCall();
+                    done = jit.jump();
+                }
+                
+                slowPath.link(&jit);
+
+                if (isTailCall)
+                    jit.emitRestoreCalleeSaves();
+                jit.move(CCallHelpers::TrustedImmPtr(callLinkInfo), GPRInfo::regT2);
+                CCallHelpers::Call slowCall = jit.nearCall();
+                
+                if (isTailCall)
+                    jit.abortWithReason(JITDidReturnFromTailCall);
+                else
+                    done.link(&jit);
+                
+                callLinkInfo->setUpCall(callType, node->origin.semantic, GPRInfo::regT0);
+                
+                jit.addPtr(
+                    CCallHelpers::TrustedImm32(-originalStackHeight),
+                    GPRInfo::callFrameRegister, CCallHelpers::stackPointerRegister);
+                
+                jit.addLinkTask(
+                    [=] (LinkBuffer& linkBuffer) {
+                        MacroAssemblerCodePtr linkCall =
+                            linkBuffer.vm().getCTIStub(linkCallThunkGenerator).code();
+                        linkBuffer.link(slowCall, FunctionPtr(linkCall.executableAddress()));
+                        
+                        callLinkInfo->setCallLocations(
+                            CodeLocationLabel(linkBuffer.locationOfNearCall(slowCall)),
+                            CodeLocationLabel(linkBuffer.locationOf(targetToCheck)),
+                            linkBuffer.locationOfNearCall(fastCall));
+                    });
+            });
+
+        switch (node->op()) {
+        case TailCallVarargs:
+        case TailCallForwardVarargs:
+            m_out.unreachable();
+            break;
+
+        default:
+            setJSValue(patchpoint);
+            break;
+        }
+    }
+    
+    void compileCallEval()
+    {
+        Node* node = m_node;
+        unsigned numArgs = node->numChildren() - 1;
+        
+        LValue jsCallee = lowJSValue(m_graph.varArgChild(node, 0));
+        
+        unsigned frameSize = (CallFrame::headerSizeInRegisters + numArgs) * sizeof(EncodedJSValue);
+        unsigned alignedFrameSize = WTF::roundUpToMultipleOf(stackAlignmentBytes(), frameSize);
+        
+        m_proc.requestCallArgAreaSizeInBytes(alignedFrameSize);
+        
+        Vector<ConstrainedValue> arguments;
+        arguments.append(ConstrainedValue(jsCallee, ValueRep::reg(GPRInfo::regT0)));
+        
+        auto addArgument = [&] (LValue value, VirtualRegister reg, int offset) {
+            intptr_t offsetFromSP = 
+                (reg.offset() - CallerFrameAndPC::sizeInRegisters) * sizeof(EncodedJSValue) + offset;
+            arguments.append(ConstrainedValue(value, ValueRep::stackArgument(offsetFromSP)));
+        };
+        
+        addArgument(jsCallee, VirtualRegister(CallFrameSlot::callee), 0);
+        addArgument(m_out.constInt32(numArgs), VirtualRegister(CallFrameSlot::argumentCount), PayloadOffset);
+        for (unsigned i = 0; i < numArgs; ++i)
+            addArgument(lowJSValue(m_graph.varArgChild(node, 1 + i)), virtualRegisterForArgument(i), 0);
+        
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+        patchpoint->appendVector(arguments);
+        
+        RefPtr<PatchpointExceptionHandle> exceptionHandle = preparePatchpointForExceptions(patchpoint);
+        
+        patchpoint->append(m_tagMask, ValueRep::reg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::reg(GPRInfo::tagTypeNumberRegister));
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        patchpoint->clobberLate(RegisterSet::volatileRegistersForJSCall());
+        patchpoint->resultConstraint = ValueRep::reg(GPRInfo::returnValueGPR);
+        
+        CodeOrigin codeOrigin = codeOriginDescriptionOfCallSite();
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+                CallSiteIndex callSiteIndex = state->jitCode->common.addUniqueCallSiteIndex(codeOrigin);
+                
+                Box<CCallHelpers::JumpList> exceptions = exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+                
+                exceptionHandle->scheduleExitCreationForUnwind(params, callSiteIndex);
+                
+                jit.store32(
+                    CCallHelpers::TrustedImm32(callSiteIndex.bits()),
+                    CCallHelpers::tagFor(VirtualRegister(CallFrameSlot::argumentCount)));
+                
+                CallLinkInfo* callLinkInfo = jit.codeBlock()->addCallLinkInfo();
+                callLinkInfo->setUpCall(CallLinkInfo::Call, node->origin.semantic, GPRInfo::regT0);
+                
+                jit.addPtr(CCallHelpers::TrustedImm32(-static_cast<ptrdiff_t>(sizeof(CallerFrameAndPC))), CCallHelpers::stackPointerRegister, GPRInfo::regT1);
+                jit.storePtr(GPRInfo::callFrameRegister, CCallHelpers::Address(GPRInfo::regT1, CallFrame::callerFrameOffset()));
+                
+                // Now we need to make room for:
+                // - The caller frame and PC for a call to operationCallEval.
+                // - Potentially two arguments on the stack.
+                unsigned requiredBytes = sizeof(CallerFrameAndPC) + sizeof(ExecState*) * 2;
+                requiredBytes = WTF::roundUpToMultipleOf(stackAlignmentBytes(), requiredBytes);
+                jit.subPtr(CCallHelpers::TrustedImm32(requiredBytes), CCallHelpers::stackPointerRegister);
+                jit.setupArgumentsWithExecState(GPRInfo::regT1);
+                jit.move(CCallHelpers::TrustedImmPtr(bitwise_cast<void*>(operationCallEval)), GPRInfo::nonPreservedNonArgumentGPR);
+                jit.call(GPRInfo::nonPreservedNonArgumentGPR);
+                exceptions->append(jit.emitExceptionCheck(AssemblyHelpers::NormalExceptionCheck, AssemblyHelpers::FarJumpWidth));
+                
+                CCallHelpers::Jump done = jit.branchTest64(CCallHelpers::NonZero, GPRInfo::returnValueGPR);
+                
+                jit.addPtr(CCallHelpers::TrustedImm32(requiredBytes), CCallHelpers::stackPointerRegister);
+                jit.load64(CCallHelpers::calleeFrameSlot(CallFrameSlot::callee), GPRInfo::regT0);
+                jit.emitDumbVirtualCall(callLinkInfo);
+                
+                done.link(&jit);
+                jit.addPtr(
+                    CCallHelpers::TrustedImm32(-params.proc().frameSize()),
+                    GPRInfo::callFrameRegister, CCallHelpers::stackPointerRegister);
+            });
+        
+        setJSValue(patchpoint);
+    }
+    
+    void compileLoadVarargs()
+    {
+        LoadVarargsData* data = m_node->loadVarargsData();
+        LValue jsArguments = lowJSValue(m_node->child1());
+        
+        LValue length = vmCall(
+            Int32, m_out.operation(operationSizeOfVarargs), m_callFrame, jsArguments,
+            m_out.constInt32(data->offset));
+        
+        // FIXME: There is a chance that we will call an effectful length property twice. This is safe
+        // from the standpoint of the VM's integrity, but it's subtly wrong from a spec compliance
+        // standpoint. The best solution would be one where we can exit *into* the op_call_varargs right
+        // past the sizing.
+        // https://bugs.webkit.org/show_bug.cgi?id=141448
+        
+        LValue lengthIncludingThis = m_out.add(length, m_out.int32One);
+        speculate(
+            VarargsOverflow, noValue(), nullptr,
+            m_out.above(lengthIncludingThis, m_out.constInt32(data->limit)));
+        
+        m_out.store32(lengthIncludingThis, payloadFor(data->machineCount));
+        
+        // FIXME: This computation is rather silly. If operationLaodVarargs just took a pointer instead
+        // of a VirtualRegister, we wouldn't have to do this.
+        // https://bugs.webkit.org/show_bug.cgi?id=141660
+        LValue machineStart = m_out.lShr(
+            m_out.sub(addressFor(data->machineStart.offset()).value(), m_callFrame),
+            m_out.constIntPtr(3));
+        
+        vmCall(
+            Void, m_out.operation(operationLoadVarargs), m_callFrame,
+            m_out.castToInt32(machineStart), jsArguments, m_out.constInt32(data->offset),
+            length, m_out.constInt32(data->mandatoryMinimum));
+    }
+    
+    void compileForwardVarargs()
+    {
+        if (m_node->child1() && m_node->child1()->op() == PhantomNewArrayWithSpread) {
+            compileForwardVarargsWithSpread();
+            return;
+        }
+
+        LoadVarargsData* data = m_node->loadVarargsData();
+        InlineCallFrame* inlineCallFrame;
+        if (m_node->child1())
+            inlineCallFrame = m_node->child1()->origin.semantic.inlineCallFrame;
+        else
+            inlineCallFrame = m_node->origin.semantic.inlineCallFrame;
+
+        LValue length = nullptr; 
+        LValue lengthIncludingThis = nullptr;
+        ArgumentsLength argumentsLength = getArgumentsLength(inlineCallFrame);
+        if (argumentsLength.isKnown) {
+            unsigned knownLength = argumentsLength.known;
+            if (knownLength >= data->offset)
+                knownLength = knownLength - data->offset;
+            else
+                knownLength = 0;
+            length = m_out.constInt32(knownLength);
+            lengthIncludingThis = m_out.constInt32(knownLength + 1);
+        } else {
+            // We need to perform the same logical operation as the code above, but through dynamic operations.
+            if (!data->offset)
+                length = argumentsLength.value;
+            else {
+                LBasicBlock isLarger = m_out.newBlock();
+                LBasicBlock continuation = m_out.newBlock();
+
+                ValueFromBlock smallerOrEqualLengthResult = m_out.anchor(m_out.constInt32(0));
+                m_out.branch(
+                    m_out.above(argumentsLength.value, m_out.constInt32(data->offset)), unsure(isLarger), unsure(continuation));
+                LBasicBlock lastNext = m_out.appendTo(isLarger, continuation);
+                ValueFromBlock largerLengthResult = m_out.anchor(m_out.sub(argumentsLength.value, m_out.constInt32(data->offset)));
+                m_out.jump(continuation);
+
+                m_out.appendTo(continuation, lastNext);
+                length = m_out.phi(Int32, smallerOrEqualLengthResult, largerLengthResult);
+            }
+            lengthIncludingThis = m_out.add(length, m_out.constInt32(1));
+        }
+
+        speculate(
+            VarargsOverflow, noValue(), nullptr,
+            m_out.above(lengthIncludingThis, m_out.constInt32(data->limit)));
+        
+        m_out.store32(lengthIncludingThis, payloadFor(data->machineCount));
+        
+        unsigned numberOfArgumentsToSkip = data->offset;
+        LValue sourceStart = getArgumentsStart(inlineCallFrame, numberOfArgumentsToSkip);
+        LValue targetStart = addressFor(data->machineStart).value();
+
+        LBasicBlock undefinedLoop = m_out.newBlock();
+        LBasicBlock mainLoopEntry = m_out.newBlock();
+        LBasicBlock mainLoop = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LValue lengthAsPtr = m_out.zeroExtPtr(length);
+        LValue loopBoundValue = m_out.constIntPtr(data->mandatoryMinimum);
+        ValueFromBlock loopBound = m_out.anchor(loopBoundValue);
+        m_out.branch(
+            m_out.above(loopBoundValue, lengthAsPtr), unsure(undefinedLoop), unsure(mainLoopEntry));
+        
+        LBasicBlock lastNext = m_out.appendTo(undefinedLoop, mainLoopEntry);
+        LValue previousIndex = m_out.phi(pointerType(), loopBound);
+        LValue currentIndex = m_out.sub(previousIndex, m_out.intPtrOne);
+        m_out.store64(
+            m_out.constInt64(JSValue::encode(jsUndefined())),
+            m_out.baseIndex(m_heaps.variables, targetStart, currentIndex));
+        ValueFromBlock nextIndex = m_out.anchor(currentIndex);
+        m_out.addIncomingToPhi(previousIndex, nextIndex);
+        m_out.branch(
+            m_out.above(currentIndex, lengthAsPtr), unsure(undefinedLoop), unsure(mainLoopEntry));
+        
+        m_out.appendTo(mainLoopEntry, mainLoop);
+        loopBound = m_out.anchor(lengthAsPtr);
+        m_out.branch(m_out.notNull(lengthAsPtr), unsure(mainLoop), unsure(continuation));
+        
+        m_out.appendTo(mainLoop, continuation);
+        previousIndex = m_out.phi(pointerType(), loopBound);
+        currentIndex = m_out.sub(previousIndex, m_out.intPtrOne);
+        LValue value = m_out.load64(
+            m_out.baseIndex(m_heaps.variables, sourceStart, currentIndex));
+        m_out.store64(value, m_out.baseIndex(m_heaps.variables, targetStart, currentIndex));
+        nextIndex = m_out.anchor(currentIndex);
+        m_out.addIncomingToPhi(previousIndex, nextIndex);
+        m_out.branch(m_out.isNull(currentIndex), unsure(continuation), unsure(mainLoop));
+        
+        m_out.appendTo(continuation, lastNext);
+    }
+
+    LValue getSpreadLengthFromInlineCallFrame(InlineCallFrame* inlineCallFrame, unsigned numberOfArgumentsToSkip)
+    {
+        ArgumentsLength argumentsLength = getArgumentsLength(inlineCallFrame);
+        if (argumentsLength.isKnown) {
+            unsigned knownLength = argumentsLength.known;
+            if (knownLength >= numberOfArgumentsToSkip)
+                knownLength = knownLength - numberOfArgumentsToSkip;
+            else
+                knownLength = 0;
+            return m_out.constInt32(knownLength);
+        }
+
+
+        // We need to perform the same logical operation as the code above, but through dynamic operations.
+        if (!numberOfArgumentsToSkip)
+            return argumentsLength.value;
+
+        LBasicBlock isLarger = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        ValueFromBlock smallerOrEqualLengthResult = m_out.anchor(m_out.constInt32(0));
+        m_out.branch(
+            m_out.above(argumentsLength.value, m_out.constInt32(numberOfArgumentsToSkip)), unsure(isLarger), unsure(continuation));
+        LBasicBlock lastNext = m_out.appendTo(isLarger, continuation);
+        ValueFromBlock largerLengthResult = m_out.anchor(m_out.sub(argumentsLength.value, m_out.constInt32(numberOfArgumentsToSkip)));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        return m_out.phi(Int32, smallerOrEqualLengthResult, largerLengthResult);
+    }
+
+    void compileForwardVarargsWithSpread()
+    {
+        HashMap<InlineCallFrame*, LValue, WTF::DefaultHash<InlineCallFrame*>::Hash, WTF::NullableHashTraits<InlineCallFrame*>> cachedSpreadLengths;
+
+        Node* arrayWithSpread = m_node->child1().node();
+        RELEASE_ASSERT(arrayWithSpread->op() == PhantomNewArrayWithSpread);
+        BitVector* bitVector = arrayWithSpread->bitVector();
+
+        unsigned numberOfStaticArguments = 0;
+        Vector<LValue, 2> spreadLengths;
+        for (unsigned i = 0; i < arrayWithSpread->numChildren(); i++) {
+            if (bitVector->get(i)) {
+                Node* child = m_graph.varArgChild(arrayWithSpread, i).node();
+                ASSERT(child->op() == PhantomSpread);
+                ASSERT(child->child1()->op() == PhantomCreateRest);
+                InlineCallFrame* inlineCallFrame = child->child1()->origin.semantic.inlineCallFrame;
+                LValue length = cachedSpreadLengths.ensure(inlineCallFrame, [&] () {
+                    return getSpreadLengthFromInlineCallFrame(inlineCallFrame, child->child1()->numberOfArgumentsToSkip());
+                }).iterator->value;
+                spreadLengths.append(length);
+            } else
+                ++numberOfStaticArguments;
+        }
+
+        LValue lengthIncludingThis = m_out.constInt32(1 + numberOfStaticArguments);
+        for (LValue length : spreadLengths)
+            lengthIncludingThis = m_out.add(lengthIncludingThis, length);
+
+        LoadVarargsData* data = m_node->loadVarargsData();
+        speculate(
+            VarargsOverflow, noValue(), nullptr,
+            m_out.above(lengthIncludingThis, m_out.constInt32(data->limit)));
+        
+        m_out.store32(lengthIncludingThis, payloadFor(data->machineCount));
+
+        LValue targetStart = addressFor(data->machineStart).value();
+        LValue storeIndex = m_out.constIntPtr(0);
+        for (unsigned i = 0; i < arrayWithSpread->numChildren(); i++) {
+            if (bitVector->get(i)) {
+                Node* child = m_graph.varArgChild(arrayWithSpread, i).node();
+                RELEASE_ASSERT(child->op() == PhantomSpread);
+                RELEASE_ASSERT(child->child1()->op() == PhantomCreateRest);
+                InlineCallFrame* inlineCallFrame = child->child1()->origin.semantic.inlineCallFrame;
+
+                LValue sourceStart = getArgumentsStart(inlineCallFrame, child->child1()->numberOfArgumentsToSkip());
+                LValue spreadLength = m_out.zeroExtPtr(cachedSpreadLengths.get(inlineCallFrame));
+
+                LBasicBlock loop = m_out.newBlock();
+                LBasicBlock continuation = m_out.newBlock();
+                ValueFromBlock startLoadIndex = m_out.anchor(m_out.constIntPtr(0));
+                ValueFromBlock startStoreIndex = m_out.anchor(storeIndex);
+                ValueFromBlock startStoreIndexForEnd = m_out.anchor(storeIndex);
+
+                m_out.branch(m_out.isZero64(spreadLength), unsure(continuation), unsure(loop));
+
+                LBasicBlock lastNext = m_out.appendTo(loop, continuation);
+                LValue loopStoreIndex = m_out.phi(Int64, startStoreIndex);
+                LValue loadIndex = m_out.phi(Int64, startLoadIndex);
+                LValue value = m_out.load64(
+                    m_out.baseIndex(m_heaps.variables, sourceStart, loadIndex));
+                m_out.store64(value, m_out.baseIndex(m_heaps.variables, targetStart, loopStoreIndex));
+                LValue nextLoadIndex = m_out.add(m_out.constIntPtr(1), loadIndex);
+                m_out.addIncomingToPhi(loadIndex, m_out.anchor(nextLoadIndex));
+                LValue nextStoreIndex = m_out.add(m_out.constIntPtr(1), loopStoreIndex);
+                m_out.addIncomingToPhi(loopStoreIndex, m_out.anchor(nextStoreIndex));
+                ValueFromBlock loopStoreIndexForEnd = m_out.anchor(nextStoreIndex);
+                m_out.branch(m_out.below(nextLoadIndex, spreadLength), unsure(loop), unsure(continuation));
+
+                m_out.appendTo(continuation, lastNext);
+                storeIndex = m_out.phi(Int64, startStoreIndexForEnd, loopStoreIndexForEnd);
+            } else {
+                LValue value = lowJSValue(m_graph.varArgChild(arrayWithSpread, i));
+                m_out.store64(value, m_out.baseIndex(m_heaps.variables, targetStart, storeIndex));
+                storeIndex = m_out.add(m_out.constIntPtr(1), storeIndex);
+            }
+        }
+
+        LBasicBlock undefinedLoop = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        ValueFromBlock startStoreIndex = m_out.anchor(storeIndex);
+        LValue loopBoundValue = m_out.constIntPtr(data->mandatoryMinimum);
+        m_out.branch(m_out.below(storeIndex, loopBoundValue),
+            unsure(undefinedLoop), unsure(continuation));
+
+        LBasicBlock lastNext = m_out.appendTo(undefinedLoop, continuation);
+        LValue loopStoreIndex = m_out.phi(Int64, startStoreIndex);
+        m_out.store64(
+            m_out.constInt64(JSValue::encode(jsUndefined())),
+            m_out.baseIndex(m_heaps.variables, targetStart, loopStoreIndex));
+        LValue nextIndex = m_out.add(loopStoreIndex, m_out.constIntPtr(1));
+        m_out.addIncomingToPhi(loopStoreIndex, m_out.anchor(nextIndex));
+        m_out.branch(
+            m_out.below(nextIndex, loopBoundValue), unsure(undefinedLoop), unsure(continuation));
+
+        m_out.appendTo(continuation, lastNext);
+    }
+
+    void compileJump()
+    {
+        m_out.jump(lowBlock(m_node->targetBlock()));
+    }
+    
+    void compileBranch()
+    {
+        m_out.branch(
+            boolify(m_node->child1()),
+            WeightedTarget(
+                lowBlock(m_node->branchData()->taken.block),
+                m_node->branchData()->taken.count),
+            WeightedTarget(
+                lowBlock(m_node->branchData()->notTaken.block),
+                m_node->branchData()->notTaken.count));
+    }
+    
+    void compileSwitch()
+    {
+        SwitchData* data = m_node->switchData();
+        switch (data->kind) {
+        case SwitchImm: {
+            Vector<ValueFromBlock, 2> intValues;
+            LBasicBlock switchOnInts = m_out.newBlock();
+            
+            LBasicBlock lastNext = m_out.appendTo(m_out.m_block, switchOnInts);
+            
+            switch (m_node->child1().useKind()) {
+            case Int32Use: {
+                intValues.append(m_out.anchor(lowInt32(m_node->child1())));
+                m_out.jump(switchOnInts);
+                break;
+            }
+                
+            case UntypedUse: {
+                LBasicBlock isInt = m_out.newBlock();
+                LBasicBlock isNotInt = m_out.newBlock();
+                LBasicBlock isDouble = m_out.newBlock();
+                
+                LValue boxedValue = lowJSValue(m_node->child1());
+                m_out.branch(isNotInt32(boxedValue), unsure(isNotInt), unsure(isInt));
+                
+                LBasicBlock innerLastNext = m_out.appendTo(isInt, isNotInt);
+                
+                intValues.append(m_out.anchor(unboxInt32(boxedValue)));
+                m_out.jump(switchOnInts);
+                
+                m_out.appendTo(isNotInt, isDouble);
+                m_out.branch(
+                    isCellOrMisc(boxedValue, provenType(m_node->child1())),
+                    usually(lowBlock(data->fallThrough.block)), rarely(isDouble));
+                
+                m_out.appendTo(isDouble, innerLastNext);
+                LValue doubleValue = unboxDouble(boxedValue);
+                LValue intInDouble = m_out.doubleToInt(doubleValue);
+                intValues.append(m_out.anchor(intInDouble));
+                m_out.branch(
+                    m_out.doubleEqual(m_out.intToDouble(intInDouble), doubleValue),
+                    unsure(switchOnInts), unsure(lowBlock(data->fallThrough.block)));
+                break;
+            }
+                
+            default:
+                DFG_CRASH(m_graph, m_node, "Bad use kind");
+                break;
+            }
+            
+            m_out.appendTo(switchOnInts, lastNext);
+            buildSwitch(data, Int32, m_out.phi(Int32, intValues));
+            return;
+        }
+        
+        case SwitchChar: {
+            LValue stringValue;
+            
+            // FIXME: We should use something other than unsure() for the branch weight
+            // of the fallThrough block. The main challenge is just that we have multiple
+            // branches to fallThrough but a single count, so we would need to divvy it up
+            // among the different lowered branches.
+            // https://bugs.webkit.org/show_bug.cgi?id=129082
+            
+            switch (m_node->child1().useKind()) {
+            case StringUse: {
+                stringValue = lowString(m_node->child1());
+                break;
+            }
+                
+            case UntypedUse: {
+                LValue unboxedValue = lowJSValue(m_node->child1());
+                
+                LBasicBlock isCellCase = m_out.newBlock();
+                LBasicBlock isStringCase = m_out.newBlock();
+                
+                m_out.branch(
+                    isNotCell(unboxedValue, provenType(m_node->child1())),
+                    unsure(lowBlock(data->fallThrough.block)), unsure(isCellCase));
+                
+                LBasicBlock lastNext = m_out.appendTo(isCellCase, isStringCase);
+                LValue cellValue = unboxedValue;
+                m_out.branch(
+                    isNotString(cellValue, provenType(m_node->child1())),
+                    unsure(lowBlock(data->fallThrough.block)), unsure(isStringCase));
+                
+                m_out.appendTo(isStringCase, lastNext);
+                stringValue = cellValue;
+                break;
+            }
+                
+            default:
+                DFG_CRASH(m_graph, m_node, "Bad use kind");
+                break;
+            }
+            
+            LBasicBlock lengthIs1 = m_out.newBlock();
+            LBasicBlock needResolution = m_out.newBlock();
+            LBasicBlock resolved = m_out.newBlock();
+            LBasicBlock is8Bit = m_out.newBlock();
+            LBasicBlock is16Bit = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            m_out.branch(
+                m_out.notEqual(
+                    m_out.load32NonNegative(stringValue, m_heaps.JSString_length),
+                    m_out.int32One),
+                unsure(lowBlock(data->fallThrough.block)), unsure(lengthIs1));
+            
+            LBasicBlock lastNext = m_out.appendTo(lengthIs1, needResolution);
+            Vector<ValueFromBlock, 2> values;
+            LValue fastValue = m_out.loadPtr(stringValue, m_heaps.JSString_value);
+            values.append(m_out.anchor(fastValue));
+            m_out.branch(m_out.isNull(fastValue), rarely(needResolution), usually(resolved));
+            
+            m_out.appendTo(needResolution, resolved);
+            values.append(m_out.anchor(
+                vmCall(pointerType(), m_out.operation(operationResolveRope), m_callFrame, stringValue)));
+            m_out.jump(resolved);
+            
+            m_out.appendTo(resolved, is8Bit);
+            LValue value = m_out.phi(pointerType(), values);
+            LValue characterData = m_out.loadPtr(value, m_heaps.StringImpl_data);
+            m_out.branch(
+                m_out.testNonZero32(
+                    m_out.load32(value, m_heaps.StringImpl_hashAndFlags),
+                    m_out.constInt32(StringImpl::flagIs8Bit())),
+                unsure(is8Bit), unsure(is16Bit));
+            
+            Vector<ValueFromBlock, 2> characters;
+            m_out.appendTo(is8Bit, is16Bit);
+            characters.append(m_out.anchor(m_out.load8ZeroExt32(characterData, m_heaps.characters8[0])));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(is16Bit, continuation);
+            characters.append(m_out.anchor(m_out.load16ZeroExt32(characterData, m_heaps.characters16[0])));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            buildSwitch(data, Int32, m_out.phi(Int32, characters));
+            return;
+        }
+        
+        case SwitchString: {
+            switch (m_node->child1().useKind()) {
+            case StringIdentUse: {
+                LValue stringImpl = lowStringIdent(m_node->child1());
+                
+                Vector<SwitchCase> cases;
+                for (unsigned i = 0; i < data->cases.size(); ++i) {
+                    LValue value = m_out.constIntPtr(data->cases[i].value.stringImpl());
+                    LBasicBlock block = lowBlock(data->cases[i].target.block);
+                    Weight weight = Weight(data->cases[i].target.count);
+                    cases.append(SwitchCase(value, block, weight));
+                }
+                
+                m_out.switchInstruction(
+                    stringImpl, cases, lowBlock(data->fallThrough.block),
+                    Weight(data->fallThrough.count));
+                return;
+            }
+                
+            case StringUse: {
+                switchString(data, lowString(m_node->child1()));
+                return;
+            }
+                
+            case UntypedUse: {
+                LValue value = lowJSValue(m_node->child1());
+                
+                LBasicBlock isCellBlock = m_out.newBlock();
+                LBasicBlock isStringBlock = m_out.newBlock();
+                
+                m_out.branch(
+                    isCell(value, provenType(m_node->child1())),
+                    unsure(isCellBlock), unsure(lowBlock(data->fallThrough.block)));
+                
+                LBasicBlock lastNext = m_out.appendTo(isCellBlock, isStringBlock);
+                
+                m_out.branch(
+                    isString(value, provenType(m_node->child1())),
+                    unsure(isStringBlock), unsure(lowBlock(data->fallThrough.block)));
+                
+                m_out.appendTo(isStringBlock, lastNext);
+                
+                switchString(data, value);
+                return;
+            }
+                
+            default:
+                DFG_CRASH(m_graph, m_node, "Bad use kind");
+                return;
+            }
+            return;
+        }
+            
+        case SwitchCell: {
+            LValue cell;
+            switch (m_node->child1().useKind()) {
+            case CellUse: {
+                cell = lowCell(m_node->child1());
+                break;
+            }
+                
+            case UntypedUse: {
+                LValue value = lowJSValue(m_node->child1());
+                LBasicBlock cellCase = m_out.newBlock();
+                m_out.branch(
+                    isCell(value, provenType(m_node->child1())),
+                    unsure(cellCase), unsure(lowBlock(data->fallThrough.block)));
+                m_out.appendTo(cellCase);
+                cell = value;
+                break;
+            }
+                
+            default:
+                DFG_CRASH(m_graph, m_node, "Bad use kind");
+                return;
+            }
+            
+            buildSwitch(m_node->switchData(), pointerType(), cell);
+            return;
+        } }
+        
+        DFG_CRASH(m_graph, m_node, "Bad switch kind");
+    }
+    
+    void compileReturn()
+    {
+        m_out.ret(lowJSValue(m_node->child1()));
+    }
+    
+    void compileForceOSRExit()
+    {
+        terminate(InadequateCoverage);
+    }
+    
+    void compileThrow()
+    {
+        terminate(Uncountable);
+    }
+    
+    void compileInvalidationPoint()
+    {
+        if (verboseCompilationEnabled())
+            dataLog("    Invalidation point with availability: ", availabilityMap(), "\n");
+
+        DFG_ASSERT(m_graph, m_node, m_origin.exitOK);
+        
+        PatchpointValue* patchpoint = m_out.patchpoint(Void);
+        OSRExitDescriptor* descriptor = appendOSRExitDescriptor(noValue(), nullptr);
+        NodeOrigin origin = m_origin;
+        patchpoint->appendColdAnys(buildExitArguments(descriptor, origin.forExit, noValue()));
+        
+        State* state = &m_ftlState;
+
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const B3::StackmapGenerationParams& params) {
+                // The MacroAssembler knows more about this than B3 does. The watchpointLabel() method
+                // will ensure that this is followed by a nop shadow but only when this is actually
+                // necessary.
+                CCallHelpers::Label label = jit.watchpointLabel();
+
+                RefPtr<OSRExitHandle> handle = descriptor->emitOSRExitLater(
+                    *state, UncountableInvalidation, origin, params);
+
+                RefPtr<JITCode> jitCode = state->jitCode.get();
+
+                jit.addLinkTask(
+                    [=] (LinkBuffer& linkBuffer) {
+                        JumpReplacement jumpReplacement(
+                            linkBuffer.locationOf(label),
+                            linkBuffer.locationOf(handle->label));
+                        jitCode->common.jumpReplacements.append(jumpReplacement);
+                    });
+            });
+
+        // Set some obvious things.
+        patchpoint->effects.terminal = false;
+        patchpoint->effects.writesLocalState = false;
+        patchpoint->effects.readsLocalState = false;
+        
+        // This is how we tell B3 about the possibility of jump replacement.
+        patchpoint->effects.exitsSideways = true;
+        
+        // It's not possible for some prior branch to determine the safety of this operation. It's always
+        // fine to execute this on some path that wouldn't have originally executed it before
+        // optimization.
+        patchpoint->effects.controlDependent = false;
+
+        // If this falls through then it won't write anything.
+        patchpoint->effects.writes = HeapRange();
+
+        // When this abruptly terminates, it could read any heap location.
+        patchpoint->effects.reads = HeapRange::top();
+    }
+
+    void compileIsEmpty()
+    {
+        setBoolean(m_out.isZero64(lowJSValue(m_node->child1())));
+    }
+    
+    void compileIsUndefined()
+    {
+        setBoolean(equalNullOrUndefined(m_node->child1(), AllCellsAreFalse, EqualUndefined));
+    }
+    
+    void compileIsBoolean()
+    {
+        setBoolean(isBoolean(lowJSValue(m_node->child1()), provenType(m_node->child1())));
+    }
+    
+    void compileIsNumber()
+    {
+        setBoolean(isNumber(lowJSValue(m_node->child1()), provenType(m_node->child1())));
+    }
+    
+    void compileIsCellWithType()
+    {
+        if (m_node->child1().useKind() == UntypedUse) {
+            LValue value = lowJSValue(m_node->child1());
+
+            LBasicBlock isCellCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            ValueFromBlock notCellResult = m_out.anchor(m_out.booleanFalse);
+            m_out.branch(
+                isCell(value, provenType(m_node->child1())), unsure(isCellCase), unsure(continuation));
+
+            LBasicBlock lastNext = m_out.appendTo(isCellCase, continuation);
+            ValueFromBlock cellResult = m_out.anchor(isCellWithType(value, m_node->queriedType(), m_node->speculatedTypeForQuery(), provenType(m_node->child1())));
+            m_out.jump(continuation);
+
+            m_out.appendTo(continuation, lastNext);
+            setBoolean(m_out.phi(Int32, notCellResult, cellResult));
+        } else {
+            ASSERT(m_node->child1().useKind() == CellUse);
+            setBoolean(isCellWithType(lowCell(m_node->child1()), m_node->queriedType(), m_node->speculatedTypeForQuery(), provenType(m_node->child1())));
+        }
+    }
+
+    void compileIsObject()
+    {
+        LValue value = lowJSValue(m_node->child1());
+
+        LBasicBlock isCellCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        ValueFromBlock notCellResult = m_out.anchor(m_out.booleanFalse);
+        m_out.branch(
+            isCell(value, provenType(m_node->child1())), unsure(isCellCase), unsure(continuation));
+
+        LBasicBlock lastNext = m_out.appendTo(isCellCase, continuation);
+        ValueFromBlock cellResult = m_out.anchor(isObject(value, provenType(m_node->child1())));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setBoolean(m_out.phi(Int32, notCellResult, cellResult));
+    }
+
+    LValue wangsInt64Hash(LValue input)
+    {
+        // key += ~(key << 32);
+        LValue key = input;
+        LValue temp = key;
+        temp = m_out.shl(temp, m_out.constInt32(32));
+        temp = m_out.bitNot(temp);
+        key = m_out.add(key, temp);
+        // key ^= (key >> 22);
+        temp = key;
+        temp = m_out.lShr(temp, m_out.constInt32(22));
+        key = m_out.bitXor(key, temp);
+        // key += ~(key << 13);
+        temp = key;
+        temp = m_out.shl(temp, m_out.constInt32(13));
+        temp = m_out.bitNot(temp);
+        key = m_out.add(key, temp);
+        // key ^= (key >> 8);
+        temp = key;
+        temp = m_out.lShr(temp, m_out.constInt32(8));
+        key = m_out.bitXor(key, temp);
+        // key += (key << 3);
+        temp = key;
+        temp = m_out.shl(temp, m_out.constInt32(3));
+        key = m_out.add(key, temp);
+        // key ^= (key >> 15);
+        temp = key;
+        temp = m_out.lShr(temp, m_out.constInt32(15));
+        key = m_out.bitXor(key, temp);
+        // key += ~(key << 27);
+        temp = key;
+        temp = m_out.shl(temp, m_out.constInt32(27));
+        temp = m_out.bitNot(temp);
+        key = m_out.add(key, temp);
+        // key ^= (key >> 31);
+        temp = key;
+        temp = m_out.lShr(temp, m_out.constInt32(31));
+        key = m_out.bitXor(key, temp);
+        key = m_out.castToInt32(key);
+
+        return key;
+    }
+
+    LValue mapHashString(LValue string)
+    {
+        LBasicBlock nonEmptyStringCase = m_out.newBlock();
+        LBasicBlock slowCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        LValue stringImpl = m_out.loadPtr(string, m_heaps.JSString_value);
+        m_out.branch(
+            m_out.equal(stringImpl, m_out.constIntPtr(0)), unsure(slowCase), unsure(nonEmptyStringCase));
+
+        LBasicBlock lastNext = m_out.appendTo(nonEmptyStringCase, slowCase);
+        LValue hash = m_out.lShr(m_out.load32(stringImpl, m_heaps.StringImpl_hashAndFlags), m_out.constInt32(StringImpl::s_flagCount));
+        ValueFromBlock nonEmptyStringHashResult = m_out.anchor(hash);
+        m_out.branch(m_out.equal(hash, m_out.constInt32(0)),
+            unsure(slowCase), unsure(continuation));
+
+        m_out.appendTo(slowCase, continuation);
+        ValueFromBlock slowResult = m_out.anchor(
+            vmCall(Int32, m_out.operation(operationMapHash), m_callFrame, string));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        return m_out.phi(Int32, slowResult, nonEmptyStringHashResult);
+    }
+
+    void compileMapHash()
+    {
+        switch (m_node->child1().useKind()) {
+        case BooleanUse:
+        case Int32Use:
+        case SymbolUse:
+        case ObjectUse: {
+            LValue key = lowJSValue(m_node->child1(), ManualOperandSpeculation);
+            speculate(m_node->child1());
+            setInt32(wangsInt64Hash(key));
+            return;
+        }
+
+        case CellUse: {
+            LBasicBlock isString = m_out.newBlock();
+            LBasicBlock notString = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            LValue value = lowCell(m_node->child1());
+            LValue isStringValue = m_out.equal(m_out.load8ZeroExt32(value, m_heaps.JSCell_typeInfoType), m_out.constInt32(StringType));
+            m_out.branch(
+                isStringValue, unsure(isString), unsure(notString));
+
+            LBasicBlock lastNext = m_out.appendTo(isString, notString);
+            ValueFromBlock stringResult = m_out.anchor(mapHashString(value));
+            m_out.jump(continuation);
+
+            m_out.appendTo(notString, continuation);
+            ValueFromBlock notStringResult = m_out.anchor(wangsInt64Hash(value));
+            m_out.jump(continuation);
+
+            m_out.appendTo(continuation, lastNext);
+            setInt32(m_out.phi(Int32, stringResult, notStringResult));
+            return;
+        }
+
+        case StringUse: {
+            LValue string = lowString(m_node->child1());
+            setInt32(mapHashString(string));
+            return;
+        }
+
+        default:
+            RELEASE_ASSERT(m_node->child1().useKind() == UntypedUse);
+            break;
+        }
+
+        LValue value = lowJSValue(m_node->child1());
+
+        LBasicBlock isCellCase = m_out.newBlock();
+        LBasicBlock notCell = m_out.newBlock();
+        LBasicBlock slowCase = m_out.newBlock();
+        LBasicBlock straightHash = m_out.newBlock();
+        LBasicBlock isNumberCase = m_out.newBlock();
+        LBasicBlock isStringCase = m_out.newBlock();
+        LBasicBlock nonEmptyStringCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(
+            isCell(value, provenType(m_node->child1())), unsure(isCellCase), unsure(notCell));
+
+        LBasicBlock lastNext = m_out.appendTo(isCellCase, isStringCase);
+        LValue isString = m_out.equal(m_out.load8ZeroExt32(value, m_heaps.JSCell_typeInfoType), m_out.constInt32(StringType));
+        m_out.branch(
+            isString, unsure(isStringCase), unsure(straightHash));
+
+        m_out.appendTo(isStringCase, nonEmptyStringCase);
+        LValue stringImpl = m_out.loadPtr(value, m_heaps.JSString_value);
+        m_out.branch(
+            m_out.equal(stringImpl, m_out.constIntPtr(0)), rarely(slowCase), usually(nonEmptyStringCase));
+
+        m_out.appendTo(nonEmptyStringCase, notCell);
+        LValue hash = m_out.lShr(m_out.load32(stringImpl, m_heaps.StringImpl_hashAndFlags), m_out.constInt32(StringImpl::s_flagCount));
+        ValueFromBlock nonEmptyStringHashResult = m_out.anchor(hash);
+        m_out.branch(m_out.equal(hash, m_out.constInt32(0)),
+            unsure(slowCase), unsure(continuation));
+
+        m_out.appendTo(notCell, isNumberCase);
+        m_out.branch(
+            isNumber(value), unsure(isNumberCase), unsure(straightHash));
+
+        m_out.appendTo(isNumberCase, straightHash);
+        m_out.branch(
+            isInt32(value), unsure(straightHash), unsure(slowCase));
+
+        m_out.appendTo(straightHash, slowCase);
+        ValueFromBlock fastResult = m_out.anchor(wangsInt64Hash(value));
+        m_out.jump(continuation);
+
+        m_out.appendTo(slowCase, continuation);
+        ValueFromBlock slowResult = m_out.anchor(
+            vmCall(Int32, m_out.operation(operationMapHash), m_callFrame, value));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setInt32(m_out.phi(Int32, fastResult, slowResult, nonEmptyStringHashResult));
+    }
+
+    void compileGetMapBucket()
+    {
+        LBasicBlock loopStart = m_out.newBlock();
+        LBasicBlock loopAround = m_out.newBlock();
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock notPresentInTable = m_out.newBlock();
+        LBasicBlock notEmptyValue = m_out.newBlock();
+        LBasicBlock notDeletedValue = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(loopStart);
+
+        LValue map;
+        if (m_node->child1().useKind() == MapObjectUse)
+            map = lowMapObject(m_node->child1());
+        else if (m_node->child1().useKind() == SetObjectUse)
+            map = lowSetObject(m_node->child1());
+        else
+            RELEASE_ASSERT_NOT_REACHED();
+
+        LValue key = lowJSValue(m_node->child2(), ManualOperandSpeculation);
+        if (m_node->child2().useKind() != UntypedUse)
+            speculate(m_node->child2());
+
+        LValue hash = lowInt32(m_node->child3());
+
+        LValue hashMapImpl = m_out.loadPtr(map, m_node->child1().useKind() == MapObjectUse ? m_heaps.JSMap_hashMapImpl : m_heaps.JSSet_hashMapImpl);
+        LValue buffer = m_out.loadPtr(hashMapImpl, m_heaps.HashMapImpl_buffer);
+        LValue mask = m_out.sub(m_out.load32(hashMapImpl, m_heaps.HashMapImpl_capacity), m_out.int32One);
+
+        ValueFromBlock indexStart = m_out.anchor(hash);
+        m_out.jump(loopStart);
+
+        m_out.appendTo(loopStart, notEmptyValue);
+        LValue unmaskedIndex = m_out.phi(Int32, indexStart);
+        LValue index = m_out.bitAnd(mask, unmaskedIndex);
+        LValue hashMapBucket = m_out.load64(m_out.baseIndex(m_heaps.properties.atAnyNumber(), buffer, m_out.zeroExt(index, Int64), ScaleEight));
+        ValueFromBlock bucketResult = m_out.anchor(hashMapBucket);
+        m_out.branch(m_out.equal(hashMapBucket, m_out.constIntPtr(bitwise_cast<intptr_t>(HashMapImpl<HashMapBucket<HashMapBucketDataKey>>::emptyValue()))),
+            unsure(notPresentInTable), unsure(notEmptyValue));
+
+        m_out.appendTo(notEmptyValue, notDeletedValue);
+        m_out.branch(m_out.equal(hashMapBucket, m_out.constIntPtr(bitwise_cast<intptr_t>(HashMapImpl<HashMapBucket<HashMapBucketDataKey>>::deletedValue()))),
+            unsure(loopAround), unsure(notDeletedValue));
+
+        m_out.appendTo(notDeletedValue, loopAround);
+        LValue bucketKey = m_out.load64(hashMapBucket, m_heaps.HashMapBucket_key);
+
+        // Perform Object.is()
+        switch (m_node->child2().useKind()) {
+        case BooleanUse:
+        case Int32Use:
+        case SymbolUse:
+        case ObjectUse: {
+            m_out.branch(m_out.equal(key, bucketKey),
+                unsure(continuation), unsure(loopAround));
+            break;
+        }
+        case StringUse: {
+            LBasicBlock notBitEqual = m_out.newBlock();
+            LBasicBlock bucketKeyIsCell = m_out.newBlock();
+
+            m_out.branch(m_out.equal(key, bucketKey),
+                unsure(continuation), unsure(notBitEqual));
+
+            m_out.appendTo(notBitEqual, bucketKeyIsCell);
+            m_out.branch(isCell(bucketKey),
+                unsure(bucketKeyIsCell), unsure(loopAround));
+
+            m_out.appendTo(bucketKeyIsCell, loopAround);
+            m_out.branch(isString(bucketKey),
+                unsure(slowPath), unsure(loopAround));
+            break;
+        }
+        case CellUse: {
+            LBasicBlock notBitEqual = m_out.newBlock();
+            LBasicBlock bucketKeyIsCell = m_out.newBlock();
+            LBasicBlock bucketKeyIsString = m_out.newBlock();
+
+            m_out.branch(m_out.equal(key, bucketKey),
+                unsure(continuation), unsure(notBitEqual));
+
+            m_out.appendTo(notBitEqual, bucketKeyIsCell);
+            m_out.branch(isCell(bucketKey),
+                unsure(bucketKeyIsCell), unsure(loopAround));
+
+            m_out.appendTo(bucketKeyIsCell, bucketKeyIsString);
+            m_out.branch(isString(bucketKey),
+                unsure(bucketKeyIsString), unsure(loopAround));
+
+            m_out.appendTo(bucketKeyIsString, loopAround);
+            m_out.branch(isString(key),
+                unsure(slowPath), unsure(loopAround));
+            break;
+        }
+        case UntypedUse: {
+            LBasicBlock notBitEqual = m_out.newBlock();
+            LBasicBlock bucketKeyIsCell = m_out.newBlock();
+            LBasicBlock bothAreCells = m_out.newBlock();
+            LBasicBlock bucketKeyIsString = m_out.newBlock();
+            LBasicBlock bucketKeyNotCell = m_out.newBlock();
+            LBasicBlock bucketKeyIsNumber = m_out.newBlock();
+            LBasicBlock bothAreNumbers = m_out.newBlock();
+            LBasicBlock bucketKeyIsInt32 = m_out.newBlock();
+
+            m_out.branch(m_out.equal(key, bucketKey),
+                unsure(continuation), unsure(notBitEqual));
+
+            m_out.appendTo(notBitEqual, bucketKeyIsCell);
+            m_out.branch(isCell(bucketKey),
+                unsure(bucketKeyIsCell), unsure(bucketKeyNotCell));
+
+            m_out.appendTo(bucketKeyIsCell, bothAreCells);
+            m_out.branch(isCell(key),
+                unsure(bothAreCells), unsure(loopAround));
+
+            m_out.appendTo(bothAreCells, bucketKeyIsString);
+            m_out.branch(isString(bucketKey),
+                unsure(bucketKeyIsString), unsure(loopAround));
+
+            m_out.appendTo(bucketKeyIsString, bucketKeyNotCell);
+            m_out.branch(isString(key),
+                unsure(slowPath), unsure(loopAround));
+
+            m_out.appendTo(bucketKeyNotCell, bucketKeyIsNumber);
+            m_out.branch(isNotNumber(bucketKey),
+                unsure(loopAround), unsure(bucketKeyIsNumber));
+
+            m_out.appendTo(bucketKeyIsNumber, bothAreNumbers);
+            m_out.branch(isNotNumber(key),
+                unsure(loopAround), unsure(bothAreNumbers));
+
+            m_out.appendTo(bothAreNumbers, bucketKeyIsInt32);
+            m_out.branch(isNotInt32(bucketKey),
+                unsure(slowPath), unsure(bucketKeyIsInt32));
+
+            m_out.appendTo(bucketKeyIsInt32, loopAround);
+            m_out.branch(isNotInt32(key),
+                unsure(slowPath), unsure(loopAround));
+            break;
+        }
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+        }
+
+        m_out.appendTo(loopAround, slowPath);
+        m_out.addIncomingToPhi(unmaskedIndex, m_out.anchor(m_out.add(index, m_out.int32One)));
+        m_out.jump(loopStart);
+
+        m_out.appendTo(slowPath, notPresentInTable);
+        ValueFromBlock slowPathResult = m_out.anchor(vmCall(pointerType(),
+            m_out.operation(m_node->child1().useKind() == MapObjectUse ? operationJSMapFindBucket : operationJSSetFindBucket), m_callFrame, map, key, hash));
+        m_out.jump(continuation);
+
+        m_out.appendTo(notPresentInTable, continuation);
+        ValueFromBlock notPresentResult = m_out.anchor(m_out.constIntPtr(0));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setMapBucket(m_out.phi(pointerType(), bucketResult, slowPathResult, notPresentResult));
+    }
+
+    void compileLoadFromJSMapBucket()
+    {
+        LValue mapBucket = lowMapBucket(m_node->child1());
+
+        LBasicBlock continuation = m_out.newBlock();
+        LBasicBlock hasBucket = m_out.newBlock();
+
+        ValueFromBlock noBucketResult = m_out.anchor(m_out.constInt64(JSValue::encode(jsUndefined())));
+
+        m_out.branch(m_out.equal(mapBucket, m_out.constIntPtr(0)),
+            unsure(continuation), unsure(hasBucket));
+
+        LBasicBlock lastNext = m_out.appendTo(hasBucket, continuation);
+        ValueFromBlock bucketResult = m_out.anchor(m_out.load64(mapBucket, m_heaps.HashMapBucket_value));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, noBucketResult, bucketResult));
+    }
+
+    void compileIsNonEmptyMapBucket()
+    {
+        LValue bucket = lowMapBucket(m_node->child1());
+        LValue result = m_out.notEqual(bucket, m_out.constIntPtr(0));
+        setBoolean(result);
+    }
+
+    void compileIsObjectOrNull()
+    {
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+        
+        Edge child = m_node->child1();
+        LValue value = lowJSValue(child);
+        
+        LBasicBlock cellCase = m_out.newBlock();
+        LBasicBlock notFunctionCase = m_out.newBlock();
+        LBasicBlock objectCase = m_out.newBlock();
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock notCellCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        m_out.branch(isCell(value, provenType(child)), unsure(cellCase), unsure(notCellCase));
+        
+        LBasicBlock lastNext = m_out.appendTo(cellCase, notFunctionCase);
+        ValueFromBlock isFunctionResult = m_out.anchor(m_out.booleanFalse);
+        m_out.branch(
+            isFunction(value, provenType(child)),
+            unsure(continuation), unsure(notFunctionCase));
+        
+        m_out.appendTo(notFunctionCase, objectCase);
+        ValueFromBlock notObjectResult = m_out.anchor(m_out.booleanFalse);
+        m_out.branch(
+            isObject(value, provenType(child)),
+            unsure(objectCase), unsure(continuation));
+        
+        m_out.appendTo(objectCase, slowPath);
+        ValueFromBlock objectResult = m_out.anchor(m_out.booleanTrue);
+        m_out.branch(
+            isExoticForTypeof(value, provenType(child)),
+            rarely(slowPath), usually(continuation));
+        
+        m_out.appendTo(slowPath, notCellCase);
+        LValue slowResultValue = lazySlowPath(
+            [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                return createLazyCallGenerator(
+                    operationObjectIsObject, locations[0].directGPR(),
+                    CCallHelpers::TrustedImmPtr(globalObject), locations[1].directGPR());
+            }, value);
+        ValueFromBlock slowResult = m_out.anchor(m_out.notZero64(slowResultValue));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(notCellCase, continuation);
+        LValue notCellResultValue = m_out.equal(value, m_out.constInt64(JSValue::encode(jsNull())));
+        ValueFromBlock notCellResult = m_out.anchor(notCellResultValue);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        LValue result = m_out.phi(
+            Int32,
+            isFunctionResult, notObjectResult, objectResult, slowResult, notCellResult);
+        setBoolean(result);
+    }
+    
+    void compileIsFunction()
+    {
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+        
+        Edge child = m_node->child1();
+        LValue value = lowJSValue(child);
+        
+        LBasicBlock cellCase = m_out.newBlock();
+        LBasicBlock notFunctionCase = m_out.newBlock();
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        ValueFromBlock notCellResult = m_out.anchor(m_out.booleanFalse);
+        m_out.branch(
+            isCell(value, provenType(child)), unsure(cellCase), unsure(continuation));
+        
+        LBasicBlock lastNext = m_out.appendTo(cellCase, notFunctionCase);
+        ValueFromBlock functionResult = m_out.anchor(m_out.booleanTrue);
+        m_out.branch(
+            isFunction(value, provenType(child)),
+            unsure(continuation), unsure(notFunctionCase));
+        
+        m_out.appendTo(notFunctionCase, slowPath);
+        ValueFromBlock objectResult = m_out.anchor(m_out.booleanFalse);
+        m_out.branch(
+            isExoticForTypeof(value, provenType(child)),
+            rarely(slowPath), usually(continuation));
+        
+        m_out.appendTo(slowPath, continuation);
+        LValue slowResultValue = lazySlowPath(
+            [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                return createLazyCallGenerator(
+                    operationObjectIsFunction, locations[0].directGPR(),
+                    CCallHelpers::TrustedImmPtr(globalObject), locations[1].directGPR());
+            }, value);
+        ValueFromBlock slowResult = m_out.anchor(m_out.notNull(slowResultValue));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        LValue result = m_out.phi(
+            Int32, notCellResult, functionResult, objectResult, slowResult);
+        setBoolean(result);
+    }
+
+    void compileIsTypedArrayView()
+    {
+        LValue value = lowJSValue(m_node->child1());
+
+        LBasicBlock isCellCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        ValueFromBlock notCellResult = m_out.anchor(m_out.booleanFalse);
+        m_out.branch(isCell(value, provenType(m_node->child1())), unsure(isCellCase), unsure(continuation));
+
+        LBasicBlock lastNext = m_out.appendTo(isCellCase, continuation);
+        ValueFromBlock cellResult = m_out.anchor(isTypedArrayView(value, provenType(m_node->child1())));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setBoolean(m_out.phi(Int32, notCellResult, cellResult));
+    }
+
+    void compileTypeOf()
+    {
+        Edge child = m_node->child1();
+        LValue value = lowJSValue(child);
+        
+        LBasicBlock continuation = m_out.newBlock();
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(continuation);
+        
+        Vector<ValueFromBlock> results;
+        
+        buildTypeOf(
+            child, value,
+            [&] (TypeofType type) {
+                results.append(m_out.anchor(weakPointer(vm().smallStrings.typeString(type))));
+                m_out.jump(continuation);
+            });
+        
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, results));
+    }
+    
+    void compileIn()
+    {
+        DFG_ASSERT(m_graph, m_node, m_node->child1().useKind() == CellUse);
+
+        Node* node = m_node;
+        Edge base = node->child1();
+        LValue cell = lowCell(base);
+        if (JSString* string = node->child2()->dynamicCastConstant<JSString*>(vm())) {
+            if (string->tryGetValueImpl() && string->tryGetValueImpl()->isAtomic()) {
+                UniquedStringImpl* str = bitwise_cast<UniquedStringImpl*>(string->tryGetValueImpl());
+                B3::PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+                patchpoint->appendSomeRegister(cell);
+                patchpoint->append(m_tagMask, ValueRep::lateReg(GPRInfo::tagMaskRegister));
+                patchpoint->append(m_tagTypeNumber, ValueRep::lateReg(GPRInfo::tagTypeNumberRegister));
+                patchpoint->clobber(RegisterSet::macroScratchRegisters());
+
+                RefPtr<PatchpointExceptionHandle> exceptionHandle = preparePatchpointForExceptions(patchpoint);
+
+                State* state = &m_ftlState;
+                patchpoint->setGenerator(
+                    [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                        AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                        // This is the direct exit target for operation calls. We don't need a JS exceptionHandle because we don't
+                        // cache Proxy objects.
+                        Box<CCallHelpers::JumpList> exceptions = exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+
+                        GPRReg baseGPR = params[1].gpr();
+                        GPRReg resultGPR = params[0].gpr();
+
+                        StructureStubInfo* stubInfo =
+                            jit.codeBlock()->addStubInfo(AccessType::In);
+                        stubInfo->callSiteIndex =
+                            state->jitCode->common.addCodeOrigin(node->origin.semantic);
+                        stubInfo->codeOrigin = node->origin.semantic;
+                        stubInfo->patch.baseGPR = static_cast<int8_t>(baseGPR);
+                        stubInfo->patch.valueGPR = static_cast<int8_t>(resultGPR);
+                        stubInfo->patch.usedRegisters = params.unavailableRegisters();
+
+                        CCallHelpers::PatchableJump jump = jit.patchableJump();
+                        CCallHelpers::Label done = jit.label();
+
+                        params.addLatePath(
+                            [=] (CCallHelpers& jit) {
+                                AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                                jump.m_jump.link(&jit);
+                                CCallHelpers::Label slowPathBegin = jit.label();
+                                CCallHelpers::Call slowPathCall = callOperation(
+                                    *state, params.unavailableRegisters(), jit,
+                                    node->origin.semantic, exceptions.get(), operationInOptimize,
+                                    resultGPR, CCallHelpers::TrustedImmPtr(stubInfo), baseGPR,
+                                    CCallHelpers::TrustedImmPtr(str)).call();
+                                jit.jump().linkTo(done, &jit);
+
+                                jit.addLinkTask(
+                                    [=] (LinkBuffer& linkBuffer) {
+                                        CodeLocationLabel start = linkBuffer.locationOf(jump);
+                                        stubInfo->patch.start = start;
+                                        ptrdiff_t inlineSize = MacroAssembler::differenceBetweenCodePtr(
+                                            start, linkBuffer.locationOf(done));
+                                        RELEASE_ASSERT(inlineSize >= 0);
+                                        stubInfo->patch.inlineSize = inlineSize;
+
+                                        stubInfo->patch.deltaFromStartToSlowPathCallLocation = MacroAssembler::differenceBetweenCodePtr(
+                                            start, linkBuffer.locationOf(slowPathCall));
+
+                                        stubInfo->patch.deltaFromStartToSlowPathStart = MacroAssembler::differenceBetweenCodePtr(
+                                            start, linkBuffer.locationOf(slowPathBegin));
+
+                                    });
+                            });
+                    });
+
+                setJSValue(patchpoint);
+                return;
+            }
+        } 
+
+        setJSValue(vmCall(Int64, m_out.operation(operationGenericIn), m_callFrame, cell, lowJSValue(m_node->child2())));
+    }
+
+    void compileHasOwnProperty()
+    {
+        LBasicBlock slowCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        LBasicBlock lastNext = nullptr;
+
+        LValue object = lowObject(m_node->child1());
+        LValue uniquedStringImpl;
+        LValue keyAsValue = nullptr;
+        switch (m_node->child2().useKind()) {
+        case StringUse: {
+            LBasicBlock isNonEmptyString = m_out.newBlock();
+            LBasicBlock isAtomicString = m_out.newBlock();
+
+            keyAsValue = lowString(m_node->child2());
+            uniquedStringImpl = m_out.loadPtr(keyAsValue, m_heaps.JSString_value);
+            m_out.branch(m_out.notNull(uniquedStringImpl), usually(isNonEmptyString), rarely(slowCase));
+
+            lastNext = m_out.appendTo(isNonEmptyString, isAtomicString);
+            LValue isNotAtomic = m_out.testIsZero32(m_out.load32(uniquedStringImpl, m_heaps.StringImpl_hashAndFlags), m_out.constInt32(StringImpl::flagIsAtomic()));
+            m_out.branch(isNotAtomic, rarely(slowCase), usually(isAtomicString));
+
+            m_out.appendTo(isAtomicString, slowCase);
+            break;
+        }
+        case SymbolUse: {
+            keyAsValue = lowSymbol(m_node->child2());
+            uniquedStringImpl = m_out.loadPtr(keyAsValue, m_heaps.Symbol_symbolImpl);
+            lastNext = m_out.insertNewBlocksBefore(slowCase);
+            break;
+        }
+        case UntypedUse: {
+            LBasicBlock isCellCase = m_out.newBlock();
+            LBasicBlock isStringCase = m_out.newBlock();
+            LBasicBlock notStringCase = m_out.newBlock();
+            LBasicBlock isNonEmptyString = m_out.newBlock();
+            LBasicBlock isSymbolCase = m_out.newBlock();
+            LBasicBlock hasUniquedStringImpl = m_out.newBlock();
+
+            keyAsValue = lowJSValue(m_node->child2());
+            m_out.branch(isCell(keyAsValue), usually(isCellCase), rarely(slowCase));
+
+            lastNext = m_out.appendTo(isCellCase, isStringCase);
+            m_out.branch(isString(keyAsValue), unsure(isStringCase), unsure(notStringCase));
+
+            m_out.appendTo(isStringCase, isNonEmptyString);
+            LValue implFromString = m_out.loadPtr(keyAsValue, m_heaps.JSString_value);
+            ValueFromBlock stringResult = m_out.anchor(implFromString);
+            m_out.branch(m_out.notNull(implFromString), usually(isNonEmptyString), rarely(slowCase));
+
+            m_out.appendTo(isNonEmptyString, notStringCase);
+            LValue isNotAtomic = m_out.testIsZero32(m_out.load32(implFromString, m_heaps.StringImpl_hashAndFlags), m_out.constInt32(StringImpl::flagIsAtomic()));
+            m_out.branch(isNotAtomic, rarely(slowCase), usually(hasUniquedStringImpl));
+
+            m_out.appendTo(notStringCase, isSymbolCase);
+            m_out.branch(isSymbol(keyAsValue), unsure(isSymbolCase), unsure(slowCase));
+
+            m_out.appendTo(isSymbolCase, hasUniquedStringImpl);
+            ValueFromBlock symbolResult = m_out.anchor(m_out.loadPtr(keyAsValue, m_heaps.Symbol_symbolImpl));
+            m_out.jump(hasUniquedStringImpl);
+
+            m_out.appendTo(hasUniquedStringImpl, slowCase);
+            uniquedStringImpl = m_out.phi(pointerType(), stringResult, symbolResult);
+            break;
+        }
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+        }
+
+        ASSERT(keyAsValue);
+
+        // Note that we don't test if the hash is zero here. AtomicStringImpl's can't have a zero
+        // hash, however, a SymbolImpl may. But, because this is a cache, we don't care. We only
+        // ever load the result from the cache if the cache entry matches what we are querying for.
+        // So we either get super lucky and use zero for the hash and somehow collide with the entity
+        // we're looking for, or we realize we're comparing against another entity, and go to the
+        // slow path anyways.
+        LValue hash = m_out.lShr(m_out.load32(uniquedStringImpl, m_heaps.StringImpl_hashAndFlags), m_out.constInt32(StringImpl::s_flagCount));
+
+        LValue structureID = m_out.load32(object, m_heaps.JSCell_structureID);
+        LValue index = m_out.add(hash, structureID);
+        index = m_out.zeroExtPtr(m_out.bitAnd(index, m_out.constInt32(HasOwnPropertyCache::mask)));
+        ASSERT(vm().hasOwnPropertyCache());
+        LValue cache = m_out.constIntPtr(vm().hasOwnPropertyCache());
+
+        IndexedAbstractHeap& heap = m_heaps.HasOwnPropertyCache;
+        LValue sameStructureID = m_out.equal(structureID, m_out.load32(m_out.baseIndex(heap, cache, index, JSValue(), HasOwnPropertyCache::Entry::offsetOfStructureID())));
+        LValue sameImpl = m_out.equal(uniquedStringImpl, m_out.loadPtr(m_out.baseIndex(heap, cache, index, JSValue(), HasOwnPropertyCache::Entry::offsetOfImpl())));
+        ValueFromBlock fastResult = m_out.anchor(m_out.load8ZeroExt32(m_out.baseIndex(heap, cache, index, JSValue(), HasOwnPropertyCache::Entry::offsetOfResult())));
+        LValue cacheHit = m_out.bitAnd(sameStructureID, sameImpl);
+
+        m_out.branch(m_out.notZero32(cacheHit), usually(continuation), rarely(slowCase));
+
+        m_out.appendTo(slowCase, continuation);
+        ValueFromBlock slowResult;
+        slowResult = m_out.anchor(vmCall(Int32, m_out.operation(operationHasOwnProperty), m_callFrame, object, keyAsValue));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setBoolean(m_out.phi(Int32, fastResult, slowResult));
+    }
+
+    void compileParseInt()
+    {
+        RELEASE_ASSERT(m_node->child1().useKind() == UntypedUse || m_node->child1().useKind() == StringUse);
+        LValue result;
+        if (m_node->child2()) {
+            LValue radix = lowInt32(m_node->child2());
+            if (m_node->child1().useKind() == UntypedUse)
+                result = vmCall(Int64, m_out.operation(operationParseIntGeneric), m_callFrame, lowJSValue(m_node->child1()), radix);
+            else
+                result = vmCall(Int64, m_out.operation(operationParseIntString), m_callFrame, lowString(m_node->child1()), radix);
+        } else {
+            if (m_node->child1().useKind() == UntypedUse)
+                result = vmCall(Int64, m_out.operation(operationParseIntNoRadixGeneric), m_callFrame, lowJSValue(m_node->child1()));
+            else
+                result = vmCall(Int64, m_out.operation(operationParseIntStringNoRadix), m_callFrame, lowString(m_node->child1()));
+        }
+        setJSValue(result);
+    }
+
+    void compileOverridesHasInstance()
+    {
+        FrozenValue* defaultHasInstanceFunction = m_node->cellOperand();
+        ASSERT(defaultHasInstanceFunction->cell()->inherits(vm(), JSFunction::info()));
+
+        LValue constructor = lowCell(m_node->child1());
+        LValue hasInstance = lowJSValue(m_node->child2());
+
+        LBasicBlock defaultHasInstance = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        // Unlike in the DFG, we don't worry about cleaning this code up for the case where we have proven the hasInstanceValue is a constant as B3 should fix it for us.
+
+        ValueFromBlock notDefaultHasInstanceResult = m_out.anchor(m_out.booleanTrue);
+        m_out.branch(m_out.notEqual(hasInstance, frozenPointer(defaultHasInstanceFunction)), unsure(continuation), unsure(defaultHasInstance));
+
+        LBasicBlock lastNext = m_out.appendTo(defaultHasInstance, continuation);
+        ValueFromBlock implementsDefaultHasInstanceResult = m_out.anchor(m_out.testIsZero32(
+            m_out.load8ZeroExt32(constructor, m_heaps.JSCell_typeInfoFlags),
+            m_out.constInt32(ImplementsDefaultHasInstance)));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setBoolean(m_out.phi(Int32, implementsDefaultHasInstanceResult, notDefaultHasInstanceResult));
+    }
+
+    void compileCheckTypeInfoFlags()
+    {
+        speculate(
+            BadTypeInfoFlags, noValue(), 0,
+            m_out.testIsZero32(
+                m_out.load8ZeroExt32(lowCell(m_node->child1()), m_heaps.JSCell_typeInfoFlags),
+                m_out.constInt32(m_node->typeInfoOperand())));
+    }
+    
+    void compileInstanceOf()
+    {
+        LValue cell;
+        
+        if (m_node->child1().useKind() == UntypedUse)
+            cell = lowJSValue(m_node->child1());
+        else
+            cell = lowCell(m_node->child1());
+        
+        LValue prototype = lowCell(m_node->child2());
+        
+        LBasicBlock isCellCase = m_out.newBlock();
+        LBasicBlock loop = m_out.newBlock();
+        LBasicBlock notYetInstance = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        LBasicBlock loadPrototypeDirect = m_out.newBlock();
+        LBasicBlock defaultHasInstanceSlow = m_out.newBlock();
+        
+        LValue condition;
+        if (m_node->child1().useKind() == UntypedUse)
+            condition = isCell(cell, provenType(m_node->child1()));
+        else
+            condition = m_out.booleanTrue;
+        
+        ValueFromBlock notCellResult = m_out.anchor(m_out.booleanFalse);
+        m_out.branch(condition, unsure(isCellCase), unsure(continuation));
+        
+        LBasicBlock lastNext = m_out.appendTo(isCellCase, loop);
+        
+        speculate(BadType, noValue(), 0, isNotObject(prototype, provenType(m_node->child2())));
+        
+        ValueFromBlock originalValue = m_out.anchor(cell);
+        m_out.jump(loop);
+        
+        m_out.appendTo(loop, loadPrototypeDirect);
+        LValue value = m_out.phi(Int64, originalValue);
+        LValue type = m_out.load8ZeroExt32(value, m_heaps.JSCell_typeInfoType);
+        m_out.branch(
+            m_out.notEqual(type, m_out.constInt32(ProxyObjectType)),
+            usually(loadPrototypeDirect), rarely(defaultHasInstanceSlow));
+
+        m_out.appendTo(loadPrototypeDirect, notYetInstance);
+        LValue structure = loadStructure(value);
+        LValue currentPrototype = m_out.load64(structure, m_heaps.Structure_prototype);
+        ValueFromBlock isInstanceResult = m_out.anchor(m_out.booleanTrue);
+        m_out.branch(
+            m_out.equal(currentPrototype, prototype),
+            unsure(continuation), unsure(notYetInstance));
+        
+        m_out.appendTo(notYetInstance, defaultHasInstanceSlow);
+        ValueFromBlock notInstanceResult = m_out.anchor(m_out.booleanFalse);
+        m_out.addIncomingToPhi(value, m_out.anchor(currentPrototype));
+        m_out.branch(isCell(currentPrototype), unsure(loop), unsure(continuation));
+
+        m_out.appendTo(defaultHasInstanceSlow, continuation);
+        // We can use the value that we're looping with because we
+        // can just continue off from wherever we bailed from the
+        // loop.
+        ValueFromBlock defaultHasInstanceResult = m_out.anchor(
+            vmCall(Int32, m_out.operation(operationDefaultHasInstance), m_callFrame, value, prototype));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setBoolean(
+            m_out.phi(Int32, notCellResult, isInstanceResult, notInstanceResult, defaultHasInstanceResult));
+    }
+
+    void compileInstanceOfCustom()
+    {
+        LValue value = lowJSValue(m_node->child1());
+        LValue constructor = lowCell(m_node->child2());
+        LValue hasInstance = lowJSValue(m_node->child3());
+
+        setBoolean(m_out.logicalNot(m_out.equal(m_out.constInt32(0), vmCall(Int32, m_out.operation(operationInstanceOfCustom), m_callFrame, value, constructor, hasInstance))));
+    }
+    
+    void compileCountExecution()
+    {
+        TypedPointer counter = m_out.absolute(m_node->executionCounter()->address());
+        m_out.store64(m_out.add(m_out.load64(counter), m_out.constInt64(1)), counter);
+    }
+    
+    void compileStoreBarrier()
+    {
+        emitStoreBarrier(lowCell(m_node->child1()), m_node->op() == FencedStoreBarrier);
+    }
+    
+    void compileHasIndexedProperty()
+    {
+        switch (m_node->arrayMode().type()) {
+        case Array::Int32:
+        case Array::Contiguous: {
+            LValue base = lowCell(m_node->child1());
+            LValue index = lowInt32(m_node->child2());
+            LValue storage = lowStorage(m_node->child3());
+            LValue internalMethodType = m_out.constInt32(static_cast<int32_t>(m_node->internalMethodType()));
+
+            IndexedAbstractHeap& heap = m_node->arrayMode().type() == Array::Int32 ?
+                m_heaps.indexedInt32Properties : m_heaps.indexedContiguousProperties;
+
+            LBasicBlock checkHole = m_out.newBlock();
+            LBasicBlock slowCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            if (!m_node->arrayMode().isInBounds()) {
+                m_out.branch(
+                    m_out.aboveOrEqual(
+                        index, m_out.load32NonNegative(storage, m_heaps.Butterfly_publicLength)),
+                    rarely(slowCase), usually(checkHole));
+            } else
+                m_out.jump(checkHole);
+
+            LBasicBlock lastNext = m_out.appendTo(checkHole, slowCase);
+            LValue checkHoleResultValue =
+                m_out.notZero64(m_out.load64(baseIndex(heap, storage, index, m_node->child2())));
+            ValueFromBlock checkHoleResult = m_out.anchor(checkHoleResultValue);
+            m_out.branch(checkHoleResultValue, usually(continuation), rarely(slowCase));
+
+            m_out.appendTo(slowCase, continuation);
+            ValueFromBlock slowResult = m_out.anchor(m_out.equal(
+                m_out.constInt64(JSValue::encode(jsBoolean(true))), 
+                vmCall(Int64, m_out.operation(operationHasIndexedProperty), m_callFrame, base, index, internalMethodType)));
+            m_out.jump(continuation);
+
+            m_out.appendTo(continuation, lastNext);
+            setBoolean(m_out.phi(Int32, checkHoleResult, slowResult));
+            return;
+        }
+        case Array::Double: {
+            LValue base = lowCell(m_node->child1());
+            LValue index = lowInt32(m_node->child2());
+            LValue storage = lowStorage(m_node->child3());
+            LValue internalMethodType = m_out.constInt32(static_cast<int32_t>(m_node->internalMethodType()));
+            
+            IndexedAbstractHeap& heap = m_heaps.indexedDoubleProperties;
+            
+            LBasicBlock checkHole = m_out.newBlock();
+            LBasicBlock slowCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            if (!m_node->arrayMode().isInBounds()) {
+                m_out.branch(
+                    m_out.aboveOrEqual(
+                        index, m_out.load32NonNegative(storage, m_heaps.Butterfly_publicLength)),
+                    rarely(slowCase), usually(checkHole));
+            } else
+                m_out.jump(checkHole);
+
+            LBasicBlock lastNext = m_out.appendTo(checkHole, slowCase);
+            LValue doubleValue = m_out.loadDouble(baseIndex(heap, storage, index, m_node->child2()));
+            LValue checkHoleResultValue = m_out.doubleEqual(doubleValue, doubleValue);
+            ValueFromBlock checkHoleResult = m_out.anchor(checkHoleResultValue);
+            m_out.branch(checkHoleResultValue, usually(continuation), rarely(slowCase));
+            
+            m_out.appendTo(slowCase, continuation);
+            ValueFromBlock slowResult = m_out.anchor(m_out.equal(
+                m_out.constInt64(JSValue::encode(jsBoolean(true))), 
+                vmCall(Int64, m_out.operation(operationHasIndexedProperty), m_callFrame, base, index, internalMethodType)));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            setBoolean(m_out.phi(Int32, checkHoleResult, slowResult));
+            return;
+        }
+            
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+            return;
+        }
+    }
+
+    void compileHasGenericProperty()
+    {
+        LValue base = lowJSValue(m_node->child1());
+        LValue property = lowCell(m_node->child2());
+        setJSValue(vmCall(Int64, m_out.operation(operationHasGenericProperty), m_callFrame, base, property));
+    }
+
+    void compileHasStructureProperty()
+    {
+        LValue base = lowJSValue(m_node->child1());
+        LValue property = lowString(m_node->child2());
+        LValue enumerator = lowCell(m_node->child3());
+
+        LBasicBlock correctStructure = m_out.newBlock();
+        LBasicBlock wrongStructure = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(m_out.notEqual(
+            m_out.load32(base, m_heaps.JSCell_structureID),
+            m_out.load32(enumerator, m_heaps.JSPropertyNameEnumerator_cachedStructureID)),
+            rarely(wrongStructure), usually(correctStructure));
+
+        LBasicBlock lastNext = m_out.appendTo(correctStructure, wrongStructure);
+        ValueFromBlock correctStructureResult = m_out.anchor(m_out.booleanTrue);
+        m_out.jump(continuation);
+
+        m_out.appendTo(wrongStructure, continuation);
+        ValueFromBlock wrongStructureResult = m_out.anchor(
+            m_out.equal(
+                m_out.constInt64(JSValue::encode(jsBoolean(true))), 
+                vmCall(Int64, m_out.operation(operationHasGenericProperty), m_callFrame, base, property)));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setBoolean(m_out.phi(Int32, correctStructureResult, wrongStructureResult));
+    }
+
+    void compileGetDirectPname()
+    {
+        LValue base = lowCell(m_graph.varArgChild(m_node, 0));
+        LValue property = lowCell(m_graph.varArgChild(m_node, 1));
+        LValue index = lowInt32(m_graph.varArgChild(m_node, 2));
+        LValue enumerator = lowCell(m_graph.varArgChild(m_node, 3));
+
+        LBasicBlock checkOffset = m_out.newBlock();
+        LBasicBlock inlineLoad = m_out.newBlock();
+        LBasicBlock outOfLineLoad = m_out.newBlock();
+        LBasicBlock slowCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(m_out.notEqual(
+            m_out.load32(base, m_heaps.JSCell_structureID),
+            m_out.load32(enumerator, m_heaps.JSPropertyNameEnumerator_cachedStructureID)),
+            rarely(slowCase), usually(checkOffset));
+
+        LBasicBlock lastNext = m_out.appendTo(checkOffset, inlineLoad);
+        m_out.branch(m_out.aboveOrEqual(index, m_out.load32(enumerator, m_heaps.JSPropertyNameEnumerator_cachedInlineCapacity)),
+            unsure(outOfLineLoad), unsure(inlineLoad));
+
+        m_out.appendTo(inlineLoad, outOfLineLoad);
+        ValueFromBlock inlineResult = m_out.anchor(
+            m_out.load64(m_out.baseIndex(m_heaps.properties.atAnyNumber(), 
+                base, m_out.zeroExt(index, Int64), ScaleEight, JSObject::offsetOfInlineStorage())));
+        m_out.jump(continuation);
+
+        m_out.appendTo(outOfLineLoad, slowCase);
+        LValue storage = m_out.loadPtr(base, m_heaps.JSObject_butterfly);
+        LValue realIndex = m_out.signExt32To64(
+            m_out.neg(m_out.sub(index, m_out.load32(enumerator, m_heaps.JSPropertyNameEnumerator_cachedInlineCapacity))));
+        int32_t offsetOfFirstProperty = static_cast<int32_t>(offsetInButterfly(firstOutOfLineOffset)) * sizeof(EncodedJSValue);
+        ValueFromBlock outOfLineResult = m_out.anchor(
+            m_out.load64(m_out.baseIndex(m_heaps.properties.atAnyNumber(), storage, realIndex, ScaleEight, offsetOfFirstProperty)));
+        m_out.jump(continuation);
+
+        m_out.appendTo(slowCase, continuation);
+        ValueFromBlock slowCaseResult = m_out.anchor(
+            vmCall(Int64, m_out.operation(operationGetByVal), m_callFrame, base, property));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, inlineResult, outOfLineResult, slowCaseResult));
+    }
+
+    void compileGetEnumerableLength()
+    {
+        LValue enumerator = lowCell(m_node->child1());
+        setInt32(m_out.load32(enumerator, m_heaps.JSPropertyNameEnumerator_indexLength));
+    }
+
+    void compileGetPropertyEnumerator()
+    {
+        LValue base = lowCell(m_node->child1());
+        setJSValue(vmCall(Int64, m_out.operation(operationGetPropertyEnumerator), m_callFrame, base));
+    }
+
+    void compileGetEnumeratorStructurePname()
+    {
+        LValue enumerator = lowCell(m_node->child1());
+        LValue index = lowInt32(m_node->child2());
+
+        LBasicBlock inBounds = m_out.newBlock();
+        LBasicBlock outOfBounds = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(m_out.below(index, m_out.load32(enumerator, m_heaps.JSPropertyNameEnumerator_endStructurePropertyIndex)),
+            usually(inBounds), rarely(outOfBounds));
+
+        LBasicBlock lastNext = m_out.appendTo(inBounds, outOfBounds);
+        LValue storage = m_out.loadPtr(enumerator, m_heaps.JSPropertyNameEnumerator_cachedPropertyNamesVector);
+        ValueFromBlock inBoundsResult = m_out.anchor(
+            m_out.loadPtr(m_out.baseIndex(m_heaps.JSPropertyNameEnumerator_cachedPropertyNamesVectorContents, storage, m_out.zeroExtPtr(index))));
+        m_out.jump(continuation);
+
+        m_out.appendTo(outOfBounds, continuation);
+        ValueFromBlock outOfBoundsResult = m_out.anchor(m_out.constInt64(ValueNull));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, inBoundsResult, outOfBoundsResult));
+    }
+
+    void compileGetEnumeratorGenericPname()
+    {
+        LValue enumerator = lowCell(m_node->child1());
+        LValue index = lowInt32(m_node->child2());
+
+        LBasicBlock inBounds = m_out.newBlock();
+        LBasicBlock outOfBounds = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(m_out.below(index, m_out.load32(enumerator, m_heaps.JSPropertyNameEnumerator_endGenericPropertyIndex)),
+            usually(inBounds), rarely(outOfBounds));
+
+        LBasicBlock lastNext = m_out.appendTo(inBounds, outOfBounds);
+        LValue storage = m_out.loadPtr(enumerator, m_heaps.JSPropertyNameEnumerator_cachedPropertyNamesVector);
+        ValueFromBlock inBoundsResult = m_out.anchor(
+            m_out.loadPtr(m_out.baseIndex(m_heaps.JSPropertyNameEnumerator_cachedPropertyNamesVectorContents, storage, m_out.zeroExtPtr(index))));
+        m_out.jump(continuation);
+
+        m_out.appendTo(outOfBounds, continuation);
+        ValueFromBlock outOfBoundsResult = m_out.anchor(m_out.constInt64(ValueNull));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(Int64, inBoundsResult, outOfBoundsResult));
+    }
+    
+    void compileToIndexString()
+    {
+        LValue index = lowInt32(m_node->child1());
+        setJSValue(vmCall(Int64, m_out.operation(operationToIndexString), m_callFrame, index));
+    }
+    
+    void compileCheckStructureImmediate()
+    {
+        LValue structure = lowCell(m_node->child1());
+        checkStructure(
+            structure, noValue(), BadCache, m_node->structureSet(),
+            [this] (RegisteredStructure structure) {
+                return weakStructure(structure);
+            });
+    }
+    
+    void compileMaterializeNewObject()
+    {
+        ObjectMaterializationData& data = m_node->objectMaterializationData();
+        
+        // Lower the values first, to avoid creating values inside a control flow diamond.
+        
+        Vector<LValue, 8> values;
+        for (unsigned i = 0; i < data.m_properties.size(); ++i) {
+            Edge edge = m_graph.varArgChild(m_node, 1 + i);
+            switch (data.m_properties[i].kind()) {
+            case PublicLengthPLoc:
+            case VectorLengthPLoc:
+                values.append(lowInt32(edge));
+                break;
+            default:
+                values.append(lowJSValue(edge));
+                break;
+            }
+        }
+        
+        RegisteredStructureSet set = m_node->structureSet();
+
+        Vector<LBasicBlock, 1> blocks(set.size());
+        for (unsigned i = set.size(); i--;)
+            blocks[i] = m_out.newBlock();
+        LBasicBlock dummyDefault = m_out.newBlock();
+        LBasicBlock outerContinuation = m_out.newBlock();
+        
+        Vector<SwitchCase, 1> cases(set.size());
+        for (unsigned i = set.size(); i--;)
+            cases[i] = SwitchCase(weakStructure(set.at(i)), blocks[i], Weight(1));
+        m_out.switchInstruction(
+            lowCell(m_graph.varArgChild(m_node, 0)), cases, dummyDefault, Weight(0));
+        
+        LBasicBlock outerLastNext = m_out.m_nextBlock;
+        
+        Vector<ValueFromBlock, 1> results;
+        
+        for (unsigned i = set.size(); i--;) {
+            m_out.appendTo(blocks[i], i + 1 < set.size() ? blocks[i + 1] : dummyDefault);
+            
+            RegisteredStructure structure = set.at(i);
+            
+            LValue object;
+            LValue butterfly;
+            
+            if (structure->outOfLineCapacity() || hasIndexedProperties(structure->indexingType())) {
+                size_t allocationSize = JSFinalObject::allocationSize(structure->inlineCapacity());
+                MarkedAllocator* cellAllocator = subspaceFor<JSFinalObject>(vm())->allocatorFor(allocationSize);
+                DFG_ASSERT(m_graph, m_node, cellAllocator);
+
+                bool hasIndexingHeader = hasIndexedProperties(structure->indexingType());
+                unsigned indexingHeaderSize = 0;
+                LValue indexingPayloadSizeInBytes = m_out.intPtrZero;
+                LValue vectorLength = m_out.int32Zero;
+                LValue publicLength = m_out.int32Zero;
+                if (hasIndexingHeader) {
+                    indexingHeaderSize = sizeof(IndexingHeader);
+                    for (unsigned i = data.m_properties.size(); i--;) {
+                        PromotedLocationDescriptor descriptor = data.m_properties[i];
+                        switch (descriptor.kind()) {
+                        case PublicLengthPLoc:
+                            publicLength = values[i];
+                            break;
+                        case VectorLengthPLoc:
+                            vectorLength = values[i];
+                            break;
+                        default:
+                            break;
+                        }
+                    }
+                    indexingPayloadSizeInBytes =
+                        m_out.mul(m_out.zeroExtPtr(vectorLength), m_out.intPtrEight);
+                }
+                
+                LValue butterflySize = m_out.add(
+                    m_out.constIntPtr(
+                        structure->outOfLineCapacity() * sizeof(JSValue) + indexingHeaderSize),
+                    indexingPayloadSizeInBytes);
+                
+                LBasicBlock slowPath = m_out.newBlock();
+                LBasicBlock continuation = m_out.newBlock();
+                
+                LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
+                
+                ValueFromBlock noButterfly = m_out.anchor(m_out.intPtrZero);
+                
+                LValue startOfStorage = allocateHeapCell(
+                    allocatorForSize(vm().auxiliarySpace, butterflySize, slowPath),
+                    slowPath);
+
+                LValue fastButterflyValue = m_out.add(
+                    startOfStorage,
+                    m_out.constIntPtr(
+                        structure->outOfLineCapacity() * sizeof(JSValue) + sizeof(IndexingHeader)));
+                
+                ValueFromBlock haveButterfly = m_out.anchor(fastButterflyValue);
+                
+                splatWords(
+                    fastButterflyValue,
+                    m_out.constInt32(-structure->outOfLineCapacity() - 1),
+                    m_out.constInt32(-1),
+                    m_out.int64Zero, m_heaps.properties.atAnyNumber());
+
+                m_out.store32(vectorLength, fastButterflyValue, m_heaps.Butterfly_vectorLength);
+                
+                LValue fastObjectValue = allocateObject(
+                    m_out.constIntPtr(cellAllocator), structure, fastButterflyValue, slowPath);
+
+                ValueFromBlock fastObject = m_out.anchor(fastObjectValue);
+                ValueFromBlock fastButterfly = m_out.anchor(fastButterflyValue);
+                m_out.jump(continuation);
+                
+                m_out.appendTo(slowPath, continuation);
+                
+                LValue butterflyValue = m_out.phi(pointerType(), noButterfly, haveButterfly);
+
+                LValue slowObjectValue;
+                if (hasIndexingHeader) {
+                    slowObjectValue = lazySlowPath(
+                        [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                            return createLazyCallGenerator(
+                                operationNewObjectWithButterflyWithIndexingHeaderAndVectorLength,
+                                locations[0].directGPR(), CCallHelpers::TrustedImmPtr(structure.get()),
+                                locations[1].directGPR(), locations[2].directGPR());
+                        },
+                        vectorLength, butterflyValue);
+                } else {
+                    slowObjectValue = lazySlowPath(
+                        [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                            return createLazyCallGenerator(
+                                operationNewObjectWithButterfly, locations[0].directGPR(),
+                                CCallHelpers::TrustedImmPtr(structure.get()), locations[1].directGPR());
+                        },
+                        butterflyValue);
+                }
+                ValueFromBlock slowObject = m_out.anchor(slowObjectValue);
+                ValueFromBlock slowButterfly = m_out.anchor(
+                    m_out.loadPtr(slowObjectValue, m_heaps.JSObject_butterfly));
+                
+                m_out.jump(continuation);
+                
+                m_out.appendTo(continuation, lastNext);
+                
+                object = m_out.phi(pointerType(), fastObject, slowObject);
+                butterfly = m_out.phi(pointerType(), fastButterfly, slowButterfly);
+
+                m_out.store32(publicLength, butterfly, m_heaps.Butterfly_publicLength);
+
+                initializeArrayElements(m_out.constInt32(structure->indexingType()), m_out.int32Zero, vectorLength, butterfly);
+
+                HashMap<int32_t, LValue, DefaultHash<int32_t>::Hash, WTF::UnsignedWithZeroKeyHashTraits<int32_t>> indexMap;
+                Vector<int32_t> indices;
+                for (unsigned i = data.m_properties.size(); i--;) {
+                    PromotedLocationDescriptor descriptor = data.m_properties[i];
+                    if (descriptor.kind() != IndexedPropertyPLoc)
+                        continue;
+                    int32_t index = static_cast<int32_t>(descriptor.info());
+                    
+                    auto result = indexMap.add(index, values[i]);
+                    DFG_ASSERT(m_graph, m_node, result); // Duplicates are illegal.
+
+                    indices.append(index);
+                }
+
+                if (!indices.isEmpty()) {
+                    std::sort(indices.begin(), indices.end());
+                    
+                    Vector<LBasicBlock> blocksWithStores(indices.size());
+                    Vector<LBasicBlock> blocksWithChecks(indices.size());
+                    
+                    for (unsigned i = indices.size(); i--;) {
+                        blocksWithStores[i] = m_out.newBlock();
+                        blocksWithChecks[i] = m_out.newBlock(); // blocksWithChecks[0] is the continuation.
+                    }
+
+                    LBasicBlock indexLastNext = m_out.m_nextBlock;
+                    
+                    for (unsigned i = indices.size(); i--;) {
+                        int32_t index = indices[i];
+                        LValue value = indexMap.get(index);
+                        
+                        m_out.branch(
+                            m_out.below(m_out.constInt32(index), publicLength),
+                            unsure(blocksWithStores[i]), unsure(blocksWithChecks[i]));
+
+                        m_out.appendTo(blocksWithStores[i], blocksWithChecks[i]);
+
+                        // This has to type-check and convert its inputs, but it cannot do so in a
+                        // way that updates AI. That's a bit annoying, but if you think about how
+                        // sinking works, it's actually not a bad thing. We are virtually guaranteed
+                        // that these type checks will not fail, since the type checks that guarded
+                        // the original stores to the array are still somewhere above this point.
+                        Output::StoreType storeType;
+                        IndexedAbstractHeap* heap;
+                        switch (structure->indexingType()) {
+                        case ALL_INT32_INDEXING_TYPES:
+                            // FIXME: This could use the proven type if we had the Edge for the
+                            // value. https://bugs.webkit.org/show_bug.cgi?id=155311
+                            speculate(BadType, noValue(), nullptr, isNotInt32(value));
+                            storeType = Output::Store64;
+                            heap = &m_heaps.indexedInt32Properties;
+                            break;
+
+                        case ALL_DOUBLE_INDEXING_TYPES: {
+                            // FIXME: If the source is ValueRep, we should avoid emitting any
+                            // checks. We could also avoid emitting checks if we had the Edge of
+                            // this value. https://bugs.webkit.org/show_bug.cgi?id=155311
+
+                            LBasicBlock intCase = m_out.newBlock();
+                            LBasicBlock doubleCase = m_out.newBlock();
+                            LBasicBlock continuation = m_out.newBlock();
+
+                            m_out.branch(isInt32(value), unsure(intCase), unsure(doubleCase));
+
+                            LBasicBlock lastNext = m_out.appendTo(intCase, doubleCase);
+
+                            ValueFromBlock intResult =
+                                m_out.anchor(m_out.intToDouble(unboxInt32(value)));
+                            m_out.jump(continuation);
+
+                            m_out.appendTo(doubleCase, continuation);
+
+                            speculate(BadType, noValue(), nullptr, isNumber(value));
+                            ValueFromBlock doubleResult = m_out.anchor(unboxDouble(value));
+                            m_out.jump(continuation);
+
+                            m_out.appendTo(continuation, lastNext);
+                            value = m_out.phi(Double, intResult, doubleResult);
+                            storeType = Output::StoreDouble;
+                            heap = &m_heaps.indexedDoubleProperties;
+                            break;
+                        }
+
+                        case ALL_CONTIGUOUS_INDEXING_TYPES:
+                            storeType = Output::Store64;
+                            heap = &m_heaps.indexedContiguousProperties;
+                            break;
+
+                        default:
+                            DFG_CRASH(m_graph, m_node, "Invalid indexing type");
+                            break;
+                        }
+                        
+                        m_out.store(value, m_out.address(butterfly, heap->at(index)), storeType);
+
+                        m_out.jump(blocksWithChecks[i]);
+                        m_out.appendTo(
+                            blocksWithChecks[i], i ? blocksWithStores[i - 1] : indexLastNext);
+                    }
+                }
+            } else {
+                // In the easy case where we can do a one-shot allocation, we simply allocate the
+                // object to directly have the desired structure.
+                object = allocateObject(structure);
+                butterfly = nullptr; // Don't have one, don't need one.
+            }
+
+            BitVector setInlineOffsets;
+            for (PropertyMapEntry entry : structure->getPropertiesConcurrently()) {
+                for (unsigned i = data.m_properties.size(); i--;) {
+                    PromotedLocationDescriptor descriptor = data.m_properties[i];
+                    if (descriptor.kind() != NamedPropertyPLoc)
+                        continue;
+                    if (m_graph.identifiers()[descriptor.info()] != entry.key)
+                        continue;
+                    
+                    LValue base;
+                    if (isInlineOffset(entry.offset)) {
+                        setInlineOffsets.set(entry.offset);
+                        base = object;
+                    } else
+                        base = butterfly;
+                    storeProperty(values[i], base, descriptor.info(), entry.offset);
+                    break;
+                }
+            }
+            for (unsigned i = structure->inlineCapacity(); i--;) {
+                if (!setInlineOffsets.get(i))
+                    m_out.store64(m_out.int64Zero, m_out.address(m_heaps.properties.atAnyNumber(), object, offsetRelativeToBase(i)));
+            }
+            
+            results.append(m_out.anchor(object));
+            m_out.jump(outerContinuation);
+        }
+        
+        m_out.appendTo(dummyDefault, outerContinuation);
+        m_out.unreachable();
+        
+        m_out.appendTo(outerContinuation, outerLastNext);
+        setJSValue(m_out.phi(pointerType(), results));
+        mutatorFence();
+    }
+
+    void compileMaterializeCreateActivation()
+    {
+        ObjectMaterializationData& data = m_node->objectMaterializationData();
+
+        Vector<LValue, 8> values;
+        for (unsigned i = 0; i < data.m_properties.size(); ++i)
+            values.append(lowJSValue(m_graph.varArgChild(m_node, 2 + i)));
+
+        LValue scope = lowCell(m_graph.varArgChild(m_node, 1));
+        SymbolTable* table = m_node->castOperand<SymbolTable*>();
+        ASSERT(table == m_graph.varArgChild(m_node, 0)->castConstant<SymbolTable*>(vm()));
+        RegisteredStructure structure = m_graph.registerStructure(m_graph.globalObjectFor(m_node->origin.semantic)->activationStructure());
+
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
+
+        LValue fastObject = allocateObject<JSLexicalEnvironment>(
+            JSLexicalEnvironment::allocationSize(table), structure, m_out.intPtrZero, slowPath);
+
+        m_out.storePtr(scope, fastObject, m_heaps.JSScope_next);
+        m_out.storePtr(weakPointer(table), fastObject, m_heaps.JSSymbolTableObject_symbolTable);
+
+
+        ValueFromBlock fastResult = m_out.anchor(fastObject);
+        m_out.jump(continuation);
+
+        m_out.appendTo(slowPath, continuation);
+        // We ensure allocation sinking explictly sets bottom values for all field members. 
+        // Therefore, it doesn't matter what JSValue we pass in as the initialization value
+        // because all fields will be overwritten.
+        // FIXME: It may be worth creating an operation that calls a constructor on JSLexicalEnvironment that 
+        // doesn't initialize every slot because we are guaranteed to do that here.
+        LValue callResult = lazySlowPath(
+            [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                return createLazyCallGenerator(
+                    operationCreateActivationDirect, locations[0].directGPR(),
+                    CCallHelpers::TrustedImmPtr(structure.get()), locations[1].directGPR(),
+                    CCallHelpers::TrustedImmPtr(table),
+                    CCallHelpers::TrustedImm64(JSValue::encode(jsUndefined())));
+            }, scope);
+        ValueFromBlock slowResult =  m_out.anchor(callResult);
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        LValue activation = m_out.phi(pointerType(), fastResult, slowResult);
+        RELEASE_ASSERT(data.m_properties.size() == table->scopeSize());
+        for (unsigned i = 0; i < data.m_properties.size(); ++i) {
+            PromotedLocationDescriptor descriptor = data.m_properties[i];
+            ASSERT(descriptor.kind() == ClosureVarPLoc);
+            m_out.store64(
+                values[i], activation,
+                m_heaps.JSEnvironmentRecord_variables[descriptor.info()]);
+        }
+
+        if (validationEnabled()) {
+            // Validate to make sure every slot in the scope has one value.
+            ConcurrentJSLocker locker(table->m_lock);
+            for (auto iter = table->begin(locker), end = table->end(locker); iter != end; ++iter) {
+                bool found = false;
+                for (unsigned i = 0; i < data.m_properties.size(); ++i) {
+                    PromotedLocationDescriptor descriptor = data.m_properties[i];
+                    ASSERT(descriptor.kind() == ClosureVarPLoc);
+                    if (iter->value.scopeOffset().offset() == descriptor.info()) {
+                        found = true;
+                        break;
+                    }
+                }
+                ASSERT_UNUSED(found, found);
+            }
+        }
+
+        mutatorFence();
+        setJSValue(activation);
+    }
+
+    void compileCheckWatchdogTimer()
+    {
+        LBasicBlock timerDidFire = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LValue state = m_out.load8ZeroExt32(m_out.absolute(vm().watchdog()->timerDidFireAddress()));
+        m_out.branch(m_out.isZero32(state),
+            usually(continuation), rarely(timerDidFire));
+
+        LBasicBlock lastNext = m_out.appendTo(timerDidFire, continuation);
+
+        lazySlowPath(
+            [=] (const Vector<Location>&) -> RefPtr<LazySlowPath::Generator> {
+                return createLazyCallGenerator(operationHandleWatchdogTimer, InvalidGPRReg);
+            });
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+    }
+
+    void compileRegExpExec()
+    {
+        LValue globalObject = lowCell(m_node->child1());
+        
+        if (m_node->child2().useKind() == RegExpObjectUse) {
+            LValue base = lowRegExpObject(m_node->child2());
+            
+            if (m_node->child3().useKind() == StringUse) {
+                LValue argument = lowString(m_node->child3());
+                LValue result = vmCall(
+                    Int64, m_out.operation(operationRegExpExecString), m_callFrame, globalObject,
+                    base, argument);
+                setJSValue(result);
+                return;
+            }
+            
+            LValue argument = lowJSValue(m_node->child3());
+            LValue result = vmCall(
+                Int64, m_out.operation(operationRegExpExec), m_callFrame, globalObject, base,
+                argument);
+            setJSValue(result);
+            return;
+        }
+        
+        LValue base = lowJSValue(m_node->child2());
+        LValue argument = lowJSValue(m_node->child3());
+        LValue result = vmCall(
+            Int64, m_out.operation(operationRegExpExecGeneric), m_callFrame, globalObject, base,
+            argument);
+        setJSValue(result);
+    }
+
+    void compileRegExpTest()
+    {
+        LValue globalObject = lowCell(m_node->child1());
+        
+        if (m_node->child2().useKind() == RegExpObjectUse) {
+            LValue base = lowRegExpObject(m_node->child2());
+            
+            if (m_node->child3().useKind() == StringUse) {
+                LValue argument = lowString(m_node->child3());
+                LValue result = vmCall(
+                    Int32, m_out.operation(operationRegExpTestString), m_callFrame, globalObject,
+                    base, argument);
+                setBoolean(result);
+                return;
+            }
+
+            LValue argument = lowJSValue(m_node->child3());
+            LValue result = vmCall(
+                Int32, m_out.operation(operationRegExpTest), m_callFrame, globalObject, base,
+                argument);
+            setBoolean(result);
+            return;
+        }
+
+        LValue base = lowJSValue(m_node->child2());
+        LValue argument = lowJSValue(m_node->child3());
+        LValue result = vmCall(
+            Int32, m_out.operation(operationRegExpTestGeneric), m_callFrame, globalObject, base,
+            argument);
+        setBoolean(result);
+    }
+
+    void compileNewRegexp()
+    {
+        FrozenValue* regexp = m_node->cellOperand();
+        ASSERT(regexp->cell()->inherits(vm(), RegExp::info()));
+        LValue result = vmCall(
+            pointerType(),
+            m_out.operation(operationNewRegexp), m_callFrame,
+            frozenPointer(regexp));
+        
+        setJSValue(result);
+    }
+
+    void compileSetFunctionName()
+    {
+        vmCall(Void, m_out.operation(operationSetFunctionName), m_callFrame,
+            lowCell(m_node->child1()), lowJSValue(m_node->child2()));
+    }
+    
+    void compileStringReplace()
+    {
+        if (m_node->child1().useKind() == StringUse
+            && m_node->child2().useKind() == RegExpObjectUse
+            && m_node->child3().useKind() == StringUse) {
+
+            if (JSString* replace = m_node->child3()->dynamicCastConstant<JSString*>(vm())) {
+                if (!replace->length()) {
+                    LValue string = lowString(m_node->child1());
+                    LValue regExp = lowRegExpObject(m_node->child2());
+
+                    LValue result = vmCall(
+                        Int64, m_out.operation(operationStringProtoFuncReplaceRegExpEmptyStr),
+                        m_callFrame, string, regExp);
+
+                    setJSValue(result);
+                    return;
+                }
+            }
+            
+            LValue string = lowString(m_node->child1());
+            LValue regExp = lowRegExpObject(m_node->child2());
+            LValue replace = lowString(m_node->child3());
+
+            LValue result = vmCall(
+                Int64, m_out.operation(operationStringProtoFuncReplaceRegExpString),
+                m_callFrame, string, regExp, replace);
+
+            setJSValue(result);
+            return;
+        }
+
+        LValue search;
+        if (m_node->child2().useKind() == StringUse)
+            search = lowString(m_node->child2());
+        else
+            search = lowJSValue(m_node->child2());
+
+        LValue result = vmCall(
+            Int64, m_out.operation(operationStringProtoFuncReplaceGeneric), m_callFrame,
+            lowJSValue(m_node->child1()), search,
+            lowJSValue(m_node->child3()));
+
+        setJSValue(result);
+    }
+
+    void compileGetRegExpObjectLastIndex()
+    {
+        setJSValue(m_out.load64(lowRegExpObject(m_node->child1()), m_heaps.RegExpObject_lastIndex));
+    }
+
+    void compileSetRegExpObjectLastIndex()
+    {
+        LValue regExp = lowRegExpObject(m_node->child1());
+        LValue value = lowJSValue(m_node->child2());
+
+        speculate(
+            ExoticObjectMode, noValue(), nullptr,
+            m_out.isZero32(m_out.load8ZeroExt32(regExp, m_heaps.RegExpObject_lastIndexIsWritable)));
+        
+        m_out.store64(value, regExp, m_heaps.RegExpObject_lastIndex);
+    }
+    
+    void compileLogShadowChickenPrologue()
+    {
+        LValue packet = ensureShadowChickenPacket();
+        LValue scope = lowCell(m_node->child1());
+
+        m_out.storePtr(m_callFrame, packet, m_heaps.ShadowChicken_Packet_frame);
+        m_out.storePtr(m_out.loadPtr(addressFor(0)), packet, m_heaps.ShadowChicken_Packet_callerFrame);
+        m_out.storePtr(m_out.loadPtr(payloadFor(CallFrameSlot::callee)), packet, m_heaps.ShadowChicken_Packet_callee);
+        m_out.storePtr(scope, packet, m_heaps.ShadowChicken_Packet_scope);
+    }
+    
+    void compileLogShadowChickenTail()
+    {
+        LValue packet = ensureShadowChickenPacket();
+        LValue thisValue = lowJSValue(m_node->child1());
+        LValue scope = lowCell(m_node->child2());
+        CallSiteIndex callSiteIndex = m_ftlState.jitCode->common.addCodeOrigin(m_node->origin.semantic);
+        
+        m_out.storePtr(m_callFrame, packet, m_heaps.ShadowChicken_Packet_frame);
+        m_out.storePtr(m_out.constIntPtr(bitwise_cast<intptr_t>(ShadowChicken::Packet::tailMarker())), packet, m_heaps.ShadowChicken_Packet_callee);
+        m_out.store64(thisValue, packet, m_heaps.ShadowChicken_Packet_thisValue);
+        m_out.storePtr(scope, packet, m_heaps.ShadowChicken_Packet_scope);
+        // We don't want the CodeBlock to have a weak pointer to itself because
+        // that would cause it to always get collected.
+        m_out.storePtr(m_out.constIntPtr(bitwise_cast<intptr_t>(codeBlock())), packet, m_heaps.ShadowChicken_Packet_codeBlock);
+        m_out.store32(m_out.constInt32(callSiteIndex.bits()), packet, m_heaps.ShadowChicken_Packet_callSiteIndex);
+    }
+
+    void compileRecordRegExpCachedResult()
+    {
+        Edge constructorEdge = m_graph.varArgChild(m_node, 0);
+        Edge regExpEdge = m_graph.varArgChild(m_node, 1);
+        Edge stringEdge = m_graph.varArgChild(m_node, 2);
+        Edge startEdge = m_graph.varArgChild(m_node, 3);
+        Edge endEdge = m_graph.varArgChild(m_node, 4);
+        
+        LValue constructor = lowCell(constructorEdge);
+        LValue regExp = lowCell(regExpEdge);
+        LValue string = lowCell(stringEdge);
+        LValue start = lowInt32(startEdge);
+        LValue end = lowInt32(endEdge);
+
+        m_out.storePtr(regExp, constructor, m_heaps.RegExpConstructor_cachedResult_lastRegExp);
+        m_out.storePtr(string, constructor, m_heaps.RegExpConstructor_cachedResult_lastInput);
+        m_out.store32(start, constructor, m_heaps.RegExpConstructor_cachedResult_result_start);
+        m_out.store32(end, constructor, m_heaps.RegExpConstructor_cachedResult_result_end);
+        m_out.store32As8(
+            m_out.constInt32(0),
+            m_out.address(constructor, m_heaps.RegExpConstructor_cachedResult_reified));
+    }
+    
+    struct ArgumentsLength {
+        ArgumentsLength()
+            : isKnown(false)
+            , known(UINT_MAX)
+            , value(nullptr)
+        {
+        }
+        
+        bool isKnown;
+        unsigned known;
+        LValue value;
+    };
+    ArgumentsLength getArgumentsLength(InlineCallFrame* inlineCallFrame)
+    {
+        ArgumentsLength length;
+
+        if (inlineCallFrame && !inlineCallFrame->isVarargs()) {
+            length.known = inlineCallFrame->arguments.size() - 1;
+            length.isKnown = true;
+            length.value = m_out.constInt32(length.known);
+        } else {
+            length.known = UINT_MAX;
+            length.isKnown = false;
+            
+            VirtualRegister argumentCountRegister;
+            if (!inlineCallFrame)
+                argumentCountRegister = VirtualRegister(CallFrameSlot::argumentCount);
+            else
+                argumentCountRegister = inlineCallFrame->argumentCountRegister;
+            length.value = m_out.sub(m_out.load32(payloadFor(argumentCountRegister)), m_out.int32One);
+        }
+        
+        return length;
+    }
+    
+    ArgumentsLength getArgumentsLength()
+    {
+        return getArgumentsLength(m_node->origin.semantic.inlineCallFrame);
+    }
+    
+    LValue getCurrentCallee()
+    {
+        if (InlineCallFrame* frame = m_node->origin.semantic.inlineCallFrame) {
+            if (frame->isClosureCall)
+                return m_out.loadPtr(addressFor(frame->calleeRecovery.virtualRegister()));
+            return weakPointer(frame->calleeRecovery.constant().asCell());
+        }
+        return m_out.loadPtr(addressFor(CallFrameSlot::callee));
+    }
+    
+    LValue getArgumentsStart(InlineCallFrame* inlineCallFrame, unsigned offset = 0)
+    {
+        VirtualRegister start = AssemblyHelpers::argumentsStart(inlineCallFrame) + offset;
+        return addressFor(start).value();
+    }
+    
+    LValue getArgumentsStart()
+    {
+        return getArgumentsStart(m_node->origin.semantic.inlineCallFrame);
+    }
+    
+    template<typename Functor>
+    void checkStructure(
+        LValue structureDiscriminant, const FormattedValue& formattedValue, ExitKind exitKind,
+        RegisteredStructureSet set, const Functor& weakStructureDiscriminant)
+    {
+        if (set.isEmpty()) {
+            terminate(exitKind);
+            return;
+        }
+
+        if (set.size() == 1) {
+            speculate(
+                exitKind, formattedValue, 0,
+                m_out.notEqual(structureDiscriminant, weakStructureDiscriminant(set[0])));
+            return;
+        }
+        
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(continuation);
+        for (unsigned i = 0; i < set.size() - 1; ++i) {
+            LBasicBlock nextStructure = m_out.newBlock();
+            m_out.branch(
+                m_out.equal(structureDiscriminant, weakStructureDiscriminant(set[i])),
+                unsure(continuation), unsure(nextStructure));
+            m_out.appendTo(nextStructure);
+        }
+        
+        speculate(
+            exitKind, formattedValue, 0,
+            m_out.notEqual(structureDiscriminant, weakStructureDiscriminant(set.last())));
+        
+        m_out.jump(continuation);
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    LValue numberOrNotCellToInt32(Edge edge, LValue value)
+    {
+        LBasicBlock intCase = m_out.newBlock();
+        LBasicBlock notIntCase = m_out.newBlock();
+        LBasicBlock doubleCase = 0;
+        LBasicBlock notNumberCase = 0;
+        if (edge.useKind() == NotCellUse) {
+            doubleCase = m_out.newBlock();
+            notNumberCase = m_out.newBlock();
+        }
+        LBasicBlock continuation = m_out.newBlock();
+        
+        Vector<ValueFromBlock> results;
+        
+        m_out.branch(isNotInt32(value), unsure(notIntCase), unsure(intCase));
+        
+        LBasicBlock lastNext = m_out.appendTo(intCase, notIntCase);
+        results.append(m_out.anchor(unboxInt32(value)));
+        m_out.jump(continuation);
+        
+        if (edge.useKind() == NumberUse) {
+            m_out.appendTo(notIntCase, continuation);
+            FTL_TYPE_CHECK(jsValueValue(value), edge, SpecBytecodeNumber, isCellOrMisc(value));
+            results.append(m_out.anchor(doubleToInt32(unboxDouble(value))));
+            m_out.jump(continuation);
+        } else {
+            m_out.appendTo(notIntCase, doubleCase);
+            m_out.branch(
+                isCellOrMisc(value, provenType(edge)), unsure(notNumberCase), unsure(doubleCase));
+            
+            m_out.appendTo(doubleCase, notNumberCase);
+            results.append(m_out.anchor(doubleToInt32(unboxDouble(value))));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(notNumberCase, continuation);
+            
+            FTL_TYPE_CHECK(jsValueValue(value), edge, ~SpecCell, isCell(value));
+            
+            LValue specialResult = m_out.select(
+                m_out.equal(value, m_out.constInt64(JSValue::encode(jsBoolean(true)))),
+                m_out.int32One, m_out.int32Zero);
+            results.append(m_out.anchor(specialResult));
+            m_out.jump(continuation);
+        }
+        
+        m_out.appendTo(continuation, lastNext);
+        return m_out.phi(Int32, results);
+    }
+
+    void checkInferredType(Edge edge, LValue value, const InferredType::Descriptor& type)
+    {
+        // This cannot use FTL_TYPE_CHECK or typeCheck() because it is called partially, as in a node like:
+        //
+        //     MultiPutByOffset(...)
+        //
+        // may be lowered to:
+        //
+        //     switch (object->structure) {
+        //     case 42:
+        //         checkInferredType(..., type1);
+        //         ...
+        //         break;
+        //     case 43:
+        //         checkInferredType(..., type2);
+        //         ...
+        //         break;
+        //     }
+        //
+        // where type1 and type2 are different. Using typeCheck() would mean that the edge would be
+        // filtered by type1 & type2, instead of type1 | type2.
+        
+        switch (type.kind()) {
+        case InferredType::Bottom:
+            speculate(BadType, jsValueValue(value), edge.node(), m_out.booleanTrue);
+            return;
+
+        case InferredType::Boolean:
+            speculate(BadType, jsValueValue(value), edge.node(), isNotBoolean(value, provenType(edge)));
+            return;
+
+        case InferredType::Other:
+            speculate(BadType, jsValueValue(value), edge.node(), isNotOther(value, provenType(edge)));
+            return;
+
+        case InferredType::Int32:
+            speculate(BadType, jsValueValue(value), edge.node(), isNotInt32(value, provenType(edge)));
+            return;
+
+        case InferredType::Number:
+            speculate(BadType, jsValueValue(value), edge.node(), isNotNumber(value, provenType(edge)));
+            return;
+
+        case InferredType::String:
+            speculate(BadType, jsValueValue(value), edge.node(), isNotCell(value, provenType(edge)));
+            speculate(BadType, jsValueValue(value), edge.node(), isNotString(value, provenType(edge)));
+            return;
+
+        case InferredType::Symbol:
+            speculate(BadType, jsValueValue(value), edge.node(), isNotCell(value, provenType(edge)));
+            speculate(BadType, jsValueValue(value), edge.node(), isNotSymbol(value, provenType(edge)));
+            return;
+
+        case InferredType::ObjectWithStructure: {
+            RegisteredStructure structure = m_graph.registerStructure(type.structure());
+            speculate(BadType, jsValueValue(value), edge.node(), isNotCell(value, provenType(edge)));
+            if (!abstractValue(edge).m_structure.isSubsetOf(RegisteredStructureSet(structure))) {
+                speculate(
+                    BadType, jsValueValue(value), edge.node(),
+                    m_out.notEqual(
+                        m_out.load32(value, m_heaps.JSCell_structureID),
+                        weakStructureID(structure)));
+            }
+            return;
+        }
+
+        case InferredType::ObjectWithStructureOrOther: {
+            LBasicBlock cellCase = m_out.newBlock();
+            LBasicBlock notCellCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            m_out.branch(isCell(value, provenType(edge)), unsure(cellCase), unsure(notCellCase));
+
+            LBasicBlock lastNext = m_out.appendTo(cellCase, notCellCase);
+
+            RegisteredStructure structure = m_graph.registerStructure(type.structure());
+            if (!abstractValue(edge).m_structure.isSubsetOf(RegisteredStructureSet(structure))) {
+                speculate(
+                    BadType, jsValueValue(value), edge.node(),
+                    m_out.notEqual(
+                        m_out.load32(value, m_heaps.JSCell_structureID),
+                        weakStructureID(structure)));
+            }
+
+            m_out.jump(continuation);
+
+            m_out.appendTo(notCellCase, continuation);
+
+            speculate(
+                BadType, jsValueValue(value), edge.node(),
+                isNotOther(value, provenType(edge) & ~SpecCell));
+
+            m_out.jump(continuation);
+
+            m_out.appendTo(continuation, lastNext);
+            return;
+        }
+
+        case InferredType::Object:
+            speculate(BadType, jsValueValue(value), edge.node(), isNotCell(value, provenType(edge)));
+            speculate(BadType, jsValueValue(value), edge.node(), isNotObject(value, provenType(edge)));
+            return;
+
+        case InferredType::ObjectOrOther: {
+            LBasicBlock cellCase = m_out.newBlock();
+            LBasicBlock notCellCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            m_out.branch(isCell(value, provenType(edge)), unsure(cellCase), unsure(notCellCase));
+
+            LBasicBlock lastNext = m_out.appendTo(cellCase, notCellCase);
+
+            speculate(
+                BadType, jsValueValue(value), edge.node(),
+                isNotObject(value, provenType(edge) & SpecCell));
+
+            m_out.jump(continuation);
+
+            m_out.appendTo(notCellCase, continuation);
+
+            speculate(
+                BadType, jsValueValue(value), edge.node(),
+                isNotOther(value, provenType(edge) & ~SpecCell));
+
+            m_out.jump(continuation);
+
+            m_out.appendTo(continuation, lastNext);
+            return;
+        }
+
+        case InferredType::Top:
+            return;
+        }
+
+        DFG_CRASH(m_graph, m_node, "Bad inferred type");
+    }
+    
+    LValue loadProperty(LValue storage, unsigned identifierNumber, PropertyOffset offset)
+    {
+        return m_out.load64(addressOfProperty(storage, identifierNumber, offset));
+    }
+    
+    void storeProperty(
+        LValue value, LValue storage, unsigned identifierNumber, PropertyOffset offset)
+    {
+        m_out.store64(value, addressOfProperty(storage, identifierNumber, offset));
+    }
+    
+    TypedPointer addressOfProperty(
+        LValue storage, unsigned identifierNumber, PropertyOffset offset)
+    {
+        return m_out.address(
+            m_heaps.properties[identifierNumber], storage, offsetRelativeToBase(offset));
+    }
+    
+    LValue storageForTransition(
+        LValue object, PropertyOffset offset,
+        Structure* previousStructure, Structure* nextStructure)
+    {
+        if (isInlineOffset(offset))
+            return object;
+        
+        if (previousStructure->outOfLineCapacity() == nextStructure->outOfLineCapacity())
+            return m_out.loadPtr(object, m_heaps.JSObject_butterfly);
+        
+        LValue result;
+        if (!previousStructure->outOfLineCapacity())
+            result = allocatePropertyStorage(object, previousStructure);
+        else {
+            result = reallocatePropertyStorage(
+                object, m_out.loadPtr(object, m_heaps.JSObject_butterfly),
+                previousStructure, nextStructure);
+        }
+        
+        nukeStructureAndSetButterfly(result, object);
+        return result;
+    }
+
+    void initializeArrayElements(LValue indexingType, LValue begin, LValue end, LValue butterfly)
+    {
+        
+        if (begin == end)
+            return;
+        
+        if (indexingType->hasInt32()) {
+            IndexingType rawIndexingType = static_cast<IndexingType>(indexingType->asInt32());
+            if (hasUndecided(rawIndexingType))
+                return;
+            IndexedAbstractHeap* heap = m_heaps.forIndexingType(rawIndexingType);
+            DFG_ASSERT(m_graph, m_node, heap);
+            
+            LValue hole;
+            if (hasDouble(rawIndexingType))
+                hole = m_out.constInt64(bitwise_cast<int64_t>(PNaN));
+            else
+                hole = m_out.constInt64(JSValue::encode(JSValue()));
+            
+            splatWords(butterfly, begin, end, hole, heap->atAnyIndex());
+        } else {
+            LValue hole = m_out.select(
+                m_out.equal(m_out.bitAnd(indexingType, m_out.constInt32(IndexingShapeMask)), m_out.constInt32(DoubleShape)),
+                m_out.constInt64(bitwise_cast<int64_t>(PNaN)),
+                m_out.constInt64(JSValue::encode(JSValue())));
+            splatWords(butterfly, begin, end, hole, m_heaps.root);
+        }
+    }
+
+    void splatWords(LValue base, LValue begin, LValue end, LValue value, const AbstractHeap& heap)
+    {
+        const uint64_t unrollingLimit = 10;
+        if (begin->hasInt() && end->hasInt()) {
+            uint64_t beginConst = static_cast<uint64_t>(begin->asInt());
+            uint64_t endConst = static_cast<uint64_t>(end->asInt());
+            
+            if (endConst - beginConst <= unrollingLimit) {
+                for (uint64_t i = beginConst; i < endConst; ++i) {
+                    LValue pointer = m_out.add(base, m_out.constIntPtr(i * sizeof(uint64_t)));
+                    m_out.store64(value, TypedPointer(heap, pointer));
+                }
+                return;
+            }
+        }
+
+        LBasicBlock initLoop = m_out.newBlock();
+        LBasicBlock initDone = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(initLoop);
+        
+        ValueFromBlock originalIndex = m_out.anchor(end);
+        ValueFromBlock originalPointer = m_out.anchor(
+            m_out.add(base, m_out.shl(m_out.signExt32ToPtr(begin), m_out.constInt32(3))));
+        m_out.branch(m_out.notEqual(end, begin), unsure(initLoop), unsure(initDone));
+        
+        m_out.appendTo(initLoop, initDone);
+        LValue index = m_out.phi(Int32, originalIndex);
+        LValue pointer = m_out.phi(pointerType(), originalPointer);
+        
+        m_out.store64(value, TypedPointer(heap, pointer));
+        
+        LValue nextIndex = m_out.sub(index, m_out.int32One);
+        m_out.addIncomingToPhi(index, m_out.anchor(nextIndex));
+        m_out.addIncomingToPhi(pointer, m_out.anchor(m_out.add(pointer, m_out.intPtrEight)));
+        m_out.branch(
+            m_out.notEqual(nextIndex, begin), unsure(initLoop), unsure(initDone));
+        
+        m_out.appendTo(initDone, lastNext);
+    }
+    
+    LValue allocatePropertyStorage(LValue object, Structure* previousStructure)
+    {
+        if (previousStructure->couldHaveIndexingHeader()) {
+            return vmCall(
+                pointerType(),
+                m_out.operation(operationAllocateComplexPropertyStorageWithInitialCapacity),
+                m_callFrame, object);
+        }
+        
+        LValue result = allocatePropertyStorageWithSizeImpl(initialOutOfLineCapacity);
+
+        splatWords(
+            result,
+            m_out.constInt32(-initialOutOfLineCapacity - 1), m_out.constInt32(-1),
+            m_out.int64Zero, m_heaps.properties.atAnyNumber());
+        
+        return result;
+    }
+    
+    LValue reallocatePropertyStorage(
+        LValue object, LValue oldStorage, Structure* previous, Structure* next)
+    {
+        size_t oldSize = previous->outOfLineCapacity();
+        size_t newSize = oldSize * outOfLineGrowthFactor; 
+
+        ASSERT_UNUSED(next, newSize == next->outOfLineCapacity());
+        
+        if (previous->couldHaveIndexingHeader()) {
+            LValue newAllocSize = m_out.constIntPtr(newSize);                    
+            return vmCall(pointerType(), m_out.operation(operationAllocateComplexPropertyStorage), m_callFrame, object, newAllocSize);
+        }
+        
+        LValue result = allocatePropertyStorageWithSizeImpl(newSize);
+
+        ptrdiff_t headerSize = -sizeof(IndexingHeader) - sizeof(void*);
+        ptrdiff_t endStorage = headerSize - static_cast<ptrdiff_t>(oldSize * sizeof(JSValue));
+
+        for (ptrdiff_t offset = headerSize; offset > endStorage; offset -= sizeof(void*)) {
+            LValue loaded = 
+                m_out.loadPtr(m_out.address(m_heaps.properties.atAnyNumber(), oldStorage, offset));
+            m_out.storePtr(loaded, m_out.address(m_heaps.properties.atAnyNumber(), result, offset));
+        }
+        
+        splatWords(
+            result,
+            m_out.constInt32(-newSize - 1), m_out.constInt32(-oldSize - 1),
+            m_out.int64Zero, m_heaps.properties.atAnyNumber());
+        
+        return result;
+    }
+    
+    LValue allocatePropertyStorageWithSizeImpl(size_t sizeInValues)
+    {
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
+
+        size_t sizeInBytes = sizeInValues * sizeof(JSValue);
+        MarkedAllocator* allocator = vm().auxiliarySpace.allocatorFor(sizeInBytes);
+        LValue startOfStorage = allocateHeapCell(m_out.constIntPtr(allocator), slowPath);
+        ValueFromBlock fastButterfly = m_out.anchor(
+            m_out.add(m_out.constIntPtr(sizeInBytes + sizeof(IndexingHeader)), startOfStorage));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(slowPath, continuation);
+        
+        LValue slowButterflyValue;
+        if (sizeInValues == initialOutOfLineCapacity) {
+            slowButterflyValue = lazySlowPath(
+                [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                    return createLazyCallGenerator(
+                        operationAllocateSimplePropertyStorageWithInitialCapacity,
+                        locations[0].directGPR());
+                });
+        } else {
+            slowButterflyValue = lazySlowPath(
+                [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                    return createLazyCallGenerator(
+                        operationAllocateSimplePropertyStorage, locations[0].directGPR(),
+                        CCallHelpers::TrustedImmPtr(sizeInValues));
+                });
+        }
+        ValueFromBlock slowButterfly = m_out.anchor(slowButterflyValue);
+        
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        
+        return m_out.phi(pointerType(), fastButterfly, slowButterfly);
+    }
+    
+    LValue getById(LValue base, AccessType type)
+    {
+        Node* node = m_node;
+        UniquedStringImpl* uid = m_graph.identifiers()[node->identifierNumber()];
+
+        B3::PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+        patchpoint->appendSomeRegister(base);
+        patchpoint->append(m_tagMask, ValueRep::lateReg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::lateReg(GPRInfo::tagTypeNumberRegister));
+
+        // FIXME: If this is a GetByIdFlush, we might get some performance boost if we claim that it
+        // clobbers volatile registers late. It's not necessary for correctness, though, since the
+        // IC code is super smart about saving registers.
+        // https://bugs.webkit.org/show_bug.cgi?id=152848
+        
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+
+        RefPtr<PatchpointExceptionHandle> exceptionHandle =
+            preparePatchpointForExceptions(patchpoint);
+
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                CallSiteIndex callSiteIndex =
+                    state->jitCode->common.addUniqueCallSiteIndex(node->origin.semantic);
+
+                // This is the direct exit target for operation calls.
+                Box<CCallHelpers::JumpList> exceptions =
+                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+
+                // This is the exit for call IC's created by the getById for getters. We don't have
+                // to do anything weird other than call this, since it will associate the exit with
+                // the callsite index.
+                exceptionHandle->scheduleExitCreationForUnwind(params, callSiteIndex);
+
+                auto generator = Box<JITGetByIdGenerator>::create(
+                    jit.codeBlock(), node->origin.semantic, callSiteIndex,
+                    params.unavailableRegisters(), uid, JSValueRegs(params[1].gpr()),
+                    JSValueRegs(params[0].gpr()), type);
+
+                generator->generateFastPath(jit);
+                CCallHelpers::Label done = jit.label();
+
+                params.addLatePath(
+                    [=] (CCallHelpers& jit) {
+                        AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                        J_JITOperation_ESsiJI optimizationFunction;
+                        if (type == AccessType::Get)
+                            optimizationFunction = operationGetByIdOptimize;
+                        else
+                            optimizationFunction = operationTryGetByIdOptimize;
+
+                        generator->slowPathJump().link(&jit);
+                        CCallHelpers::Label slowPathBegin = jit.label();
+                        CCallHelpers::Call slowPathCall = callOperation(
+                            *state, params.unavailableRegisters(), jit, node->origin.semantic,
+                            exceptions.get(), optimizationFunction, params[0].gpr(),
+                            CCallHelpers::TrustedImmPtr(generator->stubInfo()), params[1].gpr(),
+                            CCallHelpers::TrustedImmPtr(uid)).call();
+                        jit.jump().linkTo(done, &jit);
+
+                        generator->reportSlowPathCall(slowPathBegin, slowPathCall);
+
+                        jit.addLinkTask(
+                            [=] (LinkBuffer& linkBuffer) {
+                                generator->finalize(linkBuffer);
+                            });
+                    });
+            });
+
+        return patchpoint;
+    }
+
+    LValue isFastTypedArray(LValue object)
+    {
+        return m_out.equal(
+            m_out.load32(object, m_heaps.JSArrayBufferView_mode),
+            m_out.constInt32(FastTypedArray));
+    }
+    
+    TypedPointer baseIndex(IndexedAbstractHeap& heap, LValue storage, LValue index, Edge edge, ptrdiff_t offset = 0)
+    {
+        return m_out.baseIndex(
+            heap, storage, m_out.zeroExtPtr(index), provenValue(edge), offset);
+    }
+
+    template<typename IntFunctor, typename DoubleFunctor>
+    void compare(
+        const IntFunctor& intFunctor, const DoubleFunctor& doubleFunctor,
+        C_JITOperation_TT stringIdentFunction,
+        C_JITOperation_B_EJssJss stringFunction,
+        S_JITOperation_EJJ fallbackFunction)
+    {
+        if (m_node->isBinaryUseKind(Int32Use)) {
+            LValue left = lowInt32(m_node->child1());
+            LValue right = lowInt32(m_node->child2());
+            setBoolean(intFunctor(left, right));
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(Int52RepUse)) {
+            Int52Kind kind;
+            LValue left = lowWhicheverInt52(m_node->child1(), kind);
+            LValue right = lowInt52(m_node->child2(), kind);
+            setBoolean(intFunctor(left, right));
+            return;
+        }
+        
+        if (m_node->isBinaryUseKind(DoubleRepUse)) {
+            LValue left = lowDouble(m_node->child1());
+            LValue right = lowDouble(m_node->child2());
+            setBoolean(doubleFunctor(left, right));
+            return;
+        }
+
+        if (m_node->isBinaryUseKind(StringIdentUse)) {
+            LValue left = lowStringIdent(m_node->child1());
+            LValue right = lowStringIdent(m_node->child2());
+            setBoolean(m_out.callWithoutSideEffects(Int32, stringIdentFunction, left, right));
+            return;
+        }
+
+        if (m_node->isBinaryUseKind(StringUse)) {
+            LValue left = lowCell(m_node->child1());
+            LValue right = lowCell(m_node->child2());
+            speculateString(m_node->child1(), left);
+            speculateString(m_node->child2(), right);
+
+            LValue result = vmCall(
+                Int32, m_out.operation(stringFunction),
+                m_callFrame, left, right);
+            setBoolean(result);
+            return;
+        }
+
+        DFG_ASSERT(m_graph, m_node, m_node->isBinaryUseKind(UntypedUse));
+        nonSpeculativeCompare(intFunctor, fallbackFunction);
+    }
+
+    void compileToLowerCase()
+    {
+        LBasicBlock notRope = m_out.newBlock();
+        LBasicBlock is8Bit = m_out.newBlock();
+        LBasicBlock loopTop = m_out.newBlock();
+        LBasicBlock loopBody = m_out.newBlock();
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        LValue string = lowString(m_node->child1());
+        ValueFromBlock startIndex = m_out.anchor(m_out.constInt32(0));
+        ValueFromBlock startIndexForCall = m_out.anchor(m_out.constInt32(0));
+        LValue impl = m_out.loadPtr(string, m_heaps.JSString_value);
+        m_out.branch(m_out.isZero64(impl),
+            unsure(slowPath), unsure(notRope));
+
+        LBasicBlock lastNext = m_out.appendTo(notRope, is8Bit);
+
+        m_out.branch(
+            m_out.testIsZero32(
+                m_out.load32(impl, m_heaps.StringImpl_hashAndFlags),
+                m_out.constInt32(StringImpl::flagIs8Bit())),
+            unsure(slowPath), unsure(is8Bit));
+
+        m_out.appendTo(is8Bit, loopTop);
+        LValue length = m_out.load32(impl, m_heaps.StringImpl_length);
+        LValue buffer = m_out.loadPtr(impl, m_heaps.StringImpl_data);
+        ValueFromBlock fastResult = m_out.anchor(string);
+        m_out.jump(loopTop);
+
+        m_out.appendTo(loopTop, loopBody);
+        LValue index = m_out.phi(Int32, startIndex);
+        ValueFromBlock indexFromBlock = m_out.anchor(index);
+        m_out.branch(m_out.below(index, length),
+            unsure(loopBody), unsure(continuation));
+
+        m_out.appendTo(loopBody, slowPath);
+
+        LValue byte = m_out.load8ZeroExt32(m_out.baseIndex(m_heaps.characters8, buffer, m_out.zeroExtPtr(index)));
+        LValue isInvalidAsciiRange = m_out.bitAnd(byte, m_out.constInt32(~0x7F));
+        LValue isUpperCase = m_out.belowOrEqual(m_out.sub(byte, m_out.constInt32('A')), m_out.constInt32('Z' - 'A'));
+        LValue isBadCharacter = m_out.bitOr(isInvalidAsciiRange, isUpperCase);
+        m_out.addIncomingToPhi(index, m_out.anchor(m_out.add(index, m_out.int32One)));
+        m_out.branch(isBadCharacter, unsure(slowPath), unsure(loopTop));
+
+        m_out.appendTo(slowPath, continuation);
+        LValue slowPathIndex = m_out.phi(Int32, startIndexForCall, indexFromBlock);
+        ValueFromBlock slowResult = m_out.anchor(vmCall(pointerType(), m_out.operation(operationToLowerCase), m_callFrame, string, slowPathIndex));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        setJSValue(m_out.phi(pointerType(), fastResult, slowResult));
+    }
+
+    void compileNumberToStringWithRadix()
+    {
+        bool validRadixIsGuaranteed = false;
+        if (m_node->child2()->isInt32Constant()) {
+            int32_t radix = m_node->child2()->asInt32();
+            if (radix >= 2 && radix <= 36)
+                validRadixIsGuaranteed = true;
+        }
+
+        switch (m_node->child1().useKind()) {
+        case Int32Use:
+            setJSValue(vmCall(pointerType(), m_out.operation(validRadixIsGuaranteed ? operationInt32ToStringWithValidRadix : operationInt32ToString), m_callFrame, lowInt32(m_node->child1()), lowInt32(m_node->child2())));
+            break;
+        case Int52RepUse:
+            setJSValue(vmCall(pointerType(), m_out.operation(validRadixIsGuaranteed ? operationInt52ToStringWithValidRadix : operationInt52ToString), m_callFrame, lowStrictInt52(m_node->child1()), lowInt32(m_node->child2())));
+            break;
+        case DoubleRepUse:
+            setJSValue(vmCall(pointerType(), m_out.operation(validRadixIsGuaranteed ? operationDoubleToStringWithValidRadix : operationDoubleToString), m_callFrame, lowDouble(m_node->child1()), lowInt32(m_node->child2())));
+            break;
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+        }
+    }
+
+    void compileResolveScope()
+    {
+        UniquedStringImpl* uid = m_graph.identifiers()[m_node->identifierNumber()];
+        setJSValue(vmCall(pointerType(), m_out.operation(operationResolveScope),
+            m_callFrame, lowCell(m_node->child1()), m_out.constIntPtr(uid)));
+    }
+
+    void compileGetDynamicVar()
+    {
+        UniquedStringImpl* uid = m_graph.identifiers()[m_node->identifierNumber()];
+        setJSValue(vmCall(Int64, m_out.operation(operationGetDynamicVar),
+            m_callFrame, lowCell(m_node->child1()), m_out.constIntPtr(uid), m_out.constInt32(m_node->getPutInfo())));
+    }
+
+    void compilePutDynamicVar()
+    {
+        UniquedStringImpl* uid = m_graph.identifiers()[m_node->identifierNumber()];
+        setJSValue(vmCall(Void, m_out.operation(operationPutDynamicVar),
+            m_callFrame, lowCell(m_node->child1()), lowJSValue(m_node->child2()), m_out.constIntPtr(uid), m_out.constInt32(m_node->getPutInfo())));
+    }
+    
+    void compileUnreachable()
+    {
+        // It's so tempting to assert that AI has proved that this is unreachable. But that's
+        // simply not a requirement of the Unreachable opcode at all. If you emit an opcode that
+        // *you* know will not return, then it's fine to end the basic block with Unreachable
+        // after that opcode. You don't have to also prove to AI that your opcode does not return.
+        // Hence, there is nothing to do here but emit code that will crash, so that we catch
+        // cases where you said Unreachable but you lied.
+        
+        crash();
+    }
+
+    void compileCheckDOM()
+    {
+        LValue cell = lowCell(m_node->child1());
+
+        DOMJIT::Patchpoint* domJIT = m_node->checkDOMPatchpoint();
+
+        PatchpointValue* patchpoint = m_out.patchpoint(Void);
+        patchpoint->appendSomeRegister(cell);
+        patchpoint->append(m_tagMask, ValueRep::reg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::reg(GPRInfo::tagTypeNumberRegister));
+
+        NodeOrigin origin = m_origin;
+        unsigned osrExitArgumentOffset = patchpoint->numChildren();
+        OSRExitDescriptor* exitDescriptor = appendOSRExitDescriptor(jsValueValue(cell), m_node->child1().node());
+        patchpoint->appendColdAnys(buildExitArguments(exitDescriptor, origin.forExit, jsValueValue(cell)));
+
+        patchpoint->numGPScratchRegisters = domJIT->numGPScratchRegisters;
+        patchpoint->numFPScratchRegisters = domJIT->numFPScratchRegisters;
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+
+        State* state = &m_ftlState;
+        Node* node = m_node;
+        JSValue child1Constant = m_state.forNode(m_node->child1()).value();
+
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                Vector<GPRReg> gpScratch;
+                Vector<FPRReg> fpScratch;
+                Vector<DOMJIT::Value> regs;
+
+                regs.append(DOMJIT::Value(params[0].gpr(), child1Constant));
+
+                for (unsigned i = 0; i < domJIT->numGPScratchRegisters; ++i)
+                    gpScratch.append(params.gpScratch(i));
+
+                for (unsigned i = 0; i < domJIT->numFPScratchRegisters; ++i)
+                    fpScratch.append(params.fpScratch(i));
+
+                RefPtr<OSRExitHandle> handle = exitDescriptor->emitOSRExitLater(*state, BadType, origin, params, osrExitArgumentOffset);
+
+                DOMJITPatchpointParams domJITParams(*state, params, node, nullptr, WTFMove(regs), WTFMove(gpScratch), WTFMove(fpScratch));
+                CCallHelpers::JumpList failureCases = domJIT->generator()->run(jit, domJITParams);
+
+                jit.addLinkTask([=] (LinkBuffer& linkBuffer) {
+                    linkBuffer.link(failureCases, linkBuffer.locationOf(handle->label));
+                });
+            });
+        patchpoint->effects = Effects::forCheck();
+    }
+
+    void compileCallDOM()
+    {
+        const DOMJIT::Signature* signature = m_node->signature();
+
+        // FIXME: We should have a way to call functions with the vector of registers.
+        // https://bugs.webkit.org/show_bug.cgi?id=163099
+        Vector<LValue, JSC_DOMJIT_SIGNATURE_MAX_ARGUMENTS_INCLUDING_THIS> operands;
+
+        unsigned index = 0;
+        DFG_NODE_DO_TO_CHILDREN(m_graph, m_node, [&](Node*, Edge edge) {
+            if (!index)
+                operands.append(lowCell(edge));
+            else {
+                switch (signature->arguments[index - 1]) {
+                case SpecString:
+                    operands.append(lowString(edge));
+                    break;
+                case SpecInt32Only:
+                    operands.append(lowInt32(edge));
+                    break;
+                case SpecBoolean:
+                    operands.append(lowBoolean(edge));
+                    break;
+                default:
+                    RELEASE_ASSERT_NOT_REACHED();
+                    break;
+                }
+            }
+            ++index;
+        });
+
+        unsigned argumentCountIncludingThis = signature->argumentCount + 1;
+        LValue result;
+        switch (argumentCountIncludingThis) {
+        case 1:
+            result = vmCall(Int64, m_out.operation(reinterpret_cast<J_JITOperation_EP>(signature->unsafeFunction)), m_callFrame, operands[0]);
+            break;
+        case 2:
+            result = vmCall(Int64, m_out.operation(reinterpret_cast<J_JITOperation_EPP>(signature->unsafeFunction)), m_callFrame, operands[0], operands[1]);
+            break;
+        case 3:
+            result = vmCall(Int64, m_out.operation(reinterpret_cast<J_JITOperation_EPPP>(signature->unsafeFunction)), m_callFrame, operands[0], operands[1], operands[2]);
+            break;
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+            break;
+        }
+
+        setJSValue(result);
+    }
+
+    void compileCallDOMGetter()
+    {
+        DOMJIT::CallDOMGetterPatchpoint* domJIT = m_node->callDOMGetterData()->patchpoint;
+
+        Edge& baseEdge = m_node->child1();
+        LValue base = lowCell(baseEdge);
+        JSValue baseConstant = m_state.forNode(baseEdge).value();
+
+        LValue globalObject;
+        JSValue globalObjectConstant;
+        if (domJIT->requireGlobalObject) {
+            Edge& globalObjectEdge = m_node->child2();
+            globalObject = lowCell(globalObjectEdge);
+            globalObjectConstant = m_state.forNode(globalObjectEdge).value();
+        }
+
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+        patchpoint->appendSomeRegister(base);
+        if (domJIT->requireGlobalObject)
+            patchpoint->appendSomeRegister(globalObject);
+        patchpoint->append(m_tagMask, ValueRep::reg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::reg(GPRInfo::tagTypeNumberRegister));
+        RefPtr<PatchpointExceptionHandle> exceptionHandle = preparePatchpointForExceptions(patchpoint);
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        patchpoint->numGPScratchRegisters = domJIT->numGPScratchRegisters;
+        patchpoint->numFPScratchRegisters = domJIT->numFPScratchRegisters;
+        patchpoint->resultConstraint = ValueRep::SomeEarlyRegister;
+
+        State* state = &m_ftlState;
+        Node* node = m_node;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                Vector<GPRReg> gpScratch;
+                Vector<FPRReg> fpScratch;
+                Vector<DOMJIT::Value> regs;
+
+                regs.append(JSValueRegs(params[0].gpr()));
+                regs.append(DOMJIT::Value(params[1].gpr(), baseConstant));
+                if (domJIT->requireGlobalObject)
+                    regs.append(DOMJIT::Value(params[2].gpr(), globalObjectConstant));
+
+                for (unsigned i = 0; i < domJIT->numGPScratchRegisters; ++i)
+                    gpScratch.append(params.gpScratch(i));
+
+                for (unsigned i = 0; i < domJIT->numFPScratchRegisters; ++i)
+                    fpScratch.append(params.fpScratch(i));
+
+                Box<CCallHelpers::JumpList> exceptions = exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+
+                DOMJITPatchpointParams domJITParams(*state, params, node, exceptions, WTFMove(regs), WTFMove(gpScratch), WTFMove(fpScratch));
+                domJIT->generator()->run(jit, domJITParams);
+            });
+        patchpoint->effects = Effects::forCall();
+        setJSValue(patchpoint);
+    }
+    
+    void compareEqObjectOrOtherToObject(Edge leftChild, Edge rightChild)
+    {
+        LValue rightCell = lowCell(rightChild);
+        LValue leftValue = lowJSValue(leftChild, ManualOperandSpeculation);
+        
+        speculateTruthyObject(rightChild, rightCell, SpecObject);
+        
+        LBasicBlock leftCellCase = m_out.newBlock();
+        LBasicBlock leftNotCellCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        m_out.branch(
+            isCell(leftValue, provenType(leftChild)),
+            unsure(leftCellCase), unsure(leftNotCellCase));
+        
+        LBasicBlock lastNext = m_out.appendTo(leftCellCase, leftNotCellCase);
+        speculateTruthyObject(leftChild, leftValue, SpecObject | (~SpecCell));
+        ValueFromBlock cellResult = m_out.anchor(m_out.equal(rightCell, leftValue));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(leftNotCellCase, continuation);
+        FTL_TYPE_CHECK(
+            jsValueValue(leftValue), leftChild, SpecOther | SpecCell, isNotOther(leftValue));
+        ValueFromBlock notCellResult = m_out.anchor(m_out.booleanFalse);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setBoolean(m_out.phi(Int32, cellResult, notCellResult));
+    }
+    
+    void speculateTruthyObject(Edge edge, LValue cell, SpeculatedType filter)
+    {
+        if (masqueradesAsUndefinedWatchpointIsStillValid()) {
+            FTL_TYPE_CHECK(jsValueValue(cell), edge, filter, isNotObject(cell));
+            return;
+        }
+        
+        FTL_TYPE_CHECK(jsValueValue(cell), edge, filter, isNotObject(cell));
+        speculate(
+            BadType, jsValueValue(cell), edge.node(),
+            m_out.testNonZero32(
+                m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoFlags),
+                m_out.constInt32(MasqueradesAsUndefined)));
+    }
+
+    template<typename IntFunctor>
+    void nonSpeculativeCompare(const IntFunctor& intFunctor, S_JITOperation_EJJ helperFunction)
+    {
+        LValue left = lowJSValue(m_node->child1());
+        LValue right = lowJSValue(m_node->child2());
+        
+        LBasicBlock leftIsInt = m_out.newBlock();
+        LBasicBlock fastPath = m_out.newBlock();
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        m_out.branch(isNotInt32(left, provenType(m_node->child1())), rarely(slowPath), usually(leftIsInt));
+        
+        LBasicBlock lastNext = m_out.appendTo(leftIsInt, fastPath);
+        m_out.branch(isNotInt32(right, provenType(m_node->child2())), rarely(slowPath), usually(fastPath));
+        
+        m_out.appendTo(fastPath, slowPath);
+        ValueFromBlock fastResult = m_out.anchor(intFunctor(unboxInt32(left), unboxInt32(right)));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(slowPath, continuation);
+        ValueFromBlock slowResult = m_out.anchor(m_out.notNull(vmCall(
+            pointerType(), m_out.operation(helperFunction), m_callFrame, left, right)));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        setBoolean(m_out.phi(Int32, fastResult, slowResult));
+    }
+
+    LValue stringsEqual(LValue leftJSString, LValue rightJSString)
+    {
+        LBasicBlock notTriviallyUnequalCase = m_out.newBlock();
+        LBasicBlock notEmptyCase = m_out.newBlock();
+        LBasicBlock leftReadyCase = m_out.newBlock();
+        LBasicBlock rightReadyCase = m_out.newBlock();
+        LBasicBlock left8BitCase = m_out.newBlock();
+        LBasicBlock right8BitCase = m_out.newBlock();
+        LBasicBlock loop = m_out.newBlock();
+        LBasicBlock bytesEqual = m_out.newBlock();
+        LBasicBlock trueCase = m_out.newBlock();
+        LBasicBlock falseCase = m_out.newBlock();
+        LBasicBlock slowCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        LValue length = m_out.load32(leftJSString, m_heaps.JSString_length);
+
+        m_out.branch(
+            m_out.notEqual(length, m_out.load32(rightJSString, m_heaps.JSString_length)),
+            unsure(falseCase), unsure(notTriviallyUnequalCase));
+
+        LBasicBlock lastNext = m_out.appendTo(notTriviallyUnequalCase, notEmptyCase);
+
+        m_out.branch(m_out.isZero32(length), unsure(trueCase), unsure(notEmptyCase));
+
+        m_out.appendTo(notEmptyCase, leftReadyCase);
+
+        LValue left = m_out.loadPtr(leftJSString, m_heaps.JSString_value);
+        LValue right = m_out.loadPtr(rightJSString, m_heaps.JSString_value);
+
+        m_out.branch(m_out.notNull(left), usually(leftReadyCase), rarely(slowCase));
+
+        m_out.appendTo(leftReadyCase, rightReadyCase);
+        
+        m_out.branch(m_out.notNull(right), usually(rightReadyCase), rarely(slowCase));
+
+        m_out.appendTo(rightReadyCase, left8BitCase);
+
+        m_out.branch(
+            m_out.testIsZero32(
+                m_out.load32(left, m_heaps.StringImpl_hashAndFlags),
+                m_out.constInt32(StringImpl::flagIs8Bit())),
+            unsure(slowCase), unsure(left8BitCase));
+
+        m_out.appendTo(left8BitCase, right8BitCase);
+
+        m_out.branch(
+            m_out.testIsZero32(
+                m_out.load32(right, m_heaps.StringImpl_hashAndFlags),
+                m_out.constInt32(StringImpl::flagIs8Bit())),
+            unsure(slowCase), unsure(right8BitCase));
+
+        m_out.appendTo(right8BitCase, loop);
+
+        LValue leftData = m_out.loadPtr(left, m_heaps.StringImpl_data);
+        LValue rightData = m_out.loadPtr(right, m_heaps.StringImpl_data);
+
+        ValueFromBlock indexAtStart = m_out.anchor(length);
+
+        m_out.jump(loop);
+
+        m_out.appendTo(loop, bytesEqual);
+
+        LValue indexAtLoopTop = m_out.phi(Int32, indexAtStart);
+        LValue indexInLoop = m_out.sub(indexAtLoopTop, m_out.int32One);
+
+        LValue leftByte = m_out.load8ZeroExt32(
+            m_out.baseIndex(m_heaps.characters8, leftData, m_out.zeroExtPtr(indexInLoop)));
+        LValue rightByte = m_out.load8ZeroExt32(
+            m_out.baseIndex(m_heaps.characters8, rightData, m_out.zeroExtPtr(indexInLoop)));
+
+        m_out.branch(m_out.notEqual(leftByte, rightByte), unsure(falseCase), unsure(bytesEqual));
+
+        m_out.appendTo(bytesEqual, trueCase);
+
+        ValueFromBlock indexForNextIteration = m_out.anchor(indexInLoop);
+        m_out.addIncomingToPhi(indexAtLoopTop, indexForNextIteration);
+        m_out.branch(m_out.notZero32(indexInLoop), unsure(loop), unsure(trueCase));
+
+        m_out.appendTo(trueCase, falseCase);
+        
+        ValueFromBlock trueResult = m_out.anchor(m_out.booleanTrue);
+        m_out.jump(continuation);
+
+        m_out.appendTo(falseCase, slowCase);
+
+        ValueFromBlock falseResult = m_out.anchor(m_out.booleanFalse);
+        m_out.jump(continuation);
+
+        m_out.appendTo(slowCase, continuation);
+
+        LValue slowResultValue = vmCall(
+            Int64, m_out.operation(operationCompareStringEq), m_callFrame,
+            leftJSString, rightJSString);
+        ValueFromBlock slowResult = m_out.anchor(unboxBoolean(slowResultValue));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+        return m_out.phi(Int32, trueResult, falseResult, slowResult);
+    }
+
+    enum ScratchFPRUsage {
+        DontNeedScratchFPR,
+        NeedScratchFPR
+    };
+    template<typename BinaryArithOpGenerator, ScratchFPRUsage scratchFPRUsage = DontNeedScratchFPR>
+    void emitBinarySnippet(J_JITOperation_EJJ slowPathFunction)
+    {
+        Node* node = m_node;
+        
+        LValue left = lowJSValue(node->child1());
+        LValue right = lowJSValue(node->child2());
+
+        SnippetOperand leftOperand(m_state.forNode(node->child1()).resultType());
+        SnippetOperand rightOperand(m_state.forNode(node->child2()).resultType());
+            
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+        patchpoint->appendSomeRegister(left);
+        patchpoint->appendSomeRegister(right);
+        patchpoint->append(m_tagMask, ValueRep::lateReg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::lateReg(GPRInfo::tagTypeNumberRegister));
+        RefPtr<PatchpointExceptionHandle> exceptionHandle =
+            preparePatchpointForExceptions(patchpoint);
+        patchpoint->numGPScratchRegisters = 1;
+        patchpoint->numFPScratchRegisters = 2;
+        if (scratchFPRUsage == NeedScratchFPR)
+            patchpoint->numFPScratchRegisters++;
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        patchpoint->resultConstraint = ValueRep::SomeEarlyRegister;
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+
+                Box<CCallHelpers::JumpList> exceptions =
+                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+
+                auto generator = Box<BinaryArithOpGenerator>::create(
+                    leftOperand, rightOperand, JSValueRegs(params[0].gpr()),
+                    JSValueRegs(params[1].gpr()), JSValueRegs(params[2].gpr()),
+                    params.fpScratch(0), params.fpScratch(1), params.gpScratch(0),
+                    scratchFPRUsage == NeedScratchFPR ? params.fpScratch(2) : InvalidFPRReg);
+
+                generator->generateFastPath(jit);
+
+                if (generator->didEmitFastPath()) {
+                    generator->endJumpList().link(&jit);
+                    CCallHelpers::Label done = jit.label();
+                    
+                    params.addLatePath(
+                        [=] (CCallHelpers& jit) {
+                            AllowMacroScratchRegisterUsage allowScratch(jit);
+                            
+                            generator->slowPathJumpList().link(&jit);
+                            callOperation(
+                                *state, params.unavailableRegisters(), jit, node->origin.semantic,
+                                exceptions.get(), slowPathFunction, params[0].gpr(),
+                                params[1].gpr(), params[2].gpr());
+                            jit.jump().linkTo(done, &jit);
+                        });
+                } else {
+                    callOperation(
+                        *state, params.unavailableRegisters(), jit, node->origin.semantic,
+                        exceptions.get(), slowPathFunction, params[0].gpr(), params[1].gpr(),
+                        params[2].gpr());
+                }
+            });
+
+        setJSValue(patchpoint);
+    }
+
+    template<typename BinaryBitOpGenerator>
+    void emitBinaryBitOpSnippet(J_JITOperation_EJJ slowPathFunction)
+    {
+        Node* node = m_node;
+        
+        LValue left = lowJSValue(node->child1());
+        LValue right = lowJSValue(node->child2());
+
+        SnippetOperand leftOperand(m_state.forNode(node->child1()).resultType());
+        SnippetOperand rightOperand(m_state.forNode(node->child2()).resultType());
+            
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+        patchpoint->appendSomeRegister(left);
+        patchpoint->appendSomeRegister(right);
+        patchpoint->append(m_tagMask, ValueRep::lateReg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::lateReg(GPRInfo::tagTypeNumberRegister));
+        RefPtr<PatchpointExceptionHandle> exceptionHandle =
+            preparePatchpointForExceptions(patchpoint);
+        patchpoint->numGPScratchRegisters = 1;
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        patchpoint->resultConstraint = ValueRep::SomeEarlyRegister;
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+                    
+                Box<CCallHelpers::JumpList> exceptions =
+                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+                    
+                auto generator = Box<BinaryBitOpGenerator>::create(
+                    leftOperand, rightOperand, JSValueRegs(params[0].gpr()),
+                    JSValueRegs(params[1].gpr()), JSValueRegs(params[2].gpr()), params.gpScratch(0));
+
+                generator->generateFastPath(jit);
+                generator->endJumpList().link(&jit);
+                CCallHelpers::Label done = jit.label();
+
+                params.addLatePath(
+                    [=] (CCallHelpers& jit) {
+                        AllowMacroScratchRegisterUsage allowScratch(jit);
+                            
+                        generator->slowPathJumpList().link(&jit);
+                        callOperation(
+                            *state, params.unavailableRegisters(), jit, node->origin.semantic,
+                            exceptions.get(), slowPathFunction, params[0].gpr(),
+                            params[1].gpr(), params[2].gpr());
+                        jit.jump().linkTo(done, &jit);
+                    });
+            });
+
+        setJSValue(patchpoint);
+    }
+
+    void emitRightShiftSnippet(JITRightShiftGenerator::ShiftType shiftType)
+    {
+        Node* node = m_node;
+        
+        // FIXME: Make this do exceptions.
+        // https://bugs.webkit.org/show_bug.cgi?id=151686
+            
+        LValue left = lowJSValue(node->child1());
+        LValue right = lowJSValue(node->child2());
+
+        SnippetOperand leftOperand(m_state.forNode(node->child1()).resultType());
+        SnippetOperand rightOperand(m_state.forNode(node->child2()).resultType());
+            
+        PatchpointValue* patchpoint = m_out.patchpoint(Int64);
+        patchpoint->appendSomeRegister(left);
+        patchpoint->appendSomeRegister(right);
+        patchpoint->append(m_tagMask, ValueRep::lateReg(GPRInfo::tagMaskRegister));
+        patchpoint->append(m_tagTypeNumber, ValueRep::lateReg(GPRInfo::tagTypeNumberRegister));
+        RefPtr<PatchpointExceptionHandle> exceptionHandle =
+            preparePatchpointForExceptions(patchpoint);
+        patchpoint->numGPScratchRegisters = 1;
+        patchpoint->numFPScratchRegisters = 1;
+        patchpoint->clobber(RegisterSet::macroScratchRegisters());
+        patchpoint->resultConstraint = ValueRep::SomeEarlyRegister;
+        State* state = &m_ftlState;
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+                    
+                Box<CCallHelpers::JumpList> exceptions =
+                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);
+                    
+                auto generator = Box<JITRightShiftGenerator>::create(
+                    leftOperand, rightOperand, JSValueRegs(params[0].gpr()),
+                    JSValueRegs(params[1].gpr()), JSValueRegs(params[2].gpr()),
+                    params.fpScratch(0), params.gpScratch(0), InvalidFPRReg, shiftType);
+
+                generator->generateFastPath(jit);
+                generator->endJumpList().link(&jit);
+                CCallHelpers::Label done = jit.label();
+
+                params.addLatePath(
+                    [=] (CCallHelpers& jit) {
+                        AllowMacroScratchRegisterUsage allowScratch(jit);
+                            
+                        generator->slowPathJumpList().link(&jit);
+
+                        J_JITOperation_EJJ slowPathFunction =
+                            shiftType == JITRightShiftGenerator::SignedShift
+                            ? operationValueBitRShift : operationValueBitURShift;
+                        
+                        callOperation(
+                            *state, params.unavailableRegisters(), jit, node->origin.semantic,
+                            exceptions.get(), slowPathFunction, params[0].gpr(),
+                            params[1].gpr(), params[2].gpr());
+                        jit.jump().linkTo(done, &jit);
+                    });
+            });
+
+        setJSValue(patchpoint);
+    }
+
+    LValue allocateHeapCell(LValue allocator, LBasicBlock slowPath)
+    {
+        MarkedAllocator* actualAllocator = nullptr;
+        if (allocator->hasIntPtr())
+            actualAllocator = bitwise_cast<MarkedAllocator*>(allocator->asIntPtr());
+        
+        if (!actualAllocator) {
+            // This means that either we know that the allocator is null or we don't know what the
+            // allocator is. In either case, we need the null check.
+            LBasicBlock haveAllocator = m_out.newBlock();
+            LBasicBlock lastNext = m_out.insertNewBlocksBefore(haveAllocator);
+            m_out.branch(allocator, usually(haveAllocator), rarely(slowPath));
+            m_out.appendTo(haveAllocator, lastNext);
+        }
+        
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(continuation);
+        
+        PatchpointValue* patchpoint = m_out.patchpoint(pointerType());
+        patchpoint->effects.terminal = true;
+        patchpoint->appendSomeRegister(allocator);
+        patchpoint->numGPScratchRegisters++;
+        patchpoint->resultConstraint = ValueRep::SomeEarlyRegister;
+        
+        m_out.appendSuccessor(usually(continuation));
+        m_out.appendSuccessor(rarely(slowPath));
+        
+        patchpoint->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                CCallHelpers::JumpList jumpToSlowPath;
+                
+                // We use a patchpoint to emit the allocation path because whenever we mess with
+                // allocation paths, we already reason about them at the machine code level. We know
+                // exactly what instruction sequence we want. We're confident that no compiler
+                // optimization could make this code better. So, it's best to have the code in
+                // AssemblyHelpers::emitAllocate(). That way, the same optimized path is shared by
+                // all of the compiler tiers.
+                jit.emitAllocateWithNonNullAllocator(
+                    params[0].gpr(), actualAllocator, params[1].gpr(), params.gpScratch(0),
+                    jumpToSlowPath);
+                
+                CCallHelpers::Jump jumpToSuccess;
+                if (!params.fallsThroughToSuccessor(0))
+                    jumpToSuccess = jit.jump();
+                
+                Vector<Box<CCallHelpers::Label>> labels = params.successorLabels();
+                
+                params.addLatePath(
+                    [=] (CCallHelpers& jit) {
+                        jumpToSlowPath.linkTo(*labels[1], &jit);
+                        if (jumpToSuccess.isSet())
+                            jumpToSuccess.linkTo(*labels[0], &jit);
+                    });
+            });
+        
+        m_out.appendTo(continuation, lastNext);
+        return patchpoint;
+    }
+    
+    void storeStructure(LValue object, Structure* structure)
+    {
+        m_out.store32(m_out.constInt32(structure->id()), object, m_heaps.JSCell_structureID);
+        m_out.store32(
+            m_out.constInt32(structure->objectInitializationBlob()),
+            object, m_heaps.JSCell_usefulBytes);
+    }
+
+    void storeStructure(LValue object, LValue structure)
+    {
+        if (structure->hasIntPtr()) {
+            storeStructure(object, bitwise_cast<Structure*>(structure->asIntPtr()));
+            return;
+        }
+
+        LValue id = m_out.load32(structure, m_heaps.Structure_structureID);
+        m_out.store32(id, object, m_heaps.JSCell_structureID);
+
+        LValue blob = m_out.load32(structure, m_heaps.Structure_indexingTypeIncludingHistory);
+        m_out.store32(blob, object, m_heaps.JSCell_usefulBytes);
+    }
+
+    template <typename StructureType>
+    LValue allocateCell(LValue allocator, StructureType structure, LBasicBlock slowPath)
+    {
+        LValue result = allocateHeapCell(allocator, slowPath);
+        storeStructure(result, structure);
+        return result;
+    }
+
+    LValue allocateObject(LValue allocator, RegisteredStructure structure, LValue butterfly, LBasicBlock slowPath)
+    {
+        return allocateObject(allocator, weakStructure(structure), butterfly, slowPath);
+    }
+
+    LValue allocateObject(LValue allocator, LValue structure, LValue butterfly, LBasicBlock slowPath)
+    {
+        LValue result = allocateCell(allocator, structure, slowPath);
+        if (structure->hasIntPtr()) {
+            splatWords(
+                result,
+                m_out.constInt32(JSFinalObject::offsetOfInlineStorage() / 8),
+                m_out.constInt32(JSFinalObject::offsetOfInlineStorage() / 8 + bitwise_cast<Structure*>(structure->asIntPtr())->inlineCapacity()),
+                m_out.int64Zero,
+                m_heaps.properties.atAnyNumber());
+        } else {
+            LValue end = m_out.add(
+                m_out.constInt32(JSFinalObject::offsetOfInlineStorage() / 8),
+                m_out.load8ZeroExt32(structure, m_heaps.Structure_inlineCapacity));
+            splatWords(
+                result,
+                m_out.constInt32(JSFinalObject::offsetOfInlineStorage() / 8),
+                end,
+                m_out.int64Zero,
+                m_heaps.properties.atAnyNumber());
+        }
+        
+        m_out.storePtr(butterfly, result, m_heaps.JSObject_butterfly);
+        return result;
+    }
+    
+    template<typename ClassType, typename StructureType>
+    LValue allocateObject(
+        size_t size, StructureType structure, LValue butterfly, LBasicBlock slowPath)
+    {
+        MarkedAllocator* allocator = subspaceFor<ClassType>(vm())->allocatorFor(size);
+        return allocateObject(m_out.constIntPtr(allocator), structure, butterfly, slowPath);
+    }
+    
+    template<typename ClassType, typename StructureType>
+    LValue allocateObject(StructureType structure, LValue butterfly, LBasicBlock slowPath)
+    {
+        return allocateObject<ClassType>(
+            ClassType::allocationSize(0), structure, butterfly, slowPath);
+    }
+    
+    LValue allocatorForSize(LValue subspace, LValue size, LBasicBlock slowPath)
+    {
+        static_assert(!(MarkedSpace::sizeStep & (MarkedSpace::sizeStep - 1)), "MarkedSpace::sizeStep must be a power of two.");
+        
+        // Try to do some constant-folding here.
+        if (subspace->hasIntPtr() && size->hasIntPtr()) {
+            Subspace* actualSubspace = bitwise_cast<Subspace*>(subspace->asIntPtr());
+            size_t actualSize = size->asIntPtr();
+            
+            MarkedAllocator* actualAllocator = actualSubspace->allocatorFor(actualSize);
+            if (!actualAllocator) {
+                LBasicBlock continuation = m_out.newBlock();
+                LBasicBlock lastNext = m_out.insertNewBlocksBefore(continuation);
+                m_out.jump(slowPath);
+                m_out.appendTo(continuation, lastNext);
+                return m_out.intPtrZero;
+            }
+            
+            return m_out.constIntPtr(actualAllocator);
+        }
+        
+        unsigned stepShift = getLSBSet(MarkedSpace::sizeStep);
+        
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(continuation);
+        
+        LValue sizeClassIndex = m_out.lShr(
+            m_out.add(size, m_out.constIntPtr(MarkedSpace::sizeStep - 1)),
+            m_out.constInt32(stepShift));
+        
+        m_out.branch(
+            m_out.above(sizeClassIndex, m_out.constIntPtr(MarkedSpace::largeCutoff >> stepShift)),
+            rarely(slowPath), usually(continuation));
+        
+        m_out.appendTo(continuation, lastNext);
+        
+        return m_out.loadPtr(
+            m_out.baseIndex(
+                m_heaps.Subspace_allocatorForSizeStep,
+                subspace, m_out.sub(sizeClassIndex, m_out.intPtrOne)));
+    }
+    
+    LValue allocatorForSize(Subspace& subspace, LValue size, LBasicBlock slowPath)
+    {
+        return allocatorForSize(m_out.constIntPtr(&subspace), size, slowPath);
+    }
+    
+    template<typename ClassType>
+    LValue allocateVariableSizedObject(
+        LValue size, RegisteredStructure structure, LValue butterfly, LBasicBlock slowPath)
+    {
+        LValue allocator = allocatorForSize(
+            *subspaceFor<ClassType>(vm()), size, slowPath);
+        return allocateObject(allocator, structure, butterfly, slowPath);
+    }
+
+    template<typename ClassType>
+    LValue allocateVariableSizedCell(
+        LValue size, Structure* structure, LBasicBlock slowPath)
+    {
+        LValue allocator = allocatorForSize(
+            *subspaceFor<ClassType>(vm()), size, slowPath);
+        return allocateCell(allocator, structure, slowPath);
+    }
+    
+    LValue allocateObject(RegisteredStructure structure)
+    {
+        size_t allocationSize = JSFinalObject::allocationSize(structure.get()->inlineCapacity());
+        MarkedAllocator* allocator = subspaceFor<JSFinalObject>(vm())->allocatorFor(allocationSize);
+        
+        // FIXME: If the allocator is null, we could simply emit a normal C call to the allocator
+        // instead of putting it on the slow path.
+        // https://bugs.webkit.org/show_bug.cgi?id=161062
+        
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
+        
+        ValueFromBlock fastResult = m_out.anchor(allocateObject(
+            m_out.constIntPtr(allocator), structure, m_out.intPtrZero, slowPath));
+        
+        m_out.jump(continuation);
+        
+        m_out.appendTo(slowPath, continuation);
+
+        LValue slowResultValue = lazySlowPath(
+            [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                return createLazyCallGenerator(
+                    operationNewObject, locations[0].directGPR(),
+                    CCallHelpers::TrustedImmPtr(structure.get()));
+            });
+        ValueFromBlock slowResult = m_out.anchor(slowResultValue);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        return m_out.phi(pointerType(), fastResult, slowResult);
+    }
+    
+    struct ArrayValues {
+        ArrayValues()
+            : array(0)
+            , butterfly(0)
+        {
+        }
+        
+        ArrayValues(LValue array, LValue butterfly)
+            : array(array)
+            , butterfly(butterfly)
+        {
+        }
+        
+        LValue array;
+        LValue butterfly;
+    };
+
+    ArrayValues allocateJSArray(LValue publicLength, LValue structure, LValue indexingType, bool shouldInitializeElements = true, bool shouldLargeArraySizeCreateArrayStorage = true)
+    {
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+        if (indexingType->hasInt32()) {
+            IndexingType type = static_cast<IndexingType>(indexingType->asInt32());
+            ASSERT_UNUSED(type,
+                hasUndecided(type)
+                || hasInt32(type)
+                || hasDouble(type)
+                || hasContiguous(type));
+        }
+
+        LBasicBlock fastCase = m_out.newBlock();
+        LBasicBlock largeCase = m_out.newBlock();
+        LBasicBlock failCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        LBasicBlock slowCase = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(fastCase);
+        
+        ValueFromBlock noButterfly = m_out.anchor(m_out.intPtrZero);
+        
+        LValue predicate;
+        if (shouldLargeArraySizeCreateArrayStorage)
+            predicate = m_out.aboveOrEqual(publicLength, m_out.constInt32(MIN_ARRAY_STORAGE_CONSTRUCTION_LENGTH));
+        else
+            predicate = m_out.booleanFalse;
+        
+        m_out.branch(predicate, rarely(largeCase), usually(fastCase));
+        
+        m_out.appendTo(fastCase, largeCase);
+
+        LValue vectorLength = nullptr;
+        if (publicLength->hasInt32() && structure->hasIntPtr()) {
+            unsigned publicLengthConst = static_cast<unsigned>(publicLength->asInt32());
+            if (publicLengthConst <= MAX_STORAGE_VECTOR_LENGTH) {
+                vectorLength = m_out.constInt32(
+                    Butterfly::optimalContiguousVectorLength(
+                        bitwise_cast<Structure*>(structure->asIntPtr())->outOfLineCapacity(), publicLengthConst));
+            }
+        }
+        
+        if (!vectorLength) {
+            // We don't compute the optimal vector length for new Array(blah) where blah is not
+            // statically known, since the compute effort of doing it here is probably not worth it.
+            vectorLength = publicLength;
+        }
+            
+        LValue payloadSize =
+            m_out.shl(m_out.zeroExt(vectorLength, pointerType()), m_out.constIntPtr(3));
+            
+        LValue butterflySize = m_out.add(
+            payloadSize, m_out.constIntPtr(sizeof(IndexingHeader)));
+            
+        LValue allocator = allocatorForSize(vm().auxiliarySpace, butterflySize, failCase);
+        LValue startOfStorage = allocateHeapCell(allocator, failCase);
+            
+        LValue butterfly = m_out.add(startOfStorage, m_out.constIntPtr(sizeof(IndexingHeader)));
+        
+        m_out.store32(publicLength, butterfly, m_heaps.Butterfly_publicLength);
+        m_out.store32(vectorLength, butterfly, m_heaps.Butterfly_vectorLength);
+    
+        initializeArrayElements(
+            indexingType,
+            shouldInitializeElements ? m_out.int32Zero : publicLength, vectorLength,
+            butterfly);
+        
+        ValueFromBlock haveButterfly = m_out.anchor(butterfly);
+        
+        LValue object = allocateObject<JSArray>(structure, butterfly, failCase);
+
+        ValueFromBlock fastResult = m_out.anchor(object);
+        ValueFromBlock fastButterfly = m_out.anchor(butterfly);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(largeCase, failCase);
+        ValueFromBlock largeStructure = m_out.anchor(
+            weakStructure(m_graph.registerStructure(globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithArrayStorage))));
+        m_out.jump(slowCase);
+        
+        m_out.appendTo(failCase, slowCase);
+        ValueFromBlock failStructure = m_out.anchor(structure);
+        m_out.jump(slowCase);
+        
+        m_out.appendTo(slowCase, continuation);
+        LValue structureValue = m_out.phi(pointerType(), largeStructure, failStructure);
+        LValue butterflyValue = m_out.phi(pointerType(), noButterfly, haveButterfly);
+
+        LValue slowResultValue = lazySlowPath(
+            [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                return createLazyCallGenerator(
+                    operationNewArrayWithSize, locations[0].directGPR(),
+                    locations[1].directGPR(), locations[2].directGPR(), locations[3].directGPR());
+            },
+            structureValue, publicLength, butterflyValue);
+        ValueFromBlock slowResult = m_out.anchor(slowResultValue);
+        ValueFromBlock slowButterfly = m_out.anchor(
+            m_out.loadPtr(slowResultValue, m_heaps.JSObject_butterfly));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        return ArrayValues(
+            m_out.phi(pointerType(), fastResult, slowResult),
+            m_out.phi(pointerType(), fastButterfly, slowButterfly));
+    }
+    
+    ArrayValues allocateUninitializedContiguousJSArray(LValue publicLength, RegisteredStructure structure)
+    {
+        bool shouldInitializeElements = false;
+        bool shouldLargeArraySizeCreateArrayStorage = false;
+        return allocateJSArray(
+            publicLength, weakStructure(structure), m_out.constInt32(structure->indexingType()), shouldInitializeElements,
+            shouldLargeArraySizeCreateArrayStorage);
+    }
+    
+    LValue ensureShadowChickenPacket()
+    {
+        LBasicBlock slowCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        TypedPointer addressOfLogCursor = m_out.absolute(vm().shadowChicken().addressOfLogCursor());
+        LValue logCursor = m_out.loadPtr(addressOfLogCursor);
+        
+        ValueFromBlock fastResult = m_out.anchor(logCursor);
+        
+        m_out.branch(
+            m_out.below(logCursor, m_out.constIntPtr(vm().shadowChicken().logEnd())),
+            usually(continuation), rarely(slowCase));
+        
+        LBasicBlock lastNext = m_out.appendTo(slowCase, continuation);
+        
+        vmCall(Void, m_out.operation(operationProcessShadowChickenLog), m_callFrame);
+        
+        ValueFromBlock slowResult = m_out.anchor(m_out.loadPtr(addressOfLogCursor));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        LValue result = m_out.phi(pointerType(), fastResult, slowResult);
+        
+        m_out.storePtr(
+            m_out.add(result, m_out.constIntPtr(sizeof(ShadowChicken::Packet))),
+            addressOfLogCursor);
+        
+        return result;
+    }
+    
+    LValue boolify(Edge edge)
+    {
+        switch (edge.useKind()) {
+        case BooleanUse:
+        case KnownBooleanUse:
+            return lowBoolean(edge);
+        case Int32Use:
+            return m_out.notZero32(lowInt32(edge));
+        case DoubleRepUse:
+            return m_out.doubleNotEqualAndOrdered(lowDouble(edge), m_out.doubleZero);
+        case ObjectOrOtherUse:
+            return m_out.logicalNot(
+                equalNullOrUndefined(
+                    edge, CellCaseSpeculatesObject, SpeculateNullOrUndefined,
+                    ManualOperandSpeculation));
+        case StringUse: {
+            LValue stringValue = lowString(edge);
+            LValue length = m_out.load32NonNegative(stringValue, m_heaps.JSString_length);
+            return m_out.notEqual(length, m_out.int32Zero);
+        }
+        case StringOrOtherUse: {
+            LValue value = lowJSValue(edge, ManualOperandSpeculation);
+
+            LBasicBlock cellCase = m_out.newBlock();
+            LBasicBlock notCellCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+
+            m_out.branch(isCell(value, provenType(edge)), unsure(cellCase), unsure(notCellCase));
+            
+            LBasicBlock lastNext = m_out.appendTo(cellCase, notCellCase);
+            
+            FTL_TYPE_CHECK(jsValueValue(value), edge, (~SpecCell) | SpecString, isNotString(value));
+            LValue length = m_out.load32NonNegative(value, m_heaps.JSString_length);
+            ValueFromBlock cellResult = m_out.anchor(m_out.notEqual(length, m_out.int32Zero));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(notCellCase, continuation);
+            
+            FTL_TYPE_CHECK(jsValueValue(value), edge, SpecCell | SpecOther, isNotOther(value));
+            ValueFromBlock notCellResult = m_out.anchor(m_out.booleanFalse);
+            m_out.jump(continuation);
+            m_out.appendTo(continuation, lastNext);
+
+            return m_out.phi(Int32, cellResult, notCellResult);
+        }
+        case UntypedUse: {
+            LValue value = lowJSValue(edge);
+            
+            // Implements the following control flow structure:
+            // if (value is cell) {
+            //     if (value is string)
+            //         result = !!value->length
+            //     else {
+            //         do evil things for masquerades-as-undefined
+            //         result = true
+            //     }
+            // } else if (value is int32) {
+            //     result = !!unboxInt32(value)
+            // } else if (value is number) {
+            //     result = !!unboxDouble(value)
+            // } else {
+            //     result = value == jsTrue
+            // }
+            
+            LBasicBlock cellCase = m_out.newBlock();
+            LBasicBlock stringCase = m_out.newBlock();
+            LBasicBlock notStringCase = m_out.newBlock();
+            LBasicBlock notCellCase = m_out.newBlock();
+            LBasicBlock int32Case = m_out.newBlock();
+            LBasicBlock notInt32Case = m_out.newBlock();
+            LBasicBlock doubleCase = m_out.newBlock();
+            LBasicBlock notDoubleCase = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            
+            Vector<ValueFromBlock> results;
+            
+            m_out.branch(isCell(value, provenType(edge)), unsure(cellCase), unsure(notCellCase));
+            
+            LBasicBlock lastNext = m_out.appendTo(cellCase, stringCase);
+            m_out.branch(
+                isString(value, provenType(edge) & SpecCell),
+                unsure(stringCase), unsure(notStringCase));
+            
+            m_out.appendTo(stringCase, notStringCase);
+            LValue nonEmptyString = m_out.notZero32(
+                m_out.load32NonNegative(value, m_heaps.JSString_length));
+            results.append(m_out.anchor(nonEmptyString));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(notStringCase, notCellCase);
+            LValue isTruthyObject;
+            if (masqueradesAsUndefinedWatchpointIsStillValid())
+                isTruthyObject = m_out.booleanTrue;
+            else {
+                LBasicBlock masqueradesCase = m_out.newBlock();
+                
+                results.append(m_out.anchor(m_out.booleanTrue));
+                
+                m_out.branch(
+                    m_out.testIsZero32(
+                        m_out.load8ZeroExt32(value, m_heaps.JSCell_typeInfoFlags),
+                        m_out.constInt32(MasqueradesAsUndefined)),
+                    usually(continuation), rarely(masqueradesCase));
+                
+                m_out.appendTo(masqueradesCase);
+                
+                isTruthyObject = m_out.notEqual(
+                    weakPointer(m_graph.globalObjectFor(m_node->origin.semantic)),
+                    m_out.loadPtr(loadStructure(value), m_heaps.Structure_globalObject));
+            }
+            results.append(m_out.anchor(isTruthyObject));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(notCellCase, int32Case);
+            m_out.branch(
+                isInt32(value, provenType(edge) & ~SpecCell),
+                unsure(int32Case), unsure(notInt32Case));
+            
+            m_out.appendTo(int32Case, notInt32Case);
+            results.append(m_out.anchor(m_out.notZero32(unboxInt32(value))));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(notInt32Case, doubleCase);
+            m_out.branch(
+                isNumber(value, provenType(edge) & ~SpecCell),
+                unsure(doubleCase), unsure(notDoubleCase));
+            
+            m_out.appendTo(doubleCase, notDoubleCase);
+            LValue doubleIsTruthy = m_out.doubleNotEqualAndOrdered(
+                unboxDouble(value), m_out.constDouble(0));
+            results.append(m_out.anchor(doubleIsTruthy));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(notDoubleCase, continuation);
+            LValue miscIsTruthy = m_out.equal(
+                value, m_out.constInt64(JSValue::encode(jsBoolean(true))));
+            results.append(m_out.anchor(miscIsTruthy));
+            m_out.jump(continuation);
+            
+            m_out.appendTo(continuation, lastNext);
+            return m_out.phi(Int32, results);
+        }
+        default:
+            DFG_CRASH(m_graph, m_node, "Bad use kind");
+            return 0;
+        }
+    }
+    
+    enum StringOrObjectMode {
+        AllCellsAreFalse,
+        CellCaseSpeculatesObject
+    };
+    enum EqualNullOrUndefinedMode {
+        EqualNull,
+        EqualUndefined,
+        EqualNullOrUndefined,
+        SpeculateNullOrUndefined
+    };
+    LValue equalNullOrUndefined(
+        Edge edge, StringOrObjectMode cellMode, EqualNullOrUndefinedMode primitiveMode,
+        OperandSpeculationMode operandMode = AutomaticOperandSpeculation)
+    {
+        bool validWatchpoint = masqueradesAsUndefinedWatchpointIsStillValid();
+        
+        LValue value = lowJSValue(edge, operandMode);
+        
+        LBasicBlock cellCase = m_out.newBlock();
+        LBasicBlock primitiveCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        m_out.branch(isNotCell(value, provenType(edge)), unsure(primitiveCase), unsure(cellCase));
+        
+        LBasicBlock lastNext = m_out.appendTo(cellCase, primitiveCase);
+        
+        Vector<ValueFromBlock, 3> results;
+        
+        switch (cellMode) {
+        case AllCellsAreFalse:
+            break;
+        case CellCaseSpeculatesObject:
+            FTL_TYPE_CHECK(
+                jsValueValue(value), edge, (~SpecCell) | SpecObject, isNotObject(value));
+            break;
+        }
+        
+        if (validWatchpoint) {
+            results.append(m_out.anchor(m_out.booleanFalse));
+            m_out.jump(continuation);
+        } else {
+            LBasicBlock masqueradesCase =
+                m_out.newBlock();
+                
+            results.append(m_out.anchor(m_out.booleanFalse));
+            
+            m_out.branch(
+                m_out.testNonZero32(
+                    m_out.load8ZeroExt32(value, m_heaps.JSCell_typeInfoFlags),
+                    m_out.constInt32(MasqueradesAsUndefined)),
+                rarely(masqueradesCase), usually(continuation));
+            
+            m_out.appendTo(masqueradesCase, primitiveCase);
+            
+            LValue structure = loadStructure(value);
+            
+            results.append(m_out.anchor(
+                m_out.equal(
+                    weakPointer(m_graph.globalObjectFor(m_node->origin.semantic)),
+                    m_out.loadPtr(structure, m_heaps.Structure_globalObject))));
+            m_out.jump(continuation);
+        }
+        
+        m_out.appendTo(primitiveCase, continuation);
+        
+        LValue primitiveResult;
+        switch (primitiveMode) {
+        case EqualNull:
+            primitiveResult = m_out.equal(value, m_out.constInt64(ValueNull));
+            break;
+        case EqualUndefined:
+            primitiveResult = m_out.equal(value, m_out.constInt64(ValueUndefined));
+            break;
+        case EqualNullOrUndefined:
+            primitiveResult = isOther(value, provenType(edge));
+            break;
+        case SpeculateNullOrUndefined:
+            FTL_TYPE_CHECK(
+                jsValueValue(value), edge, SpecCell | SpecOther, isNotOther(value));
+            primitiveResult = m_out.booleanTrue;
+            break;
+        }
+        results.append(m_out.anchor(primitiveResult));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        
+        return m_out.phi(Int32, results);
+    }
+    
+    template<typename FunctionType>
+    void contiguousPutByValOutOfBounds(
+        FunctionType slowPathFunction, LValue base, LValue storage, LValue index, LValue value,
+        LBasicBlock continuation)
+    {
+        LValue isNotInBounds = m_out.aboveOrEqual(
+            index, m_out.load32NonNegative(storage, m_heaps.Butterfly_publicLength));
+        if (!m_node->arrayMode().isInBounds()) {
+            LBasicBlock notInBoundsCase =
+                m_out.newBlock();
+            LBasicBlock performStore =
+                m_out.newBlock();
+                
+            m_out.branch(isNotInBounds, unsure(notInBoundsCase), unsure(performStore));
+                
+            LBasicBlock lastNext = m_out.appendTo(notInBoundsCase, performStore);
+                
+            LValue isOutOfBounds = m_out.aboveOrEqual(
+                index, m_out.load32NonNegative(storage, m_heaps.Butterfly_vectorLength));
+                
+            if (!m_node->arrayMode().isOutOfBounds())
+                speculate(OutOfBounds, noValue(), 0, isOutOfBounds);
+            else {
+                LBasicBlock outOfBoundsCase =
+                    m_out.newBlock();
+                LBasicBlock holeCase =
+                    m_out.newBlock();
+                    
+                m_out.branch(isOutOfBounds, rarely(outOfBoundsCase), usually(holeCase));
+                    
+                LBasicBlock innerLastNext = m_out.appendTo(outOfBoundsCase, holeCase);
+                    
+                vmCall(
+                    Void, m_out.operation(slowPathFunction),
+                    m_callFrame, base, index, value);
+                    
+                m_out.jump(continuation);
+                    
+                m_out.appendTo(holeCase, innerLastNext);
+            }
+            
+            m_out.store32(
+                m_out.add(index, m_out.int32One),
+                storage, m_heaps.Butterfly_publicLength);
+                
+            m_out.jump(performStore);
+            m_out.appendTo(performStore, lastNext);
+        }
+    }
+    
+    void buildSwitch(SwitchData* data, LType type, LValue switchValue)
+    {
+        ASSERT(type == pointerType() || type == Int32);
+
+        Vector<SwitchCase> cases;
+        for (unsigned i = 0; i < data->cases.size(); ++i) {
+            SwitchCase newCase;
+
+            if (type == pointerType()) {
+                newCase = SwitchCase(m_out.constIntPtr(data->cases[i].value.switchLookupValue(data->kind)),
+                    lowBlock(data->cases[i].target.block), Weight(data->cases[i].target.count));
+            } else if (type == Int32) {
+                newCase = SwitchCase(m_out.constInt32(data->cases[i].value.switchLookupValue(data->kind)),
+                    lowBlock(data->cases[i].target.block), Weight(data->cases[i].target.count));
+            } else
+                CRASH();
+
+            cases.append(newCase);
+        }
+        
+        m_out.switchInstruction(
+            switchValue, cases,
+            lowBlock(data->fallThrough.block), Weight(data->fallThrough.count));
+    }
+    
+    void switchString(SwitchData* data, LValue string)
+    {
+        bool canDoBinarySwitch = true;
+        unsigned totalLength = 0;
+        
+        for (DFG::SwitchCase myCase : data->cases) {
+            StringImpl* string = myCase.value.stringImpl();
+            if (!string->is8Bit()) {
+                canDoBinarySwitch = false;
+                break;
+            }
+            if (string->length() > Options::maximumBinaryStringSwitchCaseLength()) {
+                canDoBinarySwitch = false;
+                break;
+            }
+            totalLength += string->length();
+        }
+        
+        if (!canDoBinarySwitch || totalLength > Options::maximumBinaryStringSwitchTotalLength()) {
+            switchStringSlow(data, string);
+            return;
+        }
+        
+        LValue stringImpl = m_out.loadPtr(string, m_heaps.JSString_value);
+        LValue length = m_out.load32(string, m_heaps.JSString_length);
+        
+        LBasicBlock hasImplBlock = m_out.newBlock();
+        LBasicBlock is8BitBlock = m_out.newBlock();
+        LBasicBlock slowBlock = m_out.newBlock();
+        
+        m_out.branch(m_out.isNull(stringImpl), unsure(slowBlock), unsure(hasImplBlock));
+        
+        LBasicBlock lastNext = m_out.appendTo(hasImplBlock, is8BitBlock);
+        
+        m_out.branch(
+            m_out.testIsZero32(
+                m_out.load32(stringImpl, m_heaps.StringImpl_hashAndFlags),
+                m_out.constInt32(StringImpl::flagIs8Bit())),
+            unsure(slowBlock), unsure(is8BitBlock));
+        
+        m_out.appendTo(is8BitBlock, slowBlock);
+        
+        LValue buffer = m_out.loadPtr(stringImpl, m_heaps.StringImpl_data);
+        
+        // FIXME: We should propagate branch weight data to the cases of this switch.
+        // https://bugs.webkit.org/show_bug.cgi?id=144368
+        
+        Vector<StringSwitchCase> cases;
+        for (DFG::SwitchCase myCase : data->cases)
+            cases.append(StringSwitchCase(myCase.value.stringImpl(), lowBlock(myCase.target.block)));
+        std::sort(cases.begin(), cases.end());
+        switchStringRecurse(data, buffer, length, cases, 0, 0, cases.size(), 0, false);
+
+        m_out.appendTo(slowBlock, lastNext);
+        switchStringSlow(data, string);
+    }
+    
+    // The code for string switching is based closely on the same code in the DFG backend. While it
+    // would be nice to reduce the amount of similar-looking code, it seems like this is one of
+    // those algorithms where factoring out the common bits would result in more code than just
+    // duplicating.
+    
+    struct StringSwitchCase {
+        StringSwitchCase() { }
+        
+        StringSwitchCase(StringImpl* string, LBasicBlock target)
+            : string(string)
+            , target(target)
+        {
+        }
+
+        bool operator<(const StringSwitchCase& other) const
+        {
+            return stringLessThan(*string, *other.string);
+        }
+        
+        StringImpl* string;
+        LBasicBlock target;
+    };
+    
+    struct CharacterCase {
+        CharacterCase()
+            : character(0)
+            , begin(0)
+            , end(0)
+        {
+        }
+        
+        CharacterCase(LChar character, unsigned begin, unsigned end)
+            : character(character)
+            , begin(begin)
+            , end(end)
+        {
+        }
+        
+        bool operator<(const CharacterCase& other) const
+        {
+            return character < other.character;
+        }
+        
+        LChar character;
+        unsigned begin;
+        unsigned end;
+    };
+    
+    void switchStringRecurse(
+        SwitchData* data, LValue buffer, LValue length, const Vector<StringSwitchCase>& cases,
+        unsigned numChecked, unsigned begin, unsigned end, unsigned alreadyCheckedLength,
+        unsigned checkedExactLength)
+    {
+        LBasicBlock fallThrough = lowBlock(data->fallThrough.block);
+        
+        if (begin == end) {
+            m_out.jump(fallThrough);
+            return;
+        }
+        
+        unsigned minLength = cases[begin].string->length();
+        unsigned commonChars = minLength;
+        bool allLengthsEqual = true;
+        for (unsigned i = begin + 1; i < end; ++i) {
+            unsigned myCommonChars = numChecked;
+            unsigned limit = std::min(cases[begin].string->length(), cases[i].string->length());
+            for (unsigned j = numChecked; j < limit; ++j) {
+                if (cases[begin].string->at(j) != cases[i].string->at(j))
+                    break;
+                myCommonChars++;
+            }
+            commonChars = std::min(commonChars, myCommonChars);
+            if (minLength != cases[i].string->length())
+                allLengthsEqual = false;
+            minLength = std::min(minLength, cases[i].string->length());
+        }
+        
+        if (checkedExactLength) {
+            DFG_ASSERT(m_graph, m_node, alreadyCheckedLength == minLength);
+            DFG_ASSERT(m_graph, m_node, allLengthsEqual);
+        }
+        
+        DFG_ASSERT(m_graph, m_node, minLength >= commonChars);
+        
+        if (!allLengthsEqual && alreadyCheckedLength < minLength)
+            m_out.check(m_out.below(length, m_out.constInt32(minLength)), unsure(fallThrough));
+        if (allLengthsEqual && (alreadyCheckedLength < minLength || !checkedExactLength))
+            m_out.check(m_out.notEqual(length, m_out.constInt32(minLength)), unsure(fallThrough));
+        
+        for (unsigned i = numChecked; i < commonChars; ++i) {
+            m_out.check(
+                m_out.notEqual(
+                    m_out.load8ZeroExt32(buffer, m_heaps.characters8[i]),
+                    m_out.constInt32(static_cast<uint16_t>(cases[begin].string->at(i)))),
+                unsure(fallThrough));
+        }
+        
+        if (minLength == commonChars) {
+            // This is the case where one of the cases is a prefix of all of the other cases.
+            // We've already checked that the input string is a prefix of all of the cases,
+            // so we just check length to jump to that case.
+            
+            DFG_ASSERT(m_graph, m_node, cases[begin].string->length() == commonChars);
+            for (unsigned i = begin + 1; i < end; ++i)
+                DFG_ASSERT(m_graph, m_node, cases[i].string->length() > commonChars);
+            
+            if (allLengthsEqual) {
+                DFG_ASSERT(m_graph, m_node, end == begin + 1);
+                m_out.jump(cases[begin].target);
+                return;
+            }
+            
+            m_out.check(
+                m_out.equal(length, m_out.constInt32(commonChars)),
+                unsure(cases[begin].target));
+            
+            // We've checked if the length is >= minLength, and then we checked if the length is
+            // == commonChars. We get to this point if it is >= minLength but not == commonChars.
+            // Hence we know that it now must be > minLength, i.e. that it's >= minLength + 1.
+            switchStringRecurse(
+                data, buffer, length, cases, commonChars, begin + 1, end, minLength + 1, false);
+            return;
+        }
+        
+        // At this point we know that the string is longer than commonChars, and we've only verified
+        // commonChars. Use a binary switch on the next unchecked character, i.e.
+        // string[commonChars].
+        
+        DFG_ASSERT(m_graph, m_node, end >= begin + 2);
+        
+        LValue uncheckedChar = m_out.load8ZeroExt32(buffer, m_heaps.characters8[commonChars]);
+        
+        Vector<CharacterCase> characterCases;
+        CharacterCase currentCase(cases[begin].string->at(commonChars), begin, begin + 1);
+        for (unsigned i = begin + 1; i < end; ++i) {
+            LChar currentChar = cases[i].string->at(commonChars);
+            if (currentChar != currentCase.character) {
+                currentCase.end = i;
+                characterCases.append(currentCase);
+                currentCase = CharacterCase(currentChar, i, i + 1);
+            } else
+                currentCase.end = i + 1;
+        }
+        characterCases.append(currentCase);
+        
+        Vector<LBasicBlock> characterBlocks;
+        for (unsigned i = characterCases.size(); i--;)
+            characterBlocks.append(m_out.newBlock());
+        
+        Vector<SwitchCase> switchCases;
+        for (unsigned i = 0; i < characterCases.size(); ++i) {
+            if (i)
+                DFG_ASSERT(m_graph, m_node, characterCases[i - 1].character < characterCases[i].character);
+            switchCases.append(SwitchCase(
+                m_out.constInt32(characterCases[i].character), characterBlocks[i], Weight()));
+        }
+        m_out.switchInstruction(uncheckedChar, switchCases, fallThrough, Weight());
+        
+        LBasicBlock lastNext = m_out.m_nextBlock;
+        characterBlocks.append(lastNext); // Makes it convenient to set nextBlock.
+        for (unsigned i = 0; i < characterCases.size(); ++i) {
+            m_out.appendTo(characterBlocks[i], characterBlocks[i + 1]);
+            switchStringRecurse(
+                data, buffer, length, cases, commonChars + 1,
+                characterCases[i].begin, characterCases[i].end, minLength, allLengthsEqual);
+        }
+        
+        DFG_ASSERT(m_graph, m_node, m_out.m_nextBlock == lastNext);
+    }
+    
+    void switchStringSlow(SwitchData* data, LValue string)
+    {
+        // FIXME: We ought to be able to use computed gotos here. We would save the labels of the
+        // blocks we want to jump to, and then request their addresses after compilation completes.
+        // https://bugs.webkit.org/show_bug.cgi?id=144369
+        
+        LValue branchOffset = vmCall(
+            Int32, m_out.operation(operationSwitchStringAndGetBranchOffset),
+            m_callFrame, m_out.constIntPtr(data->switchTableIndex), string);
+        
+        StringJumpTable& table = codeBlock()->stringSwitchJumpTable(data->switchTableIndex);
+        
+        Vector<SwitchCase> cases;
+        std::unordered_set<int32_t> alreadyHandled; // These may be negative, or zero, or probably other stuff, too. We don't want to mess with HashSet's corner cases and we don't really care about throughput here.
+        for (unsigned i = 0; i < data->cases.size(); ++i) {
+            // FIXME: The fact that we're using the bytecode's switch table means that the
+            // following DFG IR transformation would be invalid.
+            //
+            // Original code:
+            //     switch (v) {
+            //     case "foo":
+            //     case "bar":
+            //         things();
+            //         break;
+            //     default:
+            //         break;
+            //     }
+            //
+            // New code:
+            //     switch (v) {
+            //     case "foo":
+            //         instrumentFoo();
+            //         goto _things;
+            //     case "bar":
+            //         instrumentBar();
+            //     _things:
+            //         things();
+            //         break;
+            //     default:
+            //         break;
+            //     }
+            //
+            // Luckily, we don't currently do any such transformation. But it's kind of silly that
+            // this is an issue.
+            // https://bugs.webkit.org/show_bug.cgi?id=144635
+            
+            DFG::SwitchCase myCase = data->cases[i];
+            StringJumpTable::StringOffsetTable::iterator iter =
+                table.offsetTable.find(myCase.value.stringImpl());
+            DFG_ASSERT(m_graph, m_node, iter != table.offsetTable.end());
+            
+            if (!alreadyHandled.insert(iter->value.branchOffset).second)
+                continue;
+
+            cases.append(SwitchCase(
+                m_out.constInt32(iter->value.branchOffset),
+                lowBlock(myCase.target.block), Weight(myCase.target.count)));
+        }
+        
+        m_out.switchInstruction(
+            branchOffset, cases, lowBlock(data->fallThrough.block),
+            Weight(data->fallThrough.count));
+    }
+    
+    // Calls the functor at the point of code generation where we know what the result type is.
+    // You can emit whatever code you like at that point. Expects you to terminate the basic block.
+    // When buildTypeOf() returns, it will have terminated all basic blocks that it created. So, if
+    // you aren't using this as the terminator of a high-level block, you should create your own
+    // contination and set it as the nextBlock (m_out.insertNewBlocksBefore(continuation)) before
+    // calling this. For example:
+    //
+    // LBasicBlock continuation = m_out.newBlock();
+    // LBasicBlock lastNext = m_out.insertNewBlocksBefore(continuation);
+    // buildTypeOf(
+    //     child, value,
+    //     [&] (TypeofType type) {
+    //          do things;
+    //          m_out.jump(continuation);
+    //     });
+    // m_out.appendTo(continuation, lastNext);
+    template<typename Functor>
+    void buildTypeOf(Edge child, LValue value, const Functor& functor)
+    {
+        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->origin.semantic);
+        
+        // Implements the following branching structure:
+        //
+        // if (is cell) {
+        //     if (is object) {
+        //         if (is function) {
+        //             return function;
+        //         } else if (doesn't have call trap and doesn't masquerade as undefined) {
+        //             return object
+        //         } else {
+        //             return slowPath();
+        //         }
+        //     } else if (is string) {
+        //         return string
+        //     } else {
+        //         return symbol
+        //     }
+        // } else if (is number) {
+        //     return number
+        // } else if (is null) {
+        //     return object
+        // } else if (is boolean) {
+        //     return boolean
+        // } else {
+        //     return undefined
+        // }
+        
+        LBasicBlock cellCase = m_out.newBlock();
+        LBasicBlock objectCase = m_out.newBlock();
+        LBasicBlock functionCase = m_out.newBlock();
+        LBasicBlock notFunctionCase = m_out.newBlock();
+        LBasicBlock reallyObjectCase = m_out.newBlock();
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock unreachable = m_out.newBlock();
+        LBasicBlock notObjectCase = m_out.newBlock();
+        LBasicBlock stringCase = m_out.newBlock();
+        LBasicBlock symbolCase = m_out.newBlock();
+        LBasicBlock notCellCase = m_out.newBlock();
+        LBasicBlock numberCase = m_out.newBlock();
+        LBasicBlock notNumberCase = m_out.newBlock();
+        LBasicBlock notNullCase = m_out.newBlock();
+        LBasicBlock booleanCase = m_out.newBlock();
+        LBasicBlock undefinedCase = m_out.newBlock();
+        
+        m_out.branch(isCell(value, provenType(child)), unsure(cellCase), unsure(notCellCase));
+        
+        LBasicBlock lastNext = m_out.appendTo(cellCase, objectCase);
+        m_out.branch(isObject(value, provenType(child)), unsure(objectCase), unsure(notObjectCase));
+        
+        m_out.appendTo(objectCase, functionCase);
+        m_out.branch(
+            isFunction(value, provenType(child) & SpecObject),
+            unsure(functionCase), unsure(notFunctionCase));
+        
+        m_out.appendTo(functionCase, notFunctionCase);
+        functor(TypeofType::Function);
+        
+        m_out.appendTo(notFunctionCase, reallyObjectCase);
+        m_out.branch(
+            isExoticForTypeof(value, provenType(child) & (SpecObject - SpecFunction)),
+            rarely(slowPath), usually(reallyObjectCase));
+        
+        m_out.appendTo(reallyObjectCase, slowPath);
+        functor(TypeofType::Object);
+        
+        m_out.appendTo(slowPath, unreachable);
+        LValue result = lazySlowPath(
+            [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+                return createLazyCallGenerator(
+                    operationTypeOfObjectAsTypeofType, locations[0].directGPR(),
+                    CCallHelpers::TrustedImmPtr(globalObject), locations[1].directGPR());
+            }, value);
+        Vector<SwitchCase, 3> cases;
+        cases.append(SwitchCase(m_out.constInt32(static_cast<int32_t>(TypeofType::Undefined)), undefinedCase));
+        cases.append(SwitchCase(m_out.constInt32(static_cast<int32_t>(TypeofType::Object)), reallyObjectCase));
+        cases.append(SwitchCase(m_out.constInt32(static_cast<int32_t>(TypeofType::Function)), functionCase));
+        m_out.switchInstruction(m_out.castToInt32(result), cases, unreachable, Weight());
+        
+        m_out.appendTo(unreachable, notObjectCase);
+        m_out.unreachable();
+        
+        m_out.appendTo(notObjectCase, stringCase);
+        m_out.branch(
+            isString(value, provenType(child) & (SpecCell - SpecObject)),
+            unsure(stringCase), unsure(symbolCase));
+        
+        m_out.appendTo(stringCase, symbolCase);
+        functor(TypeofType::String);
+        
+        m_out.appendTo(symbolCase, notCellCase);
+        functor(TypeofType::Symbol);
+        
+        m_out.appendTo(notCellCase, numberCase);
+        m_out.branch(
+            isNumber(value, provenType(child) & ~SpecCell),
+            unsure(numberCase), unsure(notNumberCase));
+        
+        m_out.appendTo(numberCase, notNumberCase);
+        functor(TypeofType::Number);
+        
+        m_out.appendTo(notNumberCase, notNullCase);
+        LValue isNull;
+        if (provenType(child) & SpecOther)
+            isNull = m_out.equal(value, m_out.constInt64(ValueNull));
+        else
+            isNull = m_out.booleanFalse;
+        m_out.branch(isNull, unsure(reallyObjectCase), unsure(notNullCase));
+        
+        m_out.appendTo(notNullCase, booleanCase);
+        m_out.branch(
+            isBoolean(value, provenType(child) & ~(SpecCell | SpecFullNumber)),
+            unsure(booleanCase), unsure(undefinedCase));
+        
+        m_out.appendTo(booleanCase, undefinedCase);
+        functor(TypeofType::Boolean);
+        
+        m_out.appendTo(undefinedCase, lastNext);
+        functor(TypeofType::Undefined);
+    }
+    
+    LValue doubleToInt32(LValue doubleValue, double low, double high, bool isSigned = true)
+    {
+        LBasicBlock greatEnough = m_out.newBlock();
+        LBasicBlock withinRange = m_out.newBlock();
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        Vector<ValueFromBlock, 2> results;
+        
+        m_out.branch(
+            m_out.doubleGreaterThanOrEqual(doubleValue, m_out.constDouble(low)),
+            unsure(greatEnough), unsure(slowPath));
+        
+        LBasicBlock lastNext = m_out.appendTo(greatEnough, withinRange);
+        m_out.branch(
+            m_out.doubleLessThanOrEqual(doubleValue, m_out.constDouble(high)),
+            unsure(withinRange), unsure(slowPath));
+        
+        m_out.appendTo(withinRange, slowPath);
+        LValue fastResult;
+        if (isSigned)
+            fastResult = m_out.doubleToInt(doubleValue);
+        else
+            fastResult = m_out.doubleToUInt(doubleValue);
+        results.append(m_out.anchor(fastResult));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(slowPath, continuation);
+        results.append(m_out.anchor(m_out.call(Int32, m_out.operation(operationToInt32), doubleValue)));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        return m_out.phi(Int32, results);
+    }
+    
+    LValue doubleToInt32(LValue doubleValue)
+    {
+        if (hasSensibleDoubleToInt())
+            return sensibleDoubleToInt32(doubleValue);
+        
+        double limit = pow(2, 31) - 1;
+        return doubleToInt32(doubleValue, -limit, limit);
+    }
+    
+    LValue sensibleDoubleToInt32(LValue doubleValue)
+    {
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        LValue fastResultValue = m_out.doubleToInt(doubleValue);
+        ValueFromBlock fastResult = m_out.anchor(fastResultValue);
+        m_out.branch(
+            m_out.equal(fastResultValue, m_out.constInt32(0x80000000)),
+            rarely(slowPath), usually(continuation));
+        
+        LBasicBlock lastNext = m_out.appendTo(slowPath, continuation);
+        ValueFromBlock slowResult = m_out.anchor(
+            m_out.call(Int32, m_out.operation(operationToInt32SensibleSlow), doubleValue));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        return m_out.phi(Int32, fastResult, slowResult);
+    }
+
+    // This is a mechanism for creating a code generator that fills in a gap in the code using our
+    // own MacroAssembler. This is useful for slow paths that involve a lot of code and we don't want
+    // to pay the price of B3 optimizing it. A lazy slow path will only be generated if it actually
+    // executes. On the other hand, a lazy slow path always incurs the cost of two additional jumps.
+    // Also, the lazy slow path's register allocation state is slaved to whatever B3 did, so you
+    // have to use a ScratchRegisterAllocator to try to use some unused registers and you may have
+    // to spill to top of stack if there aren't enough registers available.
+    //
+    // Lazy slow paths involve three different stages of execution. Each stage has unique
+    // capabilities and knowledge. The stages are:
+    //
+    // 1) DFG->B3 lowering, i.e. code that runs in this phase. Lowering is the last time you will
+    //    have access to LValues. If there is an LValue that needs to be fed as input to a lazy slow
+    //    path, then you must pass it as an argument here (as one of the varargs arguments after the
+    //    functor). But, lowering doesn't know which registers will be used for those LValues. Hence
+    //    you pass a lambda to lazySlowPath() and that lambda will run during stage (2):
+    //
+    // 2) FTLCompile.cpp's fixFunctionBasedOnStackMaps. This code is the only stage at which we know
+    //    the mapping from arguments passed to this method in (1) and the registers that B3
+    //    selected for those arguments. You don't actually want to generate any code here, since then
+    //    the slow path wouldn't actually be lazily generated. Instead, you want to save the
+    //    registers being used for the arguments and defer code generation to stage (3) by creating
+    //    and returning a LazySlowPath::Generator:
+    //
+    // 3) LazySlowPath's generate() method. This code runs in response to the lazy slow path
+    //    executing for the first time. It will call the generator you created in stage (2).
+    //
+    // Note that each time you invoke stage (1), stage (2) may be invoked zero, one, or many times.
+    // Stage (2) will usually be invoked once for stage (1). But, B3 may kill the code, in which
+    // case stage (2) won't run. B3 may duplicate the code (for example via tail duplication),
+    // leading to many calls to your stage (2) lambda. Stage (3) may be called zero or once for each
+    // stage (2). It will be called zero times if the slow path never runs. This is what you hope for
+    // whenever you use the lazySlowPath() mechanism.
+    //
+    // A typical use of lazySlowPath() will look like the example below, which just creates a slow
+    // path that adds some value to the input and returns it.
+    //
+    // // Stage (1) is here. This is your last chance to figure out which LValues to use as inputs.
+    // // Notice how we pass "input" as an argument to lazySlowPath().
+    // LValue input = ...;
+    // int addend = ...;
+    // LValue output = lazySlowPath(
+    //     [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+    //         // Stage (2) is here. This is your last chance to figure out which registers are used
+    //         // for which values. Location zero is always the return value. You can ignore it if
+    //         // you don't want to return anything. Location 1 is the register for the first
+    //         // argument to the lazySlowPath(), i.e. "input". Note that the Location object could
+    //         // also hold an FPR, if you are passing a double.
+    //         GPRReg outputGPR = locations[0].directGPR();
+    //         GPRReg inputGPR = locations[1].directGPR();
+    //         return LazySlowPath::createGenerator(
+    //             [=] (CCallHelpers& jit, LazySlowPath::GenerationParams& params) {
+    //                 // Stage (3) is here. This is when you generate code. You have access to the
+    //                 // registers you collected in stage (2) because this lambda closes over those
+    //                 // variables (outputGPR and inputGPR). You also have access to whatever extra
+    //                 // data you collected in stage (1), such as the addend in this case.
+    //                 jit.add32(TrustedImm32(addend), inputGPR, outputGPR);
+    //                 // You have to end by jumping to done. There is nothing to fall through to.
+    //                 // You can also jump to the exception handler (see LazySlowPath.h for more
+    //                 // info). Note that currently you cannot OSR exit.
+    //                 params.doneJumps.append(jit.jump());
+    //             });
+    //     },
+    //     input);
+    //
+    // You can basically pass as many inputs as you like, either using this varargs form, or by
+    // passing a Vector of LValues.
+    //
+    // Note that if your slow path is only doing a call, you can use the createLazyCallGenerator()
+    // helper. For example:
+    //
+    // LValue input = ...;
+    // LValue output = lazySlowPath(
+    //     [=] (const Vector<Location>& locations) -> RefPtr<LazySlowPath::Generator> {
+    //         return createLazyCallGenerator(
+    //             operationDoThings, locations[0].directGPR(), locations[1].directGPR());
+    //     }, input);
+    //
+    // Finally, note that all of the lambdas - both the stage (2) lambda and the stage (3) lambda -
+    // run after the function that created them returns. Hence, you should not use by-reference
+    // capture (i.e. [&]) in any of these lambdas.
+    template<typename Functor, typename... ArgumentTypes>
+    PatchpointValue* lazySlowPath(const Functor& functor, ArgumentTypes... arguments)
+    {
+        return lazySlowPath(functor, Vector<LValue>{ arguments... });
+    }
+
+    template<typename Functor>
+    PatchpointValue* lazySlowPath(const Functor& functor, const Vector<LValue>& userArguments)
+    {
+        CodeOrigin origin = m_node->origin.semantic;
+        
+        PatchpointValue* result = m_out.patchpoint(B3::Int64);
+        for (LValue arg : userArguments)
+            result->append(ConstrainedValue(arg, B3::ValueRep::SomeRegister));
+
+        RefPtr<PatchpointExceptionHandle> exceptionHandle =
+            preparePatchpointForExceptions(result);
+        
+        result->clobber(RegisterSet::macroScratchRegisters());
+        State* state = &m_ftlState;
+
+        result->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                Vector<Location> locations;
+                for (const B3::ValueRep& rep : params)
+                    locations.append(Location::forValueRep(rep));
+
+                RefPtr<LazySlowPath::Generator> generator = functor(locations);
+                
+                CCallHelpers::PatchableJump patchableJump = jit.patchableJump();
+                CCallHelpers::Label done = jit.label();
+
+                RegisterSet usedRegisters = params.unavailableRegisters();
+
+                RefPtr<ExceptionTarget> exceptionTarget =
+                    exceptionHandle->scheduleExitCreation(params);
+
+                // FIXME: As part of handling exceptions, we need to create a concrete OSRExit here.
+                // Doing so should automagically register late paths that emit exit thunks.
+
+                params.addLatePath(
+                    [=] (CCallHelpers& jit) {
+                        AllowMacroScratchRegisterUsage allowScratch(jit);
+                        patchableJump.m_jump.link(&jit);
+                        unsigned index = state->jitCode->lazySlowPaths.size();
+                        state->jitCode->lazySlowPaths.append(nullptr);
+                        jit.pushToSaveImmediateWithoutTouchingRegisters(
+                            CCallHelpers::TrustedImm32(index));
+                        CCallHelpers::Jump generatorJump = jit.jump();
+
+                        // Note that so long as we're here, we don't really know if our late path
+                        // runs before or after any other late paths that we might depend on, like
+                        // the exception thunk.
+
+                        RefPtr<JITCode> jitCode = state->jitCode;
+                        VM* vm = &state->graph.m_vm;
+
+                        jit.addLinkTask(
+                            [=] (LinkBuffer& linkBuffer) {
+                                linkBuffer.link(
+                                    generatorJump, CodeLocationLabel(
+                                        vm->getCTIStub(
+                                            lazySlowPathGenerationThunkGenerator).code()));
+                                
+                                CodeLocationJump linkedPatchableJump = CodeLocationJump(
+                                    linkBuffer.locationOf(patchableJump));
+                                CodeLocationLabel linkedDone = linkBuffer.locationOf(done);
+
+                                CallSiteIndex callSiteIndex =
+                                    jitCode->common.addUniqueCallSiteIndex(origin);
+                                    
+                                std::unique_ptr<LazySlowPath> lazySlowPath =
+                                    std::make_unique<LazySlowPath>(
+                                        linkedPatchableJump, linkedDone,
+                                        exceptionTarget->label(linkBuffer), usedRegisters,
+                                        callSiteIndex, generator);
+                                    
+                                jitCode->lazySlowPaths[index] = WTFMove(lazySlowPath);
+                            });
+                    });
+            });
+        return result;
+    }
+    
+    void speculate(
+        ExitKind kind, FormattedValue lowValue, Node* highValue, LValue failCondition)
+    {
+        appendOSRExit(kind, lowValue, highValue, failCondition, m_origin);
+    }
+    
+    void terminate(ExitKind kind)
+    {
+        speculate(kind, noValue(), nullptr, m_out.booleanTrue);
+        didAlreadyTerminate();
+    }
+    
+    void didAlreadyTerminate()
+    {
+        m_state.setIsValid(false);
+    }
+    
+    void typeCheck(
+        FormattedValue lowValue, Edge highValue, SpeculatedType typesPassedThrough,
+        LValue failCondition, ExitKind exitKind = BadType)
+    {
+        appendTypeCheck(lowValue, highValue, typesPassedThrough, failCondition, exitKind);
+    }
+    
+    void appendTypeCheck(
+        FormattedValue lowValue, Edge highValue, SpeculatedType typesPassedThrough,
+        LValue failCondition, ExitKind exitKind)
+    {
+        if (!m_interpreter.needsTypeCheck(highValue, typesPassedThrough))
+            return;
+        ASSERT(mayHaveTypeCheck(highValue.useKind()));
+        appendOSRExit(exitKind, lowValue, highValue.node(), failCondition, m_origin);
+        m_interpreter.filter(highValue, typesPassedThrough);
+    }
+    
+    LValue lowInt32(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
+    {
+        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || (edge.useKind() == Int32Use || edge.useKind() == KnownInt32Use));
+        
+        if (edge->hasConstant()) {
+            JSValue value = edge->asJSValue();
+            if (!value.isInt32()) {
+                terminate(Uncountable);
+                return m_out.int32Zero;
+            }
+            return m_out.constInt32(value.asInt32());
+        }
+        
+        LoweredNodeValue value = m_int32Values.get(edge.node());
+        if (isValid(value))
+            return value.value();
+        
+        value = m_strictInt52Values.get(edge.node());
+        if (isValid(value))
+            return strictInt52ToInt32(edge, value.value());
+        
+        value = m_int52Values.get(edge.node());
+        if (isValid(value))
+            return strictInt52ToInt32(edge, int52ToStrictInt52(value.value()));
+        
+        value = m_jsValueValues.get(edge.node());
+        if (isValid(value)) {
+            LValue boxedResult = value.value();
+            FTL_TYPE_CHECK(
+                jsValueValue(boxedResult), edge, SpecInt32Only, isNotInt32(boxedResult));
+            LValue result = unboxInt32(boxedResult);
+            setInt32(edge.node(), result);
+            return result;
+        }
+
+        DFG_ASSERT(m_graph, m_node, !(provenType(edge) & SpecInt32Only));
+        terminate(Uncountable);
+        return m_out.int32Zero;
+    }
+    
+    enum Int52Kind { StrictInt52, Int52 };
+    LValue lowInt52(Edge edge, Int52Kind kind)
+    {
+        DFG_ASSERT(m_graph, m_node, edge.useKind() == Int52RepUse);
+        
+        LoweredNodeValue value;
+        
+        switch (kind) {
+        case Int52:
+            value = m_int52Values.get(edge.node());
+            if (isValid(value))
+                return value.value();
+            
+            value = m_strictInt52Values.get(edge.node());
+            if (isValid(value))
+                return strictInt52ToInt52(value.value());
+            break;
+            
+        case StrictInt52:
+            value = m_strictInt52Values.get(edge.node());
+            if (isValid(value))
+                return value.value();
+            
+            value = m_int52Values.get(edge.node());
+            if (isValid(value))
+                return int52ToStrictInt52(value.value());
+            break;
+        }
+
+        DFG_ASSERT(m_graph, m_node, !provenType(edge));
+        terminate(Uncountable);
+        return m_out.int64Zero;
+    }
+    
+    LValue lowInt52(Edge edge)
+    {
+        return lowInt52(edge, Int52);
+    }
+    
+    LValue lowStrictInt52(Edge edge)
+    {
+        return lowInt52(edge, StrictInt52);
+    }
+    
+    bool betterUseStrictInt52(Node* node)
+    {
+        return !isValid(m_int52Values.get(node));
+    }
+    bool betterUseStrictInt52(Edge edge)
+    {
+        return betterUseStrictInt52(edge.node());
+    }
+    template<typename T>
+    Int52Kind bestInt52Kind(T node)
+    {
+        return betterUseStrictInt52(node) ? StrictInt52 : Int52;
+    }
+    Int52Kind opposite(Int52Kind kind)
+    {
+        switch (kind) {
+        case Int52:
+            return StrictInt52;
+        case StrictInt52:
+            return Int52;
+        }
+        DFG_CRASH(m_graph, m_node, "Bad use kind");
+        return Int52;
+    }
+    
+    LValue lowWhicheverInt52(Edge edge, Int52Kind& kind)
+    {
+        kind = bestInt52Kind(edge);
+        return lowInt52(edge, kind);
+    }
+    
+    LValue lowCell(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
+    {
+        DFG_ASSERT(m_graph, m_node, mode == ManualOperandSpeculation || DFG::isCell(edge.useKind()));
+        
+        if (edge->op() == JSConstant) {
+            FrozenValue* value = edge->constant();
+            if (!value->value().isCell()) {
+                terminate(Uncountable);
+                return m_out.intPtrZero;
+            }
+            return frozenPointer(value);
+        }
+        
+        LoweredNodeValue value = m_jsValueValues.get(edge.node());
+        if (isValid(value)) {
+            LValue uncheckedValue = value.value();
+            FTL_TYPE_CHECK(
+                jsValueValue(uncheckedValue), edge, SpecCell, isNotCell(uncheckedValue));
+            return uncheckedValue;
+        }
+        
+        DFG_ASSERT(m_graph, m_node, !(provenType(edge) & SpecCell));
+        terminate(Uncountable);
+        return m_out.intPtrZero;
+    }
+    
+    LValue lowObject(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
+    {
+        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == ObjectUse);
+        
+        LValue result = lowCell(edge, mode);
+        speculateObject(edge, result);
+        return result;
+    }
+
+    LValue lowRegExpObject(Edge edge)
+    {
+        LValue result = lowCell(edge);
+        speculateRegExpObject(edge, result);
+        return result;
+    }
+
+    LValue lowMapObject(Edge edge)
+    {
+        LValue result = lowCell(edge);
+        speculateMapObject(edge, result);
+        return result;
+    }
+
+    LValue lowSetObject(Edge edge)
+    {
+        LValue result = lowCell(edge);
+        speculateSetObject(edge, result);
+        return result;
+    }
+    
+    LValue lowString(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
+    {
+        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == StringUse || edge.useKind() == KnownStringUse || edge.useKind() == StringIdentUse);
+        
+        LValue result = lowCell(edge, mode);
+        speculateString(edge, result);
+        return result;
+    }
+    
+    LValue lowStringIdent(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
+    {
+        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == StringIdentUse);
+        
+        LValue string = lowString(edge, mode);
+        LValue stringImpl = m_out.loadPtr(string, m_heaps.JSString_value);
+        speculateStringIdent(edge, string, stringImpl);
+        return stringImpl;
+    }
+
+    LValue lowSymbol(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
+    {
+        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == SymbolUse);
+
+        LValue result = lowCell(edge, mode);
+        speculateSymbol(edge, result);
+        return result;
+    }
+    
+    LValue lowNonNullObject(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
+    {
+        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == ObjectUse);
+        
+        LValue result = lowCell(edge, mode);
+        speculateNonNullObject(edge, result);
+        return result;
+    }
+    
+    LValue lowBoolean(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
+    {
+        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == BooleanUse || edge.useKind() == KnownBooleanUse);
+        
+        if (edge->hasConstant()) {
+            JSValue value = edge->asJSValue();
+            if (!value.isBoolean()) {
+                terminate(Uncountable);
+                return m_out.booleanFalse;
+            }
+            return m_out.constBool(value.asBoolean());
+        }
+        
+        LoweredNodeValue value = m_booleanValues.get(edge.node());
+        if (isValid(value))
+            return value.value();
+        
+        value = m_jsValueValues.get(edge.node());
+        if (isValid(value)) {
+            LValue unboxedResult = value.value();
+            FTL_TYPE_CHECK(
+                jsValueValue(unboxedResult), edge, SpecBoolean, isNotBoolean(unboxedResult));
+            LValue result = unboxBoolean(unboxedResult);
+            setBoolean(edge.node(), result);
+            return result;
+        }
+        
+        DFG_ASSERT(m_graph, m_node, !(provenType(edge) & SpecBoolean));
+        terminate(Uncountable);
+        return m_out.booleanFalse;
+    }
+    
+    LValue lowDouble(Edge edge)
+    {
+        DFG_ASSERT(m_graph, m_node, isDouble(edge.useKind()));
+        
+        LoweredNodeValue value = m_doubleValues.get(edge.node());
+        if (isValid(value))
+            return value.value();
+        DFG_ASSERT(m_graph, m_node, !provenType(edge));
+        terminate(Uncountable);
+        return m_out.doubleZero;
+    }
+    
+    LValue lowJSValue(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
+    {
+        DFG_ASSERT(m_graph, m_node, mode == ManualOperandSpeculation || edge.useKind() == UntypedUse);
+        DFG_ASSERT(m_graph, m_node, !isDouble(edge.useKind()));
+        DFG_ASSERT(m_graph, m_node, edge.useKind() != Int52RepUse);
+        
+        if (edge->hasConstant())
+            return m_out.constInt64(JSValue::encode(edge->asJSValue()));
+
+        LoweredNodeValue value = m_jsValueValues.get(edge.node());
+        if (isValid(value))
+            return value.value();
+        
+        value = m_int32Values.get(edge.node());
+        if (isValid(value)) {
+            LValue result = boxInt32(value.value());
+            setJSValue(edge.node(), result);
+            return result;
+        }
+        
+        value = m_booleanValues.get(edge.node());
+        if (isValid(value)) {
+            LValue result = boxBoolean(value.value());
+            setJSValue(edge.node(), result);
+            return result;
+        }
+        
+        DFG_CRASH(m_graph, m_node, "Value not defined");
+        return 0;
+    }
+
+    LValue lowNotCell(Edge edge)
+    {
+        LValue result = lowJSValue(edge, ManualOperandSpeculation);
+        FTL_TYPE_CHECK(jsValueValue(result), edge, ~SpecCell, isCell(result));
+        return result;
+    }
+    
+    LValue lowStorage(Edge edge)
+    {
+        LoweredNodeValue value = m_storageValues.get(edge.node());
+        if (isValid(value))
+            return value.value();
+        
+        LValue result = lowCell(edge);
+        setStorage(edge.node(), result);
+        return result;
+    }
+
+    LValue lowMapBucket(Edge edge)
+    {
+        LoweredNodeValue value = m_mapBucketValues.get(edge.node());
+        if (isValid(value))
+            return value.value();
+        
+        LValue result = lowCell(edge);
+        setStorage(edge.node(), result);
+        return result;
+    }
+    
+    LValue strictInt52ToInt32(Edge edge, LValue value)
+    {
+        LValue result = m_out.castToInt32(value);
+        FTL_TYPE_CHECK(
+            noValue(), edge, SpecInt32Only,
+            m_out.notEqual(m_out.signExt32To64(result), value));
+        setInt32(edge.node(), result);
+        return result;
+    }
+    
+    LValue strictInt52ToDouble(LValue value)
+    {
+        return m_out.intToDouble(value);
+    }
+    
+    LValue strictInt52ToJSValue(LValue value)
+    {
+        LBasicBlock isInt32 = m_out.newBlock();
+        LBasicBlock isDouble = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        Vector<ValueFromBlock, 2> results;
+            
+        LValue int32Value = m_out.castToInt32(value);
+        m_out.branch(
+            m_out.equal(m_out.signExt32To64(int32Value), value),
+            unsure(isInt32), unsure(isDouble));
+        
+        LBasicBlock lastNext = m_out.appendTo(isInt32, isDouble);
+        
+        results.append(m_out.anchor(boxInt32(int32Value)));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(isDouble, continuation);
+        
+        results.append(m_out.anchor(boxDouble(m_out.intToDouble(value))));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        return m_out.phi(Int64, results);
+    }
+    
+    LValue strictInt52ToInt52(LValue value)
+    {
+        return m_out.shl(value, m_out.constInt64(JSValue::int52ShiftAmount));
+    }
+    
+    LValue int52ToStrictInt52(LValue value)
+    {
+        return m_out.aShr(value, m_out.constInt64(JSValue::int52ShiftAmount));
+    }
+    
+    LValue isInt32(LValue jsValue, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, SpecInt32Only))
+            return proven;
+        return m_out.aboveOrEqual(jsValue, m_tagTypeNumber);
+    }
+    LValue isNotInt32(LValue jsValue, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, ~SpecInt32Only))
+            return proven;
+        return m_out.below(jsValue, m_tagTypeNumber);
+    }
+    LValue unboxInt32(LValue jsValue)
+    {
+        return m_out.castToInt32(jsValue);
+    }
+    LValue boxInt32(LValue value)
+    {
+        return m_out.add(m_out.zeroExt(value, Int64), m_tagTypeNumber);
+    }
+    
+    LValue isCellOrMisc(LValue jsValue, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, SpecCell | SpecMisc))
+            return proven;
+        return m_out.testIsZero64(jsValue, m_tagTypeNumber);
+    }
+    LValue isNotCellOrMisc(LValue jsValue, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, ~(SpecCell | SpecMisc)))
+            return proven;
+        return m_out.testNonZero64(jsValue, m_tagTypeNumber);
+    }
+
+    LValue unboxDouble(LValue jsValue)
+    {
+        return m_out.bitCast(m_out.add(jsValue, m_tagTypeNumber), Double);
+    }
+    LValue boxDouble(LValue doubleValue)
+    {
+        return m_out.sub(m_out.bitCast(doubleValue, Int64), m_tagTypeNumber);
+    }
+    
+    LValue jsValueToStrictInt52(Edge edge, LValue boxedValue)
+    {
+        LBasicBlock intCase = m_out.newBlock();
+        LBasicBlock doubleCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+            
+        LValue isNotInt32;
+        if (!m_interpreter.needsTypeCheck(edge, SpecInt32Only))
+            isNotInt32 = m_out.booleanFalse;
+        else if (!m_interpreter.needsTypeCheck(edge, ~SpecInt32Only))
+            isNotInt32 = m_out.booleanTrue;
+        else
+            isNotInt32 = this->isNotInt32(boxedValue);
+        m_out.branch(isNotInt32, unsure(doubleCase), unsure(intCase));
+            
+        LBasicBlock lastNext = m_out.appendTo(intCase, doubleCase);
+            
+        ValueFromBlock intToInt52 = m_out.anchor(
+            m_out.signExt32To64(unboxInt32(boxedValue)));
+        m_out.jump(continuation);
+            
+        m_out.appendTo(doubleCase, continuation);
+        
+        LValue possibleResult = m_out.call(
+            Int64, m_out.operation(operationConvertBoxedDoubleToInt52), boxedValue);
+        FTL_TYPE_CHECK(
+            jsValueValue(boxedValue), edge, SpecInt32Only | SpecAnyIntAsDouble,
+            m_out.equal(possibleResult, m_out.constInt64(JSValue::notInt52)));
+            
+        ValueFromBlock doubleToInt52 = m_out.anchor(possibleResult);
+        m_out.jump(continuation);
+            
+        m_out.appendTo(continuation, lastNext);
+            
+        return m_out.phi(Int64, intToInt52, doubleToInt52);
+    }
+    
+    LValue doubleToStrictInt52(Edge edge, LValue value)
+    {
+        LValue possibleResult = m_out.call(
+            Int64, m_out.operation(operationConvertDoubleToInt52), value);
+        FTL_TYPE_CHECK_WITH_EXIT_KIND(Int52Overflow,
+            doubleValue(value), edge, SpecAnyIntAsDouble,
+            m_out.equal(possibleResult, m_out.constInt64(JSValue::notInt52)));
+        
+        return possibleResult;
+    }
+
+    LValue convertDoubleToInt32(LValue value, bool shouldCheckNegativeZero)
+    {
+        LValue integerValue = m_out.doubleToInt(value);
+        LValue integerValueConvertedToDouble = m_out.intToDouble(integerValue);
+        LValue valueNotConvertibleToInteger = m_out.doubleNotEqualOrUnordered(value, integerValueConvertedToDouble);
+        speculate(Overflow, FormattedValue(DataFormatDouble, value), m_node, valueNotConvertibleToInteger);
+
+        if (shouldCheckNegativeZero) {
+            LBasicBlock valueIsZero = m_out.newBlock();
+            LBasicBlock continuation = m_out.newBlock();
+            m_out.branch(m_out.isZero32(integerValue), unsure(valueIsZero), unsure(continuation));
+
+            LBasicBlock lastNext = m_out.appendTo(valueIsZero, continuation);
+
+            LValue doubleBitcastToInt64 = m_out.bitCast(value, Int64);
+            LValue signBitSet = m_out.lessThan(doubleBitcastToInt64, m_out.constInt64(0));
+
+            speculate(NegativeZero, FormattedValue(DataFormatDouble, value), m_node, signBitSet);
+            m_out.jump(continuation);
+            m_out.appendTo(continuation, lastNext);
+        }
+        return integerValue;
+    }
+
+    LValue isNumber(LValue jsValue, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, SpecFullNumber))
+            return proven;
+        return isNotCellOrMisc(jsValue);
+    }
+    LValue isNotNumber(LValue jsValue, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, ~SpecFullNumber))
+            return proven;
+        return isCellOrMisc(jsValue);
+    }
+    
+    LValue isNotCell(LValue jsValue, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, ~SpecCell))
+            return proven;
+        return m_out.testNonZero64(jsValue, m_tagMask);
+    }
+    
+    LValue isCell(LValue jsValue, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, SpecCell))
+            return proven;
+        return m_out.testIsZero64(jsValue, m_tagMask);
+    }
+    
+    LValue isNotMisc(LValue value, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, ~SpecMisc))
+            return proven;
+        return m_out.above(value, m_out.constInt64(TagBitTypeOther | TagBitBool | TagBitUndefined));
+    }
+    
+    LValue isMisc(LValue value, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, SpecMisc))
+            return proven;
+        return m_out.logicalNot(isNotMisc(value));
+    }
+    
+    LValue isNotBoolean(LValue jsValue, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, ~SpecBoolean))
+            return proven;
+        return m_out.testNonZero64(
+            m_out.bitXor(jsValue, m_out.constInt64(ValueFalse)),
+            m_out.constInt64(~1));
+    }
+    LValue isBoolean(LValue jsValue, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, SpecBoolean))
+            return proven;
+        return m_out.logicalNot(isNotBoolean(jsValue));
+    }
+    LValue unboxBoolean(LValue jsValue)
+    {
+        // We want to use a cast that guarantees that B3 knows that even the integer
+        // value is just 0 or 1. But for now we do it the dumb way.
+        return m_out.notZero64(m_out.bitAnd(jsValue, m_out.constInt64(1)));
+    }
+    LValue boxBoolean(LValue value)
+    {
+        return m_out.select(
+            value, m_out.constInt64(ValueTrue), m_out.constInt64(ValueFalse));
+    }
+    
+    LValue isNotOther(LValue value, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, ~SpecOther))
+            return proven;
+        return m_out.notEqual(
+            m_out.bitAnd(value, m_out.constInt64(~TagBitUndefined)),
+            m_out.constInt64(ValueNull));
+    }
+    LValue isOther(LValue value, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type, SpecOther))
+            return proven;
+        return m_out.equal(
+            m_out.bitAnd(value, m_out.constInt64(~TagBitUndefined)),
+            m_out.constInt64(ValueNull));
+    }
+    
+    LValue isProvenValue(SpeculatedType provenType, SpeculatedType wantedType)
+    {
+        if (!(provenType & ~wantedType))
+            return m_out.booleanTrue;
+        if (!(provenType & wantedType))
+            return m_out.booleanFalse;
+        return nullptr;
+    }
+
+    void speculate(Edge edge)
+    {
+        switch (edge.useKind()) {
+        case UntypedUse:
+            break;
+        case KnownInt32Use:
+        case KnownStringUse:
+        case KnownPrimitiveUse:
+        case DoubleRepUse:
+        case Int52RepUse:
+            ASSERT(!m_interpreter.needsTypeCheck(edge));
+            break;
+        case Int32Use:
+            speculateInt32(edge);
+            break;
+        case CellUse:
+            speculateCell(edge);
+            break;
+        case CellOrOtherUse:
+            speculateCellOrOther(edge);
+            break;
+        case KnownCellUse:
+            ASSERT(!m_interpreter.needsTypeCheck(edge));
+            break;
+        case AnyIntUse:
+            speculateAnyInt(edge);
+            break;
+        case ObjectUse:
+            speculateObject(edge);
+            break;
+        case ArrayUse:
+            speculateArray(edge);
+            break;
+        case FunctionUse:
+            speculateFunction(edge);
+            break;
+        case ObjectOrOtherUse:
+            speculateObjectOrOther(edge);
+            break;
+        case FinalObjectUse:
+            speculateFinalObject(edge);
+            break;
+        case RegExpObjectUse:
+            speculateRegExpObject(edge);
+            break;
+        case ProxyObjectUse:
+            speculateProxyObject(edge);
+            break;
+        case DerivedArrayUse:
+            speculateDerivedArray(edge);
+            break;
+        case MapObjectUse:
+            speculateMapObject(edge);
+            break;
+        case SetObjectUse:
+            speculateSetObject(edge);
+            break;
+        case StringUse:
+            speculateString(edge);
+            break;
+        case StringOrOtherUse:
+            speculateStringOrOther(edge);
+            break;
+        case StringIdentUse:
+            speculateStringIdent(edge);
+            break;
+        case SymbolUse:
+            speculateSymbol(edge);
+            break;
+        case StringObjectUse:
+            speculateStringObject(edge);
+            break;
+        case StringOrStringObjectUse:
+            speculateStringOrStringObject(edge);
+            break;
+        case NumberUse:
+            speculateNumber(edge);
+            break;
+        case RealNumberUse:
+            speculateRealNumber(edge);
+            break;
+        case DoubleRepRealUse:
+            speculateDoubleRepReal(edge);
+            break;
+        case DoubleRepAnyIntUse:
+            speculateDoubleRepAnyInt(edge);
+            break;
+        case BooleanUse:
+            speculateBoolean(edge);
+            break;
+        case NotStringVarUse:
+            speculateNotStringVar(edge);
+            break;
+        case NotCellUse:
+            speculateNotCell(edge);
+            break;
+        case OtherUse:
+            speculateOther(edge);
+            break;
+        case MiscUse:
+            speculateMisc(edge);
+            break;
+        default:
+            DFG_CRASH(m_graph, m_node, "Unsupported speculation use kind");
+        }
+    }
+    
+    void speculate(Node*, Edge edge)
+    {
+        speculate(edge);
+    }
+    
+    void speculateInt32(Edge edge)
+    {
+        lowInt32(edge);
+    }
+    
+    void speculateCell(Edge edge)
+    {
+        lowCell(edge);
+    }
+
+    void speculateNotCell(Edge edge)
+    {
+        if (!m_interpreter.needsTypeCheck(edge))
+            return;
+        lowNotCell(edge);
+    }
+    
+    void speculateCellOrOther(Edge edge)
+    {
+        LValue value = lowJSValue(edge, ManualOperandSpeculation);
+
+        LBasicBlock isNotCell = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(isCell(value, provenType(edge)), unsure(continuation), unsure(isNotCell));
+
+        LBasicBlock lastNext = m_out.appendTo(isNotCell, continuation);
+        FTL_TYPE_CHECK(jsValueValue(value), edge, SpecCell | SpecOther, isNotOther(value));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    void speculateAnyInt(Edge edge)
+    {
+        if (!m_interpreter.needsTypeCheck(edge))
+            return;
+        
+        jsValueToStrictInt52(edge, lowJSValue(edge, ManualOperandSpeculation));
+    }
+
+    LValue isCellWithType(LValue cell, JSType queriedType, SpeculatedType speculatedTypeForQuery, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type & SpecCell, speculatedTypeForQuery))
+            return proven;
+        return m_out.equal(
+            m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoType),
+            m_out.constInt32(queriedType));
+    }
+
+    LValue isTypedArrayView(LValue cell, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type & SpecCell, SpecTypedArrayView))
+            return proven;
+        LValue jsType = m_out.sub(
+            m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoType),
+            m_out.constInt32(Int8ArrayType));
+        return m_out.belowOrEqual(
+            jsType,
+            m_out.constInt32(Float64ArrayType - Int8ArrayType));
+    }
+    
+    LValue isObject(LValue cell, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type & SpecCell, SpecObject))
+            return proven;
+        return m_out.aboveOrEqual(
+            m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoType),
+            m_out.constInt32(ObjectType));
+    }
+
+    LValue isNotObject(LValue cell, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type & SpecCell, ~SpecObject))
+            return proven;
+        return m_out.below(
+            m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoType),
+            m_out.constInt32(ObjectType));
+    }
+
+    LValue isNotString(LValue cell, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type & SpecCell, ~SpecString))
+            return proven;
+        return m_out.notEqual(
+            m_out.load32(cell, m_heaps.JSCell_structureID),
+            m_out.constInt32(vm().stringStructure->id()));
+    }
+    
+    LValue isString(LValue cell, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type & SpecCell, SpecString))
+            return proven;
+        return m_out.equal(
+            m_out.load32(cell, m_heaps.JSCell_structureID),
+            m_out.constInt32(vm().stringStructure->id()));
+    }
+
+    LValue isNotSymbol(LValue cell, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type & SpecCell, ~SpecSymbol))
+            return proven;
+        return m_out.notEqual(
+            m_out.load32(cell, m_heaps.JSCell_structureID),
+            m_out.constInt32(vm().symbolStructure->id()));
+    }
+    
+    LValue isSymbol(LValue cell, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type & SpecCell, SpecSymbol))
+            return proven;
+        return m_out.equal(
+            m_out.load32(cell, m_heaps.JSCell_structureID),
+            m_out.constInt32(vm().symbolStructure->id()));
+    }
+
+    LValue isArrayType(LValue cell, ArrayMode arrayMode)
+    {
+        switch (arrayMode.type()) {
+        case Array::Int32:
+        case Array::Double:
+        case Array::Contiguous: {
+            LValue indexingType = m_out.load8ZeroExt32(cell, m_heaps.JSCell_indexingTypeAndMisc);
+            
+            switch (arrayMode.arrayClass()) {
+            case Array::OriginalArray:
+                DFG_CRASH(m_graph, m_node, "Unexpected original array");
+                return 0;
+                
+            case Array::Array:
+                return m_out.equal(
+                    m_out.bitAnd(indexingType, m_out.constInt32(IsArray | IndexingShapeMask)),
+                    m_out.constInt32(IsArray | arrayMode.shapeMask()));
+                
+            case Array::NonArray:
+            case Array::OriginalNonArray:
+                return m_out.equal(
+                    m_out.bitAnd(indexingType, m_out.constInt32(IsArray | IndexingShapeMask)),
+                    m_out.constInt32(arrayMode.shapeMask()));
+                
+            case Array::PossiblyArray:
+                return m_out.equal(
+                    m_out.bitAnd(indexingType, m_out.constInt32(IndexingShapeMask)),
+                    m_out.constInt32(arrayMode.shapeMask()));
+            }
+            
+            DFG_CRASH(m_graph, m_node, "Corrupt array class");
+        }
+            
+        case Array::DirectArguments:
+            return m_out.equal(
+                m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoType),
+                m_out.constInt32(DirectArgumentsType));
+            
+        case Array::ScopedArguments:
+            return m_out.equal(
+                m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoType),
+                m_out.constInt32(ScopedArgumentsType));
+            
+        default:
+            return m_out.equal(
+                m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoType),
+                m_out.constInt32(typeForTypedArrayType(arrayMode.typedArrayType())));
+        }
+    }
+    
+    LValue isFunction(LValue cell, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type & SpecCell, SpecFunction))
+            return proven;
+        return isType(cell, JSFunctionType);
+    }
+    LValue isNotFunction(LValue cell, SpeculatedType type = SpecFullTop)
+    {
+        if (LValue proven = isProvenValue(type & SpecCell, ~SpecFunction))
+            return proven;
+        return isNotType(cell, JSFunctionType);
+    }
+            
+    LValue isExoticForTypeof(LValue cell, SpeculatedType type = SpecFullTop)
+    {
+        if (!(type & SpecObjectOther))
+            return m_out.booleanFalse;
+        return m_out.testNonZero32(
+            m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoFlags),
+            m_out.constInt32(MasqueradesAsUndefined | TypeOfShouldCallGetCallData));
+    }
+
+    LValue isType(LValue cell, JSType type)
+    {
+        return m_out.equal(
+            m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoType),
+            m_out.constInt32(type));
+    }
+    
+    LValue isNotType(LValue cell, JSType type)
+    {
+        return m_out.logicalNot(isType(cell, type));
+    }
+    
+    void speculateObject(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(jsValueValue(cell), edge, SpecObject, isNotObject(cell));
+    }
+    
+    void speculateObject(Edge edge)
+    {
+        speculateObject(edge, lowCell(edge));
+    }
+
+    void speculateArray(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(
+            jsValueValue(cell), edge, SpecArray, isNotType(cell, ArrayType));
+    }
+
+    void speculateArray(Edge edge)
+    {
+        speculateArray(edge, lowCell(edge));
+    }
+    
+    void speculateFunction(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(jsValueValue(cell), edge, SpecFunction, isNotFunction(cell));
+    }
+    
+    void speculateFunction(Edge edge)
+    {
+        speculateFunction(edge, lowCell(edge));
+    }
+    
+    void speculateObjectOrOther(Edge edge)
+    {
+        if (!m_interpreter.needsTypeCheck(edge))
+            return;
+        
+        LValue value = lowJSValue(edge, ManualOperandSpeculation);
+        
+        LBasicBlock cellCase = m_out.newBlock();
+        LBasicBlock primitiveCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        m_out.branch(isNotCell(value, provenType(edge)), unsure(primitiveCase), unsure(cellCase));
+        
+        LBasicBlock lastNext = m_out.appendTo(cellCase, primitiveCase);
+        
+        FTL_TYPE_CHECK(
+            jsValueValue(value), edge, (~SpecCell) | SpecObject, isNotObject(value));
+        
+        m_out.jump(continuation);
+        
+        m_out.appendTo(primitiveCase, continuation);
+        
+        FTL_TYPE_CHECK(
+            jsValueValue(value), edge, SpecCell | SpecOther, isNotOther(value));
+        
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    void speculateFinalObject(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(
+            jsValueValue(cell), edge, SpecFinalObject, isNotType(cell, FinalObjectType));
+    }
+    
+    void speculateFinalObject(Edge edge)
+    {
+        speculateFinalObject(edge, lowCell(edge));
+    }
+    
+    void speculateRegExpObject(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(
+            jsValueValue(cell), edge, SpecRegExpObject, isNotType(cell, RegExpObjectType));
+    }
+    
+    void speculateRegExpObject(Edge edge)
+    {
+        speculateRegExpObject(edge, lowCell(edge));
+    }
+
+    void speculateProxyObject(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(
+            jsValueValue(cell), edge, SpecProxyObject, isNotType(cell, ProxyObjectType));
+    }
+
+    void speculateProxyObject(Edge edge)
+    {
+        speculateProxyObject(edge, lowCell(edge));
+    }
+
+    void speculateDerivedArray(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(
+            jsValueValue(cell), edge, SpecDerivedArray, isNotType(cell, DerivedArrayType));
+    }
+
+    void speculateDerivedArray(Edge edge)
+    {
+        speculateDerivedArray(edge, lowCell(edge));
+    }
+
+    void speculateMapObject(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(
+            jsValueValue(cell), edge, SpecMapObject, isNotType(cell, JSMapType));
+    }
+
+    void speculateMapObject(Edge edge)
+    {
+        speculateMapObject(edge, lowCell(edge));
+    }
+
+    void speculateSetObject(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(
+            jsValueValue(cell), edge, SpecSetObject, isNotType(cell, JSSetType));
+    }
+
+    void speculateSetObject(Edge edge)
+    {
+        speculateSetObject(edge, lowCell(edge));
+    }
+    
+    void speculateString(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(jsValueValue(cell), edge, SpecString | ~SpecCell, isNotString(cell));
+    }
+    
+    void speculateString(Edge edge)
+    {
+        speculateString(edge, lowCell(edge));
+    }
+    
+    void speculateStringOrOther(Edge edge, LValue value)
+    {
+        LBasicBlock cellCase = m_out.newBlock();
+        LBasicBlock notCellCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(isCell(value, provenType(edge)), unsure(cellCase), unsure(notCellCase));
+
+        LBasicBlock lastNext = m_out.appendTo(cellCase, notCellCase);
+
+        FTL_TYPE_CHECK(jsValueValue(value), edge, (~SpecCell) | SpecString, isNotString(value));
+
+        m_out.jump(continuation);
+        m_out.appendTo(notCellCase, continuation);
+
+        FTL_TYPE_CHECK(jsValueValue(value), edge, SpecCell | SpecOther, isNotOther(value));
+
+        m_out.jump(continuation);
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    void speculateStringOrOther(Edge edge)
+    {
+        speculateStringOrOther(edge, lowJSValue(edge, ManualOperandSpeculation));
+    }
+    
+    void speculateStringIdent(Edge edge, LValue string, LValue stringImpl)
+    {
+        if (!m_interpreter.needsTypeCheck(edge, SpecStringIdent | ~SpecString))
+            return;
+        
+        speculate(BadType, jsValueValue(string), edge.node(), m_out.isNull(stringImpl));
+        speculate(
+            BadType, jsValueValue(string), edge.node(),
+            m_out.testIsZero32(
+                m_out.load32(stringImpl, m_heaps.StringImpl_hashAndFlags),
+                m_out.constInt32(StringImpl::flagIsAtomic())));
+        m_interpreter.filter(edge, SpecStringIdent | ~SpecString);
+    }
+    
+    void speculateStringIdent(Edge edge)
+    {
+        lowStringIdent(edge);
+    }
+    
+    void speculateStringObject(Edge edge)
+    {
+        if (!m_interpreter.needsTypeCheck(edge, SpecStringObject))
+            return;
+        
+        speculateStringObjectForCell(edge, lowCell(edge));
+        m_interpreter.filter(edge, SpecStringObject);
+    }
+    
+    void speculateStringOrStringObject(Edge edge)
+    {
+        if (!m_interpreter.needsTypeCheck(edge, SpecString | SpecStringObject))
+            return;
+        
+        LBasicBlock notString = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LValue structureID = m_out.load32(lowCell(edge), m_heaps.JSCell_structureID);
+        m_out.branch(
+            m_out.equal(structureID, m_out.constInt32(vm().stringStructure->id())),
+            unsure(continuation), unsure(notString));
+        
+        LBasicBlock lastNext = m_out.appendTo(notString, continuation);
+        speculateStringObjectForStructureID(edge, structureID);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+        
+        m_interpreter.filter(edge, SpecString | SpecStringObject);
+    }
+    
+    void speculateStringObjectForCell(Edge edge, LValue cell)
+    {
+        speculateStringObjectForStructureID(edge, m_out.load32(cell, m_heaps.JSCell_structureID));
+    }
+    
+    void speculateStringObjectForStructureID(Edge edge, LValue structureID)
+    {
+        RegisteredStructure stringObjectStructure =
+            m_graph.registerStructure(m_graph.globalObjectFor(m_node->origin.semantic)->stringObjectStructure());
+
+        if (abstractStructure(edge).isSubsetOf(RegisteredStructureSet(stringObjectStructure)))
+            return;
+        
+        speculate(
+            NotStringObject, noValue(), 0,
+            m_out.notEqual(structureID, weakStructureID(stringObjectStructure)));
+    }
+
+    void speculateSymbol(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(jsValueValue(cell), edge, SpecSymbol | ~SpecCell, isNotSymbol(cell));
+    }
+
+    void speculateSymbol(Edge edge)
+    {
+        speculateSymbol(edge, lowCell(edge));
+    }
+
+    void speculateNonNullObject(Edge edge, LValue cell)
+    {
+        FTL_TYPE_CHECK(jsValueValue(cell), edge, SpecObject, isNotObject(cell));
+        if (masqueradesAsUndefinedWatchpointIsStillValid())
+            return;
+        
+        speculate(
+            BadType, jsValueValue(cell), edge.node(),
+            m_out.testNonZero32(
+                m_out.load8ZeroExt32(cell, m_heaps.JSCell_typeInfoFlags),
+                m_out.constInt32(MasqueradesAsUndefined)));
+    }
+    
+    void speculateNumber(Edge edge)
+    {
+        LValue value = lowJSValue(edge, ManualOperandSpeculation);
+        FTL_TYPE_CHECK(jsValueValue(value), edge, SpecBytecodeNumber, isNotNumber(value));
+    }
+    
+    void speculateRealNumber(Edge edge)
+    {
+        // Do an early return here because lowDouble() can create a lot of control flow.
+        if (!m_interpreter.needsTypeCheck(edge))
+            return;
+        
+        LValue value = lowJSValue(edge, ManualOperandSpeculation);
+        LValue doubleValue = unboxDouble(value);
+        
+        LBasicBlock intCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        m_out.branch(
+            m_out.doubleEqual(doubleValue, doubleValue),
+            usually(continuation), rarely(intCase));
+        
+        LBasicBlock lastNext = m_out.appendTo(intCase, continuation);
+        
+        typeCheck(
+            jsValueValue(value), m_node->child1(), SpecBytecodeRealNumber,
+            isNotInt32(value, provenType(m_node->child1()) & ~SpecFullDouble));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    void speculateDoubleRepReal(Edge edge)
+    {
+        // Do an early return here because lowDouble() can create a lot of control flow.
+        if (!m_interpreter.needsTypeCheck(edge))
+            return;
+        
+        LValue value = lowDouble(edge);
+        FTL_TYPE_CHECK(
+            doubleValue(value), edge, SpecDoubleReal,
+            m_out.doubleNotEqualOrUnordered(value, value));
+    }
+    
+    void speculateDoubleRepAnyInt(Edge edge)
+    {
+        if (!m_interpreter.needsTypeCheck(edge))
+            return;
+        
+        doubleToStrictInt52(edge, lowDouble(edge));
+    }
+    
+    void speculateBoolean(Edge edge)
+    {
+        lowBoolean(edge);
+    }
+    
+    void speculateNotStringVar(Edge edge)
+    {
+        if (!m_interpreter.needsTypeCheck(edge, ~SpecStringVar))
+            return;
+        
+        LValue value = lowJSValue(edge, ManualOperandSpeculation);
+        
+        LBasicBlock isCellCase = m_out.newBlock();
+        LBasicBlock isStringCase = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        m_out.branch(isCell(value, provenType(edge)), unsure(isCellCase), unsure(continuation));
+        
+        LBasicBlock lastNext = m_out.appendTo(isCellCase, isStringCase);
+        m_out.branch(isString(value, provenType(edge)), unsure(isStringCase), unsure(continuation));
+        
+        m_out.appendTo(isStringCase, continuation);
+        speculateStringIdent(edge, value, m_out.loadPtr(value, m_heaps.JSString_value));
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    void speculateOther(Edge edge)
+    {
+        if (!m_interpreter.needsTypeCheck(edge))
+            return;
+        
+        LValue value = lowJSValue(edge, ManualOperandSpeculation);
+        typeCheck(jsValueValue(value), edge, SpecOther, isNotOther(value));
+    }
+    
+    void speculateMisc(Edge edge)
+    {
+        if (!m_interpreter.needsTypeCheck(edge))
+            return;
+        
+        LValue value = lowJSValue(edge, ManualOperandSpeculation);
+        typeCheck(jsValueValue(value), edge, SpecMisc, isNotMisc(value));
+    }
+
+    void speculateTypedArrayIsNotNeutered(LValue base)
+    {
+        LBasicBlock isWasteful = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+
+        LValue mode = m_out.load32(base, m_heaps.JSArrayBufferView_mode);
+        m_out.branch(m_out.equal(mode, m_out.constInt32(WastefulTypedArray)),
+            unsure(isWasteful), unsure(continuation));
+
+        LBasicBlock lastNext = m_out.appendTo(isWasteful, continuation);
+        LValue vector = m_out.loadPtr(base, m_heaps.JSArrayBufferView_vector);
+        speculate(Uncountable, jsValueValue(vector), m_node, m_out.isZero64(vector));
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+    }
+
+    bool masqueradesAsUndefinedWatchpointIsStillValid()
+    {
+        return m_graph.masqueradesAsUndefinedWatchpointIsStillValid(m_node->origin.semantic);
+    }
+    
+    LValue loadCellState(LValue base)
+    {
+        return m_out.load8ZeroExt32(base, m_heaps.JSCell_cellState);
+    }
+
+    void emitStoreBarrier(LValue base, bool isFenced)
+    {
+        LBasicBlock recheckPath = nullptr;
+        if (isFenced)
+            recheckPath = m_out.newBlock();
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(isFenced ? recheckPath : slowPath);
+
+        LValue threshold;
+        if (isFenced)
+            threshold = m_out.load32(m_out.absolute(vm().heap.addressOfBarrierThreshold()));
+        else
+            threshold = m_out.constInt32(blackThreshold);
+        
+        m_out.branch(
+            m_out.above(loadCellState(base), threshold),
+            usually(continuation), rarely(isFenced ? recheckPath : slowPath));
+        
+        if (isFenced) {
+            m_out.appendTo(recheckPath, slowPath);
+            
+            m_out.fence(&m_heaps.root, &m_heaps.JSCell_cellState);
+            
+            m_out.branch(
+                m_out.above(loadCellState(base), m_out.constInt32(blackThreshold)),
+                usually(continuation), rarely(slowPath));
+        }
+
+        m_out.appendTo(slowPath, continuation);
+        
+        LValue call = vmCall(Void, m_out.operation(operationWriteBarrierSlowPath), m_callFrame, base);
+        m_heaps.decorateCCallRead(&m_heaps.root, call);
+        m_heaps.decorateCCallWrite(&m_heaps.JSCell_cellState, call);
+        
+        m_out.jump(continuation);
+
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    void mutatorFence()
+    {
+        if (isX86()) {
+            m_out.fence(&m_heaps.root, nullptr);
+            return;
+        }
+        
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
+        
+        m_out.branch(
+            m_out.load8ZeroExt32(m_out.absolute(vm().heap.addressOfMutatorShouldBeFenced())),
+            rarely(slowPath), usually(continuation));
+        
+        m_out.appendTo(slowPath, continuation);
+        
+        m_out.fence(&m_heaps.root, nullptr);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+    }
+    
+    void nukeStructureAndSetButterfly(LValue butterfly, LValue object)
+    {
+        if (isX86()) {
+            m_out.store32(
+                m_out.bitOr(
+                    m_out.load32(object, m_heaps.JSCell_structureID),
+                    m_out.constInt32(nukedStructureIDBit())),
+                object, m_heaps.JSCell_structureID);
+            m_out.fence(&m_heaps.root, nullptr);
+            m_out.storePtr(butterfly, object, m_heaps.JSObject_butterfly);
+            m_out.fence(&m_heaps.root, nullptr);
+            return;
+        }
+        
+        LBasicBlock fastPath = m_out.newBlock();
+        LBasicBlock slowPath = m_out.newBlock();
+        LBasicBlock continuation = m_out.newBlock();
+        
+        LBasicBlock lastNext = m_out.insertNewBlocksBefore(fastPath);
+        
+        m_out.branch(
+            m_out.load8ZeroExt32(m_out.absolute(vm().heap.addressOfMutatorShouldBeFenced())),
+            rarely(slowPath), usually(fastPath));
+
+        m_out.appendTo(fastPath, slowPath);
+        
+        m_out.storePtr(butterfly, object, m_heaps.JSObject_butterfly);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(slowPath, continuation);
+        
+        m_out.store32(
+            m_out.bitOr(
+                m_out.load32(object, m_heaps.JSCell_structureID),
+                m_out.constInt32(nukedStructureIDBit())),
+            object, m_heaps.JSCell_structureID);
+        m_out.fence(&m_heaps.root, nullptr);
+        m_out.storePtr(butterfly, object, m_heaps.JSObject_butterfly);
+        m_out.fence(&m_heaps.root, nullptr);
+        m_out.jump(continuation);
+        
+        m_out.appendTo(continuation, lastNext);
+    }
+
+    template<typename... Args>
+    LValue vmCall(LType type, LValue function, Args... args)
+    {
+        callPreflight();
+        LValue result = m_out.call(type, function, args...);
+        callCheck();
+        return result;
+    }
+    
+    void callPreflight(CodeOrigin codeOrigin)
+    {
+        CallSiteIndex callSiteIndex = m_ftlState.jitCode->common.addCodeOrigin(codeOrigin);
+        m_out.store32(
+            m_out.constInt32(callSiteIndex.bits()),
+            tagFor(CallFrameSlot::argumentCount));
+    }
+
+    void callPreflight()
+    {
+        callPreflight(codeOriginDescriptionOfCallSite());
+    }
+
+    CodeOrigin codeOriginDescriptionOfCallSite() const
+    {
+        CodeOrigin codeOrigin = m_node->origin.semantic;
+        if (m_node->op() == TailCallInlinedCaller
+            || m_node->op() == TailCallVarargsInlinedCaller
+            || m_node->op() == TailCallForwardVarargsInlinedCaller
+            || m_node->op() == DirectTailCallInlinedCaller) {
+            // This case arises when you have a situation like this:
+            // foo makes a call to bar, bar is inlined in foo. bar makes a call
+            // to baz and baz is inlined in bar. And then baz makes a tail-call to jaz,
+            // and jaz is inlined in baz. We want the callframe for jaz to appear to 
+            // have caller be bar.
+            codeOrigin = *codeOrigin.inlineCallFrame->getCallerSkippingTailCalls();
+        }
+
+        return codeOrigin;
+    }
+    
+    void callCheck()
+    {
+        if (Options::useExceptionFuzz())
+            m_out.call(Void, m_out.operation(operationExceptionFuzz), m_callFrame);
+        
+        LValue exception = m_out.load64(m_out.absolute(vm().addressOfException()));
+        LValue hadException = m_out.notZero64(exception);
+
+        CodeOrigin opCatchOrigin;
+        HandlerInfo* exceptionHandler;
+        if (m_graph.willCatchExceptionInMachineFrame(m_origin.forExit, opCatchOrigin, exceptionHandler)) {
+            bool exitOK = true;
+            bool isExceptionHandler = true;
+            appendOSRExit(
+                ExceptionCheck, noValue(), nullptr, hadException,
+                m_origin.withForExitAndExitOK(opCatchOrigin, exitOK), isExceptionHandler);
+            return;
+        }
+
+        LBasicBlock continuation = m_out.newBlock();
+
+        m_out.branch(
+            hadException, rarely(m_handleExceptions), usually(continuation));
+
+        m_out.appendTo(continuation);
+    }
+
+    RefPtr<PatchpointExceptionHandle> preparePatchpointForExceptions(PatchpointValue* value)
+    {
+        CodeOrigin opCatchOrigin;
+        HandlerInfo* exceptionHandler;
+        bool willCatchException = m_graph.willCatchExceptionInMachineFrame(m_origin.forExit, opCatchOrigin, exceptionHandler);
+        if (!willCatchException)
+            return PatchpointExceptionHandle::defaultHandle(m_ftlState);
+
+        if (verboseCompilationEnabled()) {
+            dataLog("    Patchpoint exception OSR exit #", m_ftlState.jitCode->osrExitDescriptors.size(), " with availability: ", availabilityMap(), "\n");
+            if (!m_availableRecoveries.isEmpty())
+                dataLog("        Available recoveries: ", listDump(m_availableRecoveries), "\n");
+        }
+
+        bool exitOK = true;
+        NodeOrigin origin = m_origin.withForExitAndExitOK(opCatchOrigin, exitOK);
+
+        OSRExitDescriptor* exitDescriptor = appendOSRExitDescriptor(noValue(), nullptr);
+
+        // Compute the offset into the StackmapGenerationParams where we will find the exit arguments
+        // we are about to append. We need to account for both the children we've already added, and
+        // for the possibility of a result value if the patchpoint is not void.
+        unsigned offset = value->numChildren();
+        if (value->type() != Void)
+            offset++;
+
+        // Use LateColdAny to ensure that the stackmap arguments interfere with the patchpoint's
+        // result and with any late-clobbered registers.
+        value->appendVectorWithRep(
+            buildExitArguments(exitDescriptor, opCatchOrigin, noValue()),
+            ValueRep::LateColdAny);
+
+        return PatchpointExceptionHandle::create(
+            m_ftlState, exitDescriptor, origin, offset, *exceptionHandler);
+    }
+
+    LBasicBlock lowBlock(DFG::BasicBlock* block)
+    {
+        return m_blocks.get(block);
+    }
+
+    OSRExitDescriptor* appendOSRExitDescriptor(FormattedValue lowValue, Node* highValue)
+    {
+        return &m_ftlState.jitCode->osrExitDescriptors.alloc(
+            lowValue.format(), m_graph.methodOfGettingAValueProfileFor(m_node, highValue),
+            availabilityMap().m_locals.numberOfArguments(),
+            availabilityMap().m_locals.numberOfLocals());
+    }
+    
+    void appendOSRExit(
+        ExitKind kind, FormattedValue lowValue, Node* highValue, LValue failCondition, 
+        NodeOrigin origin, bool isExceptionHandler = false)
+    {
+        if (verboseCompilationEnabled()) {
+            dataLog("    OSR exit #", m_ftlState.jitCode->osrExitDescriptors.size(), " with availability: ", availabilityMap(), "\n");
+            if (!m_availableRecoveries.isEmpty())
+                dataLog("        Available recoveries: ", listDump(m_availableRecoveries), "\n");
+        }
+
+        DFG_ASSERT(m_graph, m_node, origin.exitOK);
+
+        if (!isExceptionHandler
+            && Options::useOSRExitFuzz()
+            && canUseOSRExitFuzzing(m_graph.baselineCodeBlockFor(m_node->origin.semantic))
+            && doOSRExitFuzzing()) {
+            LValue numberOfFuzzChecks = m_out.add(
+                m_out.load32(m_out.absolute(&g_numberOfOSRExitFuzzChecks)),
+                m_out.int32One);
+            
+            m_out.store32(numberOfFuzzChecks, m_out.absolute(&g_numberOfOSRExitFuzzChecks));
+            
+            if (unsigned atOrAfter = Options::fireOSRExitFuzzAtOrAfter()) {
+                failCondition = m_out.bitOr(
+                    failCondition,
+                    m_out.aboveOrEqual(numberOfFuzzChecks, m_out.constInt32(atOrAfter)));
+            }
+            if (unsigned at = Options::fireOSRExitFuzzAt()) {
+                failCondition = m_out.bitOr(
+                    failCondition,
+                    m_out.equal(numberOfFuzzChecks, m_out.constInt32(at)));
+            }
+        }
+
+        if (failCondition == m_out.booleanFalse)
+            return;
+
+        blessSpeculation(
+            m_out.speculate(failCondition), kind, lowValue, highValue, origin);
+    }
+
+    void blessSpeculation(CheckValue* value, ExitKind kind, FormattedValue lowValue, Node* highValue, NodeOrigin origin)
+    {
+        OSRExitDescriptor* exitDescriptor = appendOSRExitDescriptor(lowValue, highValue);
+        
+        value->appendColdAnys(buildExitArguments(exitDescriptor, origin.forExit, lowValue));
+
+        State* state = &m_ftlState;
+        value->setGenerator(
+            [=] (CCallHelpers& jit, const B3::StackmapGenerationParams& params) {
+                exitDescriptor->emitOSRExit(
+                    *state, kind, origin, jit, params, 0);
+            });
+    }
+
+    StackmapArgumentList buildExitArguments(
+        OSRExitDescriptor* exitDescriptor, CodeOrigin exitOrigin, FormattedValue lowValue,
+        unsigned offsetOfExitArgumentsInStackmapLocations = 0)
+    {
+        StackmapArgumentList result;
+        buildExitArguments(
+            exitDescriptor, exitOrigin, result, lowValue, offsetOfExitArgumentsInStackmapLocations);
+        return result;
+    }
+    
+    void buildExitArguments(
+        OSRExitDescriptor* exitDescriptor, CodeOrigin exitOrigin, StackmapArgumentList& arguments, FormattedValue lowValue,
+        unsigned offsetOfExitArgumentsInStackmapLocations = 0)
+    {
+        if (!!lowValue)
+            arguments.append(lowValue.value());
+        
+        AvailabilityMap availabilityMap = this->availabilityMap();
+        availabilityMap.pruneByLiveness(m_graph, exitOrigin);
+        
+        HashMap<Node*, ExitTimeObjectMaterialization*> map;
+        availabilityMap.forEachAvailability(
+            [&] (Availability availability) {
+                if (!availability.shouldUseNode())
+                    return;
+                
+                Node* node = availability.node();
+                if (!node->isPhantomAllocation())
+                    return;
+                
+                auto result = map.add(node, nullptr);
+                if (result.isNewEntry) {
+                    result.iterator->value =
+                        exitDescriptor->m_materializations.add(node->op(), node->origin.semantic);
+                }
+            });
+        
+        for (unsigned i = 0; i < exitDescriptor->m_values.size(); ++i) {
+            int operand = exitDescriptor->m_values.operandForIndex(i);
+            
+            Availability availability = availabilityMap.m_locals[i];
+            
+            if (Options::validateFTLOSRExitLiveness()
+                && m_graph.m_plan.mode != FTLForOSREntryMode) {
+                
+                if (availability.isDead() && m_graph.isLiveInBytecode(VirtualRegister(operand), exitOrigin))
+                    DFG_CRASH(m_graph, m_node, toCString("Live bytecode local not available: operand = ", VirtualRegister(operand), ", availability = ", availability, ", origin = ", exitOrigin).data());
+            }
+            ExitValue exitValue = exitValueForAvailability(arguments, map, availability);
+            if (exitValue.hasIndexInStackmapLocations())
+                exitValue.adjustStackmapLocationsIndexByOffset(offsetOfExitArgumentsInStackmapLocations);
+            exitDescriptor->m_values[i] = exitValue;
+        }
+        
+        for (auto heapPair : availabilityMap.m_heap) {
+            Node* node = heapPair.key.base();
+            ExitTimeObjectMaterialization* materialization = map.get(node);
+            ExitValue exitValue = exitValueForAvailability(arguments, map, heapPair.value);
+            if (exitValue.hasIndexInStackmapLocations())
+                exitValue.adjustStackmapLocationsIndexByOffset(offsetOfExitArgumentsInStackmapLocations);
+            materialization->add(
+                heapPair.key.descriptor(),
+                exitValue);
+        }
+        
+        if (verboseCompilationEnabled()) {
+            dataLog("        Exit values: ", exitDescriptor->m_values, "\n");
+            if (!exitDescriptor->m_materializations.isEmpty()) {
+                dataLog("        Materializations: \n");
+                for (ExitTimeObjectMaterialization* materialization : exitDescriptor->m_materializations)
+                    dataLog("            ", pointerDump(materialization), "\n");
+            }
+        }
+    }
+
+    ExitValue exitValueForAvailability(
+        StackmapArgumentList& arguments, const HashMap<Node*, ExitTimeObjectMaterialization*>& map,
+        Availability availability)
+    {
+        FlushedAt flush = availability.flushedAt();
+        switch (flush.format()) {
+        case DeadFlush:
+        case ConflictingFlush:
+            if (availability.hasNode())
+                return exitValueForNode(arguments, map, availability.node());
+            
+            // This means that the value is dead. It could be dead in bytecode or it could have
+            // been killed by our DCE, which can sometimes kill things even if they were live in
+            // bytecode.
+            return ExitValue::dead();
+
+        case FlushedJSValue:
+        case FlushedCell:
+        case FlushedBoolean:
+            return ExitValue::inJSStack(flush.virtualRegister());
+                
+        case FlushedInt32:
+            return ExitValue::inJSStackAsInt32(flush.virtualRegister());
+                
+        case FlushedInt52:
+            return ExitValue::inJSStackAsInt52(flush.virtualRegister());
+                
+        case FlushedDouble:
+            return ExitValue::inJSStackAsDouble(flush.virtualRegister());
+        }
+        
+        DFG_CRASH(m_graph, m_node, "Invalid flush format");
+        return ExitValue::dead();
+    }
+    
+    ExitValue exitValueForNode(
+        StackmapArgumentList& arguments, const HashMap<Node*, ExitTimeObjectMaterialization*>& map,
+        Node* node)
+    {
+        // NOTE: In FTL->B3, we cannot generate code here, because m_output is positioned after the
+        // stackmap value. Like all values, the stackmap value cannot use a child that is defined after
+        // it.
+        
+        ASSERT(node->shouldGenerate());
+        ASSERT(node->hasResult());
+
+        if (node) {
+            switch (node->op()) {
+            case BottomValue:
+                // This might arise in object materializations. I actually doubt that it would,
+                // but it seems worthwhile to be conservative.
+                return ExitValue::dead();
+                
+            case JSConstant:
+            case Int52Constant:
+            case DoubleConstant:
+                return ExitValue::constant(node->asJSValue());
+                
+            default:
+                if (node->isPhantomAllocation())
+                    return ExitValue::materializeNewObject(map.get(node));
+                break;
+            }
+        }
+        
+        for (unsigned i = 0; i < m_availableRecoveries.size(); ++i) {
+            AvailableRecovery recovery = m_availableRecoveries[i];
+            if (recovery.node() != node)
+                continue;
+            ExitValue result = ExitValue::recovery(
+                recovery.opcode(), arguments.size(), arguments.size() + 1,
+                recovery.format());
+            arguments.append(recovery.left());
+            arguments.append(recovery.right());
+            return result;
+        }
+        
+        LoweredNodeValue value = m_int32Values.get(node);
+        if (isValid(value))
+            return exitArgument(arguments, DataFormatInt32, value.value());
+        
+        value = m_int52Values.get(node);
+        if (isValid(value))
+            return exitArgument(arguments, DataFormatInt52, value.value());
+        
+        value = m_strictInt52Values.get(node);
+        if (isValid(value))
+            return exitArgument(arguments, DataFormatStrictInt52, value.value());
+        
+        value = m_booleanValues.get(node);
+        if (isValid(value))
+            return exitArgument(arguments, DataFormatBoolean, value.value());
+        
+        value = m_jsValueValues.get(node);
+        if (isValid(value))
+            return exitArgument(arguments, DataFormatJS, value.value());
+        
+        value = m_doubleValues.get(node);
+        if (isValid(value))
+            return exitArgument(arguments, DataFormatDouble, value.value());
+
+        DFG_CRASH(m_graph, m_node, toCString("Cannot find value for node: ", node).data());
+        return ExitValue::dead();
+    }
+
+    ExitValue exitArgument(StackmapArgumentList& arguments, DataFormat format, LValue value)
+    {
+        ExitValue result = ExitValue::exitArgument(ExitArgument(format, arguments.size()));
+        arguments.append(value);
+        return result;
+    }
+
+    ExitValue exitValueForTailCall(StackmapArgumentList& arguments, Node* node)
+    {
+        ASSERT(node->shouldGenerate());
+        ASSERT(node->hasResult());
+
+        switch (node->op()) {
+        case JSConstant:
+        case Int52Constant:
+        case DoubleConstant:
+            return ExitValue::constant(node->asJSValue());
+
+        default:
+            break;
+        }
+
+        LoweredNodeValue value = m_jsValueValues.get(node);
+        if (isValid(value))
+            return exitArgument(arguments, DataFormatJS, value.value());
+
+        value = m_int32Values.get(node);
+        if (isValid(value))
+            return exitArgument(arguments, DataFormatJS, boxInt32(value.value()));
+
+        value = m_booleanValues.get(node);
+        if (isValid(value))
+            return exitArgument(arguments, DataFormatJS, boxBoolean(value.value()));
+
+        // Doubles and Int52 have been converted by ValueRep()
+        DFG_CRASH(m_graph, m_node, toCString("Cannot find value for node: ", node).data());
+    }
+
+    void addAvailableRecovery(
+        Node* node, RecoveryOpcode opcode, LValue left, LValue right, DataFormat format)
+    {
+        m_availableRecoveries.append(AvailableRecovery(node, opcode, left, right, format));
+    }
+    
+    void addAvailableRecovery(
+        Edge edge, RecoveryOpcode opcode, LValue left, LValue right, DataFormat format)
+    {
+        addAvailableRecovery(edge.node(), opcode, left, right, format);
+    }
+    
+    void setInt32(Node* node, LValue value)
+    {
+        m_int32Values.set(node, LoweredNodeValue(value, m_highBlock));
+    }
+    void setInt52(Node* node, LValue value)
+    {
+        m_int52Values.set(node, LoweredNodeValue(value, m_highBlock));
+    }
+    void setStrictInt52(Node* node, LValue value)
+    {
+        m_strictInt52Values.set(node, LoweredNodeValue(value, m_highBlock));
+    }
+    void setInt52(Node* node, LValue value, Int52Kind kind)
+    {
+        switch (kind) {
+        case Int52:
+            setInt52(node, value);
+            return;
+            
+        case StrictInt52:
+            setStrictInt52(node, value);
+            return;
+        }
+        
+        DFG_CRASH(m_graph, m_node, "Corrupt int52 kind");
+    }
+    void setJSValue(Node* node, LValue value)
+    {
+        m_jsValueValues.set(node, LoweredNodeValue(value, m_highBlock));
+    }
+    void setBoolean(Node* node, LValue value)
+    {
+        m_booleanValues.set(node, LoweredNodeValue(value, m_highBlock));
+    }
+    void setStorage(Node* node, LValue value)
+    {
+        m_storageValues.set(node, LoweredNodeValue(value, m_highBlock));
+    }
+    void setMapBucket(Node* node, LValue value)
+    {
+        m_mapBucketValues.set(node, LoweredNodeValue(value, m_highBlock));
+    }
+    void setDouble(Node* node, LValue value)
+    {
+        m_doubleValues.set(node, LoweredNodeValue(value, m_highBlock));
+    }
+
+    void setInt32(LValue value)
+    {
+        setInt32(m_node, value);
+    }
+    void setInt52(LValue value)
+    {
+        setInt52(m_node, value);
+    }
+    void setStrictInt52(LValue value)
+    {
+        setStrictInt52(m_node, value);
+    }
+    void setInt52(LValue value, Int52Kind kind)
+    {
+        setInt52(m_node, value, kind);
+    }
+    void setJSValue(LValue value)
+    {
+        setJSValue(m_node, value);
+    }
+    void setBoolean(LValue value)
+    {
+        setBoolean(m_node, value);
+    }
+    void setStorage(LValue value)
+    {
+        setStorage(m_node, value);
+    }
+    void setMapBucket(LValue value)
+    {
+        setMapBucket(m_node, value);
+    }
+    void setDouble(LValue value)
+    {
+        setDouble(m_node, value);
+    }
+    
+    bool isValid(const LoweredNodeValue& value)
+    {
+        if (!value)
+            return false;
+        if (!m_graph.m_dominators->dominates(value.block(), m_highBlock))
+            return false;
+        return true;
+    }
+    
+    void addWeakReference(JSCell* target)
+    {
+        m_graph.m_plan.weakReferences.addLazily(target);
+    }
+
+    LValue loadStructure(LValue value)
+    {
+        LValue tableIndex = m_out.load32(value, m_heaps.JSCell_structureID);
+        LValue tableBase = m_out.loadPtr(
+            m_out.absolute(vm().heap.structureIDTable().base()));
+        TypedPointer address = m_out.baseIndex(
+            m_heaps.structureTable, tableBase, m_out.zeroExtPtr(tableIndex));
+        return m_out.loadPtr(address);
+    }
+
+    LValue weakPointer(JSCell* pointer)
+    {
+        // There are weird relationships in how optimized CodeBlocks
+        // point to other CodeBlocks. We don't want to have them be
+        // part of the weak pointer set. For example, an optimized CodeBlock
+        // having a weak pointer to itself will cause it to get collected.
+        RELEASE_ASSERT(!jsDynamicCast<CodeBlock*>(vm(), pointer));
+
+        addWeakReference(pointer);
+        return m_out.weakPointer(m_graph, pointer);
+    }
+
+    LValue frozenPointer(FrozenValue* value)
+    {
+        return m_out.weakPointer(value);
+    }
+
+    LValue weakStructureID(RegisteredStructure structure)
+    {
+        return m_out.constInt32(structure->id());
+    }
+    
+    LValue weakStructure(RegisteredStructure structure)
+    {
+        ASSERT(!!structure.get());
+        return m_out.weakPointer(m_graph, structure.get());
+    }
+    
+    TypedPointer addressFor(LValue base, int operand, ptrdiff_t offset = 0)
+    {
+        return m_out.address(base, m_heaps.variables[operand], offset);
+    }
+    TypedPointer payloadFor(LValue base, int operand)
+    {
+        return addressFor(base, operand, PayloadOffset);
+    }
+    TypedPointer tagFor(LValue base, int operand)
+    {
+        return addressFor(base, operand, TagOffset);
+    }
+    TypedPointer addressFor(int operand, ptrdiff_t offset = 0)
+    {
+        return addressFor(VirtualRegister(operand), offset);
+    }
+    TypedPointer addressFor(VirtualRegister operand, ptrdiff_t offset = 0)
+    {
+        if (operand.isLocal())
+            return addressFor(m_captured, operand.offset(), offset);
+        return addressFor(m_callFrame, operand.offset(), offset);
+    }
+    TypedPointer payloadFor(int operand)
+    {
+        return payloadFor(VirtualRegister(operand));
+    }
+    TypedPointer payloadFor(VirtualRegister operand)
+    {
+        return addressFor(operand, PayloadOffset);
+    }
+    TypedPointer tagFor(int operand)
+    {
+        return tagFor(VirtualRegister(operand));
+    }
+    TypedPointer tagFor(VirtualRegister operand)
+    {
+        return addressFor(operand, TagOffset);
+    }
+    
+    AbstractValue abstractValue(Node* node)
+    {
+        return m_state.forNode(node);
+    }
+    AbstractValue abstractValue(Edge edge)
+    {
+        return abstractValue(edge.node());
+    }
+    
+    SpeculatedType provenType(Node* node)
+    {
+        return abstractValue(node).m_type;
+    }
+    SpeculatedType provenType(Edge edge)
+    {
+        return provenType(edge.node());
+    }
+    
+    JSValue provenValue(Node* node)
+    {
+        return abstractValue(node).m_value;
+    }
+    JSValue provenValue(Edge edge)
+    {
+        return provenValue(edge.node());
+    }
+    
+    StructureAbstractValue abstractStructure(Node* node)
+    {
+        return abstractValue(node).m_structure;
+    }
+    StructureAbstractValue abstractStructure(Edge edge)
+    {
+        return abstractStructure(edge.node());
+    }
+    
+#if ENABLE(MASM_PROBE)
+    void probe(std::function<void (CCallHelpers::ProbeContext*)> probeFunc)
+    {
+        UNUSED_PARAM(probeFunc);
+    }
+#endif
+
+    void crash()
+    {
+        crash(m_highBlock, m_node);
+    }
+    void crash(DFG::BasicBlock* block, Node* node)
+    {
+        BlockIndex blockIndex = block->index;
+        unsigned nodeIndex = node ? node->index() : UINT_MAX;
+#if ASSERT_DISABLED
+        m_out.patchpoint(Void)->setGenerator(
+            [=] (CCallHelpers& jit, const StackmapGenerationParams&) {
+                AllowMacroScratchRegisterUsage allowScratch(jit);
+                
+                jit.move(CCallHelpers::TrustedImm32(blockIndex), GPRInfo::regT0);
+                jit.move(CCallHelpers::TrustedImm32(nodeIndex), GPRInfo::regT1);
+                if (node)
+                    jit.move(CCallHelpers::TrustedImm32(node->op()), GPRInfo::regT2);
+                jit.abortWithReason(FTLCrash);
+            });
+#else
+        m_out.call(
+            Void,
+            m_out.constIntPtr(ftlUnreachable),
+            // We don't want the CodeBlock to have a weak pointer to itself because
+            // that would cause it to always get collected.
+            m_out.constIntPtr(bitwise_cast<intptr_t>(codeBlock())), m_out.constInt32(blockIndex),
+            m_out.constInt32(nodeIndex));
+#endif
+        m_out.unreachable();
+    }
+
+    AvailabilityMap& availabilityMap() { return m_availabilityCalculator.m_availability; }
+    
+    VM& vm() { return m_graph.m_vm; }
+    CodeBlock* codeBlock() { return m_graph.m_codeBlock; }
+    
+    Graph& m_graph;
+    State& m_ftlState;
+    AbstractHeapRepository m_heaps;
+    Output m_out;
+    Procedure& m_proc;
+    
+    LBasicBlock m_prologue;
+    LBasicBlock m_handleExceptions;
+    HashMap<DFG::BasicBlock*, LBasicBlock> m_blocks;
+    
+    LValue m_callFrame;
+    LValue m_captured;
+    LValue m_tagTypeNumber;
+    LValue m_tagMask;
+    
+    HashMap<Node*, LoweredNodeValue> m_int32Values;
+    HashMap<Node*, LoweredNodeValue> m_strictInt52Values;
+    HashMap<Node*, LoweredNodeValue> m_int52Values;
+    HashMap<Node*, LoweredNodeValue> m_jsValueValues;
+    HashMap<Node*, LoweredNodeValue> m_booleanValues;
+    HashMap<Node*, LoweredNodeValue> m_storageValues;
+    HashMap<Node*, LoweredNodeValue> m_mapBucketValues;
+    HashMap<Node*, LoweredNodeValue> m_doubleValues;
+    
+    // This is a bit of a hack. It prevents B3 from having to do CSE on loading of arguments.
+    // It's nice to have these optimizations on our end because we can guarantee them a bit better.
+    // Probably also saves B3 compile time.
+    HashMap<Node*, LValue> m_loadedArgumentValues;
+    
+    HashMap<Node*, LValue> m_phis;
+    
+    LocalOSRAvailabilityCalculator m_availabilityCalculator;
+    
+    Vector<AvailableRecovery, 3> m_availableRecoveries;
+    
+    InPlaceAbstractState m_state;
+    AbstractInterpreter<InPlaceAbstractState> m_interpreter;
+    DFG::BasicBlock* m_highBlock;
+    DFG::BasicBlock* m_nextHighBlock;
+    LBasicBlock m_nextLowBlock;
+
+    NodeOrigin m_origin;
+    unsigned m_nodeIndex;
+    Node* m_node;
+};
+
+} // anonymous namespace
+
+void lowerDFGToB3(State& state)
+{
+    LowerDFGToB3 lowering(state);
+    lowering.lower();
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLLowerDFGToLLVM.h b/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.h
index ad7d44c4d..e9569f4d3 100644
--- a/Source/JavaScriptCore/ftl/FTLLowerDFGToLLVM.h
+++ b/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLLowerDFGToLLVM_h
-#define FTLLowerDFGToLLVM_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -35,11 +32,8 @@
 
 namespace JSC { namespace FTL {
 
-void lowerDFGToLLVM(State&);
+void lowerDFGToB3(State&);
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLLowerDFGToLLVM_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLLowerDFGToLLVM.cpp b/Source/JavaScriptCore/ftl/FTLLowerDFGToLLVM.cpp
deleted file mode 100644
index be2a40c7d..000000000
--- a/Source/JavaScriptCore/ftl/FTLLowerDFGToLLVM.cpp
+++ /dev/null
@@ -1,4515 +0,0 @@
-/*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
- */
-
-#include "config.h"
-#include "FTLLowerDFGToLLVM.h"
-
-#if ENABLE(FTL_JIT)
-
-#include "CodeBlockWithJITType.h"
-#include "DFGAbstractInterpreterInlines.h"
-#include "DFGInPlaceAbstractState.h"
-#include "FTLAbstractHeapRepository.h"
-#include "FTLForOSREntryJITCode.h"
-#include "FTLFormattedValue.h"
-#include "FTLInlineCacheSize.h"
-#include "FTLLoweredNodeValue.h"
-#include "FTLOutput.h"
-#include "FTLThunks.h"
-#include "LinkBuffer.h"
-#include "OperandsInlines.h"
-#include "Operations.h"
-#include "VirtualRegister.h"
-#include <atomic>
-#include <wtf/ProcessID.h>
-
-namespace JSC { namespace FTL {
-
-using namespace DFG;
-
-static std::atomic<int> compileCounter;
-
-// Using this instead of typeCheck() helps to reduce the load on LLVM, by creating
-// significantly less dead code.
-#define FTL_TYPE_CHECK(lowValue, highValue, typesPassedThrough, failCondition) do { \
-        FormattedValue _ftc_lowValue = (lowValue);                      \
-        Edge _ftc_highValue = (highValue);                              \
-        SpeculatedType _ftc_typesPassedThrough = (typesPassedThrough);  \
-        if (!m_interpreter.needsTypeCheck(_ftc_highValue, _ftc_typesPassedThrough)) \
-            break;                                                      \
-        typeCheck(_ftc_lowValue, _ftc_highValue, _ftc_typesPassedThrough, (failCondition)); \
-    } while (false)
-
-class LowerDFGToLLVM {
-public:
-    LowerDFGToLLVM(State& state)
-        : m_graph(state.graph)
-        , m_ftlState(state)
-        , m_heaps(state.context)
-        , m_out(state.context)
-        , m_availability(OperandsLike, state.graph.block(0)->variablesAtHead)
-        , m_state(state.graph)
-        , m_interpreter(state.graph, m_state)
-        , m_stackmapIDs(0)
-    {
-    }
-    
-    void lower()
-    {
-        CString name;
-        if (verboseCompilationEnabled()) {
-            name = toCString(
-                "jsBody_", ++compileCounter, "_", codeBlock()->inferredName(),
-                "_", codeBlock()->hash());
-        } else
-            name = "jsBody";
-        
-        m_graph.m_dominators.computeIfNecessary(m_graph);
-        
-        m_ftlState.module =
-            llvm->ModuleCreateWithNameInContext(name.data(), m_ftlState.context);
-        
-        m_ftlState.function = addFunction(
-            m_ftlState.module, name.data(), functionType(m_out.int64, m_out.intPtr));
-        setFunctionCallingConv(m_ftlState.function, LLVMCCallConv);
-        
-        m_out.initialize(m_ftlState.module, m_ftlState.function, m_heaps);
-        
-        m_prologue = appendBasicBlock(m_ftlState.context, m_ftlState.function);
-        m_out.appendTo(m_prologue);
-        createPhiVariables();
-        
-        m_callFrame = m_out.param(0);
-        m_tagTypeNumber = m_out.constInt64(TagTypeNumber);
-        m_tagMask = m_out.constInt64(TagMask);
-        
-        for (BlockIndex blockIndex = 0; blockIndex < m_graph.numBlocks(); ++blockIndex) {
-            m_highBlock = m_graph.block(blockIndex);
-            if (!m_highBlock)
-                continue;
-            m_blocks.add(m_highBlock, FTL_NEW_BLOCK(m_out, ("Block ", *m_highBlock)));
-        }
-        
-        m_out.appendTo(m_prologue);
-        m_out.jump(lowBlock(m_graph.block(0)));
-        
-        Vector<BasicBlock*> depthFirst;
-        m_graph.getBlocksInDepthFirstOrder(depthFirst);
-        for (unsigned i = 0; i < depthFirst.size(); ++i)
-            compileBlock(depthFirst[i]);
-        
-        if (Options::dumpLLVMIR())
-            dumpModule(m_ftlState.module);
-        
-        if (verboseCompilationEnabled())
-            m_ftlState.dumpState("after lowering");
-        if (validationEnabled())
-            verifyModule(m_ftlState.module);
-    }
-
-private:
-    
-    void createPhiVariables()
-    {
-        for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
-            BasicBlock* block = m_graph.block(blockIndex);
-            if (!block)
-                continue;
-            for (unsigned nodeIndex = block->size(); nodeIndex--;) {
-                Node* node = block->at(nodeIndex);
-                if (node->op() != Phi)
-                    continue;
-                LType type;
-                switch (node->flags() & NodeResultMask) {
-                case NodeResultNumber:
-                    type = m_out.doubleType;
-                    break;
-                case NodeResultInt32:
-                    type = m_out.int32;
-                    break;
-                case NodeResultInt52:
-                    type = m_out.int64;
-                    break;
-                case NodeResultBoolean:
-                    type = m_out.boolean;
-                    break;
-                case NodeResultJS:
-                    type = m_out.int64;
-                    break;
-                default:
-                    RELEASE_ASSERT_NOT_REACHED();
-                    break;
-                }
-                m_phis.add(node, buildAlloca(m_out.m_builder, type));
-            }
-        }
-    }
-    
-    void compileBlock(BasicBlock* block)
-    {
-        if (!block)
-            return;
-        
-        if (verboseCompilationEnabled())
-            dataLog("Compiling block ", *block, "\n");
-        
-        m_highBlock = block;
-        
-        LBasicBlock lowBlock = m_blocks.get(m_highBlock);
-        
-        m_nextHighBlock = 0;
-        for (BlockIndex nextBlockIndex = m_highBlock->index + 1; nextBlockIndex < m_graph.numBlocks(); ++nextBlockIndex) {
-            m_nextHighBlock = m_graph.block(nextBlockIndex);
-            if (m_nextHighBlock)
-                break;
-        }
-        m_nextLowBlock = m_nextHighBlock ? m_blocks.get(m_nextHighBlock) : 0;
-        
-        // All of this effort to find the next block gives us the ability to keep the
-        // generated IR in roughly program order. This ought not affect the performance
-        // of the generated code (since we expect LLVM to reorder things) but it will
-        // make IR dumps easier to read.
-        m_out.appendTo(lowBlock, m_nextLowBlock);
-        
-        if (Options::ftlCrashes())
-            m_out.crashNonTerminal();
-        
-        if (!m_highBlock->cfaHasVisited) {
-            m_out.crash();
-            return;
-        }
-        
-        initializeOSRExitStateForBlock();
-        
-        m_state.reset();
-        m_state.beginBasicBlock(m_highBlock);
-        
-        for (m_nodeIndex = 0; m_nodeIndex < m_highBlock->size(); ++m_nodeIndex) {
-            if (!compileNode(m_nodeIndex))
-                break;
-        }
-    }
-    
-    bool compileNode(unsigned nodeIndex)
-    {
-        if (!m_state.isValid()) {
-            m_out.unreachable();
-            return false;
-        }
-        
-        m_node = m_highBlock->at(nodeIndex);
-        m_codeOriginForExitProfile = m_node->codeOrigin;
-        m_codeOriginForExitTarget = m_node->codeOriginForExitTarget;
-        
-        if (verboseCompilationEnabled())
-            dataLog("Lowering ", m_node, "\n");
-        
-        bool shouldExecuteEffects = m_interpreter.startExecuting(m_node);
-        
-        switch (m_node->op()) {
-        case Upsilon:
-            compileUpsilon();
-            break;
-        case Phi:
-            compilePhi();
-            break;
-        case JSConstant:
-            break;
-        case WeakJSConstant:
-            compileWeakJSConstant();
-            break;
-        case GetArgument:
-            compileGetArgument();
-            break;
-        case ExtractOSREntryLocal:
-            compileExtractOSREntryLocal();
-            break;
-        case GetLocal:
-            compileGetLocal();
-            break;
-        case SetLocal:
-            compileSetLocal();
-            break;
-        case MovHint:
-            compileMovHint();
-            break;
-        case ZombieHint:
-            compileZombieHint();
-            break;
-        case Phantom:
-            compilePhantom();
-            break;
-        case ValueAdd:
-            compileValueAdd();
-            break;
-        case ArithAdd:
-            compileAddSub();
-            break;
-        case ArithSub:
-            compileAddSub();
-            break;
-        case ArithMul:
-            compileArithMul();
-            break;
-        case ArithDiv:
-            compileArithDivMod();
-            break;
-        case ArithMod:
-            compileArithDivMod();
-            break;
-        case ArithMin:
-        case ArithMax:
-            compileArithMinOrMax();
-            break;
-        case ArithAbs:
-            compileArithAbs();
-            break;
-        case ArithNegate:
-            compileArithNegate();
-            break;
-        case BitAnd:
-            compileBitAnd();
-            break;
-        case BitOr:
-            compileBitOr();
-            break;
-        case BitXor:
-            compileBitXor();
-            break;
-        case BitRShift:
-            compileBitRShift();
-            break;
-        case BitLShift:
-            compileBitLShift();
-            break;
-        case BitURShift:
-            compileBitURShift();
-            break;
-        case UInt32ToNumber:
-            compileUInt32ToNumber();
-            break;
-        case Int32ToDouble:
-            compileInt32ToDouble();
-            break;
-        case CheckStructure:
-            compileCheckStructure();
-            break;
-        case StructureTransitionWatchpoint:
-            compileStructureTransitionWatchpoint();
-            break;
-        case CheckFunction:
-            compileCheckFunction();
-            break;
-        case ArrayifyToStructure:
-            compileArrayifyToStructure();
-            break;
-        case PutStructure:
-            compilePutStructure();
-            break;
-        case PhantomPutStructure:
-            compilePhantomPutStructure();
-            break;
-        case GetById:
-            compileGetById();
-            break;
-        case PutById:
-            compilePutById();
-            break;
-        case GetButterfly:
-            compileGetButterfly();
-            break;
-        case ConstantStoragePointer:
-            compileConstantStoragePointer();
-            break;
-        case GetIndexedPropertyStorage:
-            compileGetIndexedPropertyStorage();
-            break;
-        case CheckArray:
-            compileCheckArray();
-            break;
-        case GetArrayLength:
-            compileGetArrayLength();
-            break;
-        case CheckInBounds:
-            compileCheckInBounds();
-            break;
-        case GetByVal:
-            compileGetByVal();
-            break;
-        case PutByVal:
-        case PutByValAlias:
-        case PutByValDirect:
-            compilePutByVal();
-            break;
-        case NewObject:
-            compileNewObject();
-            break;
-        case NewArray:
-            compileNewArray();
-            break;
-        case NewArrayBuffer:
-            compileNewArrayBuffer();
-            break;
-        case AllocatePropertyStorage:
-            compileAllocatePropertyStorage();
-            break;
-        case StringCharAt:
-            compileStringCharAt();
-            break;
-        case StringCharCodeAt:
-            compileStringCharCodeAt();
-            break;
-        case GetByOffset:
-            compileGetByOffset();
-            break;
-        case PutByOffset:
-            compilePutByOffset();
-            break;
-        case GetGlobalVar:
-            compileGetGlobalVar();
-            break;
-        case PutGlobalVar:
-            compilePutGlobalVar();
-            break;
-        case NotifyWrite:
-            compileNotifyWrite();
-            break;
-        case GetMyScope:
-            compileGetMyScope();
-            break;
-        case SkipScope:
-            compileSkipScope();
-            break;
-        case GetClosureRegisters:
-            compileGetClosureRegisters();
-            break;
-        case GetClosureVar:
-            compileGetClosureVar();
-            break;
-        case PutClosureVar:
-            compilePutClosureVar();
-            break;
-        case CompareEq:
-            compileCompareEq();
-            break;
-        case CompareEqConstant:
-            compileCompareEqConstant();
-            break;
-        case CompareStrictEq:
-            compileCompareStrictEq();
-            break;
-        case CompareStrictEqConstant:
-            compileCompareStrictEqConstant();
-            break;
-        case CompareLess:
-            compileCompareLess();
-            break;
-        case CompareLessEq:
-            compileCompareLessEq();
-            break;
-        case CompareGreater:
-            compileCompareGreater();
-            break;
-        case CompareGreaterEq:
-            compileCompareGreaterEq();
-            break;
-        case LogicalNot:
-            compileLogicalNot();
-            break;
-        case Call:
-        case Construct:
-            compileCallOrConstruct();
-            break;
-        case Jump:
-            compileJump();
-            break;
-        case Branch:
-            compileBranch();
-            break;
-        case Switch:
-            compileSwitch();
-            break;
-        case Return:
-            compileReturn();
-            break;
-        case ForceOSRExit:
-            compileForceOSRExit();
-            break;
-        case InvalidationPoint:
-            compileInvalidationPoint();
-            break;
-        case ValueToInt32:
-            compileValueToInt32();
-            break;
-        case Int52ToValue:
-            compileInt52ToValue();
-            break;
-        case StoreBarrier:
-            compileStoreBarrier();
-            break;
-        case ConditionalStoreBarrier:
-            compileConditionalStoreBarrier();
-            break;
-        case StoreBarrierWithNullCheck:
-            compileStoreBarrierWithNullCheck();
-            break;
-        case Flush:
-        case PhantomLocal:
-        case SetArgument:
-        case LoopHint:
-        case VariableWatchpoint:
-        case FunctionReentryWatchpoint:
-        case TypedArrayWatchpoint:
-            break;
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-        
-        if (shouldExecuteEffects)
-            m_interpreter.executeEffects(nodeIndex);
-        
-        return true;
-    }
-
-    void compileValueToInt32()
-    {
-        switch (m_node->child1().useKind()) {
-        case Int32Use:
-            setInt32(lowInt32(m_node->child1()));
-            break;
-            
-        case MachineIntUse:
-            setInt32(m_out.castToInt32(lowStrictInt52(m_node->child1())));
-            break;
-            
-        case NumberUse:
-        case NotCellUse: {
-            LoweredNodeValue value = m_int32Values.get(m_node->child1().node());
-            if (isValid(value)) {
-                setInt32(value.value());
-                break;
-            }
-            
-            value = m_jsValueValues.get(m_node->child1().node());
-            if (isValid(value)) {
-                LBasicBlock intCase = FTL_NEW_BLOCK(m_out, ("ValueToInt32 int case"));
-                LBasicBlock notIntCase = FTL_NEW_BLOCK(m_out, ("ValueToInt32 not int case"));
-                LBasicBlock doubleCase = 0;
-                LBasicBlock notNumberCase = 0;
-                if (m_node->child1().useKind() == NotCellUse) {
-                    doubleCase = FTL_NEW_BLOCK(m_out, ("ValueToInt32 double case"));
-                    notNumberCase = FTL_NEW_BLOCK(m_out, ("ValueToInt32 not number case"));
-                }
-                LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("ValueToInt32 continuation"));
-                
-                Vector<ValueFromBlock> results;
-                
-                m_out.branch(isNotInt32(value.value()), notIntCase, intCase);
-                
-                LBasicBlock lastNext = m_out.appendTo(intCase, notIntCase);
-                results.append(m_out.anchor(unboxInt32(value.value())));
-                m_out.jump(continuation);
-                
-                if (m_node->child1().useKind() == NumberUse) {
-                    m_out.appendTo(notIntCase, continuation);
-                    FTL_TYPE_CHECK(
-                        jsValueValue(value.value()), m_node->child1(), SpecFullNumber,
-                        isCellOrMisc(value.value()));
-                    results.append(m_out.anchor(doubleToInt32(unboxDouble(value.value()))));
-                    m_out.jump(continuation);
-                } else {
-                    m_out.appendTo(notIntCase, doubleCase);
-                    m_out.branch(isCellOrMisc(value.value()), notNumberCase, doubleCase);
-                    
-                    m_out.appendTo(doubleCase, notNumberCase);
-                    results.append(m_out.anchor(doubleToInt32(unboxDouble(value.value()))));
-                    m_out.jump(continuation);
-                    
-                    m_out.appendTo(notNumberCase, continuation);
-                    
-                    FTL_TYPE_CHECK(
-                        jsValueValue(value.value()), m_node->child1(), ~SpecCell,
-                        isCell(value.value()));
-                    
-                    LValue specialResult = m_out.select(
-                        m_out.equal(
-                            value.value(),
-                            m_out.constInt64(JSValue::encode(jsBoolean(true)))),
-                        m_out.int32One, m_out.int32Zero);
-                    results.append(m_out.anchor(specialResult));
-                    m_out.jump(continuation);
-                }
-                
-                m_out.appendTo(continuation, lastNext);
-                setInt32(m_out.phi(m_out.int32, results));
-                break;
-            }
-            
-            value = m_doubleValues.get(m_node->child1().node());
-            if (isValid(value)) {
-                setInt32(doubleToInt32(value.value()));
-                break;
-            }
-            
-            terminate(Uncountable);
-            break;
-        }
-            
-        case BooleanUse:
-            setInt32(m_out.zeroExt(lowBoolean(m_node->child1()), m_out.int32));
-            break;
-            
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-
-    void compileInt52ToValue()
-    {
-        setJSValue(lowJSValue(m_node->child1()));
-    }
-
-    void compileStoreBarrier()
-    {
-        emitStoreBarrier(lowCell(m_node->child1()));
-    }
-
-    void compileConditionalStoreBarrier()
-    {
-        LValue base = lowCell(m_node->child1());
-        LValue value = lowJSValue(m_node->child2());
-        emitStoreBarrier(base, value, m_node->child2());
-    }
-
-    void compileStoreBarrierWithNullCheck()
-    {
-#if ENABLE(GGC)
-        LBasicBlock isNotNull = FTL_NEW_BLOCK(m_out, ("Store barrier with null check value not null"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("Store barrier continuation"));
-
-        LValue base = lowJSValue(m_node->child1());
-        m_out.branch(m_out.isZero64(base), continuation, isNotNull);
-        LBasicBlock lastNext = m_out.appendTo(isNotNull, continuation);
-        emitStoreBarrier(base);
-        m_out.appendTo(continuation, lastNext);
-#else
-        speculate(m_node->child1());
-#endif
-    }
-
-    void compileUpsilon()
-    {
-        LValue destination = m_phis.get(m_node->phi());
-        
-        switch (m_node->child1().useKind()) {
-        case NumberUse:
-            m_out.set(lowDouble(m_node->child1()), destination);
-            break;
-        case Int32Use:
-            m_out.set(lowInt32(m_node->child1()), destination);
-            break;
-        case MachineIntUse:
-            m_out.set(lowInt52(m_node->child1()), destination);
-            break;
-        case BooleanUse:
-            m_out.set(lowBoolean(m_node->child1()), destination);
-            break;
-        case CellUse:
-            m_out.set(lowCell(m_node->child1()), destination);
-            break;
-        case UntypedUse:
-            m_out.set(lowJSValue(m_node->child1()), destination);
-            break;
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-    
-    void compilePhi()
-    {
-        LValue source = m_phis.get(m_node);
-        
-        switch (m_node->flags() & NodeResultMask) {
-        case NodeResultNumber:
-            setDouble(m_out.get(source));
-            break;
-        case NodeResultInt32:
-            setInt32(m_out.get(source));
-            break;
-        case NodeResultInt52:
-            setInt52(m_out.get(source));
-            break;
-        case NodeResultBoolean:
-            setBoolean(m_out.get(source));
-            break;
-        case NodeResultJS:
-            setJSValue(m_out.get(source));
-            break;
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-    
-    void compileWeakJSConstant()
-    {
-        setJSValue(weakPointer(m_node->weakConstant()));
-    }
-    
-    void compileGetArgument()
-    {
-        VariableAccessData* variable = m_node->variableAccessData();
-        VirtualRegister operand = variable->machineLocal();
-        RELEASE_ASSERT(operand.isArgument());
-
-        LValue jsValue = m_out.load64(addressFor(operand));
-
-        switch (useKindFor(variable->flushFormat())) {
-        case Int32Use:
-            speculate(BadType, jsValueValue(jsValue), m_node, isNotInt32(jsValue));
-            setInt32(unboxInt32(jsValue));
-            break;
-        case CellUse:
-            speculate(BadType, jsValueValue(jsValue), m_node, isNotCell(jsValue));
-            setJSValue(jsValue);
-            break;
-        case BooleanUse:
-            speculate(BadType, jsValueValue(jsValue), m_node, isNotBoolean(jsValue));
-            setBoolean(unboxBoolean(jsValue));
-            break;
-        case UntypedUse:
-            setJSValue(jsValue);
-            break;
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-    
-    void compileExtractOSREntryLocal()
-    {
-        EncodedJSValue* buffer = static_cast<EncodedJSValue*>(
-            m_ftlState.jitCode->ftlForOSREntry()->entryBuffer()->dataBuffer());
-        setJSValue(m_out.load64(m_out.absolute(buffer + m_node->unlinkedLocal().toLocal())));
-    }
-    
-    void compileGetLocal()
-    {
-        // GetLocals arise only for captured variables.
-        
-        VariableAccessData* variable = m_node->variableAccessData();
-        AbstractValue& value = m_state.variables().operand(variable->local());
-        
-        RELEASE_ASSERT(variable->isCaptured());
-        
-        if (isInt32Speculation(value.m_type))
-            setInt32(m_out.load32(payloadFor(variable->machineLocal())));
-        else
-            setJSValue(m_out.load64(addressFor(variable->machineLocal())));
-    }
-    
-    void compileSetLocal()
-    {
-        VariableAccessData* variable = m_node->variableAccessData();
-        switch (variable->flushFormat()) {
-        case FlushedJSValue: {
-            LValue value = lowJSValue(m_node->child1());
-            m_out.store64(value, addressFor(variable->machineLocal()));
-            break;
-        }
-            
-        case FlushedDouble: {
-            LValue value = lowDouble(m_node->child1());
-            m_out.storeDouble(value, addressFor(variable->machineLocal()));
-            break;
-        }
-            
-        case FlushedInt32: {
-            LValue value = lowInt32(m_node->child1());
-            m_out.store32(value, payloadFor(variable->machineLocal()));
-            break;
-        }
-            
-        case FlushedInt52: {
-            LValue value = lowInt52(m_node->child1());
-            m_out.store64(value, addressFor(variable->machineLocal()));
-            break;
-        }
-            
-        case FlushedCell: {
-            LValue value = lowCell(m_node->child1());
-            m_out.store64(value, addressFor(variable->machineLocal()));
-            break;
-        }
-            
-        case FlushedBoolean: {
-            speculateBoolean(m_node->child1());
-            m_out.store64(
-                lowJSValue(m_node->child1(), ManualOperandSpeculation),
-                addressFor(variable->machineLocal()));
-            break;
-        }
-            
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-        
-        m_availability.operand(variable->local()) = Availability(variable->flushedAt());
-    }
-    
-    void compileMovHint()
-    {
-        ASSERT(m_node->containsMovHint());
-        ASSERT(m_node->op() != ZombieHint);
-        
-        VirtualRegister operand = m_node->unlinkedLocal();
-        m_availability.operand(operand) = Availability(m_node->child1().node());
-    }
-    
-    void compileZombieHint()
-    {
-        m_availability.operand(m_node->unlinkedLocal()) = Availability::unavailable();
-    }
-    
-    void compilePhantom()
-    {
-        DFG_NODE_DO_TO_CHILDREN(m_graph, m_node, speculate);
-    }
-    
-    void compileValueAdd()
-    {
-        J_JITOperation_EJJ operation;
-        if (!(m_state.forNode(m_node->child1()).m_type & SpecFullNumber)
-            && !(m_state.forNode(m_node->child2()).m_type & SpecFullNumber))
-            operation = operationValueAddNotNumber;
-        else
-            operation = operationValueAdd;
-        setJSValue(vmCall(
-            m_out.operation(operation), m_callFrame,
-            lowJSValue(m_node->child1()), lowJSValue(m_node->child2())));
-    }
-    
-    void compileAddSub()
-    {
-        bool isSub =  m_node->op() == ArithSub;
-        switch (m_node->binaryUseKind()) {
-        case Int32Use: {
-            LValue left = lowInt32(m_node->child1());
-            LValue right = lowInt32(m_node->child2());
-            LValue result = isSub ? m_out.sub(left, right) : m_out.add(left, right);
-
-            if (!shouldCheckOverflow(m_node->arithMode())) {
-                setInt32(result);
-                break;
-            }
-
-            LValue overflow = isSub ? m_out.subWithOverflow32(left, right) : m_out.addWithOverflow32(left, right);
-
-            speculate(Overflow, noValue(), 0, m_out.extractValue(overflow, 1));
-            setInt32(result);
-            break;
-        }
-            
-        case MachineIntUse: {
-            if (!m_state.forNode(m_node->child1()).couldBeType(SpecInt52)
-                && !m_state.forNode(m_node->child2()).couldBeType(SpecInt52)) {
-                Int52Kind kind;
-                LValue left = lowWhicheverInt52(m_node->child1(), kind);
-                LValue right = lowInt52(m_node->child2(), kind);
-                setInt52(isSub ? m_out.sub(left, right) : m_out.add(left, right), kind);
-                break;
-            }
-            
-            LValue left = lowInt52(m_node->child1());
-            LValue right = lowInt52(m_node->child2());
-            LValue result = isSub ? m_out.sub(left, right) : m_out.add(left, right);
-
-            LValue overflow = isSub ? m_out.subWithOverflow64(left, right) : m_out.addWithOverflow64(left, right);
-            speculate(Int52Overflow, noValue(), 0, m_out.extractValue(overflow, 1));
-            setInt52(result);
-            break;
-        }
-            
-        case NumberUse: {
-            LValue C1 = lowDouble(m_node->child1());
-            LValue C2 = lowDouble(m_node->child2());
-
-            setDouble(isSub ? m_out.doubleSub(C1, C2) : m_out.doubleAdd(C1, C2));
-            break;
-        }
-            
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-    
-    void compileArithMul()
-    {
-        switch (m_node->binaryUseKind()) {
-        case Int32Use: {
-            LValue left = lowInt32(m_node->child1());
-            LValue right = lowInt32(m_node->child2());
-            LValue result = m_out.mul(left, right);
-
-            if (shouldCheckOverflow(m_node->arithMode())) {
-                LValue overflowResult = m_out.mulWithOverflow32(left, right);
-                speculate(Overflow, noValue(), 0, m_out.extractValue(overflowResult, 1));
-            }
-            
-            if (shouldCheckNegativeZero(m_node->arithMode())) {
-                LBasicBlock slowCase = FTL_NEW_BLOCK(m_out, ("ArithMul slow case"));
-                LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("ArithMul continuation"));
-                
-                m_out.branch(m_out.notZero32(result), continuation, slowCase);
-                
-                LBasicBlock lastNext = m_out.appendTo(slowCase, continuation);
-                LValue cond = m_out.bitOr(m_out.lessThan(left, m_out.int32Zero), m_out.lessThan(right, m_out.int32Zero));
-                speculate(NegativeZero, noValue(), 0, cond);
-                m_out.jump(continuation);
-                m_out.appendTo(continuation, lastNext);
-            }
-            
-            setInt32(result);
-            break;
-        }
-            
-        case MachineIntUse: {
-            Int52Kind kind;
-            LValue left = lowWhicheverInt52(m_node->child1(), kind);
-            LValue right = lowInt52(m_node->child2(), opposite(kind));
-            LValue result = m_out.mul(left, right);
-
-
-            LValue overflowResult = m_out.mulWithOverflow64(left, right);
-            speculate(Int52Overflow, noValue(), 0, m_out.extractValue(overflowResult, 1));
-
-            if (shouldCheckNegativeZero(m_node->arithMode())) {
-                LBasicBlock slowCase = FTL_NEW_BLOCK(m_out, ("ArithMul slow case"));
-                LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("ArithMul continuation"));
-                
-                m_out.branch(m_out.notZero64(result), continuation, slowCase);
-                
-                LBasicBlock lastNext = m_out.appendTo(slowCase, continuation);
-                LValue cond = m_out.bitOr(m_out.lessThan(left, m_out.int64Zero), m_out.lessThan(right, m_out.int64Zero));
-                speculate(NegativeZero, noValue(), 0, cond);
-                m_out.jump(continuation);
-                m_out.appendTo(continuation, lastNext);
-            }
-            
-            setInt52(result);
-            break;
-        }
-            
-        case NumberUse: {
-            setDouble(
-                m_out.doubleMul(lowDouble(m_node->child1()), lowDouble(m_node->child2())));
-            break;
-        }
-            
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-
-    void compileArithDivMod()
-    {
-        switch (m_node->binaryUseKind()) {
-        case Int32Use: {
-            LValue numerator = lowInt32(m_node->child1());
-            LValue denominator = lowInt32(m_node->child2());
-            
-            LBasicBlock unsafeDenominator = FTL_NEW_BLOCK(m_out, ("ArithDivMod unsafe denominator"));
-            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("ArithDivMod continuation"));
-            LBasicBlock done = FTL_NEW_BLOCK(m_out, ("ArithDivMod done"));
-            
-            Vector<ValueFromBlock, 3> results;
-            
-            LValue adjustedDenominator = m_out.add(denominator, m_out.int32One);
-            
-            m_out.branch(m_out.above(adjustedDenominator, m_out.int32One), continuation, unsafeDenominator);
-            
-            LBasicBlock lastNext = m_out.appendTo(unsafeDenominator, continuation);
-            
-            LValue neg2ToThe31 = m_out.constInt32(-2147483647-1);
-            
-            if (shouldCheckOverflow(m_node->arithMode())) {
-                LValue cond = m_out.bitOr(m_out.isZero32(denominator), m_out.equal(numerator, neg2ToThe31));
-                speculate(Overflow, noValue(), 0, cond);
-                m_out.jump(continuation);
-            } else {
-                // This is the case where we convert the result to an int after we're done. So,
-                // if the denominator is zero, then the result should be zero.
-                // If the denominator is not zero (i.e. it's -1 because we're guarded by the
-                // check above) and the numerator is -2^31 then the result should be -2^31.
-                
-                LBasicBlock divByZero = FTL_NEW_BLOCK(m_out, ("ArithDiv divide by zero"));
-                LBasicBlock notDivByZero = FTL_NEW_BLOCK(m_out, ("ArithDiv not divide by zero"));
-                LBasicBlock neg2ToThe31ByNeg1 = FTL_NEW_BLOCK(m_out, ("ArithDiv -2^31/-1"));
-                
-                m_out.branch(m_out.isZero32(denominator), divByZero, notDivByZero);
-                
-                m_out.appendTo(divByZero, notDivByZero);
-                results.append(m_out.anchor(m_out.int32Zero));
-                m_out.jump(done);
-                
-                m_out.appendTo(notDivByZero, neg2ToThe31ByNeg1);
-                m_out.branch(m_out.equal(numerator, neg2ToThe31), neg2ToThe31ByNeg1, continuation);
-                
-                m_out.appendTo(neg2ToThe31ByNeg1, continuation);
-                results.append(m_out.anchor(neg2ToThe31));
-                m_out.jump(done);
-            }
-            
-            m_out.appendTo(continuation, done);
-            
-            if (shouldCheckNegativeZero(m_node->arithMode())) {
-                LBasicBlock zeroNumerator = FTL_NEW_BLOCK(m_out, ("ArithDivMod zero numerator"));
-                LBasicBlock numeratorContinuation = FTL_NEW_BLOCK(m_out, ("ArithDivMod numerator continuation"));
-                
-                m_out.branch(m_out.isZero32(numerator), zeroNumerator, numeratorContinuation);
-                
-                LBasicBlock innerLastNext = m_out.appendTo(zeroNumerator, numeratorContinuation);
-                
-                speculate(
-                    NegativeZero, noValue(), 0, m_out.lessThan(denominator, m_out.int32Zero));
-                
-                m_out.jump(numeratorContinuation);
-                
-                m_out.appendTo(numeratorContinuation, innerLastNext);
-            }
-            
-            LValue divModResult = m_node->op() == ArithDiv
-                ? m_out.div(numerator, denominator)
-                : m_out.rem(numerator, denominator);
-            
-            if (shouldCheckOverflow(m_node->arithMode())) {
-                speculate(
-                    Overflow, noValue(), 0,
-                    m_out.notEqual(m_out.mul(divModResult, denominator), numerator));
-            }
-            
-            results.append(m_out.anchor(divModResult));
-            m_out.jump(done);
-            
-            m_out.appendTo(done, lastNext);
-            
-            setInt32(m_out.phi(m_out.int32, results));
-            break;
-        }
-            
-        case NumberUse: {
-            LValue C1 = lowDouble(m_node->child1());
-            LValue C2 = lowDouble(m_node->child2());
-            setDouble(m_node->op() == ArithDiv ? m_out.doubleDiv(C1, C2) : m_out.doubleRem(C1, C2));
-            break;
-        }
-            
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-    
-    void compileArithMinOrMax()
-    {
-        switch (m_node->binaryUseKind()) {
-        case Int32Use: {
-            LValue left = lowInt32(m_node->child1());
-            LValue right = lowInt32(m_node->child2());
-            
-            setInt32(
-                m_out.select(
-                    m_node->op() == ArithMin
-                        ? m_out.lessThan(left, right)
-                        : m_out.lessThan(right, left),
-                    left, right));
-            break;
-        }
-            
-        case NumberUse: {
-            LValue left = lowDouble(m_node->child1());
-            LValue right = lowDouble(m_node->child2());
-            
-            LBasicBlock notLessThan = FTL_NEW_BLOCK(m_out, ("ArithMin/ArithMax not less than"));
-            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("ArithMin/ArithMax continuation"));
-            
-            Vector<ValueFromBlock, 2> results;
-            
-            results.append(m_out.anchor(left));
-            m_out.branch(
-                m_node->op() == ArithMin
-                    ? m_out.doubleLessThan(left, right)
-                    : m_out.doubleGreaterThan(left, right),
-                continuation, notLessThan);
-            
-            LBasicBlock lastNext = m_out.appendTo(notLessThan, continuation);
-            results.append(m_out.anchor(m_out.select(
-                m_node->op() == ArithMin
-                    ? m_out.doubleGreaterThanOrEqual(left, right)
-                    : m_out.doubleLessThanOrEqual(left, right),
-                right, m_out.constDouble(0.0 / 0.0))));
-            m_out.jump(continuation);
-            
-            m_out.appendTo(continuation, lastNext);
-            setDouble(m_out.phi(m_out.doubleType, results));
-            break;
-        }
-            
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-    
-    void compileArithAbs()
-    {
-        switch (m_node->child1().useKind()) {
-        case Int32Use: {
-            LValue value = lowInt32(m_node->child1());
-            
-            LValue mask = m_out.aShr(value, m_out.constInt32(31));
-            LValue result = m_out.bitXor(mask, m_out.add(mask, value));
-            
-            speculate(Overflow, noValue(), 0, m_out.equal(result, m_out.constInt32(1 << 31)));
-            
-            setInt32(result);
-            break;
-        }
-            
-        case NumberUse: {
-            setDouble(m_out.doubleAbs(lowDouble(m_node->child1())));
-            break;
-        }
-            
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-    
-    void compileArithNegate()
-    {
-        switch (m_node->child1().useKind()) {
-        case Int32Use: {
-            LValue value = lowInt32(m_node->child1());
-            
-            LValue result = m_out.neg(value);
-            if (shouldCheckOverflow(m_node->arithMode())) {
-                if (!shouldCheckNegativeZero(m_node->arithMode())) {
-                    // We don't have a negate-with-overflow intrinsic. Hopefully this
-                    // does the trick, though.
-                    LValue overflowResult = m_out.subWithOverflow32(m_out.int32Zero, value);
-                    speculate(Overflow, noValue(), 0, m_out.extractValue(overflowResult, 1));
-                } else
-                    speculate(Overflow, noValue(), 0, m_out.testIsZero32(value, m_out.constInt32(0x7fffffff)));
-
-            }
-
-            setInt32(result);
-            break;
-        }
-            
-        case MachineIntUse: {
-            if (!m_state.forNode(m_node->child1()).couldBeType(SpecInt52)) {
-                Int52Kind kind;
-                LValue value = lowWhicheverInt52(m_node->child1(), kind);
-                LValue result = m_out.neg(value);
-                if (shouldCheckNegativeZero(m_node->arithMode()))
-                    speculate(NegativeZero, noValue(), 0, m_out.isZero64(result));
-                setInt52(result, kind);
-                break;
-            }
-            
-            LValue value = lowInt52(m_node->child1());
-            LValue overflowResult = m_out.subWithOverflow64(m_out.int64Zero, value);
-            speculate(Int52Overflow, noValue(), 0, m_out.extractValue(overflowResult, 1));
-            LValue result = m_out.neg(value);
-            speculate(NegativeZero, noValue(), 0, m_out.isZero64(result));
-            setInt52(result);
-            break;
-        }
-            
-        case NumberUse: {
-            setDouble(m_out.doubleNeg(lowDouble(m_node->child1())));
-            break;
-        }
-            
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-    
-    void compileBitAnd()
-    {
-        setInt32(m_out.bitAnd(lowInt32(m_node->child1()), lowInt32(m_node->child2())));
-    }
-    
-    void compileBitOr()
-    {
-        setInt32(m_out.bitOr(lowInt32(m_node->child1()), lowInt32(m_node->child2())));
-    }
-    
-    void compileBitXor()
-    {
-        setInt32(m_out.bitXor(lowInt32(m_node->child1()), lowInt32(m_node->child2())));
-    }
-    
-    void compileBitRShift()
-    {
-        setInt32(m_out.aShr(
-            lowInt32(m_node->child1()),
-            m_out.bitAnd(lowInt32(m_node->child2()), m_out.constInt32(31))));
-    }
-    
-    void compileBitLShift()
-    {
-        setInt32(m_out.shl(
-            lowInt32(m_node->child1()),
-            m_out.bitAnd(lowInt32(m_node->child2()), m_out.constInt32(31))));
-    }
-    
-    void compileBitURShift()
-    {
-        setInt32(m_out.lShr(
-            lowInt32(m_node->child1()),
-            m_out.bitAnd(lowInt32(m_node->child2()), m_out.constInt32(31))));
-    }
-    
-    void compileUInt32ToNumber()
-    {
-        LValue value = lowInt32(m_node->child1());
-
-        if (doesOverflow(m_node->arithMode())) {
-            setDouble(m_out.unsignedToDouble(value));
-            return;
-        }
-        
-        speculate(Overflow, noValue(), 0, m_out.lessThan(value, m_out.int32Zero));
-        setInt32(value);
-    }
-    
-    void compileInt32ToDouble()
-    {
-        setDouble(lowDouble(m_node->child1()));
-    }
-    
-    void compileCheckStructure()
-    {
-        LValue cell = lowCell(m_node->child1());
-        
-        ExitKind exitKind;
-        if (m_node->child1()->op() == WeakJSConstant)
-            exitKind = BadWeakConstantCache;
-        else
-            exitKind = BadCache;
-        
-        LValue structure = m_out.loadPtr(cell, m_heaps.JSCell_structure);
-        
-        if (m_node->structureSet().size() == 1) {
-            speculate(
-                exitKind, jsValueValue(cell), 0,
-                m_out.notEqual(structure, weakPointer(m_node->structureSet()[0])));
-            return;
-        }
-        
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("CheckStructure continuation"));
-        
-        LBasicBlock lastNext = m_out.insertNewBlocksBefore(continuation);
-        for (unsigned i = 0; i < m_node->structureSet().size() - 1; ++i) {
-            LBasicBlock nextStructure = FTL_NEW_BLOCK(m_out, ("CheckStructure nextStructure"));
-            m_out.branch(
-                m_out.equal(structure, weakPointer(m_node->structureSet()[i])),
-                continuation, nextStructure);
-            m_out.appendTo(nextStructure);
-        }
-        
-        speculate(
-            exitKind, jsValueValue(cell), 0,
-            m_out.notEqual(structure, weakPointer(m_node->structureSet().last())));
-        
-        m_out.jump(continuation);
-        m_out.appendTo(continuation, lastNext);
-    }
-    
-    void compileStructureTransitionWatchpoint()
-    {
-        addWeakReference(m_node->structure());
-        speculateCell(m_node->child1());
-    }
-    
-    void compileCheckFunction()
-    {
-        LValue cell = lowCell(m_node->child1());
-        
-        speculate(
-            BadFunction, jsValueValue(cell), m_node->child1().node(),
-            m_out.notEqual(cell, weakPointer(m_node->function())));
-    }
-    
-    void compileArrayifyToStructure()
-    {
-        LValue cell = lowCell(m_node->child1());
-        LValue property = !!m_node->child2() ? lowInt32(m_node->child2()) : 0;
-        
-        LBasicBlock unexpectedStructure = FTL_NEW_BLOCK(m_out, ("ArrayifyToStructure unexpected structure"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("ArrayifyToStructure continuation"));
-        
-        LValue structure = m_out.loadPtr(cell, m_heaps.JSCell_structure);
-        
-        m_out.branch(
-            m_out.notEqual(structure, weakPointer(m_node->structure())),
-            unexpectedStructure, continuation);
-        
-        LBasicBlock lastNext = m_out.appendTo(unexpectedStructure, continuation);
-        
-        if (property) {
-            switch (m_node->arrayMode().type()) {
-            case Array::Int32:
-            case Array::Double:
-            case Array::Contiguous:
-                speculate(
-                    Uncountable, noValue(), 0,
-                    m_out.aboveOrEqual(property, m_out.constInt32(MIN_SPARSE_ARRAY_INDEX)));
-                break;
-            default:
-                break;
-            }
-        }
-        
-        switch (m_node->arrayMode().type()) {
-        case Array::Int32:
-            vmCall(m_out.operation(operationEnsureInt32), m_callFrame, cell);
-            break;
-        case Array::Double:
-            vmCall(m_out.operation(operationEnsureDouble), m_callFrame, cell);
-            break;
-        case Array::Contiguous:
-            if (m_node->arrayMode().conversion() == Array::RageConvert)
-                vmCall(m_out.operation(operationRageEnsureContiguous), m_callFrame, cell);
-            else
-                vmCall(m_out.operation(operationEnsureContiguous), m_callFrame, cell);
-            break;
-        case Array::ArrayStorage:
-        case Array::SlowPutArrayStorage:
-            vmCall(m_out.operation(operationEnsureArrayStorage), m_callFrame, cell);
-            break;
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-        
-        structure = m_out.loadPtr(cell, m_heaps.JSCell_structure);
-        speculate(
-            BadIndexingType, jsValueValue(cell), 0,
-            m_out.notEqual(structure, weakPointer(m_node->structure())));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-    }
-    
-    void compilePutStructure()
-    {
-        m_ftlState.jitCode->common.notifyCompilingStructureTransition(m_graph.m_plan, codeBlock(), m_node);
-        
-        m_out.store64(
-            m_out.constIntPtr(m_node->structureTransitionData().newStructure),
-            lowCell(m_node->child1()), m_heaps.JSCell_structure);
-    }
-    
-    void compilePhantomPutStructure()
-    {
-        m_ftlState.jitCode->common.notifyCompilingStructureTransition(m_graph.m_plan, codeBlock(), m_node);
-    }
-    
-    void compileGetById()
-    {
-        // UntypedUse is a bit harder to reason about and I'm not sure how best to do it, yet.
-        // Basically we need to emit a cell branch that takes you to the slow path, but the slow
-        // path is generated by the IC generator so we can't jump to it from here. And the IC
-        // generator currently doesn't know how to emit such a branch. So, for now, we just
-        // restrict this to CellUse.
-        ASSERT(m_node->child1().useKind() == CellUse);
-
-        LValue base = lowCell(m_node->child1());
-        StringImpl* uid = m_graph.identifiers()[m_node->identifierNumber()];
-
-        // Arguments: id, bytes, target, numArgs, args...
-        unsigned stackmapID = m_stackmapIDs++;
-        
-        if (Options::verboseCompilation())
-            dataLog("    Emitting GetById patchpoint with stackmap #", stackmapID, "\n");
-        
-        LValue call = m_out.call(
-            m_out.patchpointInt64Intrinsic(),
-            m_out.constInt32(stackmapID), m_out.constInt32(sizeOfGetById()),
-            constNull(m_out.ref8), m_out.constInt32(2), m_callFrame, base);
-        setInstructionCallingConvention(call, LLVMAnyRegCallConv);
-        setJSValue(call);
-        
-        m_ftlState.getByIds.append(GetByIdDescriptor(stackmapID, m_node->codeOrigin, uid));
-    }
-    
-    void compilePutById()
-    {
-        // See above; CellUse is easier so we do only that for now.
-        ASSERT(m_node->child1().useKind() == CellUse);
-        
-        LValue base = lowCell(m_node->child1());
-        LValue value = lowJSValue(m_node->child2());
-        StringImpl* uid = m_graph.identifiers()[m_node->identifierNumber()];
-
-        // Arguments: id, bytes, target, numArgs, args...
-        unsigned stackmapID = m_stackmapIDs++;
-
-        if (Options::verboseCompilation())
-            dataLog("    Emitting PutById patchpoint with stackmap #", stackmapID, "\n");
-        
-        LValue call = m_out.call(
-            m_out.patchpointVoidIntrinsic(),
-            m_out.constInt32(stackmapID), m_out.constInt32(sizeOfPutById()),
-            constNull(m_out.ref8), m_out.constInt32(3), m_callFrame, base, value);
-        setInstructionCallingConvention(call, LLVMAnyRegCallConv);
-        
-        m_ftlState.putByIds.append(PutByIdDescriptor(
-            stackmapID, m_node->codeOrigin, uid,
-            m_graph.executableFor(m_node->codeOrigin)->ecmaMode(),
-            m_node->op() == PutByIdDirect ? Direct : NotDirect));
-    }
-    
-    void compileGetButterfly()
-    {
-        setStorage(m_out.loadPtr(lowCell(m_node->child1()), m_heaps.JSObject_butterfly));
-    }
-    
-    void compileConstantStoragePointer()
-    {
-        setStorage(m_out.constIntPtr(m_node->storagePointer()));
-    }
-    
-    void compileGetIndexedPropertyStorage()
-    {
-        LValue cell = lowCell(m_node->child1());
-        
-        if (m_node->arrayMode().type() == Array::String) {
-            LBasicBlock slowPath = FTL_NEW_BLOCK(m_out, ("GetIndexedPropertyStorage String slow case"));
-            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("GetIndexedPropertyStorage String continuation"));
-            
-            ValueFromBlock fastResult = m_out.anchor(
-                m_out.loadPtr(cell, m_heaps.JSString_value));
-            
-            m_out.branch(m_out.notNull(fastResult.value()), continuation, slowPath);
-            
-            LBasicBlock lastNext = m_out.appendTo(slowPath, continuation);
-            
-            ValueFromBlock slowResult = m_out.anchor(
-                vmCall(m_out.operation(operationResolveRope), m_callFrame, cell));
-            
-            m_out.jump(continuation);
-            
-            m_out.appendTo(continuation, lastNext);
-            
-            setStorage(m_out.loadPtr(m_out.phi(m_out.intPtr, fastResult, slowResult), m_heaps.StringImpl_data));
-            return;
-        }
-        
-        setStorage(m_out.loadPtr(cell, m_heaps.JSArrayBufferView_vector));
-    }
-    
-    void compileCheckArray()
-    {
-        Edge edge = m_node->child1();
-        LValue cell = lowCell(edge);
-        
-        if (m_node->arrayMode().alreadyChecked(m_graph, m_node, m_state.forNode(edge)))
-            return;
-        
-        speculate(
-            BadIndexingType, jsValueValue(cell), 0,
-            m_out.bitNot(isArrayType(cell, m_node->arrayMode())));
-    }
-    
-    void compileGetArrayLength()
-    {
-        switch (m_node->arrayMode().type()) {
-        case Array::Int32:
-        case Array::Double:
-        case Array::Contiguous: {
-            setInt32(m_out.load32(lowStorage(m_node->child2()), m_heaps.Butterfly_publicLength));
-            return;
-        }
-            
-        case Array::String: {
-            LValue string = lowCell(m_node->child1());
-            setInt32(m_out.load32(string, m_heaps.JSString_length));
-            return;
-        }
-            
-        default:
-            if (isTypedView(m_node->arrayMode().typedArrayType())) {
-                setInt32(
-                    m_out.load32(lowCell(m_node->child1()), m_heaps.JSArrayBufferView_length));
-                return;
-            }
-            
-            RELEASE_ASSERT_NOT_REACHED();
-            return;
-        }
-    }
-    
-    void compileCheckInBounds()
-    {
-        speculate(
-            OutOfBounds, noValue(), 0,
-            m_out.aboveOrEqual(lowInt32(m_node->child1()), lowInt32(m_node->child2())));
-    }
-    
-    void compileGetByVal()
-    {
-        switch (m_node->arrayMode().type()) {
-        case Array::Int32:
-        case Array::Contiguous: {
-            LValue index = lowInt32(m_node->child2());
-            LValue storage = lowStorage(m_node->child3());
-            
-            IndexedAbstractHeap& heap = m_node->arrayMode().type() == Array::Int32 ?
-                m_heaps.indexedInt32Properties : m_heaps.indexedContiguousProperties;
-            
-            if (m_node->arrayMode().isInBounds()) {
-                LValue result = m_out.load64(baseIndex(heap, storage, index, m_node->child2()));
-                speculate(LoadFromHole, noValue(), 0, m_out.isZero64(result));
-                setJSValue(result);
-                return;
-            }
-            
-            LValue base = lowCell(m_node->child1());
-            
-            LBasicBlock fastCase = FTL_NEW_BLOCK(m_out, ("GetByVal int/contiguous fast case"));
-            LBasicBlock slowCase = FTL_NEW_BLOCK(m_out, ("GetByVal int/contiguous slow case"));
-            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("GetByVal int/contiguous continuation"));
-            
-            m_out.branch(
-                m_out.aboveOrEqual(
-                    index, m_out.load32(storage, m_heaps.Butterfly_publicLength)),
-                slowCase, fastCase);
-            
-            LBasicBlock lastNext = m_out.appendTo(fastCase, slowCase);
-            
-            ValueFromBlock fastResult = m_out.anchor(
-                m_out.load64(baseIndex(heap, storage, index, m_node->child2())));
-            m_out.branch(m_out.isZero64(fastResult.value()), slowCase, continuation);
-            
-            m_out.appendTo(slowCase, continuation);
-            ValueFromBlock slowResult = m_out.anchor(
-                vmCall(m_out.operation(operationGetByValArrayInt), m_callFrame, base, index));
-            m_out.jump(continuation);
-            
-            m_out.appendTo(continuation, lastNext);
-            setJSValue(m_out.phi(m_out.int64, fastResult, slowResult));
-            return;
-        }
-            
-        case Array::Double: {
-            LValue index = lowInt32(m_node->child2());
-            LValue storage = lowStorage(m_node->child3());
-            
-            IndexedAbstractHeap& heap = m_heaps.indexedDoubleProperties;
-            
-            if (m_node->arrayMode().isInBounds()) {
-                LValue result = m_out.loadDouble(
-                    baseIndex(heap, storage, index, m_node->child2()));
-                
-                if (!m_node->arrayMode().isSaneChain()) {
-                    speculate(
-                        LoadFromHole, noValue(), 0,
-                        m_out.doubleNotEqualOrUnordered(result, result));
-                }
-                setDouble(result);
-                break;
-            }
-            
-            LValue base = lowCell(m_node->child1());
-            
-            LBasicBlock inBounds = FTL_NEW_BLOCK(m_out, ("GetByVal double in bounds"));
-            LBasicBlock boxPath = FTL_NEW_BLOCK(m_out, ("GetByVal double boxing"));
-            LBasicBlock slowCase = FTL_NEW_BLOCK(m_out, ("GetByVal double slow case"));
-            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("GetByVal double continuation"));
-            
-            m_out.branch(
-                m_out.aboveOrEqual(
-                    index, m_out.load32(storage, m_heaps.Butterfly_publicLength)),
-                slowCase, inBounds);
-            
-            LBasicBlock lastNext = m_out.appendTo(inBounds, boxPath);
-            LValue doubleValue = m_out.loadDouble(
-                baseIndex(heap, storage, index, m_node->child2()));
-            m_out.branch(
-                m_out.doubleNotEqualOrUnordered(doubleValue, doubleValue), slowCase, boxPath);
-            
-            m_out.appendTo(boxPath, slowCase);
-            ValueFromBlock fastResult = m_out.anchor(boxDouble(doubleValue));
-            m_out.jump(continuation);
-            
-            m_out.appendTo(slowCase, continuation);
-            ValueFromBlock slowResult = m_out.anchor(
-                vmCall(m_out.operation(operationGetByValArrayInt), m_callFrame, base, index));
-            m_out.jump(continuation);
-            
-            m_out.appendTo(continuation, lastNext);
-            setJSValue(m_out.phi(m_out.int64, fastResult, slowResult));
-            return;
-        }
-            
-        case Array::Generic: {
-            setJSValue(vmCall(
-                m_out.operation(operationGetByVal), m_callFrame,
-                lowJSValue(m_node->child1()), lowJSValue(m_node->child2())));
-            return;
-        }
-            
-        case Array::String: {
-            compileStringCharAt();
-            return;
-        }
-            
-        default: {
-            LValue index = lowInt32(m_node->child2());
-            LValue storage = lowStorage(m_node->child3());
-            
-            TypedArrayType type = m_node->arrayMode().typedArrayType();
-            
-            if (isTypedView(type)) {
-                TypedPointer pointer = TypedPointer(
-                    m_heaps.typedArrayProperties,
-                    m_out.add(
-                        storage,
-                        m_out.shl(
-                            m_out.zeroExt(index, m_out.intPtr),
-                            m_out.constIntPtr(logElementSize(type)))));
-                
-                if (isInt(type)) {
-                    LValue result;
-                    switch (elementSize(type)) {
-                    case 1:
-                        result = m_out.load8(pointer);
-                        break;
-                    case 2:
-                        result = m_out.load16(pointer);
-                        break;
-                    case 4:
-                        result = m_out.load32(pointer);
-                        break;
-                    default:
-                        RELEASE_ASSERT_NOT_REACHED();
-                    }
-                    
-                    if (elementSize(type) < 4) {
-                        if (isSigned(type))
-                            result = m_out.signExt(result, m_out.int32);
-                        else
-                            result = m_out.zeroExt(result, m_out.int32);
-                        setInt32(result);
-                        return;
-                    }
-                    
-                    if (isSigned(type)) {
-                        setInt32(result);
-                        return;
-                    }
-                    
-                    if (m_node->shouldSpeculateInt32()) {
-                        speculate(
-                            Overflow, noValue(), 0, m_out.lessThan(result, m_out.int32Zero));
-                        setInt32(result);
-                        return;
-                    }
-                    
-                    setDouble(m_out.unsignedToFP(result, m_out.doubleType));
-                    return;
-                }
-            
-                ASSERT(isFloat(type));
-                
-                LValue result;
-                switch (type) {
-                case TypeFloat32:
-                    result = m_out.fpCast(m_out.loadFloat(pointer), m_out.doubleType);
-                    break;
-                case TypeFloat64:
-                    result = m_out.loadDouble(pointer);
-                    break;
-                default:
-                    RELEASE_ASSERT_NOT_REACHED();
-                }
-                
-                result = m_out.select(
-                    m_out.doubleEqual(result, result), result, m_out.constDouble(QNaN));
-                setDouble(result);
-                return;
-            }
-            
-            RELEASE_ASSERT_NOT_REACHED();
-            return;
-        } }
-    }
-    
-    void compilePutByVal()
-    {
-        Edge child1 = m_graph.varArgChild(m_node, 0);
-        Edge child2 = m_graph.varArgChild(m_node, 1);
-        Edge child3 = m_graph.varArgChild(m_node, 2);
-        Edge child4 = m_graph.varArgChild(m_node, 3);
-        
-        switch (m_node->arrayMode().type()) {
-        case Array::Generic: {
-            V_JITOperation_EJJJ operation;
-            if (m_node->op() == PutByValDirect) {
-                if (m_graph.isStrictModeFor(m_node->codeOrigin))
-                    operation = operationPutByValDirectStrict;
-                else
-                    operation = operationPutByValDirectNonStrict;
-            } else {
-                if (m_graph.isStrictModeFor(m_node->codeOrigin))
-                    operation = operationPutByValStrict;
-                else
-                    operation = operationPutByValNonStrict;
-            }
-                
-            vmCall(
-                m_out.operation(operation), m_callFrame,
-                lowJSValue(child1), lowJSValue(child2), lowJSValue(child3));
-            return;
-        }
-            
-        default:
-            break;
-        }
-
-        LValue base = lowCell(child1);
-        LValue index = lowInt32(child2);
-        LValue storage = lowStorage(child4);
-        
-        switch (m_node->arrayMode().type()) {
-        case Array::Int32:
-        case Array::Double:
-        case Array::Contiguous: {
-            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("PutByVal continuation"));
-            LBasicBlock outerLastNext = m_out.appendTo(m_out.m_block, continuation);
-            
-            switch (m_node->arrayMode().type()) {
-            case Array::Int32:
-            case Array::Contiguous: {
-                LValue value = lowJSValue(child3, ManualOperandSpeculation);
-                
-                if (m_node->arrayMode().type() == Array::Int32)
-                    FTL_TYPE_CHECK(jsValueValue(value), child3, SpecInt32, isNotInt32(value));
-                
-                TypedPointer elementPointer = m_out.baseIndex(
-                    m_node->arrayMode().type() == Array::Int32 ?
-                    m_heaps.indexedInt32Properties : m_heaps.indexedContiguousProperties,
-                    storage, m_out.zeroExt(index, m_out.intPtr),
-                    m_state.forNode(child2).m_value);
-                
-                if (m_node->op() == PutByValAlias) {
-                    m_out.store64(value, elementPointer);
-                    break;
-                }
-                
-                contiguousPutByValOutOfBounds(
-                    codeBlock()->isStrictMode()
-                    ? operationPutByValBeyondArrayBoundsStrict
-                    : operationPutByValBeyondArrayBoundsNonStrict,
-                    base, storage, index, value, continuation);
-                
-                m_out.store64(value, elementPointer);
-                break;
-            }
-                
-            case Array::Double: {
-                LValue value = lowDouble(child3);
-                
-                FTL_TYPE_CHECK(
-                    doubleValue(value), child3, SpecFullRealNumber,
-                    m_out.doubleNotEqualOrUnordered(value, value));
-                
-                TypedPointer elementPointer = m_out.baseIndex(
-                    m_heaps.indexedDoubleProperties,
-                    storage, m_out.zeroExt(index, m_out.intPtr),
-                    m_state.forNode(child2).m_value);
-                
-                if (m_node->op() == PutByValAlias) {
-                    m_out.storeDouble(value, elementPointer);
-                    break;
-                }
-                
-                contiguousPutByValOutOfBounds(
-                    codeBlock()->isStrictMode()
-                    ? operationPutDoubleByValBeyondArrayBoundsStrict
-                    : operationPutDoubleByValBeyondArrayBoundsNonStrict,
-                    base, storage, index, value, continuation);
-                
-                m_out.storeDouble(value, elementPointer);
-                break;
-            }
-                
-            default:
-                RELEASE_ASSERT_NOT_REACHED();
-            }
-
-            m_out.jump(continuation);
-            m_out.appendTo(continuation, outerLastNext);
-            return;
-        }
-            
-        default:
-            TypedArrayType type = m_node->arrayMode().typedArrayType();
-            
-            if (isTypedView(type)) {
-                TypedPointer pointer = TypedPointer(
-                    m_heaps.typedArrayProperties,
-                    m_out.add(
-                        storage,
-                        m_out.shl(
-                            m_out.zeroExt(index, m_out.intPtr),
-                            m_out.constIntPtr(logElementSize(type)))));
-                
-                if (isInt(type)) {
-                    LValue intValue;
-                    switch (child3.useKind()) {
-                    case MachineIntUse:
-                    case Int32Use: {
-                        if (child3.useKind() == Int32Use)
-                            intValue = lowInt32(child3);
-                        else
-                            intValue = m_out.castToInt32(lowStrictInt52(child3));
-
-                        if (isClamped(type)) {
-                            ASSERT(elementSize(type) == 1);
-                            
-                            LBasicBlock atLeastZero = FTL_NEW_BLOCK(m_out, ("PutByVal int clamp atLeastZero"));
-                            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("PutByVal int clamp continuation"));
-                            
-                            Vector<ValueFromBlock, 2> intValues;
-                            intValues.append(m_out.anchor(m_out.int32Zero));
-                            m_out.branch(
-                                m_out.lessThan(intValue, m_out.int32Zero),
-                                continuation, atLeastZero);
-                            
-                            LBasicBlock lastNext = m_out.appendTo(atLeastZero, continuation);
-                            
-                            intValues.append(m_out.anchor(m_out.select(
-                                m_out.greaterThan(intValue, m_out.constInt32(255)),
-                                m_out.constInt32(255),
-                                intValue)));
-                            m_out.jump(continuation);
-                            
-                            m_out.appendTo(continuation, lastNext);
-                            intValue = m_out.phi(m_out.int32, intValues);
-                        }
-                        break;
-                    }
-                        
-                    case NumberUse: {
-                        LValue doubleValue = lowDouble(child3);
-                        
-                        if (isClamped(type)) {
-                            ASSERT(elementSize(type) == 1);
-                            
-                            LBasicBlock atLeastZero = FTL_NEW_BLOCK(m_out, ("PutByVal double clamp atLeastZero"));
-                            LBasicBlock withinRange = FTL_NEW_BLOCK(m_out, ("PutByVal double clamp withinRange"));
-                            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("PutByVal double clamp continuation"));
-                            
-                            Vector<ValueFromBlock, 3> intValues;
-                            intValues.append(m_out.anchor(m_out.int32Zero));
-                            m_out.branch(
-                                m_out.doubleLessThanOrUnordered(doubleValue, m_out.doubleZero),
-                                continuation, atLeastZero);
-                            
-                            LBasicBlock lastNext = m_out.appendTo(atLeastZero, withinRange);
-                            intValues.append(m_out.anchor(m_out.constInt32(255)));
-                            m_out.branch(
-                                m_out.doubleGreaterThan(doubleValue, m_out.constDouble(255)),
-                                continuation, withinRange);
-                            
-                            m_out.appendTo(withinRange, continuation);
-                            intValues.append(m_out.anchor(m_out.fpToInt32(doubleValue)));
-                            m_out.jump(continuation);
-                            
-                            m_out.appendTo(continuation, lastNext);
-                            intValue = m_out.phi(m_out.int32, intValues);
-                        } else
-                            intValue = doubleToInt32(doubleValue);
-                        break;
-                    }
-                        
-                    default:
-                        RELEASE_ASSERT_NOT_REACHED();
-                    }
-                    
-                    switch (elementSize(type)) {
-                    case 1:
-                        m_out.store8(m_out.intCast(intValue, m_out.int8), pointer);
-                        break;
-                    case 2:
-                        m_out.store16(m_out.intCast(intValue, m_out.int16), pointer);
-                        break;
-                    case 4:
-                        m_out.store32(intValue, pointer);
-                        break;
-                    default:
-                        RELEASE_ASSERT_NOT_REACHED();
-                    }
-                    
-                    return;
-                }
-                
-                ASSERT(isFloat(type));
-                
-                LValue value = lowDouble(child3);
-                switch (type) {
-                case TypeFloat32:
-                    m_out.storeFloat(m_out.fpCast(value, m_out.floatType), pointer);
-                    break;
-                case TypeFloat64:
-                    m_out.storeDouble(value, pointer);
-                    break;
-                default:
-                    RELEASE_ASSERT_NOT_REACHED();
-                }
-                return;
-            }
-            
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-    }
-    
-    void compileNewObject()
-    {
-        Structure* structure = m_node->structure();
-        size_t allocationSize = JSFinalObject::allocationSize(structure->inlineCapacity());
-        MarkedAllocator* allocator = &vm().heap.allocatorForObjectWithoutDestructor(allocationSize);
-        
-        LBasicBlock slowPath = FTL_NEW_BLOCK(m_out, ("NewObject slow path"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("NewObject continuation"));
-        
-        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
-        
-        ValueFromBlock fastResult = m_out.anchor(allocateObject(
-            m_out.constIntPtr(allocator), m_out.constIntPtr(structure), m_out.intPtrZero, slowPath));
-        
-        m_out.jump(continuation);
-        
-        m_out.appendTo(slowPath, continuation);
-        
-        ValueFromBlock slowResult = m_out.anchor(vmCall(
-            m_out.operation(operationNewObject), m_callFrame, m_out.constIntPtr(structure)));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-        setJSValue(m_out.phi(m_out.intPtr, fastResult, slowResult));
-    }
-    
-    void compileNewArray()
-    {
-        // First speculate appropriately on all of the children. Do this unconditionally up here
-        // because some of the slow paths may otherwise forget to do it. It's sort of arguable
-        // that doing the speculations up here might be unprofitable for RA - so we can consider
-        // sinking this to below the allocation fast path if we find that this has a lot of
-        // register pressure.
-        for (unsigned operandIndex = 0; operandIndex < m_node->numChildren(); ++operandIndex)
-            speculate(m_graph.varArgChild(m_node, operandIndex));
-        
-        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->codeOrigin);
-        Structure* structure = globalObject->arrayStructureForIndexingTypeDuringAllocation(
-            m_node->indexingType());
-        
-        RELEASE_ASSERT(structure->indexingType() == m_node->indexingType());
-        
-        if (!globalObject->isHavingABadTime() && !hasArrayStorage(m_node->indexingType())) {
-            unsigned numElements = m_node->numChildren();
-            
-            ArrayValues arrayValues = allocateJSArray(structure, numElements);
-            
-            for (unsigned operandIndex = 0; operandIndex < m_node->numChildren(); ++operandIndex) {
-                Edge edge = m_graph.varArgChild(m_node, operandIndex);
-                
-                switch (m_node->indexingType()) {
-                case ALL_BLANK_INDEXING_TYPES:
-                case ALL_UNDECIDED_INDEXING_TYPES:
-                    CRASH();
-                    break;
-                    
-                case ALL_DOUBLE_INDEXING_TYPES:
-                    m_out.storeDouble(
-                        lowDouble(edge),
-                        arrayValues.butterfly, m_heaps.indexedDoubleProperties[operandIndex]);
-                    break;
-                    
-                case ALL_INT32_INDEXING_TYPES:
-                case ALL_CONTIGUOUS_INDEXING_TYPES:
-                    m_out.store64(
-                        lowJSValue(edge, ManualOperandSpeculation),
-                        arrayValues.butterfly,
-                        m_heaps.forIndexingType(m_node->indexingType())->at(operandIndex));
-                    break;
-                    
-                default:
-                    CRASH();
-                }
-            }
-            
-            setJSValue(arrayValues.array);
-            return;
-        }
-        
-        if (!m_node->numChildren()) {
-            setJSValue(vmCall(
-                m_out.operation(operationNewEmptyArray), m_callFrame,
-                m_out.constIntPtr(structure)));
-            return;
-        }
-        
-        size_t scratchSize = sizeof(EncodedJSValue) * m_node->numChildren();
-        ASSERT(scratchSize);
-        ScratchBuffer* scratchBuffer = vm().scratchBufferForSize(scratchSize);
-        EncodedJSValue* buffer = static_cast<EncodedJSValue*>(scratchBuffer->dataBuffer());
-        
-        for (unsigned operandIndex = 0; operandIndex < m_node->numChildren(); ++operandIndex) {
-            Edge edge = m_graph.varArgChild(m_node, operandIndex);
-            m_out.store64(
-                lowJSValue(edge, ManualOperandSpeculation),
-                m_out.absolute(buffer + operandIndex));
-        }
-        
-        m_out.storePtr(
-            m_out.constIntPtr(scratchSize), m_out.absolute(scratchBuffer->activeLengthPtr()));
-        
-        LValue result = vmCall(
-            m_out.operation(operationNewArray), m_callFrame,
-            m_out.constIntPtr(structure), m_out.constIntPtr(buffer),
-            m_out.constIntPtr(m_node->numChildren()));
-        
-        m_out.storePtr(m_out.intPtrZero, m_out.absolute(scratchBuffer->activeLengthPtr()));
-        
-        setJSValue(result);
-    }
-    
-    void compileNewArrayBuffer()
-    {
-        JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->codeOrigin);
-        Structure* structure = globalObject->arrayStructureForIndexingTypeDuringAllocation(
-            m_node->indexingType());
-        
-        RELEASE_ASSERT(structure->indexingType() == m_node->indexingType());
-        
-        if (!globalObject->isHavingABadTime() && !hasArrayStorage(m_node->indexingType())) {
-            unsigned numElements = m_node->numConstants();
-            
-            ArrayValues arrayValues = allocateJSArray(structure, numElements);
-            
-            JSValue* data = codeBlock()->constantBuffer(m_node->startConstant());
-            for (unsigned index = 0; index < m_node->numConstants(); ++index) {
-                int64_t value;
-                if (hasDouble(m_node->indexingType()))
-                    value = bitwise_cast<int64_t>(data[index].asNumber());
-                else
-                    value = JSValue::encode(data[index]);
-                
-                m_out.store64(
-                    m_out.constInt64(value),
-                    arrayValues.butterfly,
-                    m_heaps.forIndexingType(m_node->indexingType())->at(index));
-            }
-            
-            setJSValue(arrayValues.array);
-            return;
-        }
-        
-        setJSValue(vmCall(
-            m_out.operation(operationNewArrayBuffer), m_callFrame,
-            m_out.constIntPtr(structure), m_out.constIntPtr(m_node->startConstant()),
-            m_out.constIntPtr(m_node->numConstants())));
-    }
-    
-    void compileAllocatePropertyStorage()
-    {
-        StructureTransitionData& data = m_node->structureTransitionData();
-        
-        LValue object = lowCell(m_node->child1());
-        
-        if (data.previousStructure->couldHaveIndexingHeader()) {
-            setStorage(vmCall(
-                m_out.operation(
-                    operationReallocateButterflyToHavePropertyStorageWithInitialCapacity),
-                m_callFrame, object));
-            return;
-        }
-        
-        LBasicBlock slowPath = FTL_NEW_BLOCK(m_out, ("AllocatePropertyStorage slow path"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("AllocatePropertyStorage continuation"));
-        
-        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
-        
-        LValue endOfStorage = allocateBasicStorageAndGetEnd(
-            m_out.constIntPtr(initialOutOfLineCapacity * sizeof(JSValue)), slowPath);
-        
-        ValueFromBlock fastButterfly = m_out.anchor(
-            m_out.add(m_out.constIntPtr(sizeof(IndexingHeader)), endOfStorage));
-        
-        m_out.jump(continuation);
-        
-        m_out.appendTo(slowPath, continuation);
-        
-        ValueFromBlock slowButterfly = m_out.anchor(vmCall(
-            m_out.operation(operationAllocatePropertyStorageWithInitialCapacity), m_callFrame));
-        
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-        
-        LValue result = m_out.phi(m_out.intPtr, fastButterfly, slowButterfly);
-        m_out.storePtr(result, object, m_heaps.JSObject_butterfly);
-        
-        setStorage(result);
-    }
-    
-    void compileStringCharAt()
-    {
-        LValue base = lowCell(m_node->child1());
-        LValue index = lowInt32(m_node->child2());
-        LValue storage = lowStorage(m_node->child3());
-            
-        LBasicBlock fastPath = FTL_NEW_BLOCK(m_out, ("GetByVal String fast path"));
-        LBasicBlock slowPath = FTL_NEW_BLOCK(m_out, ("GetByVal String slow path"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("GetByVal String continuation"));
-            
-        m_out.branch(
-            m_out.aboveOrEqual(
-                index, m_out.load32(base, m_heaps.JSString_length)),
-            slowPath, fastPath);
-            
-        LBasicBlock lastNext = m_out.appendTo(fastPath, slowPath);
-            
-        LValue stringImpl = m_out.loadPtr(base, m_heaps.JSString_value);
-            
-        LBasicBlock is8Bit = FTL_NEW_BLOCK(m_out, ("GetByVal String 8-bit case"));
-        LBasicBlock is16Bit = FTL_NEW_BLOCK(m_out, ("GetByVal String 16-bit case"));
-        LBasicBlock bitsContinuation = FTL_NEW_BLOCK(m_out, ("GetByVal String bitness continuation"));
-        LBasicBlock bigCharacter = FTL_NEW_BLOCK(m_out, ("GetByVal String big character"));
-            
-        m_out.branch(
-            m_out.testIsZero32(
-                m_out.load32(stringImpl, m_heaps.StringImpl_hashAndFlags),
-                m_out.constInt32(StringImpl::flagIs8Bit())),
-            is16Bit, is8Bit);
-            
-        m_out.appendTo(is8Bit, is16Bit);
-            
-        ValueFromBlock char8Bit = m_out.anchor(m_out.zeroExt(
-            m_out.load8(m_out.baseIndex(
-                m_heaps.characters8,
-                storage, m_out.zeroExt(index, m_out.intPtr),
-                m_state.forNode(m_node->child2()).m_value)),
-            m_out.int32));
-        m_out.jump(bitsContinuation);
-            
-        m_out.appendTo(is16Bit, bigCharacter);
-            
-        ValueFromBlock char16Bit = m_out.anchor(m_out.zeroExt(
-            m_out.load16(m_out.baseIndex(
-                m_heaps.characters16,
-                storage, m_out.zeroExt(index, m_out.intPtr),
-                m_state.forNode(m_node->child2()).m_value)),
-            m_out.int32));
-        m_out.branch(m_out.aboveOrEqual(char16Bit.value(), m_out.constInt32(0x100)), bigCharacter, bitsContinuation);
-            
-        m_out.appendTo(bigCharacter, bitsContinuation);
-            
-        Vector<ValueFromBlock, 4> results;
-        results.append(m_out.anchor(vmCall(
-            m_out.operation(operationSingleCharacterString),
-            m_callFrame, char16Bit.value())));
-        m_out.jump(continuation);
-            
-        m_out.appendTo(bitsContinuation, slowPath);
-            
-        LValue character = m_out.phi(m_out.int32, char8Bit, char16Bit);
-            
-        LValue smallStrings = m_out.constIntPtr(vm().smallStrings.singleCharacterStrings());
-            
-        results.append(m_out.anchor(m_out.loadPtr(m_out.baseIndex(
-            m_heaps.singleCharacterStrings, smallStrings,
-            m_out.zeroExt(character, m_out.intPtr)))));
-        m_out.jump(continuation);
-            
-        m_out.appendTo(slowPath, continuation);
-            
-        if (m_node->arrayMode().isInBounds()) {
-            speculate(OutOfBounds, noValue(), 0, m_out.booleanTrue);
-            results.append(m_out.anchor(m_out.intPtrZero));
-        } else {
-            JSGlobalObject* globalObject = m_graph.globalObjectFor(m_node->codeOrigin);
-                
-            if (globalObject->stringPrototypeChainIsSane()) {
-                LBasicBlock negativeIndex = FTL_NEW_BLOCK(m_out, ("GetByVal String negative index"));
-                    
-                results.append(m_out.anchor(m_out.constInt64(JSValue::encode(jsUndefined()))));
-                m_out.branch(m_out.lessThan(index, m_out.int32Zero), negativeIndex, continuation);
-                    
-                m_out.appendTo(negativeIndex, continuation);
-            }
-                
-            results.append(m_out.anchor(vmCall(
-                m_out.operation(operationGetByValStringInt), m_callFrame, base, index)));
-        }
-            
-        m_out.jump(continuation);
-            
-        m_out.appendTo(continuation, lastNext);
-        setJSValue(m_out.phi(m_out.int64, results));
-    }
-    
-    void compileStringCharCodeAt()
-    {
-        LBasicBlock is8Bit = FTL_NEW_BLOCK(m_out, ("StringCharCodeAt 8-bit case"));
-        LBasicBlock is16Bit = FTL_NEW_BLOCK(m_out, ("StringCharCodeAt 16-bit case"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("StringCharCodeAt continuation"));
-
-        LValue base = lowCell(m_node->child1());
-        LValue index = lowInt32(m_node->child2());
-        LValue storage = lowStorage(m_node->child3());
-        
-        speculate(
-            Uncountable, noValue(), 0,
-            m_out.aboveOrEqual(index, m_out.load32(base, m_heaps.JSString_length)));
-        
-        LValue stringImpl = m_out.loadPtr(base, m_heaps.JSString_value);
-        
-        m_out.branch(
-            m_out.testIsZero32(
-                m_out.load32(stringImpl, m_heaps.StringImpl_hashAndFlags),
-                m_out.constInt32(StringImpl::flagIs8Bit())),
-            is16Bit, is8Bit);
-            
-        LBasicBlock lastNext = m_out.appendTo(is8Bit, is16Bit);
-            
-        ValueFromBlock char8Bit = m_out.anchor(m_out.zeroExt(
-            m_out.load8(m_out.baseIndex(
-                m_heaps.characters8,
-                storage, m_out.zeroExt(index, m_out.intPtr),
-                m_state.forNode(m_node->child2()).m_value)),
-            m_out.int32));
-        m_out.jump(continuation);
-            
-        m_out.appendTo(is16Bit, continuation);
-            
-        ValueFromBlock char16Bit = m_out.anchor(m_out.zeroExt(
-            m_out.load16(m_out.baseIndex(
-                m_heaps.characters16,
-                storage, m_out.zeroExt(index, m_out.intPtr),
-                m_state.forNode(m_node->child2()).m_value)),
-            m_out.int32));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-        
-        setInt32(m_out.phi(m_out.int32, char8Bit, char16Bit));
-    }
-    
-    void compileGetByOffset()
-    {
-        StorageAccessData& data =
-            m_graph.m_storageAccessData[m_node->storageAccessDataIndex()];
-        
-        setJSValue(
-            m_out.load64(
-                m_out.address(
-                    m_heaps.properties[data.identifierNumber],
-                    lowStorage(m_node->child1()),
-                    offsetRelativeToBase(data.offset))));
-    }
-    
-    void compilePutByOffset()
-    {
-        StorageAccessData& data =
-            m_graph.m_storageAccessData[m_node->storageAccessDataIndex()];
-        
-        m_out.store64(
-            lowJSValue(m_node->child3()),
-            m_out.address(
-                m_heaps.properties[data.identifierNumber],
-                lowStorage(m_node->child1()),
-                offsetRelativeToBase(data.offset)));
-    }
-    
-    void compileGetGlobalVar()
-    {
-        setJSValue(m_out.load64(m_out.absolute(m_node->registerPointer())));
-    }
-    
-    void compilePutGlobalVar()
-    {
-        m_out.store64(
-            lowJSValue(m_node->child1()), m_out.absolute(m_node->registerPointer()));
-    }
-    
-    void compileNotifyWrite()
-    {
-        VariableWatchpointSet* set = m_node->variableWatchpointSet();
-        
-        LValue value = lowJSValue(m_node->child1());
-        
-        LBasicBlock isNotInvalidated = FTL_NEW_BLOCK(m_out, ("NotifyWrite not invalidated case"));
-        LBasicBlock isClear = FTL_NEW_BLOCK(m_out, ("NotifyWrite clear case"));
-        LBasicBlock isWatched = FTL_NEW_BLOCK(m_out, ("NotifyWrite watched case"));
-        LBasicBlock invalidate = FTL_NEW_BLOCK(m_out, ("NotifyWrite invalidate case"));
-        LBasicBlock invalidateFast = FTL_NEW_BLOCK(m_out, ("NotifyWrite invalidate fast case"));
-        LBasicBlock invalidateSlow = FTL_NEW_BLOCK(m_out, ("NotifyWrite invalidate slow case"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("NotifyWrite continuation"));
-        
-        LValue state = m_out.load8(m_out.absolute(set->addressOfState()));
-        
-        m_out.branch(
-            m_out.equal(state, m_out.constInt8(IsInvalidated)),
-            continuation, isNotInvalidated);
-        
-        LBasicBlock lastNext = m_out.appendTo(isNotInvalidated, isClear);
-
-        LValue isClearValue;
-        if (set->state() == ClearWatchpoint)
-            isClearValue = m_out.equal(state, m_out.constInt8(ClearWatchpoint));
-        else
-            isClearValue = m_out.booleanFalse;
-        m_out.branch(isClearValue, isClear, isWatched);
-        
-        m_out.appendTo(isClear, isWatched);
-        
-        m_out.store64(value, m_out.absolute(set->addressOfInferredValue()));
-        m_out.store8(m_out.constInt8(IsWatched), m_out.absolute(set->addressOfState()));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(isWatched, invalidate);
-        
-        m_out.branch(
-            m_out.equal(value, m_out.load64(m_out.absolute(set->addressOfInferredValue()))),
-            continuation, invalidate);
-        
-        m_out.appendTo(invalidate, invalidateFast);
-        
-        m_out.branch(
-            m_out.notZero8(m_out.load8(m_out.absolute(set->addressOfSetIsNotEmpty()))),
-            invalidateSlow, invalidateFast);
-        
-        m_out.appendTo(invalidateFast, invalidateSlow);
-        
-        m_out.store64(
-            m_out.constInt64(JSValue::encode(JSValue())),
-            m_out.absolute(set->addressOfInferredValue()));
-        m_out.store8(m_out.constInt8(IsInvalidated), m_out.absolute(set->addressOfState()));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(invalidateSlow, continuation);
-        
-        vmCall(m_out.operation(operationInvalidate), m_callFrame, m_out.constIntPtr(set));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-    }
-    
-    void compileGetMyScope()
-    {
-        setJSValue(m_out.loadPtr(addressFor(
-            m_node->codeOrigin.stackOffset() + JSStack::ScopeChain)));
-    }
-    
-    void compileSkipScope()
-    {
-        setJSValue(m_out.loadPtr(lowCell(m_node->child1()), m_heaps.JSScope_next));
-    }
-    
-    void compileGetClosureRegisters()
-    {
-        if (WriteBarrierBase<Unknown>* registers = m_graph.tryGetRegisters(m_node->child1().node())) {
-            setStorage(m_out.constIntPtr(registers));
-            return;
-        }
-        
-        setStorage(m_out.loadPtr(
-            lowCell(m_node->child1()), m_heaps.JSVariableObject_registers));
-    }
-    
-    void compileGetClosureVar()
-    {
-        setJSValue(m_out.load64(
-            addressFor(lowStorage(m_node->child1()), m_node->varNumber())));
-    }
-    
-    void compilePutClosureVar()
-    {
-        m_out.store64(
-            lowJSValue(m_node->child3()),
-            addressFor(lowStorage(m_node->child2()), m_node->varNumber()));
-    }
-    
-    void compileCompareEq()
-    {
-        if (m_node->isBinaryUseKind(Int32Use)
-            || m_node->isBinaryUseKind(MachineIntUse)
-            || m_node->isBinaryUseKind(NumberUse)
-            || m_node->isBinaryUseKind(ObjectUse)) {
-            compileCompareStrictEq();
-            return;
-        }
-        
-        if (m_node->isBinaryUseKind(UntypedUse)) {
-            nonSpeculativeCompare(LLVMIntEQ, operationCompareEq);
-            return;
-        }
-        
-        RELEASE_ASSERT_NOT_REACHED();
-    }
-    
-    void compileCompareEqConstant()
-    {
-        ASSERT(m_graph.valueOfJSConstant(m_node->child2().node()).isNull());
-        setBoolean(
-            equalNullOrUndefined(
-                m_node->child1(), AllCellsAreFalse, EqualNullOrUndefined));
-    }
-    
-    void compileCompareStrictEq()
-    {
-        if (m_node->isBinaryUseKind(Int32Use)) {
-            setBoolean(
-                m_out.equal(lowInt32(m_node->child1()), lowInt32(m_node->child2())));
-            return;
-        }
-        
-        if (m_node->isBinaryUseKind(MachineIntUse)) {
-            Int52Kind kind;
-            LValue left = lowWhicheverInt52(m_node->child1(), kind);
-            LValue right = lowInt52(m_node->child2(), kind);
-            setBoolean(m_out.equal(left, right));
-            return;
-        }
-        
-        if (m_node->isBinaryUseKind(NumberUse)) {
-            setBoolean(
-                m_out.doubleEqual(lowDouble(m_node->child1()), lowDouble(m_node->child2())));
-            return;
-        }
-        
-        if (m_node->isBinaryUseKind(ObjectUse)) {
-            setBoolean(
-                m_out.equal(
-                    lowNonNullObject(m_node->child1()),
-                    lowNonNullObject(m_node->child2())));
-            return;
-        }
-        
-        RELEASE_ASSERT_NOT_REACHED();
-    }
-    
-    void compileCompareStrictEqConstant()
-    {
-        JSValue constant = m_graph.valueOfJSConstant(m_node->child2().node());
-
-        if (constant.isUndefinedOrNull()
-            && !masqueradesAsUndefinedWatchpointIsStillValid()) {
-            if (constant.isNull()) {
-                setBoolean(equalNullOrUndefined(m_node->child1(), AllCellsAreFalse, EqualNull));
-                return;
-            }
-        
-            ASSERT(constant.isUndefined());
-            setBoolean(equalNullOrUndefined(m_node->child1(), AllCellsAreFalse, EqualUndefined));
-            return;
-        }
-        
-        setBoolean(
-            m_out.equal(
-                lowJSValue(m_node->child1()),
-                m_out.constInt64(JSValue::encode(constant))));
-    }
-    
-    void compileCompareLess()
-    {
-        compare(LLVMIntSLT, LLVMRealOLT, operationCompareLess);
-    }
-    
-    void compileCompareLessEq()
-    {
-        compare(LLVMIntSLE, LLVMRealOLE, operationCompareLessEq);
-    }
-    
-    void compileCompareGreater()
-    {
-        compare(LLVMIntSGT, LLVMRealOGT, operationCompareGreater);
-    }
-    
-    void compileCompareGreaterEq()
-    {
-        compare(LLVMIntSGE, LLVMRealOGE, operationCompareGreaterEq);
-    }
-    
-    void compileLogicalNot()
-    {
-        setBoolean(m_out.bitNot(boolify(m_node->child1())));
-    }
-    
-    void compileCallOrConstruct()
-    {
-        // FIXME: This is unacceptably slow.
-        // https://bugs.webkit.org/show_bug.cgi?id=113621
-        
-        J_JITOperation_E function =
-            m_node->op() == Call ? operationFTLCall : operationFTLConstruct;
-        
-        int dummyThisArgument = m_node->op() == Call ? 0 : 1;
-        
-        int numPassedArgs = m_node->numChildren() - 1;
-        
-        LValue calleeFrame = m_out.add(
-            m_callFrame,
-            m_out.constIntPtr(sizeof(Register) * virtualRegisterForLocal(m_graph.frameRegisterCount()).offset()));
-        
-        m_out.store32(
-            m_out.constInt32(numPassedArgs + dummyThisArgument),
-            payloadFor(calleeFrame, JSStack::ArgumentCount));
-        m_out.store64(m_callFrame, calleeFrame, m_heaps.CallFrame_callerFrame);
-        m_out.store64(
-            lowJSValue(m_graph.varArgChild(m_node, 0)),
-            addressFor(calleeFrame, JSStack::Callee));
-        
-        for (int i = 0; i < numPassedArgs; ++i) {
-            m_out.store64(
-                lowJSValue(m_graph.varArgChild(m_node, 1 + i)),
-                addressFor(calleeFrame, virtualRegisterForArgument(i + dummyThisArgument).offset()));
-        }
-        
-        setJSValue(vmCall(m_out.operation(function), calleeFrame));
-    }
-    
-    void compileJump()
-    {
-        m_out.jump(lowBlock(m_node->takenBlock()));
-    }
-    
-    void compileBranch()
-    {
-        m_out.branch(
-            boolify(m_node->child1()),
-            lowBlock(m_node->takenBlock()),
-            lowBlock(m_node->notTakenBlock()));
-    }
-    
-    void compileSwitch()
-    {
-        SwitchData* data = m_node->switchData();
-        switch (data->kind) {
-        case SwitchImm: {
-            Vector<ValueFromBlock, 2> intValues;
-            LBasicBlock switchOnInts = FTL_NEW_BLOCK(m_out, ("Switch/SwitchImm int case"));
-            
-            LBasicBlock lastNext = m_out.appendTo(m_out.m_block, switchOnInts);
-            
-            switch (m_node->child1().useKind()) {
-            case Int32Use: {
-                intValues.append(m_out.anchor(lowInt32(m_node->child1())));
-                m_out.jump(switchOnInts);
-                break;
-            }
-                
-            case UntypedUse: {
-                LBasicBlock isInt = FTL_NEW_BLOCK(m_out, ("Switch/SwitchImm is int"));
-                LBasicBlock isNotInt = FTL_NEW_BLOCK(m_out, ("Switch/SwitchImm is not int"));
-                LBasicBlock isDouble = FTL_NEW_BLOCK(m_out, ("Switch/SwitchImm is double"));
-                
-                LValue boxedValue = lowJSValue(m_node->child1());
-                m_out.branch(isNotInt32(boxedValue), isNotInt, isInt);
-                
-                LBasicBlock innerLastNext = m_out.appendTo(isInt, isNotInt);
-                
-                intValues.append(m_out.anchor(unboxInt32(boxedValue)));
-                m_out.jump(switchOnInts);
-                
-                m_out.appendTo(isNotInt, isDouble);
-                m_out.branch(
-                    isCellOrMisc(boxedValue), lowBlock(data->fallThrough), isDouble);
-                
-                m_out.appendTo(isDouble, innerLastNext);
-                LValue doubleValue = unboxDouble(boxedValue);
-                LValue intInDouble = m_out.fpToInt32(doubleValue);
-                intValues.append(m_out.anchor(intInDouble));
-                m_out.branch(
-                    m_out.doubleEqual(m_out.intToDouble(intInDouble), doubleValue),
-                    switchOnInts, lowBlock(data->fallThrough));
-                break;
-            }
-                
-            default:
-                RELEASE_ASSERT_NOT_REACHED();
-                break;
-            }
-            
-            m_out.appendTo(switchOnInts, lastNext);
-            buildSwitch(data, m_out.int32, m_out.phi(m_out.int32, intValues));
-            return;
-        }
-        
-        case SwitchChar: {
-            LValue stringValue;
-            
-            switch (m_node->child1().useKind()) {
-            case StringUse: {
-                stringValue = lowString(m_node->child1());
-                break;
-            }
-                
-            case UntypedUse: {
-                LValue unboxedValue = lowJSValue(m_node->child1());
-                
-                LBasicBlock isCellCase = FTL_NEW_BLOCK(m_out, ("Switch/SwitchChar is cell"));
-                LBasicBlock isStringCase = FTL_NEW_BLOCK(m_out, ("Switch/SwitchChar is string"));
-                
-                m_out.branch(
-                    isNotCell(unboxedValue), lowBlock(data->fallThrough), isCellCase);
-                
-                LBasicBlock lastNext = m_out.appendTo(isCellCase, isStringCase);
-                LValue cellValue = unboxedValue;
-                m_out.branch(isNotString(cellValue), lowBlock(data->fallThrough), isStringCase);
-                
-                m_out.appendTo(isStringCase, lastNext);
-                stringValue = cellValue;
-                break;
-            }
-                
-            default:
-                RELEASE_ASSERT_NOT_REACHED();
-                break;
-            }
-            
-            LBasicBlock lengthIs1 = FTL_NEW_BLOCK(m_out, ("Switch/SwitchChar length is 1"));
-            LBasicBlock needResolution = FTL_NEW_BLOCK(m_out, ("Switch/SwitchChar resolution"));
-            LBasicBlock resolved = FTL_NEW_BLOCK(m_out, ("Switch/SwitchChar resolved"));
-            LBasicBlock is8Bit = FTL_NEW_BLOCK(m_out, ("Switch/SwitchChar 8bit"));
-            LBasicBlock is16Bit = FTL_NEW_BLOCK(m_out, ("Switch/SwitchChar 16bit"));
-            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("Switch/SwitchChar continuation"));
-            
-            m_out.branch(
-                m_out.notEqual(
-                    m_out.load32(stringValue, m_heaps.JSString_length),
-                    m_out.int32One),
-                lowBlock(data->fallThrough), lengthIs1);
-            
-            LBasicBlock lastNext = m_out.appendTo(lengthIs1, needResolution);
-            Vector<ValueFromBlock, 2> values;
-            LValue fastValue = m_out.loadPtr(stringValue, m_heaps.JSString_value);
-            values.append(m_out.anchor(fastValue));
-            m_out.branch(m_out.isNull(fastValue), needResolution, resolved);
-            
-            m_out.appendTo(needResolution, resolved);
-            values.append(m_out.anchor(
-                vmCall(m_out.operation(operationResolveRope), m_callFrame, stringValue)));
-            m_out.jump(resolved);
-            
-            m_out.appendTo(resolved, is8Bit);
-            LValue value = m_out.phi(m_out.intPtr, values);
-            LValue characterData = m_out.loadPtr(value, m_heaps.StringImpl_data);
-            m_out.branch(
-                m_out.testNonZero32(
-                    m_out.load32(value, m_heaps.StringImpl_hashAndFlags),
-                    m_out.constInt32(StringImpl::flagIs8Bit())),
-                is8Bit, is16Bit);
-            
-            Vector<ValueFromBlock, 2> characters;
-            m_out.appendTo(is8Bit, is16Bit);
-            characters.append(m_out.anchor(
-                m_out.zeroExt(m_out.load8(characterData, m_heaps.characters8[0]), m_out.int16)));
-            m_out.jump(continuation);
-            
-            m_out.appendTo(is16Bit, continuation);
-            characters.append(m_out.anchor(m_out.load16(characterData, m_heaps.characters16[0])));
-            m_out.jump(continuation);
-            
-            m_out.appendTo(continuation, lastNext);
-            buildSwitch(data, m_out.int16, m_out.phi(m_out.int16, characters));
-            return;
-        }
-        
-        case SwitchString:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
-        }
-        
-        RELEASE_ASSERT_NOT_REACHED();
-    }
-    
-    void compileReturn()
-    {
-        // FIXME: have a real epilogue when we switch to using our calling convention.
-        // https://bugs.webkit.org/show_bug.cgi?id=113621
-        m_out.ret(lowJSValue(m_node->child1()));
-    }
-    
-    void compileForceOSRExit()
-    {
-        terminate(InadequateCoverage);
-    }
-    
-    void compileInvalidationPoint()
-    {
-        if (verboseCompilationEnabled())
-            dataLog("    Invalidation point with availability: ", m_availability, "\n");
-        
-        m_ftlState.jitCode->osrExit.append(OSRExit(
-            UncountableInvalidation, InvalidValueFormat, MethodOfGettingAValueProfile(),
-            m_codeOriginForExitTarget, m_codeOriginForExitProfile,
-            m_availability.numberOfArguments(), m_availability.numberOfLocals()));
-        m_ftlState.finalizer->osrExit.append(OSRExitCompilationInfo());
-        
-        OSRExit& exit = m_ftlState.jitCode->osrExit.last();
-        OSRExitCompilationInfo& info = m_ftlState.finalizer->osrExit.last();
-        
-        ExitArgumentList arguments;
-        
-        buildExitArguments(exit, arguments, FormattedValue(), exit.m_codeOrigin);
-        callStackmap(exit, arguments);
-        
-        info.m_isInvalidationPoint = true;
-    }
-    
-    TypedPointer baseIndex(IndexedAbstractHeap& heap, LValue storage, LValue index, Edge edge)
-    {
-        return m_out.baseIndex(
-            heap, storage, m_out.zeroExt(index, m_out.intPtr),
-            m_state.forNode(edge).m_value);
-    }
-    
-    void compare(
-        LIntPredicate intCondition, LRealPredicate realCondition,
-        S_JITOperation_EJJ helperFunction)
-    {
-        if (m_node->isBinaryUseKind(Int32Use)) {
-            LValue left = lowInt32(m_node->child1());
-            LValue right = lowInt32(m_node->child2());
-            setBoolean(m_out.icmp(intCondition, left, right));
-            return;
-        }
-        
-        if (m_node->isBinaryUseKind(MachineIntUse)) {
-            Int52Kind kind;
-            LValue left = lowWhicheverInt52(m_node->child1(), kind);
-            LValue right = lowInt52(m_node->child2(), kind);
-            setBoolean(m_out.icmp(intCondition, left, right));
-            return;
-        }
-        
-        if (m_node->isBinaryUseKind(NumberUse)) {
-            LValue left = lowDouble(m_node->child1());
-            LValue right = lowDouble(m_node->child2());
-            setBoolean(m_out.fcmp(realCondition, left, right));
-            return;
-        }
-        
-        if (m_node->isBinaryUseKind(UntypedUse)) {
-            nonSpeculativeCompare(intCondition, helperFunction);
-            return;
-        }
-        
-        RELEASE_ASSERT_NOT_REACHED();
-    }
-    
-    void nonSpeculativeCompare(LIntPredicate intCondition, S_JITOperation_EJJ helperFunction)
-    {
-        LValue left = lowJSValue(m_node->child1());
-        LValue right = lowJSValue(m_node->child2());
-        
-        LBasicBlock leftIsInt = FTL_NEW_BLOCK(m_out, ("CompareEq untyped left is int"));
-        LBasicBlock fastPath = FTL_NEW_BLOCK(m_out, ("CompareEq untyped fast path"));
-        LBasicBlock slowPath = FTL_NEW_BLOCK(m_out, ("CompareEq untyped slow path"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("CompareEq untyped continuation"));
-        
-        m_out.branch(isNotInt32(left), slowPath, leftIsInt);
-        
-        LBasicBlock lastNext = m_out.appendTo(leftIsInt, fastPath);
-        m_out.branch(isNotInt32(right), slowPath, fastPath);
-        
-        m_out.appendTo(fastPath, slowPath);
-        ValueFromBlock fastResult = m_out.anchor(
-            m_out.icmp(intCondition, unboxInt32(left), unboxInt32(right)));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(slowPath, continuation);
-        ValueFromBlock slowResult = m_out.anchor(m_out.notNull(vmCall(
-            m_out.operation(helperFunction), m_callFrame, left, right)));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-        setBoolean(m_out.phi(m_out.boolean, fastResult, slowResult));
-    }
-    
-    LValue allocateCell(LValue allocator, LValue structure, LBasicBlock slowPath)
-    {
-        LBasicBlock success = FTL_NEW_BLOCK(m_out, ("object allocation success"));
-        
-        LValue result = m_out.loadPtr(
-            allocator, m_heaps.MarkedAllocator_freeListHead);
-        
-        m_out.branch(m_out.notNull(result), success, slowPath);
-        
-        m_out.appendTo(success);
-        
-        m_out.storePtr(
-            m_out.loadPtr(result, m_heaps.JSCell_freeListNext),
-            allocator, m_heaps.MarkedAllocator_freeListHead);
-        
-        m_out.storePtr(structure, result, m_heaps.JSCell_structure);
-        
-        return result;
-    }
-    
-    LValue allocateObject(
-        LValue allocator, LValue structure, LValue butterfly, LBasicBlock slowPath)
-    {
-        LValue result = allocateCell(allocator, structure, slowPath);
-        m_out.storePtr(butterfly, result, m_heaps.JSObject_butterfly);
-        return result;
-    }
-    
-    template<typename ClassType>
-    LValue allocateObject(LValue structure, LValue butterfly, LBasicBlock slowPath)
-    {
-        MarkedAllocator* allocator;
-        size_t size = ClassType::allocationSize(0);
-        if (ClassType::needsDestruction && ClassType::hasImmortalStructure)
-            allocator = &vm().heap.allocatorForObjectWithImmortalStructureDestructor(size);
-        else if (ClassType::needsDestruction)
-            allocator = &vm().heap.allocatorForObjectWithNormalDestructor(size);
-        else
-            allocator = &vm().heap.allocatorForObjectWithoutDestructor(size);
-        return allocateObject(m_out.constIntPtr(allocator), structure, butterfly, slowPath);
-    }
-    
-    // Returns a pointer to the end of the allocation.
-    LValue allocateBasicStorageAndGetEnd(LValue size, LBasicBlock slowPath)
-    {
-        CopiedAllocator& allocator = vm().heap.storageAllocator();
-        
-        LBasicBlock success = FTL_NEW_BLOCK(m_out, ("storage allocation success"));
-        
-        LValue remaining = m_out.loadPtr(m_out.absolute(&allocator.m_currentRemaining));
-        LValue newRemaining = m_out.sub(remaining, size);
-        
-        m_out.branch(m_out.lessThan(newRemaining, m_out.intPtrZero), slowPath, success);
-        
-        m_out.appendTo(success);
-        
-        m_out.storePtr(newRemaining, m_out.absolute(&allocator.m_currentRemaining));
-        return m_out.sub(
-            m_out.loadPtr(m_out.absolute(&allocator.m_currentPayloadEnd)), newRemaining);
-    }
-    
-    struct ArrayValues {
-        ArrayValues()
-            : array(0)
-            , butterfly(0)
-        {
-        }
-        
-        ArrayValues(LValue array, LValue butterfly)
-            : array(array)
-            , butterfly(butterfly)
-        {
-        }
-        
-        LValue array;
-        LValue butterfly;
-    };
-    ArrayValues allocateJSArray(
-        Structure* structure, unsigned numElements, LBasicBlock slowPath)
-    {
-        ASSERT(
-            hasUndecided(structure->indexingType())
-            || hasInt32(structure->indexingType())
-            || hasDouble(structure->indexingType())
-            || hasContiguous(structure->indexingType()));
-        
-        unsigned vectorLength = std::max(BASE_VECTOR_LEN, numElements);
-        
-        LValue endOfStorage = allocateBasicStorageAndGetEnd(
-            m_out.constIntPtr(sizeof(JSValue) * vectorLength + sizeof(IndexingHeader)),
-            slowPath);
-        
-        LValue butterfly = m_out.sub(
-            endOfStorage, m_out.constIntPtr(sizeof(JSValue) * vectorLength));
-        
-        LValue object = allocateObject<JSArray>(
-            m_out.constIntPtr(structure), butterfly, slowPath);
-        
-        m_out.store32(m_out.constInt32(numElements), butterfly, m_heaps.Butterfly_publicLength);
-        m_out.store32(m_out.constInt32(vectorLength), butterfly, m_heaps.Butterfly_vectorLength);
-        
-        if (hasDouble(structure->indexingType())) {
-            for (unsigned i = numElements; i < vectorLength; ++i) {
-                m_out.store64(
-                    m_out.constInt64(bitwise_cast<int64_t>(QNaN)),
-                    butterfly, m_heaps.indexedDoubleProperties[i]);
-            }
-        }
-        
-        return ArrayValues(object, butterfly);
-    }
-    
-    ArrayValues allocateJSArray(Structure* structure, unsigned numElements)
-    {
-        LBasicBlock slowPath = FTL_NEW_BLOCK(m_out, ("JSArray allocation slow path"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("JSArray allocation continuation"));
-        
-        LBasicBlock lastNext = m_out.insertNewBlocksBefore(slowPath);
-        
-        ArrayValues fastValues = allocateJSArray(structure, numElements, slowPath);
-        ValueFromBlock fastArray = m_out.anchor(fastValues.array);
-        ValueFromBlock fastButterfly = m_out.anchor(fastValues.butterfly);
-        
-        m_out.jump(continuation);
-        
-        m_out.appendTo(slowPath, continuation);
-        
-        ValueFromBlock slowArray = m_out.anchor(vmCall(
-            m_out.operation(operationNewArrayWithSize), m_callFrame,
-            m_out.constIntPtr(structure), m_out.constInt32(numElements)));
-        ValueFromBlock slowButterfly = m_out.anchor(
-            m_out.loadPtr(slowArray.value(), m_heaps.JSObject_butterfly));
-
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-        
-        return ArrayValues(
-            m_out.phi(m_out.intPtr, fastArray, slowArray),
-            m_out.phi(m_out.intPtr, fastButterfly, slowButterfly));
-    }
-    
-    LValue typedArrayLength(Edge baseEdge, ArrayMode arrayMode, LValue base)
-    {
-        if (JSArrayBufferView* view = m_graph.tryGetFoldableView(baseEdge.node(), arrayMode))
-            return m_out.constInt32(view->length());
-        return m_out.load32(base, m_heaps.JSArrayBufferView_length);
-    }
-    
-    LValue typedArrayLength(Edge baseEdge, ArrayMode arrayMode)
-    {
-        return typedArrayLength(baseEdge, arrayMode, lowCell(baseEdge));
-    }
-    
-    LValue boolify(Edge edge)
-    {
-        switch (edge.useKind()) {
-        case BooleanUse:
-            return lowBoolean(m_node->child1());
-        case Int32Use:
-            return m_out.notZero32(lowInt32(m_node->child1()));
-        case NumberUse:
-            return m_out.doubleNotEqual(lowDouble(edge), m_out.doubleZero);
-        case ObjectOrOtherUse:
-            return m_out.bitNot(
-                equalNullOrUndefined(
-                    edge, CellCaseSpeculatesObject, SpeculateNullOrUndefined,
-                    ManualOperandSpeculation));
-        case StringUse: {
-            LValue stringValue = lowString(m_node->child1());
-            LValue length = m_out.load32(stringValue, m_heaps.JSString_length);
-            return m_out.notEqual(length, m_out.int32Zero);
-        }
-        case UntypedUse: {
-            LValue value = lowJSValue(m_node->child1());
-            
-            LBasicBlock slowCase = FTL_NEW_BLOCK(m_out, ("Boolify untyped slow case"));
-            LBasicBlock fastCase = FTL_NEW_BLOCK(m_out, ("Boolify untyped fast case"));
-            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("Boolify untyped continuation"));
-            
-            m_out.branch(isNotBoolean(value), slowCase, fastCase);
-            
-            LBasicBlock lastNext = m_out.appendTo(fastCase, slowCase);
-            ValueFromBlock fastResult = m_out.anchor(unboxBoolean(value));
-            m_out.jump(continuation);
-            
-            m_out.appendTo(slowCase, continuation);
-            ValueFromBlock slowResult = m_out.anchor(m_out.notNull(vmCall(
-                m_out.operation(operationConvertJSValueToBoolean), m_callFrame, value)));
-            m_out.jump(continuation);
-            
-            m_out.appendTo(continuation, lastNext);
-            return m_out.phi(m_out.boolean, fastResult, slowResult);
-        }
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            return 0;
-        }
-    }
-    
-    enum StringOrObjectMode {
-        AllCellsAreFalse,
-        CellCaseSpeculatesObject
-    };
-    enum EqualNullOrUndefinedMode {
-        EqualNull,
-        EqualUndefined,
-        EqualNullOrUndefined,
-        SpeculateNullOrUndefined
-    };
-    LValue equalNullOrUndefined(
-        Edge edge, StringOrObjectMode cellMode, EqualNullOrUndefinedMode primitiveMode,
-        OperandSpeculationMode operandMode = AutomaticOperandSpeculation)
-    {
-        bool validWatchpoint = masqueradesAsUndefinedWatchpointIsStillValid();
-        
-        LValue value = lowJSValue(edge, operandMode);
-        
-        LBasicBlock cellCase = FTL_NEW_BLOCK(m_out, ("EqualNullOrUndefined cell case"));
-        LBasicBlock primitiveCase = FTL_NEW_BLOCK(m_out, ("EqualNullOrUndefined primitive case"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("EqualNullOrUndefined continuation"));
-        
-        m_out.branch(isNotCell(value), primitiveCase, cellCase);
-        
-        LBasicBlock lastNext = m_out.appendTo(cellCase, primitiveCase);
-        
-        Vector<ValueFromBlock, 3> results;
-        
-        switch (cellMode) {
-        case AllCellsAreFalse:
-            break;
-        case CellCaseSpeculatesObject:
-            FTL_TYPE_CHECK(
-                jsValueValue(value), edge, (~SpecCell) | SpecObject,
-                m_out.equal(
-                    m_out.loadPtr(value, m_heaps.JSCell_structure),
-                    m_out.constIntPtr(vm().stringStructure.get())));
-            break;
-        }
-        
-        if (validWatchpoint) {
-            results.append(m_out.anchor(m_out.booleanFalse));
-            m_out.jump(continuation);
-        } else {
-            LBasicBlock masqueradesCase =
-                FTL_NEW_BLOCK(m_out, ("EqualNullOrUndefined masquerades case"));
-                
-            LValue structure = m_out.loadPtr(value, m_heaps.JSCell_structure);
-            
-            results.append(m_out.anchor(m_out.booleanFalse));
-            
-            m_out.branch(
-                m_out.testNonZero8(
-                    m_out.load8(structure, m_heaps.Structure_typeInfoFlags),
-                    m_out.constInt8(MasqueradesAsUndefined)),
-                masqueradesCase, continuation);
-            
-            m_out.appendTo(masqueradesCase, primitiveCase);
-            
-            results.append(m_out.anchor(
-                m_out.equal(
-                    m_out.constIntPtr(m_graph.globalObjectFor(m_node->codeOrigin)),
-                    m_out.loadPtr(structure, m_heaps.Structure_globalObject))));
-            m_out.jump(continuation);
-        }
-        
-        m_out.appendTo(primitiveCase, continuation);
-        
-        LValue primitiveResult;
-        switch (primitiveMode) {
-        case EqualNull:
-            primitiveResult = m_out.equal(value, m_out.constInt64(ValueNull));
-            break;
-        case EqualUndefined:
-            primitiveResult = m_out.equal(value, m_out.constInt64(ValueUndefined));
-            break;
-        case EqualNullOrUndefined:
-            primitiveResult = m_out.equal(
-                m_out.bitAnd(value, m_out.constInt64(~TagBitUndefined)),
-                m_out.constInt64(ValueNull));
-            break;
-        case SpeculateNullOrUndefined:
-            FTL_TYPE_CHECK(
-                jsValueValue(value), edge, SpecCell | SpecOther,
-                m_out.notEqual(
-                    m_out.bitAnd(value, m_out.constInt64(~TagBitUndefined)),
-                    m_out.constInt64(ValueNull)));
-            primitiveResult = m_out.booleanTrue;
-            break;
-        }
-        results.append(m_out.anchor(primitiveResult));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-        
-        return m_out.phi(m_out.boolean, results);
-    }
-    
-    template<typename FunctionType>
-    void contiguousPutByValOutOfBounds(
-        FunctionType slowPathFunction, LValue base, LValue storage, LValue index, LValue value,
-        LBasicBlock continuation)
-    {
-        LValue isNotInBounds = m_out.aboveOrEqual(
-            index, m_out.load32(storage, m_heaps.Butterfly_publicLength));
-        if (!m_node->arrayMode().isInBounds()) {
-            LBasicBlock notInBoundsCase =
-                FTL_NEW_BLOCK(m_out, ("PutByVal not in bounds"));
-            LBasicBlock performStore =
-                FTL_NEW_BLOCK(m_out, ("PutByVal perform store"));
-                
-            m_out.branch(isNotInBounds, notInBoundsCase, performStore);
-                
-            LBasicBlock lastNext = m_out.appendTo(notInBoundsCase, performStore);
-                
-            LValue isOutOfBounds = m_out.aboveOrEqual(
-                index, m_out.load32(storage, m_heaps.Butterfly_vectorLength));
-                
-            if (!m_node->arrayMode().isOutOfBounds())
-                speculate(OutOfBounds, noValue(), 0, isOutOfBounds);
-            else {
-                LBasicBlock outOfBoundsCase =
-                    FTL_NEW_BLOCK(m_out, ("PutByVal out of bounds"));
-                LBasicBlock holeCase =
-                    FTL_NEW_BLOCK(m_out, ("PutByVal hole case"));
-                    
-                m_out.branch(isOutOfBounds, outOfBoundsCase, holeCase);
-                    
-                LBasicBlock innerLastNext = m_out.appendTo(outOfBoundsCase, holeCase);
-                    
-                vmCall(
-                    m_out.operation(slowPathFunction),
-                    m_callFrame, base, index, value);
-                    
-                m_out.jump(continuation);
-                    
-                m_out.appendTo(holeCase, innerLastNext);
-            }
-            
-            m_out.store32(
-                m_out.add(index, m_out.int32One),
-                storage, m_heaps.Butterfly_publicLength);
-                
-            m_out.jump(performStore);
-            m_out.appendTo(performStore, lastNext);
-        }
-    }
-    
-    void buildSwitch(SwitchData* data, LType type, LValue switchValue)
-    {
-        Vector<SwitchCase> cases;
-        for (unsigned i = 0; i < data->cases.size(); ++i) {
-            cases.append(SwitchCase(
-                constInt(type, data->cases[i].value.switchLookupValue()),
-                lowBlock(data->cases[i].target)));
-        }
-        
-        m_out.switchInstruction(switchValue, cases, lowBlock(data->fallThrough));
-    }
-    
-    LValue doubleToInt32(LValue doubleValue, double low, double high, bool isSigned = true)
-    {
-        // FIXME: Optimize double-to-int conversions.
-        // <rdar://problem/14938465>
-        
-        LBasicBlock greatEnough = FTL_NEW_BLOCK(m_out, ("doubleToInt32 greatEnough"));
-        LBasicBlock withinRange = FTL_NEW_BLOCK(m_out, ("doubleToInt32 withinRange"));
-        LBasicBlock slowPath = FTL_NEW_BLOCK(m_out, ("doubleToInt32 slowPath"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("doubleToInt32 continuation"));
-        
-        Vector<ValueFromBlock, 2> results;
-        
-        m_out.branch(
-            m_out.doubleGreaterThanOrEqual(doubleValue, m_out.constDouble(low)),
-            greatEnough, slowPath);
-        
-        LBasicBlock lastNext = m_out.appendTo(greatEnough, withinRange);
-        m_out.branch(
-            m_out.doubleLessThanOrEqual(doubleValue, m_out.constDouble(high)),
-            withinRange, slowPath);
-        
-        m_out.appendTo(withinRange, slowPath);
-        LValue fastResult;
-        if (isSigned)
-            fastResult = m_out.fpToInt32(doubleValue);
-        else
-            fastResult = m_out.fpToUInt32(doubleValue);
-        results.append(m_out.anchor(fastResult));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(slowPath, continuation);
-        results.append(m_out.anchor(m_out.call(m_out.operation(toInt32), doubleValue)));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-        return m_out.phi(m_out.int32, results);
-    }
-    
-    LValue doubleToInt32(LValue doubleValue)
-    {
-        if (Output::hasSensibleDoubleToInt())
-            return sensibleDoubleToInt32(doubleValue);
-        
-        double limit = pow(2, 31) - 1;
-        return doubleToInt32(doubleValue, -limit, limit);
-    }
-    
-    LValue sensibleDoubleToInt32(LValue doubleValue)
-    {
-        LBasicBlock slowPath = FTL_NEW_BLOCK(m_out, ("sensible doubleToInt32 slow path"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("sensible doubleToInt32 continuation"));
-        
-        ValueFromBlock fastResult = m_out.anchor(
-            m_out.sensibleDoubleToInt(doubleValue));
-        m_out.branch(
-            m_out.equal(fastResult.value(), m_out.constInt32(0x80000000)),
-            slowPath, continuation);
-        
-        LBasicBlock lastNext = m_out.appendTo(slowPath, continuation);
-        ValueFromBlock slowResult = m_out.anchor(
-            m_out.call(m_out.operation(toInt32), doubleValue));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-        return m_out.phi(m_out.int32, fastResult, slowResult);
-    }
-    
-    void speculate(
-        ExitKind kind, FormattedValue lowValue, Node* highValue, LValue failCondition)
-    {
-        appendOSRExit(kind, lowValue, highValue, failCondition);
-    }
-    
-    void terminate(ExitKind kind)
-    {
-        speculate(kind, noValue(), 0, m_out.booleanTrue);
-    }
-    
-    void typeCheck(
-        FormattedValue lowValue, Edge highValue, SpeculatedType typesPassedThrough,
-        LValue failCondition)
-    {
-        appendTypeCheck(lowValue, highValue, typesPassedThrough, failCondition);
-    }
-    
-    void appendTypeCheck(
-        FormattedValue lowValue, Edge highValue, SpeculatedType typesPassedThrough,
-        LValue failCondition)
-    {
-        if (!m_interpreter.needsTypeCheck(highValue, typesPassedThrough))
-            return;
-        ASSERT(mayHaveTypeCheck(highValue.useKind()));
-        appendOSRExit(BadType, lowValue, highValue.node(), failCondition);
-        m_interpreter.filter(highValue, typesPassedThrough);
-    }
-    
-    LValue lowInt32(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || (edge.useKind() == Int32Use || edge.useKind() == KnownInt32Use));
-        
-        if (edge->hasConstant()) {
-            JSValue value = m_graph.valueOfJSConstant(edge.node());
-            if (!value.isInt32()) {
-                terminate(Uncountable);
-                return m_out.int32Zero;
-            }
-            return m_out.constInt32(value.asInt32());
-        }
-        
-        LoweredNodeValue value = m_int32Values.get(edge.node());
-        if (isValid(value))
-            return value.value();
-        
-        value = m_strictInt52Values.get(edge.node());
-        if (isValid(value))
-            return strictInt52ToInt32(edge, value.value());
-        
-        value = m_int52Values.get(edge.node());
-        if (isValid(value))
-            return strictInt52ToInt32(edge, int52ToStrictInt52(value.value()));
-        
-        value = m_jsValueValues.get(edge.node());
-        if (isValid(value)) {
-            LValue boxedResult = value.value();
-            FTL_TYPE_CHECK(
-                jsValueValue(boxedResult), edge, SpecInt32, isNotInt32(boxedResult));
-            LValue result = unboxInt32(boxedResult);
-            setInt32(edge.node(), result);
-            return result;
-        }
-
-        RELEASE_ASSERT(!(m_state.forNode(edge).m_type & SpecInt32));
-        terminate(Uncountable);
-        return m_out.int32Zero;
-    }
-    
-    enum Int52Kind { StrictInt52, Int52 };
-    LValue lowInt52(Edge edge, Int52Kind kind, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == MachineIntUse);
-        
-        if (edge->hasConstant()) {
-            JSValue value = m_graph.valueOfJSConstant(edge.node());
-            if (!value.isMachineInt()) {
-                terminate(Uncountable);
-                return m_out.int64Zero;
-            }
-            int64_t result = value.asMachineInt();
-            if (kind == Int52)
-                result <<= JSValue::int52ShiftAmount;
-            return m_out.constInt64(result);
-        }
-        
-        LoweredNodeValue value;
-        
-        switch (kind) {
-        case Int52:
-            value = m_int52Values.get(edge.node());
-            if (isValid(value))
-                return value.value();
-            
-            value = m_strictInt52Values.get(edge.node());
-            if (isValid(value))
-                return strictInt52ToInt52(value.value());
-            break;
-            
-        case StrictInt52:
-            value = m_strictInt52Values.get(edge.node());
-            if (isValid(value))
-                return value.value();
-            
-            value = m_int52Values.get(edge.node());
-            if (isValid(value))
-                return int52ToStrictInt52(value.value());
-            break;
-        }
-        
-        value = m_int32Values.get(edge.node());
-        if (isValid(value)) {
-            return setInt52WithStrictValue(
-                edge.node(), m_out.signExt(value.value(), m_out.int64), kind);
-        }
-        
-        RELEASE_ASSERT(!(m_state.forNode(edge).m_type & SpecInt52));
-        
-        value = m_jsValueValues.get(edge.node());
-        if (isValid(value)) {
-            LValue boxedResult = value.value();
-            FTL_TYPE_CHECK(
-                jsValueValue(boxedResult), edge, SpecMachineInt, isNotInt32(boxedResult));
-            return setInt52WithStrictValue(
-                edge.node(), m_out.signExt(unboxInt32(boxedResult), m_out.int64), kind);
-        }
-        
-        RELEASE_ASSERT(!(m_state.forNode(edge).m_type & SpecMachineInt));
-        terminate(Uncountable);
-        return m_out.int64Zero;
-    }
-    
-    LValue lowInt52(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        return lowInt52(edge, Int52, mode);
-    }
-    
-    LValue lowStrictInt52(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        return lowInt52(edge, StrictInt52, mode);
-    }
-    
-    bool betterUseStrictInt52(Node* node)
-    {
-        return !isValid(m_int52Values.get(node));
-    }
-    bool betterUseStrictInt52(Edge edge)
-    {
-        return betterUseStrictInt52(edge.node());
-    }
-    template<typename T>
-    Int52Kind bestInt52Kind(T node)
-    {
-        return betterUseStrictInt52(node) ? StrictInt52 : Int52;
-    }
-    Int52Kind opposite(Int52Kind kind)
-    {
-        switch (kind) {
-        case Int52:
-            return StrictInt52;
-        case StrictInt52:
-            return Int52;
-        }
-        RELEASE_ASSERT_NOT_REACHED();
-    }
-    
-    LValue lowWhicheverInt52(Edge edge, Int52Kind& kind, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        kind = bestInt52Kind(edge);
-        return lowInt52(edge, kind, mode);
-    }
-    
-    LValue lowCell(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || DFG::isCell(edge.useKind()));
-        
-        if (edge->op() == JSConstant) {
-            JSValue value = m_graph.valueOfJSConstant(edge.node());
-            if (!value.isCell()) {
-                terminate(Uncountable);
-                return m_out.intPtrZero;
-            }
-            return m_out.constIntPtr(value.asCell());
-        }
-        
-        LoweredNodeValue value = m_jsValueValues.get(edge.node());
-        if (isValid(value)) {
-            LValue uncheckedValue = value.value();
-            FTL_TYPE_CHECK(
-                jsValueValue(uncheckedValue), edge, SpecCell, isNotCell(uncheckedValue));
-            return uncheckedValue;
-        }
-        
-        RELEASE_ASSERT(!(m_state.forNode(edge).m_type & SpecCell));
-        terminate(Uncountable);
-        return m_out.intPtrZero;
-    }
-    
-    LValue lowObject(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == ObjectUse);
-        
-        LValue result = lowCell(edge, mode);
-        speculateObject(edge, result);
-        return result;
-    }
-    
-    LValue lowString(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == StringUse || edge.useKind() == KnownStringUse);
-        
-        LValue result = lowCell(edge, mode);
-        speculateString(edge, result);
-        return result;
-    }
-    
-    LValue lowNonNullObject(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == ObjectUse);
-        
-        LValue result = lowCell(edge, mode);
-        speculateNonNullObject(edge, result);
-        return result;
-    }
-    
-    LValue lowBoolean(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == BooleanUse);
-        
-        if (edge->hasConstant()) {
-            JSValue value = m_graph.valueOfJSConstant(edge.node());
-            if (!value.isBoolean()) {
-                terminate(Uncountable);
-                return m_out.booleanFalse;
-            }
-            return m_out.constBool(value.asBoolean());
-        }
-        
-        LoweredNodeValue value = m_booleanValues.get(edge.node());
-        if (isValid(value))
-            return value.value();
-        
-        value = m_jsValueValues.get(edge.node());
-        if (isValid(value)) {
-            LValue unboxedResult = value.value();
-            FTL_TYPE_CHECK(
-                jsValueValue(unboxedResult), edge, SpecBoolean, isNotBoolean(unboxedResult));
-            LValue result = unboxBoolean(unboxedResult);
-            setBoolean(edge.node(), result);
-            return result;
-        }
-        
-        RELEASE_ASSERT(!(m_state.forNode(edge).m_type & SpecBoolean));
-        terminate(Uncountable);
-        return m_out.booleanFalse;
-    }
-    
-    LValue lowDouble(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || isDouble(edge.useKind()));
-        
-        if (edge->hasConstant()) {
-            JSValue value = m_graph.valueOfJSConstant(edge.node());
-            if (!value.isNumber()) {
-                terminate(Uncountable);
-                return m_out.doubleZero;
-            }
-            return m_out.constDouble(value.asNumber());
-        }
-        
-        LoweredNodeValue value = m_doubleValues.get(edge.node());
-        if (isValid(value))
-            return value.value();
-        
-        value = m_int32Values.get(edge.node());
-        if (isValid(value)) {
-            LValue result = m_out.intToDouble(value.value());
-            setDouble(edge.node(), result);
-            return result;
-        }
-        
-        value = m_strictInt52Values.get(edge.node());
-        if (isValid(value))
-            return strictInt52ToDouble(edge, value.value());
-        
-        value = m_int52Values.get(edge.node());
-        if (isValid(value))
-            return strictInt52ToDouble(edge, int52ToStrictInt52(value.value()));
-        
-        value = m_jsValueValues.get(edge.node());
-        if (isValid(value)) {
-            LValue boxedResult = value.value();
-            
-            LBasicBlock intCase = FTL_NEW_BLOCK(m_out, ("Double unboxing int case"));
-            LBasicBlock doubleCase = FTL_NEW_BLOCK(m_out, ("Double unboxing double case"));
-            LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("Double unboxing continuation"));
-            
-            m_out.branch(isNotInt32(boxedResult), doubleCase, intCase);
-            
-            LBasicBlock lastNext = m_out.appendTo(intCase, doubleCase);
-            
-            ValueFromBlock intToDouble = m_out.anchor(
-                m_out.intToDouble(unboxInt32(boxedResult)));
-            m_out.jump(continuation);
-            
-            m_out.appendTo(doubleCase, continuation);
-            
-            FTL_TYPE_CHECK(
-                jsValueValue(boxedResult), edge, SpecFullNumber, isCellOrMisc(boxedResult));
-            
-            ValueFromBlock unboxedDouble = m_out.anchor(unboxDouble(boxedResult));
-            m_out.jump(continuation);
-            
-            m_out.appendTo(continuation, lastNext);
-            
-            LValue result = m_out.phi(m_out.doubleType, intToDouble, unboxedDouble);
-            
-            setDouble(edge.node(), result);
-            return result;
-        }
-        
-        RELEASE_ASSERT(!(m_state.forNode(edge).m_type & SpecFullNumber));
-        terminate(Uncountable);
-        return m_out.doubleZero;
-    }
-    
-    LValue lowJSValue(Edge edge, OperandSpeculationMode mode = AutomaticOperandSpeculation)
-    {
-        ASSERT_UNUSED(mode, mode == ManualOperandSpeculation || edge.useKind() == UntypedUse);
-        
-        if (edge->hasConstant())
-            return m_out.constInt64(JSValue::encode(m_graph.valueOfJSConstant(edge.node())));
-        
-        LoweredNodeValue value = m_jsValueValues.get(edge.node());
-        if (isValid(value))
-            return value.value();
-        
-        value = m_int32Values.get(edge.node());
-        if (isValid(value)) {
-            LValue result = boxInt32(value.value());
-            setJSValue(edge.node(), result);
-            return result;
-        }
-        
-        value = m_strictInt52Values.get(edge.node());
-        if (isValid(value))
-            return strictInt52ToJSValue(value.value());
-        
-        value = m_int52Values.get(edge.node());
-        if (isValid(value))
-            return strictInt52ToJSValue(int52ToStrictInt52(value.value()));
-        
-        value = m_booleanValues.get(edge.node());
-        if (isValid(value)) {
-            LValue result = boxBoolean(value.value());
-            setJSValue(edge.node(), result);
-            return result;
-        }
-        
-        value = m_doubleValues.get(edge.node());
-        if (isValid(value)) {
-            LValue result = boxDouble(value.value());
-            setJSValue(edge.node(), result);
-            return result;
-        }
-        
-        RELEASE_ASSERT_NOT_REACHED();
-        return 0;
-    }
-    
-    LValue lowStorage(Edge edge)
-    {
-        LoweredNodeValue value = m_storageValues.get(edge.node());
-        if (isValid(value))
-            return value.value();
-        
-        LValue result = lowCell(edge);
-        setStorage(edge.node(), result);
-        return result;
-    }
-    
-    LValue strictInt52ToInt32(Edge edge, LValue value)
-    {
-        LValue result = m_out.castToInt32(value);
-        FTL_TYPE_CHECK(
-            noValue(), edge, SpecInt32,
-            m_out.notEqual(m_out.signExt(result, m_out.int64), value));
-        setInt32(edge.node(), result);
-        return result;
-    }
-    
-    LValue strictInt52ToDouble(Edge edge, LValue value)
-    {
-        LValue result = m_out.intToDouble(value);
-        setDouble(edge.node(), result);
-        return result;
-    }
-    
-    LValue strictInt52ToJSValue(LValue value)
-    {
-        LBasicBlock isInt32 = FTL_NEW_BLOCK(m_out, ("strictInt52ToJSValue isInt32 case"));
-        LBasicBlock isDouble = FTL_NEW_BLOCK(m_out, ("strictInt52ToJSValue isDouble case"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("strictInt52ToJSValue continuation"));
-        
-        Vector<ValueFromBlock, 2> results;
-            
-        LValue int32Value = m_out.castToInt32(value);
-        m_out.branch(
-            m_out.equal(m_out.signExt(int32Value, m_out.int64), value),
-            isInt32, isDouble);
-        
-        LBasicBlock lastNext = m_out.appendTo(isInt32, isDouble);
-        
-        results.append(m_out.anchor(boxInt32(int32Value)));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(isDouble, continuation);
-        
-        results.append(m_out.anchor(boxDouble(m_out.intToDouble(value))));
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-        return m_out.phi(m_out.int64, results);
-    }
-    
-    LValue setInt52WithStrictValue(Node* node, LValue value, Int52Kind kind)
-    {
-        switch (kind) {
-        case StrictInt52:
-            setStrictInt52(node, value);
-            return value;
-            
-        case Int52:
-            value = strictInt52ToInt52(value);
-            setInt52(node, value);
-            return value;
-        }
-        
-        RELEASE_ASSERT_NOT_REACHED();
-        return 0;
-    }
-
-    LValue strictInt52ToInt52(LValue value)
-    {
-        return m_out.shl(value, m_out.constInt64(JSValue::int52ShiftAmount));
-    }
-    
-    LValue int52ToStrictInt52(LValue value)
-    {
-        return m_out.aShr(value, m_out.constInt64(JSValue::int52ShiftAmount));
-    }
-    
-    LValue isNotInt32(LValue jsValue)
-    {
-        return m_out.below(jsValue, m_tagTypeNumber);
-    }
-    LValue unboxInt32(LValue jsValue)
-    {
-        return m_out.castToInt32(jsValue);
-    }
-    LValue boxInt32(LValue value)
-    {
-        return m_out.add(m_out.zeroExt(value, m_out.int64), m_tagTypeNumber);
-    }
-    
-    LValue isCellOrMisc(LValue jsValue)
-    {
-        return m_out.testIsZero64(jsValue, m_tagTypeNumber);
-    }
-    LValue unboxDouble(LValue jsValue)
-    {
-        return m_out.bitCast(m_out.add(jsValue, m_tagTypeNumber), m_out.doubleType);
-    }
-    LValue boxDouble(LValue doubleValue)
-    {
-        return m_out.sub(m_out.bitCast(doubleValue, m_out.int64), m_tagTypeNumber);
-    }
-    
-    LValue isNotCell(LValue jsValue)
-    {
-        return m_out.testNonZero64(jsValue, m_tagMask);
-    }
-    
-    LValue isCell(LValue jsValue)
-    {
-        return m_out.testIsZero64(jsValue, m_tagMask);
-    }
-    
-    LValue isNotBoolean(LValue jsValue)
-    {
-        return m_out.testNonZero64(
-            m_out.bitXor(jsValue, m_out.constInt64(ValueFalse)),
-            m_out.constInt64(~1));
-    }
-    LValue unboxBoolean(LValue jsValue)
-    {
-        // We want to use a cast that guarantees that LLVM knows that even the integer
-        // value is just 0 or 1. But for now we do it the dumb way.
-        return m_out.notZero64(m_out.bitAnd(jsValue, m_out.constInt64(1)));
-    }
-    LValue boxBoolean(LValue value)
-    {
-        return m_out.select(
-            value, m_out.constInt64(ValueTrue), m_out.constInt64(ValueFalse));
-    }
-
-    void speculate(Edge edge)
-    {
-        switch (edge.useKind()) {
-        case UntypedUse:
-            break;
-        case KnownInt32Use:
-        case KnownNumberUse:
-            ASSERT(!m_interpreter.needsTypeCheck(edge));
-            break;
-        case Int32Use:
-            speculateInt32(edge);
-            break;
-        case CellUse:
-            speculateCell(edge);
-            break;
-        case KnownCellUse:
-            ASSERT(!m_interpreter.needsTypeCheck(edge));
-            break;
-        case ObjectUse:
-            speculateObject(edge);
-            break;
-        case ObjectOrOtherUse:
-            speculateObjectOrOther(edge);
-            break;
-        case FinalObjectUse:
-            speculateFinalObject(edge);
-            break;
-        case StringUse:
-            speculateString(edge);
-            break;
-        case RealNumberUse:
-            speculateRealNumber(edge);
-            break;
-        case NumberUse:
-            speculateNumber(edge);
-            break;
-        case MachineIntUse:
-            speculateMachineInt(edge);
-            break;
-        case BooleanUse:
-            speculateBoolean(edge);
-            break;
-        default:
-            dataLog("Unsupported speculation use kind: ", edge.useKind(), "\n");
-            RELEASE_ASSERT_NOT_REACHED();
-        }
-    }
-    
-    void speculate(Node*, Edge edge)
-    {
-        speculate(edge);
-    }
-    
-    void speculateInt32(Edge edge)
-    {
-        lowInt32(edge);
-    }
-    
-    void speculateCell(Edge edge)
-    {
-        lowCell(edge);
-    }
-    
-    LValue isObject(LValue cell)
-    {
-        return m_out.notEqual(
-            m_out.loadPtr(cell, m_heaps.JSCell_structure),
-            m_out.constIntPtr(vm().stringStructure.get()));
-    }
-    
-    LValue isNotString(LValue cell)
-    {
-        return isObject(cell);
-    }
-    
-    LValue isString(LValue cell)
-    {
-        return m_out.equal(
-            m_out.loadPtr(cell, m_heaps.JSCell_structure),
-            m_out.constIntPtr(vm().stringStructure.get()));
-    }
-    
-    LValue isNotObject(LValue cell)
-    {
-        return isString(cell);
-    }
-    
-    LValue isArrayType(LValue cell, ArrayMode arrayMode)
-    {
-        switch (arrayMode.type()) {
-        case Array::Int32:
-        case Array::Double:
-        case Array::Contiguous: {
-            LValue indexingType = m_out.load8(
-                m_out.loadPtr(cell, m_heaps.JSCell_structure),
-                m_heaps.Structure_indexingType);
-            
-            switch (arrayMode.arrayClass()) {
-            case Array::OriginalArray:
-                RELEASE_ASSERT_NOT_REACHED();
-                return 0;
-                
-            case Array::Array:
-                return m_out.equal(
-                    m_out.bitAnd(indexingType, m_out.constInt8(IsArray | IndexingShapeMask)),
-                    m_out.constInt8(IsArray | arrayMode.shapeMask()));
-                
-            case Array::NonArray:
-            case Array::OriginalNonArray:
-                return m_out.equal(
-                    m_out.bitAnd(indexingType, m_out.constInt8(IsArray | IndexingShapeMask)),
-                    m_out.constInt8(arrayMode.shapeMask()));
-                
-            case Array::PossiblyArray:
-                return m_out.equal(
-                    m_out.bitAnd(indexingType, m_out.constInt8(IndexingShapeMask)),
-                    m_out.constInt8(arrayMode.shapeMask()));
-            }
-            
-            RELEASE_ASSERT_NOT_REACHED();
-        }
-            
-        default:
-            return hasClassInfo(cell, classInfoForType(arrayMode.typedArrayType()));
-        }
-    }
-    
-    LValue hasClassInfo(LValue cell, const ClassInfo* classInfo)
-    {
-        return m_out.equal(
-            m_out.loadPtr(
-                m_out.loadPtr(cell, m_heaps.JSCell_structure),
-                m_heaps.Structure_classInfo),
-            m_out.constIntPtr(classInfo));
-    }
-    
-    LValue isType(LValue cell, JSType type)
-    {
-        return m_out.equal(
-            m_out.load8(
-                m_out.loadPtr(cell, m_heaps.JSCell_structure),
-                m_heaps.Structure_typeInfoType),
-            m_out.constInt8(type));
-    }
-    
-    LValue isNotType(LValue cell, JSType type)
-    {
-        return m_out.bitNot(isType(cell, type));
-    }
-    
-    void speculateObject(Edge edge, LValue cell)
-    {
-        FTL_TYPE_CHECK(jsValueValue(cell), edge, SpecObject, isNotObject(cell));
-    }
-    
-    void speculateObject(Edge edge)
-    {
-        speculateObject(edge, lowCell(edge));
-    }
-    
-    void speculateObjectOrOther(Edge edge)
-    {
-        if (!m_interpreter.needsTypeCheck(edge))
-            return;
-        
-        LValue value = lowJSValue(edge);
-        
-        LBasicBlock cellCase = FTL_NEW_BLOCK(m_out, ("speculateObjectOrOther cell case"));
-        LBasicBlock primitiveCase = FTL_NEW_BLOCK(m_out, ("speculateObjectOrOther primitive case"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("speculateObjectOrOther continuation"));
-        
-        m_out.branch(isNotCell(value), primitiveCase, cellCase);
-        
-        LBasicBlock lastNext = m_out.appendTo(cellCase, primitiveCase);
-        
-        FTL_TYPE_CHECK(
-            jsValueValue(value), edge, (~SpecCell) | SpecObject,
-            m_out.equal(
-                m_out.loadPtr(value, m_heaps.JSCell_structure),
-                m_out.constIntPtr(vm().stringStructure.get())));
-        
-        m_out.jump(continuation);
-        
-        m_out.appendTo(primitiveCase, continuation);
-        
-        FTL_TYPE_CHECK(
-            jsValueValue(value), edge, SpecCell | SpecOther,
-            m_out.notEqual(
-                m_out.bitAnd(value, m_out.constInt64(~TagBitUndefined)),
-                m_out.constInt64(ValueNull)));
-        
-        m_out.jump(continuation);
-        
-        m_out.appendTo(continuation, lastNext);
-    }
-    
-    void speculateFinalObject(Edge edge, LValue cell)
-    {
-        FTL_TYPE_CHECK(
-            jsValueValue(cell), edge, SpecFinalObject, isNotType(cell, FinalObjectType));
-    }
-    
-    void speculateFinalObject(Edge edge)
-    {
-        speculateFinalObject(edge, lowCell(edge));
-    }
-    
-    void speculateString(Edge edge, LValue cell)
-    {
-        FTL_TYPE_CHECK(jsValueValue(cell), edge, SpecString, isNotString(cell));
-    }
-    
-    void speculateString(Edge edge)
-    {
-        speculateString(edge, lowCell(edge));
-    }
-    
-    void speculateNonNullObject(Edge edge, LValue cell)
-    {
-        LValue structure = m_out.loadPtr(cell, m_heaps.JSCell_structure);
-        FTL_TYPE_CHECK(
-            jsValueValue(cell), edge, SpecObject, 
-            m_out.equal(structure, m_out.constIntPtr(vm().stringStructure.get())));
-        if (masqueradesAsUndefinedWatchpointIsStillValid())
-            return;
-        
-        speculate(
-            BadType, jsValueValue(cell), edge.node(),
-            m_out.testNonZero8(
-                m_out.load8(structure, m_heaps.Structure_typeInfoFlags),
-                m_out.constInt8(MasqueradesAsUndefined)));
-    }
-    
-    void speculateNumber(Edge edge)
-    {
-        // Do an early return here because lowDouble() can create a lot of control flow.
-        if (!m_interpreter.needsTypeCheck(edge))
-            return;
-        
-        lowDouble(edge);
-    }
-    
-    void speculateRealNumber(Edge edge)
-    {
-        // Do an early return here because lowDouble() can create a lot of control flow.
-        if (!m_interpreter.needsTypeCheck(edge))
-            return;
-        
-        LValue value = lowDouble(edge);
-        FTL_TYPE_CHECK(
-            doubleValue(value), edge, SpecFullRealNumber,
-            m_out.doubleNotEqualOrUnordered(value, value));
-    }
-    
-    void speculateMachineInt(Edge edge)
-    {
-        if (!m_interpreter.needsTypeCheck(edge))
-            return;
-        
-        Int52Kind kind;
-        lowWhicheverInt52(edge, kind);
-    }
-    
-    void speculateBoolean(Edge edge)
-    {
-        lowBoolean(edge);
-    }
-    
-    bool masqueradesAsUndefinedWatchpointIsStillValid()
-    {
-        return m_graph.masqueradesAsUndefinedWatchpointIsStillValid(m_node->codeOrigin);
-    }
-    
-    LValue loadMarkByte(LValue base)
-    {
-        LValue markedBlock = m_out.bitAnd(base, m_out.constInt64(MarkedBlock::blockMask));
-        LValue baseOffset = m_out.bitAnd(base, m_out.constInt64(~MarkedBlock::blockMask));
-        LValue markByteIndex = m_out.lShr(baseOffset, m_out.constInt64(MarkedBlock::atomShiftAmount + MarkedBlock::markByteShiftAmount));
-        return m_out.load8(m_out.baseIndex(m_heaps.MarkedBlock_markBits, markedBlock, markByteIndex, ScaleOne, MarkedBlock::offsetOfMarks()));
-    }
-
-    void emitStoreBarrier(LValue base, LValue value, Edge& valueEdge)
-    {
-#if ENABLE(GGC)
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("Store barrier continuation"));
-        LBasicBlock isCell = FTL_NEW_BLOCK(m_out, ("Store barrier is cell block"));
-
-        if (m_state.forNode(valueEdge.node()).couldBeType(SpecCell))
-            m_out.branch(isNotCell(value), continuation, isCell);
-        else
-            m_out.jump(isCell);
-
-        LBasicBlock lastNext = m_out.appendTo(isCell, continuation);
-        emitStoreBarrier(base);
-        m_out.jump(continuation);
-
-        m_out.appendTo(continuation, lastNext);
-#else
-        UNUSED_PARAM(base);
-        UNUSED_PARAM(value);
-        UNUSED_PARAM(valueEdge);
-#endif
-    }
-
-    void emitStoreBarrier(LValue base)
-    {
-#if ENABLE(GGC)
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("Store barrier continuation"));
-        LBasicBlock isMarked = FTL_NEW_BLOCK(m_out, ("Store barrier is marked block"));
-        LBasicBlock bufferHasSpace = FTL_NEW_BLOCK(m_out, ("Store barrier buffer is full"));
-        LBasicBlock bufferIsFull = FTL_NEW_BLOCK(m_out, ("Store barrier buffer is full"));
-
-        // Check the mark byte. 
-        m_out.branch(m_out.isZero8(loadMarkByte(base)), continuation, isMarked);
-
-        // Append to the write barrier buffer.
-        LBasicBlock lastNext = m_out.appendTo(isMarked, bufferHasSpace);
-        LValue currentBufferIndex = m_out.load32(m_out.absolute(&vm().heap.writeBarrierBuffer().m_currentIndex));
-        LValue bufferCapacity = m_out.load32(m_out.absolute(&vm().heap.writeBarrierBuffer().m_capacity));
-        m_out.branch(m_out.lessThan(currentBufferIndex, bufferCapacity), bufferHasSpace, bufferIsFull);
-
-        // Buffer has space, store to it.
-        m_out.appendTo(bufferHasSpace, bufferIsFull);
-        LValue writeBarrierBufferBase = m_out.loadPtr(m_out.absolute(&vm().heap.writeBarrierBuffer().m_buffer));
-        m_out.storePtr(base, m_out.baseIndex(m_heaps.WriteBarrierBuffer_bufferContents, writeBarrierBufferBase, m_out.zeroExt(currentBufferIndex, m_out.intPtr), ScalePtr));
-        m_out.store32(m_out.add(currentBufferIndex, m_out.constInt32(1)), m_out.absolute(&vm().heap.writeBarrierBuffer().m_currentIndex));
-        m_out.jump(continuation);
-
-        // Buffer is out of space, flush it.
-        m_out.appendTo(bufferIsFull, continuation);
-        vmCall(m_out.operation(operationFlushWriteBarrierBuffer), m_callFrame, base);
-        m_out.jump(continuation);
-
-        m_out.appendTo(continuation, lastNext);
-#else
-        UNUSED_PARAM(base);
-#endif
-    }
-
-    enum ExceptionCheckMode { NoExceptions, CheckExceptions };
-    
-    LValue vmCall(LValue function, ExceptionCheckMode mode = CheckExceptions)
-    {
-        callPreflight();
-        LValue result = m_out.call(function);
-        callCheck(mode);
-        return result;
-    }
-    LValue vmCall(LValue function, LValue arg1, ExceptionCheckMode mode = CheckExceptions)
-    {
-        callPreflight();
-        LValue result = m_out.call(function, arg1);
-        callCheck(mode);
-        return result;
-    }
-    LValue vmCall(LValue function, LValue arg1, LValue arg2, ExceptionCheckMode mode = CheckExceptions)
-    {
-        callPreflight();
-        LValue result = m_out.call(function, arg1, arg2);
-        callCheck(mode);
-        return result;
-    }
-    LValue vmCall(LValue function, LValue arg1, LValue arg2, LValue arg3, ExceptionCheckMode mode = CheckExceptions)
-    {
-        callPreflight();
-        LValue result = m_out.call(function, arg1, arg2, arg3);
-        callCheck(mode);
-        return result;
-    }
-    LValue vmCall(LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4, ExceptionCheckMode mode = CheckExceptions)
-    {
-        callPreflight();
-        LValue result = m_out.call(function, arg1, arg2, arg3, arg4);
-        callCheck(mode);
-        return result;
-    }
-    
-    void callPreflight(CodeOrigin codeOrigin)
-    {
-        m_out.store32(
-            m_out.constInt32(
-                CallFrame::Location::encodeAsCodeOriginIndex(
-                    m_ftlState.jitCode->common.addCodeOrigin(codeOrigin))),
-            tagFor(JSStack::ArgumentCount));
-    }
-    void callPreflight()
-    {
-        callPreflight(m_node->codeOrigin);
-    }
-    
-    void callCheck(ExceptionCheckMode mode = CheckExceptions)
-    {
-        if (mode == NoExceptions)
-            return;
-        
-        LBasicBlock didHaveException = FTL_NEW_BLOCK(m_out, ("Did have exception"));
-        LBasicBlock continuation = FTL_NEW_BLOCK(m_out, ("Exception check continuation"));
-        
-        m_out.branch(
-            m_out.notZero64(m_out.load64(m_out.absolute(vm().addressOfException()))),
-            didHaveException, continuation);
-        
-        LBasicBlock lastNext = m_out.appendTo(didHaveException, continuation);
-        // FIXME: Handle exceptions. https://bugs.webkit.org/show_bug.cgi?id=113622
-        m_out.crash();
-        
-        m_out.appendTo(continuation, lastNext);
-    }
-    
-    LBasicBlock lowBlock(BasicBlock* block)
-    {
-        return m_blocks.get(block);
-    }
-    
-    void initializeOSRExitStateForBlock()
-    {
-        m_availability = m_highBlock->ssa->availabilityAtHead;
-    }
-    
-    void appendOSRExit(
-        ExitKind kind, FormattedValue lowValue, Node* highValue, LValue failCondition)
-    {
-        if (verboseCompilationEnabled())
-            dataLog("    OSR exit #", m_ftlState.jitCode->osrExit.size(), " with availability: ", m_availability, "\n");
-
-        ASSERT(m_ftlState.jitCode->osrExit.size() == m_ftlState.finalizer->osrExit.size());
-        
-        m_ftlState.jitCode->osrExit.append(OSRExit(
-            kind, lowValue.format(), m_graph.methodOfGettingAValueProfileFor(highValue),
-            m_codeOriginForExitTarget, m_codeOriginForExitProfile,
-            m_availability.numberOfArguments(), m_availability.numberOfLocals()));
-        m_ftlState.finalizer->osrExit.append(OSRExitCompilationInfo());
-        
-        OSRExit& exit = m_ftlState.jitCode->osrExit.last();
-
-        LBasicBlock lastNext = 0;
-        LBasicBlock continuation = 0;
-        
-        LBasicBlock failCase = FTL_NEW_BLOCK(m_out, ("OSR exit failCase for ", m_node));
-        continuation = FTL_NEW_BLOCK(m_out, ("OSR exit continuation for ", m_node));
-        
-        m_out.branch(failCondition, failCase, continuation);
-        
-        lastNext = m_out.appendTo(failCase, continuation);
-        
-        emitOSRExitCall(exit, lowValue);
-        
-        m_out.unreachable();
-        
-        m_out.appendTo(continuation, lastNext);
-    }
-    
-    void emitOSRExitCall(OSRExit& exit, FormattedValue lowValue)
-    {
-        ExitArgumentList arguments;
-        
-        CodeOrigin codeOrigin = exit.m_codeOrigin;
-        
-        buildExitArguments(exit, arguments, lowValue, codeOrigin);
-        
-        callStackmap(exit, arguments);
-    }
-    
-    void buildExitArguments(
-        OSRExit& exit, ExitArgumentList& arguments, FormattedValue lowValue,
-        CodeOrigin codeOrigin)
-    {
-        arguments.append(m_callFrame);
-        if (!!lowValue)
-            arguments.append(lowValue.value());
-        
-        for (unsigned i = 0; i < exit.m_values.size(); ++i) {
-            int operand = exit.m_values.operandForIndex(i);
-            bool isLive = m_graph.isLiveInBytecode(VirtualRegister(operand), codeOrigin);
-            if (!isLive) {
-                exit.m_values[i] = ExitValue::dead();
-                continue;
-            }
-            
-            Availability availability = m_availability[i];
-            FlushedAt flush = availability.flushedAt();
-            switch (flush.format()) {
-            case DeadFlush:
-            case ConflictingFlush:
-                if (availability.hasNode()) {
-                    addExitArgumentForNode(exit, arguments, i, availability.node());
-                    break;
-                }
-                
-                if (Options::validateFTLOSRExitLiveness()) {
-                    dataLog("Expected r", operand, " to be available but it wasn't.\n");
-                    RELEASE_ASSERT_NOT_REACHED();
-                }
-                
-                // This means that the DFG's DCE proved that the value is dead in bytecode
-                // even though the bytecode liveness analysis thinks it's live. This is
-                // acceptable since the DFG's DCE is by design more aggressive while still
-                // being sound.
-                exit.m_values[i] = ExitValue::dead();
-                break;
-
-            case FlushedJSValue:
-            case FlushedCell:
-            case FlushedBoolean:
-                exit.m_values[i] = ExitValue::inJSStack(flush.virtualRegister());
-                break;
-                
-            case FlushedInt32:
-                exit.m_values[i] = ExitValue::inJSStackAsInt32(flush.virtualRegister());
-                break;
-                
-            case FlushedInt52:
-                exit.m_values[i] = ExitValue::inJSStackAsInt52(flush.virtualRegister());
-                break;
-                
-            case FlushedDouble:
-                exit.m_values[i] = ExitValue::inJSStackAsDouble(flush.virtualRegister());
-                break;
-                
-            case FlushedArguments:
-                // FIXME: implement PhantomArguments.
-                // https://bugs.webkit.org/show_bug.cgi?id=113986
-                RELEASE_ASSERT_NOT_REACHED();
-                break;
-            }
-        }
-        
-        if (verboseCompilationEnabled())
-            dataLog("        Exit values: ", exit.m_values, "\n");
-    }
-    
-    void callStackmap(OSRExit& exit, ExitArgumentList& arguments)
-    {
-        exit.m_stackmapID = m_stackmapIDs++;
-        arguments.insert(0, m_out.constInt32(MacroAssembler::maxJumpReplacementSize()));
-        arguments.insert(0, m_out.constInt32(exit.m_stackmapID));
-        
-        m_out.call(m_out.stackmapIntrinsic(), arguments);
-    }
-    
-    void addExitArgumentForNode(
-        OSRExit& exit, ExitArgumentList& arguments, unsigned index, Node* node)
-    {
-        ASSERT(node->shouldGenerate());
-        ASSERT(node->hasResult());
-
-        if (tryToSetConstantExitArgument(exit, index, node))
-            return;
-        
-        LoweredNodeValue value = m_int32Values.get(node);
-        if (isValid(value)) {
-            addExitArgument(exit, arguments, index, ValueFormatInt32, value.value());
-            return;
-        }
-        
-        value = m_int52Values.get(node);
-        if (isValid(value)) {
-            addExitArgument(exit, arguments, index, ValueFormatInt52, value.value());
-            return;
-        }
-        
-        value = m_strictInt52Values.get(node);
-        if (isValid(value)) {
-            addExitArgument(exit, arguments, index, ValueFormatStrictInt52, value.value());
-            return;
-        }
-        
-        value = m_booleanValues.get(node);
-        if (isValid(value)) {
-            LValue valueToPass = m_out.zeroExt(value.value(), m_out.int32);
-            addExitArgument(exit, arguments, index, ValueFormatBoolean, valueToPass);
-            return;
-        }
-        
-        value = m_jsValueValues.get(node);
-        if (isValid(value)) {
-            addExitArgument(exit, arguments, index, ValueFormatJSValue, value.value());
-            return;
-        }
-        
-        value = m_doubleValues.get(node);
-        if (isValid(value)) {
-            addExitArgument(exit, arguments, index, ValueFormatDouble, value.value());
-            return;
-        }
-
-        dataLog("Cannot find value for node: ", node, "\n");
-        RELEASE_ASSERT_NOT_REACHED();
-    }
-    
-    bool tryToSetConstantExitArgument(OSRExit& exit, unsigned index, Node* node)
-    {
-        if (!node)
-            return false;
-        
-        switch (node->op()) {
-        case JSConstant:
-        case WeakJSConstant:
-            exit.m_values[index] = ExitValue::constant(m_graph.valueOfJSConstant(node));
-            return true;
-        case PhantomArguments:
-            // FIXME: implement PhantomArguments.
-            // https://bugs.webkit.org/show_bug.cgi?id=113986
-            RELEASE_ASSERT_NOT_REACHED();
-            return true;
-        default:
-            return false;
-        }
-    }
-    
-    void addExitArgument(
-        OSRExit& exit, ExitArgumentList& arguments, unsigned index, ValueFormat format,
-        LValue value)
-    {
-        exit.m_values[index] = ExitValue::exitArgument(ExitArgument(format, arguments.size()));
-        arguments.append(value);
-    }
-    
-    void setInt32(Node* node, LValue value)
-    {
-        m_int32Values.set(node, LoweredNodeValue(value, m_highBlock));
-    }
-    void setInt52(Node* node, LValue value)
-    {
-        m_int52Values.set(node, LoweredNodeValue(value, m_highBlock));
-    }
-    void setStrictInt52(Node* node, LValue value)
-    {
-        m_strictInt52Values.set(node, LoweredNodeValue(value, m_highBlock));
-    }
-    void setInt52(Node* node, LValue value, Int52Kind kind)
-    {
-        switch (kind) {
-        case Int52:
-            setInt52(node, value);
-            return;
-            
-        case StrictInt52:
-            setStrictInt52(node, value);
-            return;
-        }
-        
-        RELEASE_ASSERT_NOT_REACHED();
-    }
-    void setJSValue(Node* node, LValue value)
-    {
-        m_jsValueValues.set(node, LoweredNodeValue(value, m_highBlock));
-    }
-    void setBoolean(Node* node, LValue value)
-    {
-        m_booleanValues.set(node, LoweredNodeValue(value, m_highBlock));
-    }
-    void setStorage(Node* node, LValue value)
-    {
-        m_storageValues.set(node, LoweredNodeValue(value, m_highBlock));
-    }
-    void setDouble(Node* node, LValue value)
-    {
-        m_doubleValues.set(node, LoweredNodeValue(value, m_highBlock));
-    }
-
-    void setInt32(LValue value)
-    {
-        setInt32(m_node, value);
-    }
-    void setInt52(LValue value)
-    {
-        setInt52(m_node, value);
-    }
-    void setStrictInt52(LValue value)
-    {
-        setStrictInt52(m_node, value);
-    }
-    void setInt52(LValue value, Int52Kind kind)
-    {
-        setInt52(m_node, value, kind);
-    }
-    void setJSValue(LValue value)
-    {
-        setJSValue(m_node, value);
-    }
-    void setBoolean(LValue value)
-    {
-        setBoolean(m_node, value);
-    }
-    void setStorage(LValue value)
-    {
-        setStorage(m_node, value);
-    }
-    void setDouble(LValue value)
-    {
-        setDouble(m_node, value);
-    }
-    
-    bool isValid(const LoweredNodeValue& value)
-    {
-        if (!value)
-            return false;
-        if (!m_graph.m_dominators.dominates(value.block(), m_highBlock))
-            return false;
-        return true;
-    }
-    
-    void addWeakReference(JSCell* target)
-    {
-        m_graph.m_plan.weakReferences.addLazily(target);
-    }
-    
-    LValue weakPointer(JSCell* pointer)
-    {
-        addWeakReference(pointer);
-        return m_out.constIntPtr(pointer);
-    }
-    
-    TypedPointer addressFor(LValue base, int operand, ptrdiff_t offset = 0)
-    {
-        return m_out.address(base, m_heaps.variables[operand], offset);
-    }
-    TypedPointer payloadFor(LValue base, int operand)
-    {
-        return addressFor(base, operand, OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.payload));
-    }
-    TypedPointer tagFor(LValue base, int operand)
-    {
-        return addressFor(base, operand, OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.tag));
-    }
-    TypedPointer addressFor(int operand)
-    {
-        return addressFor(m_callFrame, operand);
-    }
-    TypedPointer addressFor(VirtualRegister operand)
-    {
-        return addressFor(m_callFrame, operand.offset());
-    }
-    TypedPointer payloadFor(int operand)
-    {
-        return payloadFor(m_callFrame, operand);
-    }
-    TypedPointer payloadFor(VirtualRegister operand)
-    {
-        return payloadFor(m_callFrame, operand.offset());
-    }
-    TypedPointer tagFor(int operand)
-    {
-        return tagFor(m_callFrame, operand);
-    }
-    TypedPointer tagFor(VirtualRegister operand)
-    {
-        return tagFor(m_callFrame, operand.offset());
-    }
-    
-    VM& vm() { return m_graph.m_vm; }
-    CodeBlock* codeBlock() { return m_graph.m_codeBlock; }
-    
-    Graph& m_graph;
-    State& m_ftlState;
-    AbstractHeapRepository m_heaps;
-    Output m_out;
-    
-    LBasicBlock m_prologue;
-    HashMap<BasicBlock*, LBasicBlock> m_blocks;
-    
-    LValue m_callFrame;
-    LValue m_tagTypeNumber;
-    LValue m_tagMask;
-    
-    HashMap<Node*, LoweredNodeValue> m_int32Values;
-    HashMap<Node*, LoweredNodeValue> m_strictInt52Values;
-    HashMap<Node*, LoweredNodeValue> m_int52Values;
-    HashMap<Node*, LoweredNodeValue> m_jsValueValues;
-    HashMap<Node*, LoweredNodeValue> m_booleanValues;
-    HashMap<Node*, LoweredNodeValue> m_storageValues;
-    HashMap<Node*, LoweredNodeValue> m_doubleValues;
-    
-    HashMap<Node*, LValue> m_phis;
-    
-    Operands<Availability> m_availability;
-    
-    InPlaceAbstractState m_state;
-    AbstractInterpreter<InPlaceAbstractState> m_interpreter;
-    BasicBlock* m_highBlock;
-    BasicBlock* m_nextHighBlock;
-    LBasicBlock m_nextLowBlock;
-    
-    CodeOrigin m_codeOriginForExitTarget;
-    CodeOrigin m_codeOriginForExitProfile;
-    unsigned m_nodeIndex;
-    Node* m_node;
-    
-    uint32_t m_stackmapIDs;
-};
-
-void lowerDFGToLLVM(State& state)
-{
-    LowerDFGToLLVM lowering(state);
-    lowering.lower();
-}
-
-} } // namespace JSC::FTL
-
-#endif // ENABLE(FTL_JIT)
-
diff --git a/Source/JavaScriptCore/ftl/FTLLoweredNodeValue.h b/Source/JavaScriptCore/ftl/FTLLoweredNodeValue.h
index 93e6c4d09..059667b7f 100644
--- a/Source/JavaScriptCore/ftl/FTLLoweredNodeValue.h
+++ b/Source/JavaScriptCore/ftl/FTLLoweredNodeValue.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLLoweredNodeValue_h
-#define FTLLoweredNodeValue_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -73,6 +70,3 @@ private:
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLLoweredNodeValue_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLOSREntry.cpp b/Source/JavaScriptCore/ftl/FTLOSREntry.cpp
index 185046054..9a391e34b 100644
--- a/Source/JavaScriptCore/ftl/FTLOSREntry.cpp
+++ b/Source/JavaScriptCore/ftl/FTLOSREntry.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2014, 2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -30,19 +30,22 @@
 #include "CodeBlock.h"
 #include "DFGJITCode.h"
 #include "FTLForOSREntryJITCode.h"
-#include "JSStackInlines.h"
 #include "OperandsInlines.h"
+#include "JSCInlines.h"
+#include "VMInlines.h"
 
 #if ENABLE(FTL_JIT)
 
 namespace JSC { namespace FTL {
 
+SUPPRESS_ASAN
 void* prepareOSREntry(
     ExecState* exec, CodeBlock* dfgCodeBlock, CodeBlock* entryCodeBlock,
     unsigned bytecodeIndex, unsigned streamIndex)
 {
     VM& vm = exec->vm();
     CodeBlock* baseline = dfgCodeBlock->baselineVersion();
+    ExecutableBase* executable = dfgCodeBlock->ownerExecutable();
     DFG::JITCode* dfgCode = dfgCodeBlock->jitCode()->dfg();
     ForOSREntryJITCode* entryCode = entryCodeBlock->jitCode()->ftlForOSREntry();
     
@@ -52,9 +55,12 @@ void* prepareOSREntry(
             bytecodeIndex, ".\n");
     }
     
+    if (bytecodeIndex)
+        jsCast<ScriptExecutable*>(executable)->setDidTryToEnterInLoop(true);
+
     if (bytecodeIndex != entryCode->bytecodeIndex()) {
         if (Options::verboseOSR())
-            dataLog("    OSR failed because we don't have an entrypoint for bc#", bytecodeIndex, "; ours is for bc#", entryCode->bytecodeIndex());
+            dataLog("    OSR failed because we don't have an entrypoint for bc#", bytecodeIndex, "; ours is for bc#", entryCode->bytecodeIndex(), "\n");
         return 0;
     }
     
@@ -66,12 +72,18 @@ void* prepareOSREntry(
         dataLog("    Values at entry: ", values, "\n");
     
     for (int argument = values.numberOfArguments(); argument--;) {
-        RELEASE_ASSERT(
-            exec->r(virtualRegisterForArgument(argument).offset()).jsValue() == values.argument(argument));
+        JSValue valueOnStack = exec->r(virtualRegisterForArgument(argument).offset()).asanUnsafeJSValue();
+        JSValue reconstructedValue = values.argument(argument);
+        if (valueOnStack == reconstructedValue || !argument)
+            continue;
+        dataLog("Mismatch between reconstructed values and the the value on the stack for argument arg", argument, " for ", *entryCodeBlock, " at bc#", bytecodeIndex, ":\n");
+        dataLog("    Value on stack: ", valueOnStack, "\n");
+        dataLog("    Reconstructed value: ", reconstructedValue, "\n");
+        RELEASE_ASSERT_NOT_REACHED();
     }
     
     RELEASE_ASSERT(
-        static_cast<int>(values.numberOfLocals()) == baseline->m_numCalleeRegisters);
+        static_cast<int>(values.numberOfLocals()) == baseline->m_numCalleeLocals);
     
     EncodedJSValue* scratch = static_cast<EncodedJSValue*>(
         entryCode->entryBuffer()->dataBuffer());
@@ -80,7 +92,7 @@ void* prepareOSREntry(
         scratch[local] = JSValue::encode(values.local(local));
     
     int stackFrameSize = entryCode->common.requiredRegisterCountForExecutionAndExit();
-    if (!vm.interpreter->stack().grow(&exec->registers()[virtualRegisterForLocal(stackFrameSize).offset()])) {
+    if (UNLIKELY(!vm.ensureStackCapacityFor(&exec->registers()[virtualRegisterForLocal(stackFrameSize - 1).offset()]))) {
         if (Options::verboseOSR())
             dataLog("    OSR failed because stack growth failed.\n");
         return 0;
@@ -88,7 +100,7 @@ void* prepareOSREntry(
     
     exec->setCodeBlock(entryCodeBlock);
     
-    void* result = entryCode->addressForCall().executableAddress();
+    void* result = entryCode->addressForCall(ArityCheckNotRequired).executableAddress();
     if (Options::verboseOSR())
         dataLog("    Entry will succeed, going to address", RawPointer(result), "\n");
     
diff --git a/Source/JavaScriptCore/ftl/FTLOSREntry.h b/Source/JavaScriptCore/ftl/FTLOSREntry.h
index d19f10e74..439c4c20a 100644
--- a/Source/JavaScriptCore/ftl/FTLOSREntry.h
+++ b/Source/JavaScriptCore/ftl/FTLOSREntry.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLOSREntry_h
-#define FTLOSREntry_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -44,6 +41,3 @@ void* prepareOSREntry(
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLOSREntry_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLOSRExit.cpp b/Source/JavaScriptCore/ftl/FTLOSRExit.cpp
index 00ea014cb..d7b7838d7 100644
--- a/Source/JavaScriptCore/ftl/FTLOSRExit.cpp
+++ b/Source/JavaScriptCore/ftl/FTLOSRExit.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -28,37 +28,90 @@
 
 #if ENABLE(FTL_JIT)
 
+#include "AirGenerationContext.h"
+#include "B3StackmapGenerationParams.h"
+#include "B3StackmapValue.h"
 #include "CodeBlock.h"
 #include "DFGBasicBlock.h"
 #include "DFGNode.h"
 #include "FTLExitArgument.h"
-#include "FTLExitArgumentList.h"
 #include "FTLJITCode.h"
-#include "Operations.h"
+#include "FTLLocation.h"
+#include "FTLState.h"
+#include "JSCInlines.h"
 
 namespace JSC { namespace FTL {
 
+using namespace B3;
 using namespace DFG;
 
-OSRExit::OSRExit(
-    ExitKind exitKind, ValueFormat profileValueFormat,
-    MethodOfGettingAValueProfile valueProfile, CodeOrigin codeOrigin,
-    CodeOrigin originForProfile, unsigned numberOfArguments,
-    unsigned numberOfLocals)
-    : OSRExitBase(exitKind, codeOrigin, originForProfile)
-    , m_profileValueFormat(profileValueFormat)
+OSRExitDescriptor::OSRExitDescriptor(
+    DataFormat profileDataFormat, MethodOfGettingAValueProfile valueProfile,
+    unsigned numberOfArguments, unsigned numberOfLocals)
+    : m_profileDataFormat(profileDataFormat)
     , m_valueProfile(valueProfile)
-    , m_patchableCodeOffset(0)
     , m_values(numberOfArguments, numberOfLocals)
 {
 }
 
+void OSRExitDescriptor::validateReferences(const TrackedReferences& trackedReferences)
+{
+    for (unsigned i = m_values.size(); i--;)
+        m_values[i].validateReferences(trackedReferences);
+    
+    for (ExitTimeObjectMaterialization* materialization : m_materializations)
+        materialization->validateReferences(trackedReferences);
+}
+
+RefPtr<OSRExitHandle> OSRExitDescriptor::emitOSRExit(
+    State& state, ExitKind exitKind, const NodeOrigin& nodeOrigin, CCallHelpers& jit,
+    const StackmapGenerationParams& params, unsigned offset)
+{
+    RefPtr<OSRExitHandle> handle =
+        prepareOSRExitHandle(state, exitKind, nodeOrigin, params, offset);
+    handle->emitExitThunk(state, jit);
+    return handle;
+}
+
+RefPtr<OSRExitHandle> OSRExitDescriptor::emitOSRExitLater(
+    State& state, ExitKind exitKind, const NodeOrigin& nodeOrigin,
+    const StackmapGenerationParams& params, unsigned offset)
+{
+    RefPtr<OSRExitHandle> handle =
+        prepareOSRExitHandle(state, exitKind, nodeOrigin, params, offset);
+    params.addLatePath(
+        [handle, &state] (CCallHelpers& jit) {
+            handle->emitExitThunk(state, jit);
+        });
+    return handle;
+}
+
+RefPtr<OSRExitHandle> OSRExitDescriptor::prepareOSRExitHandle(
+    State& state, ExitKind exitKind, const NodeOrigin& nodeOrigin,
+    const StackmapGenerationParams& params, unsigned offset)
+{
+    unsigned index = state.jitCode->osrExit.size();
+    OSRExit& exit = state.jitCode->osrExit.alloc(
+        this, exitKind, nodeOrigin.forExit, nodeOrigin.semantic, nodeOrigin.wasHoisted);
+    RefPtr<OSRExitHandle> handle = adoptRef(new OSRExitHandle(index, exit));
+    for (unsigned i = offset; i < params.size(); ++i)
+        exit.m_valueReps.append(params[i]);
+    exit.m_valueReps.shrinkToFit();
+    return handle;
+}
+
+OSRExit::OSRExit(
+    OSRExitDescriptor* descriptor, ExitKind exitKind, CodeOrigin codeOrigin,
+    CodeOrigin codeOriginForExitProfile, bool wasHoisted)
+    : OSRExitBase(exitKind, codeOrigin, codeOriginForExitProfile, wasHoisted)
+    , m_descriptor(descriptor)
+{
+}
+
 CodeLocationJump OSRExit::codeLocationForRepatch(CodeBlock* ftlCodeBlock) const
 {
-    return CodeLocationJump(
-        reinterpret_cast<char*>(
-            ftlCodeBlock->jitCode()->ftl()->exitThunks().dataLocation()) +
-        m_patchableCodeOffset);
+    UNUSED_PARAM(ftlCodeBlock);
+    return m_patchableJump;
 }
 
 } } // namespace JSC::FTL
diff --git a/Source/JavaScriptCore/ftl/FTLOSRExit.h b/Source/JavaScriptCore/ftl/FTLOSRExit.h
index 4e479ebdd..d17909b0a 100644
--- a/Source/JavaScriptCore/ftl/FTLOSRExit.h
+++ b/Source/JavaScriptCore/ftl/FTLOSRExit.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,154 +23,114 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLOSRExit_h
-#define FTLOSRExit_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
+#include "B3ValueRep.h"
 #include "CodeOrigin.h"
 #include "DFGExitProfile.h"
+#include "DFGNodeOrigin.h"
 #include "DFGOSRExitBase.h"
-#include "FTLAbbreviations.h"
-#include "FTLExitArgumentList.h"
+#include "FTLAbbreviatedTypes.h"
+#include "FTLExitTimeObjectMaterialization.h"
 #include "FTLExitValue.h"
 #include "FTLFormattedValue.h"
+#include "FTLOSRExitHandle.h"
+#include "FTLStackmapArgumentList.h"
+#include "HandlerInfo.h"
 #include "MethodOfGettingAValueProfile.h"
 #include "Operands.h"
+#include "Reg.h"
 #include "ValueProfile.h"
 #include "VirtualRegister.h"
 
-namespace JSC { namespace FTL {
-
-// Tracks one OSR exit site within the FTL JIT. OSR exit in FTL works by deconstructing
-// the crazy that is OSR down to simple SSA CFG primitives that any compiler backend
-// (including of course LLVM) can grok and do meaningful things to. Except for
-// watchpoint-based exits, which haven't yet been implemented (see webkit.org/b/113647),
-// an exit is just a conditional branch in the emitted code where one destination is the
-// continuation and the other is a basic block that performs a no-return tail-call to an
-// exit thunk. This thunk takes as its arguments the live non-constant
-// not-already-accounted-for bytecode state. To appreciate how this works consider the
-// following JavaScript program, and its lowering down to LLVM IR including the relevant
-// exits:
-//
-// function foo(o) {
-//     var a = o.a; // predicted int
-//     var b = o.b;
-//     var c = o.c; // NB this is dead
-//     a = a | 5; // our example OSR exit: need to check if a is an int
-//     return a + b;
-// }
-//
-// Just consider the "a | 5". In the DFG IR, this looks like:
-//
-// BitOr(Check:Int32:@a, Int32:5)
-//
-// Where @a is the node for the GetLocal node that gets the value of the 'a' variable.
-// Conceptually, this node can be further broken down to the following (note that this
-// particular lowering never actually happens - we skip this step and go straight to
-// LLVM IR - but it's still useful to see this):
-//
-// exitIf(@a is not int32);
-// continuation;
-//
-// Where 'exitIf()' is a function that will exit if the argument is true, and
-// 'continuation' is the stuff that we will do after the exitIf() check. (Note that
-// FTL refers to 'exitIf()' as 'speculate()', which is in line with DFG terminology.)
-// This then gets broken down to the following LLVM IR, assuming that %0 is the LLVM
-// value corresponding to variable 'a', and %1 is the LLVM value for variable 'b':
-//
-//   %2 = ... // the predictate corresponding to '@a is not int32'
-//   br i1 %2, label %3, label %4
-// ; <label>:3
-//   call void exitThunk1(%0, %1) // pass 'a' and 'b', since they're both live-in-bytecode
-//   unreachable
-// ; <label>:4
-//   ... // code for the continuation
-//
-// Where 'exitThunk1' is the IR to get the exit thunk for *this* OSR exit. Each OSR
-// exit will appear to LLVM to have a distinct exit thunk.
-//
-// Note that this didn't have to pass '5', 'o', or 'c' to the exit thunk. 5 is a
-// constant and the DFG already knows that, and can already tell the OSR exit machinery
-// what that contant is and which bytecode variables (if any) it needs to be dropped
-// into. This is conveyed to the exit statically, via the OSRExit data structure below.
-// See the code for ExitValue for details. 'o' is an argument, and arguments are always
-// "flushed" - if you never assign them then their values are still in the argument
-// stack slots, and if you do assign them then we eagerly store them into those slots.
-// 'c' is dead in bytecode, and the DFG knows this; we statically tell the exit thunk
-// that it's dead and don't have to pass anything. The exit thunk will "initialize" its
-// value to Undefined.
-//
-// This approach to OSR exit has a number of virtues:
-//
-// - It is an entirely unsurprising representation for a compiler that already groks
-//   CFG-like IRs for C-like languages. All existing analyses and transformations just
-//   work.
-//
-// - It lends itself naturally to modern approaches to code motion. For example, you
-//   could sink operations from above the exit to below it, if you just duplicate the
-//   operation into the OSR exit block. This is both legal and desirable. It works
-//   because the backend sees the OSR exit block as being no different than any other,
-//   and LLVM already supports sinking if it sees that a value is only partially used.
-//   Hence there exists a value that dominates the exit but is only used by the exit
-//   thunk and not by the continuation, sinking ought to kick in for that value.
-//   Hoisting operations from below it to above it is also possible, for similar
-//   reasons.
-//
-// - The no-return tail-call to the OSR exit thunk can be subjected to specialized
-//   code-size reduction optimizations, though this is optional. For example, instead
-//   of actually emitting a call along with all that goes with it (like placing the
-//   arguments into argument position), the backend could choose to simply inform us
-//   where it had placed the arguments and expect the callee (i.e. the exit thunk) to
-//   figure it out from there. It could also tell us what we need to do to pop stack,
-//   although again, it doesn't have to; it could just emit that code normally. Though
-//   we don't support this yet, we could; the only thing that would change on our end
-//   is that we'd need feedback from the backend about the location of the arguments
-//   and a description of the things that need to be done to pop stack. This would
-//   involve switching the m_values array to use something more akin to ValueRecovery
-//   rather than the current ExitValue, albeit possibly with some hacks to better
-//   understand the kinds of places where the LLVM backend would put values.
-//
-// - It could be extended to allow the backend to do its own exit hoisting, by using
-//   intrinsics (or meta-data, or something) to inform the backend that it's safe to
-//   make the predicate passed to 'exitIf()' more truthy.
-//
-// - It could be extended to support watchpoints (see webkit.org/b/113647) by making
-//   the predicate passed to 'exitIf()' be an intrinsic that the backend knows to be
-//   true at compile-time. The backend could then turn the conditional branch into a
-//   replaceable jump, much like the DFG does.
+namespace JSC {
 
-struct OSRExit : public DFG::OSRExitBase {
-    OSRExit(
-        ExitKind, ValueFormat profileValueFormat, MethodOfGettingAValueProfile,
-        CodeOrigin, CodeOrigin originForProfile,
+class TrackedReferences;
+
+namespace B3 {
+class StackmapGenerationParams;
+namespace Air {
+struct GenerationContext;
+} // namespace Air
+} // namespace B3
+
+namespace DFG {
+struct NodeOrigin;
+} // namespace DFG;
+
+namespace FTL {
+
+class State;
+struct OSRExitDescriptorImpl;
+struct OSRExitHandle;
+
+struct OSRExitDescriptor {
+    OSRExitDescriptor(
+        DataFormat profileDataFormat, MethodOfGettingAValueProfile,
         unsigned numberOfArguments, unsigned numberOfLocals);
-    
-    MacroAssemblerCodeRef m_code;
-    
+
     // The first argument to the exit call may be a value we wish to profile.
     // If that's the case, the format will be not Invalid and we'll have a
     // method of getting a value profile. Note that all of the ExitArgument's
     // are already aware of this possible off-by-one, so there is no need to
     // correct them.
-    ValueFormat m_profileValueFormat;
+    DataFormat m_profileDataFormat;
     MethodOfGettingAValueProfile m_valueProfile;
     
-    // Offset within the exit stubs of the stub for this exit.
-    unsigned m_patchableCodeOffset;
-    
     Operands<ExitValue> m_values;
-    
-    uint32_t m_stackmapID;
-    
+    Bag<ExitTimeObjectMaterialization> m_materializations;
+
+    void validateReferences(const TrackedReferences&);
+
+    // Call this once we have a place to emit the OSR exit jump and we have data about how the state
+    // should be recovered. This effectively emits code that does the exit, though the code is really a
+    // patchable jump and we emit the real code lazily. The description of how to emit the real code is
+    // up to the OSRExit object, which this creates. Note that it's OK to drop the OSRExitHandle object
+    // on the ground. It contains information that is mostly not useful if you use this API, since after
+    // this call, the OSRExit is simply ready to go.
+    RefPtr<OSRExitHandle> emitOSRExit(
+        State&, ExitKind, const DFG::NodeOrigin&, CCallHelpers&, const B3::StackmapGenerationParams&,
+        unsigned offset = 0);
+
+    // In some cases you want an OSRExit to come into existence, but you don't want to emit it right now.
+    // This will emit the OSR exit in a late path. You can't be sure exactly when that will happen, but
+    // you know that it will be done by the time late path emission is done. So, a linker task will
+    // surely happen after that. You can use the OSRExitHandle to retrieve the exit's label.
+    //
+    // This API is meant to be used for things like exception handling, where some patchpoint wants to
+    // have a place to jump to for OSR exit. It doesn't care where that OSR exit is emitted so long as it
+    // eventually gets access to its label.
+    RefPtr<OSRExitHandle> emitOSRExitLater(
+        State&, ExitKind, const DFG::NodeOrigin&, const B3::StackmapGenerationParams&,
+        unsigned offset = 0);
+
+private:
+    // This is the low-level interface. It will create a handle representing the desire to emit code for
+    // an OSR exit. You can call OSRExitHandle::emitExitThunk() once you have a place to emit it. Note
+    // that the above two APIs are written in terms of this and OSRExitHandle::emitExitThunk().
+    RefPtr<OSRExitHandle> prepareOSRExitHandle(
+        State&, ExitKind, const DFG::NodeOrigin&, const B3::StackmapGenerationParams&,
+        unsigned offset = 0);
+};
+
+struct OSRExit : public DFG::OSRExitBase {
+    OSRExit(OSRExitDescriptor*, ExitKind, CodeOrigin, CodeOrigin codeOriginForExitProfile, bool wasHoisted);
+
+    OSRExitDescriptor* m_descriptor;
+    MacroAssemblerCodeRef m_code;
+    // This tells us where to place a jump.
+    CodeLocationJump m_patchableJump;
+    Vector<B3::ValueRep> m_valueReps;
+
     CodeLocationJump codeLocationForRepatch(CodeBlock* ftlCodeBlock) const;
+    void considerAddingAsFrequentExitSite(CodeBlock* profiledCodeBlock)
+    {
+        OSRExitBase::considerAddingAsFrequentExitSite(profiledCodeBlock, ExitFromFTL);
+    }
 };
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLOSRExit_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLOSRExitCompiler.cpp b/Source/JavaScriptCore/ftl/FTLOSRExitCompiler.cpp
index 076a495ea..9919e71d7 100644
--- a/Source/JavaScriptCore/ftl/FTLOSRExitCompiler.cpp
+++ b/Source/JavaScriptCore/ftl/FTLOSRExitCompiler.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -32,155 +32,513 @@
 #include "DFGOSRExitPreparation.h"
 #include "FTLExitArgumentForOperand.h"
 #include "FTLJITCode.h"
+#include "FTLLocation.h"
 #include "FTLOSRExit.h"
+#include "FTLOperations.h"
+#include "FTLState.h"
 #include "FTLSaveRestore.h"
+#include "LinkBuffer.h"
+#include "MaxFrameExtentForSlowPathCall.h"
 #include "OperandsInlines.h"
-#include "Operations.h"
-#include "RepatchBuffer.h"
+#include "JSCInlines.h"
 
 namespace JSC { namespace FTL {
 
 using namespace DFG;
 
-static void compileStub(
-    unsigned exitID, JITCode* jitCode, OSRExit& exit, VM* vm, CodeBlock* codeBlock)
+static void reboxAccordingToFormat(
+    DataFormat format, AssemblyHelpers& jit, GPRReg value, GPRReg scratch1, GPRReg scratch2)
 {
-    StackMaps::Record* record;
-    
-    for (unsigned i = jitCode->stackmaps.records.size(); i--;) {
-        record = &jitCode->stackmaps.records[i];
-        if (record->patchpointID == exit.m_stackmapID)
+    switch (format) {
+    case DataFormatInt32: {
+        jit.zeroExtend32ToPtr(value, value);
+        jit.or64(GPRInfo::tagTypeNumberRegister, value);
+        break;
+    }
+
+    case DataFormatInt52: {
+        jit.rshift64(AssemblyHelpers::TrustedImm32(JSValue::int52ShiftAmount), value);
+        jit.moveDoubleTo64(FPRInfo::fpRegT0, scratch2);
+        jit.boxInt52(value, value, scratch1, FPRInfo::fpRegT0);
+        jit.move64ToDouble(scratch2, FPRInfo::fpRegT0);
+        break;
+    }
+
+    case DataFormatStrictInt52: {
+        jit.moveDoubleTo64(FPRInfo::fpRegT0, scratch2);
+        jit.boxInt52(value, value, scratch1, FPRInfo::fpRegT0);
+        jit.move64ToDouble(scratch2, FPRInfo::fpRegT0);
+        break;
+    }
+
+    case DataFormatBoolean: {
+        jit.zeroExtend32ToPtr(value, value);
+        jit.or32(MacroAssembler::TrustedImm32(ValueFalse), value);
+        break;
+    }
+
+    case DataFormatJS: {
+        // Done already!
+        break;
+    }
+
+    case DataFormatDouble: {
+        jit.moveDoubleTo64(FPRInfo::fpRegT0, scratch1);
+        jit.move64ToDouble(value, FPRInfo::fpRegT0);
+        jit.purifyNaN(FPRInfo::fpRegT0);
+        jit.boxDouble(FPRInfo::fpRegT0, value);
+        jit.move64ToDouble(scratch1, FPRInfo::fpRegT0);
+        break;
+    }
+
+    default:
+        RELEASE_ASSERT_NOT_REACHED();
+        break;
+    }
+}
+
+static void compileRecovery(
+    CCallHelpers& jit, const ExitValue& value,
+    Vector<B3::ValueRep>& valueReps,
+    char* registerScratch,
+    const HashMap<ExitTimeObjectMaterialization*, EncodedJSValue*>& materializationToPointer)
+{
+    switch (value.kind()) {
+    case ExitValueDead:
+        jit.move(MacroAssembler::TrustedImm64(JSValue::encode(jsUndefined())), GPRInfo::regT0);
+        break;
+            
+    case ExitValueConstant:
+        jit.move(MacroAssembler::TrustedImm64(JSValue::encode(value.constant())), GPRInfo::regT0);
+        break;
+            
+    case ExitValueArgument:
+        Location::forValueRep(valueReps[value.exitArgument().argument()]).restoreInto(
+            jit, registerScratch, GPRInfo::regT0);
+        break;
+            
+    case ExitValueInJSStack:
+    case ExitValueInJSStackAsInt32:
+    case ExitValueInJSStackAsInt52:
+    case ExitValueInJSStackAsDouble:
+        jit.load64(AssemblyHelpers::addressFor(value.virtualRegister()), GPRInfo::regT0);
+        break;
+            
+    case ExitValueRecovery:
+        Location::forValueRep(valueReps[value.rightRecoveryArgument()]).restoreInto(
+            jit, registerScratch, GPRInfo::regT1);
+        Location::forValueRep(valueReps[value.leftRecoveryArgument()]).restoreInto(
+            jit, registerScratch, GPRInfo::regT0);
+        switch (value.recoveryOpcode()) {
+        case AddRecovery:
+            switch (value.recoveryFormat()) {
+            case DataFormatInt32:
+                jit.add32(GPRInfo::regT1, GPRInfo::regT0);
+                break;
+            case DataFormatInt52:
+                jit.add64(GPRInfo::regT1, GPRInfo::regT0);
+                break;
+            default:
+                RELEASE_ASSERT_NOT_REACHED();
+                break;
+            }
             break;
+        case SubRecovery:
+            switch (value.recoveryFormat()) {
+            case DataFormatInt32:
+                jit.sub32(GPRInfo::regT1, GPRInfo::regT0);
+                break;
+            case DataFormatInt52:
+                jit.sub64(GPRInfo::regT1, GPRInfo::regT0);
+                break;
+            default:
+                RELEASE_ASSERT_NOT_REACHED();
+                break;
+            }
+            break;
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+            break;
+        }
+        break;
+        
+    case ExitValueMaterializeNewObject:
+        jit.loadPtr(materializationToPointer.get(value.objectMaterialization()), GPRInfo::regT0);
+        break;
+            
+    default:
+        RELEASE_ASSERT_NOT_REACHED();
+        break;
     }
-    
-    RELEASE_ASSERT(record->patchpointID == exit.m_stackmapID);
-    
+        
+    reboxAccordingToFormat(
+        value.dataFormat(), jit, GPRInfo::regT0, GPRInfo::regT1, GPRInfo::regT2);
+}
+
+static void compileStub(
+    unsigned exitID, JITCode* jitCode, OSRExit& exit, VM* vm, CodeBlock* codeBlock)
+{
     // This code requires framePointerRegister is the same as callFrameRegister
     static_assert(MacroAssembler::framePointerRegister == GPRInfo::callFrameRegister, "MacroAssembler::framePointerRegister and GPRInfo::callFrameRegister must be the same");
 
     CCallHelpers jit(vm, codeBlock);
+
+    // The first thing we need to do is restablish our frame in the case of an exception.
+    if (exit.isGenericUnwindHandler()) {
+        RELEASE_ASSERT(vm->callFrameForCatch); // The first time we hit this exit, like at all other times, this field should be non-null.
+        jit.restoreCalleeSavesFromVMEntryFrameCalleeSavesBuffer();
+        jit.loadPtr(vm->addressOfCallFrameForCatch(), MacroAssembler::framePointerRegister);
+        jit.addPtr(CCallHelpers::TrustedImm32(codeBlock->stackPointerOffset() * sizeof(Register)),
+            MacroAssembler::framePointerRegister, CCallHelpers::stackPointerRegister);
+
+        // Do a pushToSave because that's what the exit compiler below expects the stack
+        // to look like because that's the last thing the ExitThunkGenerator does. The code
+        // below doesn't actually use the value that was pushed, but it does rely on the
+        // general shape of the stack being as it is in the non-exception OSR case.
+        jit.pushToSaveImmediateWithoutTouchingRegisters(CCallHelpers::TrustedImm32(0xbadbeef));
+    }
+
+    // We need scratch space to save all registers, to build up the JS stack, to deal with unwind
+    // fixup, pointers to all of the objects we materialize, and the elements inside those objects
+    // that we materialize.
+    
+    // Figure out how much space we need for those object allocations.
+    unsigned numMaterializations = 0;
+    size_t maxMaterializationNumArguments = 0;
+    for (ExitTimeObjectMaterialization* materialization : exit.m_descriptor->m_materializations) {
+        numMaterializations++;
+        
+        maxMaterializationNumArguments = std::max(
+            maxMaterializationNumArguments,
+            materialization->properties().size());
+    }
     
-    // We need scratch space to save all registers and to build up the JSStack.
-    // Use a scratch buffer to transfer all values.
-    ScratchBuffer* scratchBuffer = vm->scratchBufferForSize(sizeof(EncodedJSValue) * exit.m_values.size() + requiredScratchMemorySizeInBytes());
+    ScratchBuffer* scratchBuffer = vm->scratchBufferForSize(
+        sizeof(EncodedJSValue) * (
+            exit.m_descriptor->m_values.size() + numMaterializations + maxMaterializationNumArguments) +
+        requiredScratchMemorySizeInBytes() +
+        codeBlock->calleeSaveRegisters()->size() * sizeof(uint64_t));
     EncodedJSValue* scratch = scratchBuffer ? static_cast<EncodedJSValue*>(scratchBuffer->dataBuffer()) : 0;
-    char* registerScratch = bitwise_cast<char*>(scratch + exit.m_values.size());
+    EncodedJSValue* materializationPointers = scratch + exit.m_descriptor->m_values.size();
+    EncodedJSValue* materializationArguments = materializationPointers + numMaterializations;
+    char* registerScratch = bitwise_cast<char*>(materializationArguments + maxMaterializationNumArguments);
+    uint64_t* unwindScratch = bitwise_cast<uint64_t*>(registerScratch + requiredScratchMemorySizeInBytes());
+    
+    HashMap<ExitTimeObjectMaterialization*, EncodedJSValue*> materializationToPointer;
+    unsigned materializationCount = 0;
+    for (ExitTimeObjectMaterialization* materialization : exit.m_descriptor->m_materializations) {
+        materializationToPointer.add(
+            materialization, materializationPointers + materializationCount++);
+    }
+
+    auto recoverValue = [&] (const ExitValue& value) {
+        compileRecovery(
+            jit, value,
+            exit.m_valueReps,
+            registerScratch, materializationToPointer);
+    };
     
-    // Make sure that saveAllRegisters() has a place on top of the stack to spill things. That
-    // function expects to be able to use top of stack for scratch memory.
-    jit.push(GPRInfo::regT0);
+    // Note that we come in here, the stack used to be as B3 left it except that someone called pushToSave().
+    // We don't care about the value they saved. But, we do appreciate the fact that they did it, because we use
+    // that slot for saveAllRegisters().
+
     saveAllRegisters(jit, registerScratch);
     
-    // Bring the stack back into a sane form.
-    jit.pop(GPRInfo::regT0);
-    jit.pop(GPRInfo::regT0);
+    // Bring the stack back into a sane form and assert that it's sane.
+    jit.popToRestore(GPRInfo::regT0);
+    jit.checkStackPointerAlignment();
     
+    if (vm->m_perBytecodeProfiler && jitCode->dfgCommon()->compilation) {
+        Profiler::Database& database = *vm->m_perBytecodeProfiler;
+        Profiler::Compilation* compilation = jitCode->dfgCommon()->compilation.get();
+        
+        Profiler::OSRExit* profilerExit = compilation->addOSRExit(
+            exitID, Profiler::OriginStack(database, codeBlock, exit.m_codeOrigin),
+            exit.m_kind, exit.m_kind == UncountableInvalidation);
+        jit.add64(CCallHelpers::TrustedImm32(1), CCallHelpers::AbsoluteAddress(profilerExit->counterAddress()));
+    }
+
     // The remaining code assumes that SP/FP are in the same state that they were in the FTL's
     // call frame.
     
     // Get the call frame and tag thingies.
     // Restore the exiting function's callFrame value into a regT4
-    record->locations[0].restoreInto(jit, jitCode->stackmaps, registerScratch, GPRInfo::regT4);
     jit.move(MacroAssembler::TrustedImm64(TagTypeNumber), GPRInfo::tagTypeNumberRegister);
     jit.move(MacroAssembler::TrustedImm64(TagMask), GPRInfo::tagMaskRegister);
     
     // Do some value profiling.
-    if (exit.m_profileValueFormat != InvalidValueFormat) {
-        record->locations[1].restoreInto(jit, jitCode->stackmaps, registerScratch, GPRInfo::regT0);
+    if (exit.m_descriptor->m_profileDataFormat != DataFormatNone) {
+        Location::forValueRep(exit.m_valueReps[0]).restoreInto(jit, registerScratch, GPRInfo::regT0);
         reboxAccordingToFormat(
-            exit.m_profileValueFormat, jit, GPRInfo::regT0, GPRInfo::regT1, GPRInfo::regT2);
+            exit.m_descriptor->m_profileDataFormat, jit, GPRInfo::regT0, GPRInfo::regT1, GPRInfo::regT2);
         
         if (exit.m_kind == BadCache || exit.m_kind == BadIndexingType) {
             CodeOrigin codeOrigin = exit.m_codeOriginForExitProfile;
             if (ArrayProfile* arrayProfile = jit.baselineCodeBlockFor(codeOrigin)->getArrayProfile(codeOrigin.bytecodeIndex)) {
-                jit.loadPtr(MacroAssembler::Address(GPRInfo::regT0, JSCell::structureOffset()), GPRInfo::regT1);
-                jit.storePtr(GPRInfo::regT1, arrayProfile->addressOfLastSeenStructure());
-                jit.load8(MacroAssembler::Address(GPRInfo::regT1, Structure::indexingTypeOffset()), GPRInfo::regT1);
+                jit.load32(MacroAssembler::Address(GPRInfo::regT0, JSCell::structureIDOffset()), GPRInfo::regT1);
+                jit.store32(GPRInfo::regT1, arrayProfile->addressOfLastSeenStructureID());
+                jit.load8(MacroAssembler::Address(GPRInfo::regT0, JSCell::indexingTypeAndMiscOffset()), GPRInfo::regT1);
                 jit.move(MacroAssembler::TrustedImm32(1), GPRInfo::regT2);
                 jit.lshift32(GPRInfo::regT1, GPRInfo::regT2);
                 jit.or32(GPRInfo::regT2, MacroAssembler::AbsoluteAddress(arrayProfile->addressOfArrayModes()));
             }
         }
-        
-        if (!!exit.m_valueProfile)
-            jit.store64(GPRInfo::regT0, exit.m_valueProfile.getSpecFailBucket(0));
+
+        if (exit.m_descriptor->m_valueProfile)
+            exit.m_descriptor->m_valueProfile.emitReportValue(jit, JSValueRegs(GPRInfo::regT0));
     }
 
-    // Save all state from wherever the exit data tells us it was, into the appropriate place in
-    // the scratch buffer. This doesn't rebox any values yet.
-    
-    for (unsigned index = exit.m_values.size(); index--;) {
-        ExitValue value = exit.m_values[index];
-        
-        switch (value.kind()) {
-        case ExitValueDead:
-            jit.move(MacroAssembler::TrustedImm64(JSValue::encode(jsUndefined())), GPRInfo::regT0);
-            break;
-            
-        case ExitValueConstant:
-            jit.move(MacroAssembler::TrustedImm64(JSValue::encode(value.constant())), GPRInfo::regT0);
-            break;
-            
-        case ExitValueArgument:
-            record->locations[value.exitArgument().argument()].restoreInto(
-                jit, jitCode->stackmaps, registerScratch, GPRInfo::regT0);
-            break;
-            
-        case ExitValueInJSStack:
-        case ExitValueInJSStackAsInt32:
-        case ExitValueInJSStackAsInt52:
-        case ExitValueInJSStackAsDouble:
-            jit.load64(AssemblyHelpers::addressFor(value.virtualRegister(), GPRInfo::regT4), GPRInfo::regT0);
-            break;
+    // Materialize all objects. Don't materialize an object until all
+    // of the objects it needs have been materialized. We break cycles
+    // by populating objects late - we only consider an object as
+    // needing another object if the later is needed for the
+    // allocation of the former.
+
+    HashSet<ExitTimeObjectMaterialization*> toMaterialize;
+    for (ExitTimeObjectMaterialization* materialization : exit.m_descriptor->m_materializations)
+        toMaterialize.add(materialization);
+
+    while (!toMaterialize.isEmpty()) {
+        unsigned previousToMaterializeSize = toMaterialize.size();
+
+        Vector<ExitTimeObjectMaterialization*> worklist;
+        worklist.appendRange(toMaterialize.begin(), toMaterialize.end());
+        for (ExitTimeObjectMaterialization* materialization : worklist) {
+            // Check if we can do anything about this right now.
+            bool allGood = true;
+            for (ExitPropertyValue value : materialization->properties()) {
+                if (!value.value().isObjectMaterialization())
+                    continue;
+                if (!value.location().neededForMaterialization())
+                    continue;
+                if (toMaterialize.contains(value.value().objectMaterialization())) {
+                    // Gotta skip this one, since it needs a
+                    // materialization that hasn't been materialized.
+                    allGood = false;
+                    break;
+                }
+            }
+            if (!allGood)
+                continue;
+
+            // All systems go for materializing the object. First we
+            // recover the values of all of its fields and then we
+            // call a function to actually allocate the beast.
+            // We only recover the fields that are needed for the allocation.
+            for (unsigned propertyIndex = materialization->properties().size(); propertyIndex--;) {
+                const ExitPropertyValue& property = materialization->properties()[propertyIndex];
+                if (!property.location().neededForMaterialization())
+                    continue;
+
+                recoverValue(property.value());
+                jit.storePtr(GPRInfo::regT0, materializationArguments + propertyIndex);
+            }
             
-        default:
-            RELEASE_ASSERT_NOT_REACHED();
-            break;
+            // This call assumes that we don't pass arguments on the stack.
+            jit.setupArgumentsWithExecState(
+                CCallHelpers::TrustedImmPtr(materialization),
+                CCallHelpers::TrustedImmPtr(materializationArguments));
+            jit.move(CCallHelpers::TrustedImmPtr(bitwise_cast<void*>(operationMaterializeObjectInOSR)), GPRInfo::nonArgGPR0);
+            jit.call(GPRInfo::nonArgGPR0);
+            jit.storePtr(GPRInfo::returnValueGPR, materializationToPointer.get(materialization));
+
+            // Let everyone know that we're done.
+            toMaterialize.remove(materialization);
         }
         
+        // We expect progress! This ensures that we crash rather than looping infinitely if there
+        // is something broken about this fixpoint. Or, this could happen if we ever violate the
+        // "materializations form a DAG" rule.
+        RELEASE_ASSERT(toMaterialize.size() < previousToMaterializeSize);
+    }
+
+    // Now that all the objects have been allocated, we populate them
+    // with the correct values. This time we can recover all the
+    // fields, including those that are only needed for the allocation.
+    for (ExitTimeObjectMaterialization* materialization : exit.m_descriptor->m_materializations) {
+        for (unsigned propertyIndex = materialization->properties().size(); propertyIndex--;) {
+            recoverValue(materialization->properties()[propertyIndex].value());
+            jit.storePtr(GPRInfo::regT0, materializationArguments + propertyIndex);
+        }
+
+        // This call assumes that we don't pass arguments on the stack
+        jit.setupArgumentsWithExecState(
+            CCallHelpers::TrustedImmPtr(materialization),
+            CCallHelpers::TrustedImmPtr(materializationToPointer.get(materialization)),
+            CCallHelpers::TrustedImmPtr(materializationArguments));
+        jit.move(CCallHelpers::TrustedImmPtr(bitwise_cast<void*>(operationPopulateObjectInOSR)), GPRInfo::nonArgGPR0);
+        jit.call(GPRInfo::nonArgGPR0);
+    }
+
+    // Save all state from wherever the exit data tells us it was, into the appropriate place in
+    // the scratch buffer. This also does the reboxing.
+    
+    for (unsigned index = exit.m_descriptor->m_values.size(); index--;) {
+        recoverValue(exit.m_descriptor->m_values[index]);
         jit.store64(GPRInfo::regT0, scratch + index);
     }
     
-    // Now get state out of the scratch buffer and place it back into the stack. This part does
-    // all reboxing.
-    for (unsigned index = exit.m_values.size(); index--;) {
-        int operand = exit.m_values.operandForIndex(index);
-        ExitValue value = exit.m_values[index];
-        
-        jit.load64(scratch + index, GPRInfo::regT0);
-        reboxAccordingToFormat(
-            value.valueFormat(), jit, GPRInfo::regT0, GPRInfo::regT1, GPRInfo::regT2);
-        jit.store64(GPRInfo::regT0, AssemblyHelpers::addressFor(static_cast<VirtualRegister>(operand), GPRInfo::regT4));
+    // Henceforth we make it look like the exiting function was called through a register
+    // preservation wrapper. This implies that FP must be nudged down by a certain amount. Then
+    // we restore the various things according to either exit.m_descriptor->m_values or by copying from the
+    // old frame, and finally we save the various callee-save registers into where the
+    // restoration thunk would restore them from.
+    
+    // Before we start messing with the frame, we need to set aside any registers that the
+    // FTL code was preserving.
+    for (unsigned i = codeBlock->calleeSaveRegisters()->size(); i--;) {
+        RegisterAtOffset entry = codeBlock->calleeSaveRegisters()->at(i);
+        jit.load64(
+            MacroAssembler::Address(MacroAssembler::framePointerRegister, entry.offset()),
+            GPRInfo::regT0);
+        jit.store64(GPRInfo::regT0, unwindScratch + i);
     }
     
-    // Restore the old stack pointer and then put regT4 into callFrameRegister. The idea is
-    // that the FTL call frame is pushed onto the JS call frame and we can recover the old
-    // value of the stack pointer by popping the FTL call frame. We already know what the
-    // frame pointer in the JS call frame was because it would have been passed as an argument
-    // to the FTL call frame.
-    jit.move(MacroAssembler::framePointerRegister, MacroAssembler::stackPointerRegister);
-    jit.pop(GPRInfo::nonArgGPR0);
-    jit.pop(GPRInfo::nonArgGPR0);
-    jit.move(GPRInfo::regT4, GPRInfo::callFrameRegister);
+    jit.load32(CCallHelpers::payloadFor(CallFrameSlot::argumentCount), GPRInfo::regT2);
+    
+    // Let's say that the FTL function had failed its arity check. In that case, the stack will
+    // contain some extra stuff.
+    //
+    // We compute the padded stack space:
+    //
+    //     paddedStackSpace = roundUp(codeBlock->numParameters - regT2 + 1)
+    //
+    // The stack will have regT2 + CallFrameHeaderSize stuff.
+    // We want to make the stack look like this, from higher addresses down:
+    //
+    //     - argument padding
+    //     - actual arguments
+    //     - call frame header
+
+    // This code assumes that we're dealing with FunctionCode.
+    RELEASE_ASSERT(codeBlock->codeType() == FunctionCode);
+    
+    jit.add32(
+        MacroAssembler::TrustedImm32(-codeBlock->numParameters()), GPRInfo::regT2,
+        GPRInfo::regT3);
+    MacroAssembler::Jump arityIntact = jit.branch32(
+        MacroAssembler::GreaterThanOrEqual, GPRInfo::regT3, MacroAssembler::TrustedImm32(0));
+    jit.neg32(GPRInfo::regT3);
+    jit.add32(MacroAssembler::TrustedImm32(1 + stackAlignmentRegisters() - 1), GPRInfo::regT3);
+    jit.and32(MacroAssembler::TrustedImm32(-stackAlignmentRegisters()), GPRInfo::regT3);
+    jit.add32(GPRInfo::regT3, GPRInfo::regT2);
+    arityIntact.link(&jit);
+
+    CodeBlock* baselineCodeBlock = jit.baselineCodeBlockFor(exit.m_codeOrigin);
+
+    // First set up SP so that our data doesn't get clobbered by signals.
+    unsigned conservativeStackDelta =
+        (exit.m_descriptor->m_values.numberOfLocals() + baselineCodeBlock->calleeSaveSpaceAsVirtualRegisters()) * sizeof(Register) +
+        maxFrameExtentForSlowPathCall;
+    conservativeStackDelta = WTF::roundUpToMultipleOf(
+        stackAlignmentBytes(), conservativeStackDelta);
+    jit.addPtr(
+        MacroAssembler::TrustedImm32(-conservativeStackDelta),
+        MacroAssembler::framePointerRegister, MacroAssembler::stackPointerRegister);
+    jit.checkStackPointerAlignment();
+
+    RegisterSet allFTLCalleeSaves = RegisterSet::ftlCalleeSaveRegisters();
+    RegisterAtOffsetList* baselineCalleeSaves = baselineCodeBlock->calleeSaveRegisters();
+    RegisterAtOffsetList* vmCalleeSaves = vm->getAllCalleeSaveRegisterOffsets();
+    RegisterSet vmCalleeSavesToSkip = RegisterSet::stackRegisters();
+    if (exit.isExceptionHandler()) {
+        jit.loadPtr(&vm->topVMEntryFrame, GPRInfo::regT1);
+        jit.addPtr(CCallHelpers::TrustedImm32(VMEntryFrame::calleeSaveRegistersBufferOffset()), GPRInfo::regT1);
+    }
+
+    for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {
+        if (!allFTLCalleeSaves.get(reg)) {
+            if (exit.isExceptionHandler())
+                RELEASE_ASSERT(!vmCalleeSaves->find(reg));
+            continue;
+        }
+        unsigned unwindIndex = codeBlock->calleeSaveRegisters()->indexOf(reg);
+        RegisterAtOffset* baselineRegisterOffset = baselineCalleeSaves->find(reg);
+        RegisterAtOffset* vmCalleeSave = nullptr; 
+        if (exit.isExceptionHandler())
+            vmCalleeSave = vmCalleeSaves->find(reg);
+
+        if (reg.isGPR()) {
+            GPRReg regToLoad = baselineRegisterOffset ? GPRInfo::regT0 : reg.gpr();
+            RELEASE_ASSERT(regToLoad != GPRInfo::regT1);
+
+            if (unwindIndex == UINT_MAX) {
+                // The FTL compilation didn't preserve this register. This means that it also
+                // didn't use the register. So its value at the beginning of OSR exit should be
+                // preserved by the thunk. Luckily, we saved all registers into the register
+                // scratch buffer, so we can restore them from there.
+                jit.load64(registerScratch + offsetOfReg(reg), regToLoad);
+            } else {
+                // The FTL compilation preserved the register. Its new value is therefore
+                // irrelevant, but we can get the value that was preserved by using the unwind
+                // data. We've already copied all unwind-able preserved registers into the unwind
+                // scratch buffer, so we can get it from there.
+                jit.load64(unwindScratch + unwindIndex, regToLoad);
+            }
+
+            if (baselineRegisterOffset)
+                jit.store64(regToLoad, MacroAssembler::Address(MacroAssembler::framePointerRegister, baselineRegisterOffset->offset()));
+            if (vmCalleeSave && !vmCalleeSavesToSkip.get(vmCalleeSave->reg()))
+                jit.store64(regToLoad, MacroAssembler::Address(GPRInfo::regT1, vmCalleeSave->offset()));
+        } else {
+            FPRReg fpRegToLoad = baselineRegisterOffset ? FPRInfo::fpRegT0 : reg.fpr();
+
+            if (unwindIndex == UINT_MAX)
+                jit.loadDouble(MacroAssembler::TrustedImmPtr(registerScratch + offsetOfReg(reg)), fpRegToLoad);
+            else
+                jit.loadDouble(MacroAssembler::TrustedImmPtr(unwindScratch + unwindIndex), fpRegToLoad);
+
+            if (baselineRegisterOffset)
+                jit.storeDouble(fpRegToLoad, MacroAssembler::Address(MacroAssembler::framePointerRegister, baselineRegisterOffset->offset()));
+            if (vmCalleeSave && !vmCalleeSavesToSkip.get(vmCalleeSave->reg()))
+                jit.storeDouble(fpRegToLoad, MacroAssembler::Address(GPRInfo::regT1, vmCalleeSave->offset()));
+        }
+    }
+
+    if (exit.isExceptionHandler()) {
+        RegisterAtOffset* vmCalleeSave = vmCalleeSaves->find(GPRInfo::tagTypeNumberRegister);
+        jit.store64(GPRInfo::tagTypeNumberRegister, MacroAssembler::Address(GPRInfo::regT1, vmCalleeSave->offset()));
+
+        vmCalleeSave = vmCalleeSaves->find(GPRInfo::tagMaskRegister);
+        jit.store64(GPRInfo::tagMaskRegister, MacroAssembler::Address(GPRInfo::regT1, vmCalleeSave->offset()));
+    }
+
+    size_t baselineVirtualRegistersForCalleeSaves = baselineCodeBlock->calleeSaveSpaceAsVirtualRegisters();
+
+    // Now get state out of the scratch buffer and place it back into the stack. The values are
+    // already reboxed so we just move them.
+    for (unsigned index = exit.m_descriptor->m_values.size(); index--;) {
+        VirtualRegister reg = exit.m_descriptor->m_values.virtualRegisterForIndex(index);
+
+        if (reg.isLocal() && reg.toLocal() < static_cast<int>(baselineVirtualRegistersForCalleeSaves))
+            continue;
+
+        jit.load64(scratch + index, GPRInfo::regT0);
+        jit.store64(GPRInfo::regT0, AssemblyHelpers::addressFor(reg));
+    }
     
     handleExitCounts(jit, exit);
     reifyInlinedCallFrames(jit, exit);
     adjustAndJumpToTarget(jit, exit);
     
-    LinkBuffer patchBuffer(*vm, &jit, codeBlock);
+    LinkBuffer patchBuffer(*vm, jit, codeBlock);
     exit.m_code = FINALIZE_CODE_IF(
-        shouldShowDisassembly(),
+        shouldDumpDisassembly() || Options::verboseOSR() || Options::verboseFTLOSRExit(),
         patchBuffer,
-        ("FTL OSR exit #%u (%s, %s) from %s, with operands = %s, and record = %s",
+        ("FTL OSR exit #%u (%s, %s) from %s, with operands = %s",
             exitID, toCString(exit.m_codeOrigin).data(),
             exitKindToString(exit.m_kind), toCString(*codeBlock).data(),
-            toCString(ignoringContext<DumpContext>(exit.m_values)).data(),
-            toCString(*record).data()));
+            toCString(ignoringContext<DumpContext>(exit.m_descriptor->m_values)).data())
+        );
 }
 
 extern "C" void* compileFTLOSRExit(ExecState* exec, unsigned exitID)
 {
-    SamplingRegion samplingRegion("FTL OSR Exit Compilation");
+    if (shouldDumpDisassembly() || Options::verboseOSR() || Options::verboseFTLOSRExit())
+        dataLog("Compiling OSR exit with exitID = ", exitID, "\n");
+
+    if (exec->vm().callFrameForCatch)
+        RELEASE_ASSERT(exec->vm().callFrameForCatch == exec);
     
     CodeBlock* codeBlock = exec->codeBlock();
     
@@ -196,12 +554,28 @@ extern "C" void* compileFTLOSRExit(ExecState* exec, unsigned exitID)
     JITCode* jitCode = codeBlock->jitCode()->ftl();
     OSRExit& exit = jitCode->osrExit[exitID];
     
+    if (shouldDumpDisassembly() || Options::verboseOSR() || Options::verboseFTLOSRExit()) {
+        dataLog("    Owning block: ", pointerDump(codeBlock), "\n");
+        dataLog("    Origin: ", exit.m_codeOrigin, "\n");
+        if (exit.m_codeOriginForExitProfile != exit.m_codeOrigin)
+            dataLog("    Origin for exit profile: ", exit.m_codeOriginForExitProfile, "\n");
+        dataLog("    Current call site index: ", exec->callSiteIndex().bits(), "\n");
+        dataLog("    Exit is exception handler: ", exit.isExceptionHandler(), "\n");
+        dataLog("    Is unwind handler: ", exit.isGenericUnwindHandler(), "\n");
+        dataLog("    Exit values: ", exit.m_descriptor->m_values, "\n");
+        dataLog("    Value reps: ", listDump(exit.m_valueReps), "\n");
+        if (!exit.m_descriptor->m_materializations.isEmpty()) {
+            dataLog("    Materializations:\n");
+            for (ExitTimeObjectMaterialization* materialization : exit.m_descriptor->m_materializations)
+                dataLog("        ", pointerDump(materialization), "\n");
+        }
+    }
+
     prepareCodeOriginForOSRExit(exec, exit.m_codeOrigin);
     
     compileStub(exitID, jitCode, exit, vm, codeBlock);
-    
-    RepatchBuffer repatchBuffer(codeBlock);
-    repatchBuffer.relink(
+
+    MacroAssembler::repatchJump(
         exit.codeLocationForRepatch(codeBlock), CodeLocationLabel(exit.m_code.code()));
     
     return exit.m_code.code().executableAddress();
diff --git a/Source/JavaScriptCore/ftl/FTLOSRExitCompiler.h b/Source/JavaScriptCore/ftl/FTLOSRExitCompiler.h
index eba9cb859..405b7a5e1 100644
--- a/Source/JavaScriptCore/ftl/FTLOSRExitCompiler.h
+++ b/Source/JavaScriptCore/ftl/FTLOSRExitCompiler.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLOSRExitCompiler_h
-#define FTLOSRExitCompiler_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -43,6 +40,3 @@ void* JIT_OPERATION compileFTLOSRExit(ExecState*, unsigned exitID) WTF_INTERNAL;
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLOSRExitCompiler_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLOSRExitHandle.cpp b/Source/JavaScriptCore/ftl/FTLOSRExitHandle.cpp
new file mode 100644
index 000000000..11942b766
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLOSRExitHandle.cpp
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2015-2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLOSRExitHandle.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "FTLOSRExit.h"
+#include "FTLState.h"
+#include "FTLThunks.h"
+#include "LinkBuffer.h"
+#include "ProfilerCompilation.h"
+
+namespace JSC { namespace FTL {
+
+void OSRExitHandle::emitExitThunk(State& state, CCallHelpers& jit)
+{
+    Profiler::Compilation* compilation = state.graph.compilation();
+    CCallHelpers::Label myLabel = jit.label();
+    label = myLabel;
+    jit.pushToSaveImmediateWithoutTouchingRegisters(CCallHelpers::TrustedImm32(index));
+    CCallHelpers::PatchableJump jump = jit.patchableJump();
+    RefPtr<OSRExitHandle> self = this;
+    jit.addLinkTask(
+        [self, jump, myLabel, compilation] (LinkBuffer& linkBuffer) {
+            self->exit.m_patchableJump = CodeLocationJump(linkBuffer.locationOf(jump));
+
+            linkBuffer.link(
+                jump.m_jump,
+                CodeLocationLabel(linkBuffer.vm().getCTIStub(osrExitGenerationThunkGenerator).code()));
+            if (compilation)
+                compilation->addOSRExitSite({ linkBuffer.locationOf(myLabel).executableAddress() });
+        });
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLOSRExitHandle.h b/Source/JavaScriptCore/ftl/FTLOSRExitHandle.h
new file mode 100644
index 000000000..0763d797c
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLOSRExitHandle.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#include "DFGCommon.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "CCallHelpers.h"
+#include <wtf/ThreadSafeRefCounted.h>
+
+namespace JSC { namespace FTL {
+
+class State;
+struct OSRExit;
+
+// This is an object that stores some interesting data about an OSR exit. It's expected that you will
+// scrape this data from this object by the time compilation finishes.
+struct OSRExitHandle : public ThreadSafeRefCounted<OSRExitHandle> {
+    OSRExitHandle(unsigned index, OSRExit& exit)
+        : index(index)
+        , exit(exit)
+    {
+    }
+
+    unsigned index;
+    OSRExit& exit;
+
+    // This is the label at which the OSR exit jump lives. This will get populated once the OSR exit
+    // emits its jump. This happens immediately when you call OSRExit::appendOSRExit(). It happens at
+    // some time during late path emission if you do OSRExit::appendOSRExitLater().
+    CCallHelpers::Label label;
+
+    // This emits the exit thunk and populates 'label'.
+    void emitExitThunk(State&, CCallHelpers&);
+};
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLOperations.cpp b/Source/JavaScriptCore/ftl/FTLOperations.cpp
new file mode 100644
index 000000000..1d061480f
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLOperations.cpp
@@ -0,0 +1,535 @@
+/*
+ * Copyright (C) 2014-2017 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLOperations.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "ClonedArguments.h"
+#include "DirectArguments.h"
+#include "FTLJITCode.h"
+#include "FTLLazySlowPath.h"
+#include "InlineCallFrame.h"
+#include "JSAsyncFunction.h"
+#include "JSCInlines.h"
+#include "JSFixedArray.h"
+#include "JSGeneratorFunction.h"
+#include "JSLexicalEnvironment.h"
+
+namespace JSC { namespace FTL {
+
+using namespace JSC::DFG;
+
+extern "C" void JIT_OPERATION operationPopulateObjectInOSR(
+    ExecState* exec, ExitTimeObjectMaterialization* materialization,
+    EncodedJSValue* encodedValue, EncodedJSValue* values)
+{
+    VM& vm = exec->vm();
+    CodeBlock* codeBlock = exec->codeBlock();
+
+    // We cannot GC. We've got pointers in evil places.
+    // FIXME: We are not doing anything that can GC here, and this is
+    // probably unnecessary.
+    DeferGCForAWhile deferGC(vm.heap);
+
+    switch (materialization->type()) {
+    case PhantomNewObject: {
+        JSFinalObject* object = jsCast<JSFinalObject*>(JSValue::decode(*encodedValue));
+        Structure* structure = object->structure();
+
+        // Figure out what the heck to populate the object with. Use
+        // getPropertiesConcurrently() because that happens to be
+        // lower-level and more convenient. It doesn't change the
+        // materialization of the property table. We want to have
+        // minimal visible effects on the system. Also, don't mind
+        // that this is O(n^2). It doesn't matter. We only get here
+        // from OSR exit.
+        for (PropertyMapEntry entry : structure->getPropertiesConcurrently()) {
+            for (unsigned i = materialization->properties().size(); i--;) {
+                const ExitPropertyValue& property = materialization->properties()[i];
+                if (property.location().kind() != NamedPropertyPLoc)
+                    continue;
+                if (codeBlock->identifier(property.location().info()).impl() != entry.key)
+                    continue;
+
+                object->putDirect(vm, entry.offset, JSValue::decode(values[i]));
+            }
+        }
+        break;
+    }
+
+    case PhantomNewFunction:
+    case PhantomNewGeneratorFunction:
+    case PhantomNewAsyncFunction:
+    case PhantomDirectArguments:
+    case PhantomClonedArguments:
+    case PhantomCreateRest:
+    case PhantomSpread:
+    case PhantomNewArrayWithSpread:
+        // Those are completely handled by operationMaterializeObjectInOSR
+        break;
+
+    case PhantomCreateActivation: {
+        JSLexicalEnvironment* activation = jsCast<JSLexicalEnvironment*>(JSValue::decode(*encodedValue));
+
+        // Figure out what to populate the activation with
+        for (unsigned i = materialization->properties().size(); i--;) {
+            const ExitPropertyValue& property = materialization->properties()[i];
+            if (property.location().kind() != ClosureVarPLoc)
+                continue;
+
+            activation->variableAt(ScopeOffset(property.location().info())).set(exec->vm(), activation, JSValue::decode(values[i]));
+        }
+
+        break;
+    }
+
+
+    default:
+        RELEASE_ASSERT_NOT_REACHED();
+        break;
+
+    }
+}
+
+extern "C" JSCell* JIT_OPERATION operationMaterializeObjectInOSR(
+    ExecState* exec, ExitTimeObjectMaterialization* materialization, EncodedJSValue* values)
+{
+    VM& vm = exec->vm();
+
+    // We cannot GC. We've got pointers in evil places.
+    DeferGCForAWhile deferGC(vm.heap);
+    
+    switch (materialization->type()) {
+    case PhantomNewObject: {
+        // Figure out what the structure is
+        Structure* structure = nullptr;
+        for (unsigned i = materialization->properties().size(); i--;) {
+            const ExitPropertyValue& property = materialization->properties()[i];
+            if (property.location() != PromotedLocationDescriptor(StructurePLoc))
+                continue;
+
+            RELEASE_ASSERT(JSValue::decode(values[i]).asCell()->inherits(vm, Structure::info()));
+            structure = jsCast<Structure*>(JSValue::decode(values[i]));
+            break;
+        }
+        RELEASE_ASSERT(structure);
+
+        JSFinalObject* result = JSFinalObject::create(vm, structure);
+
+        // The real values will be put subsequently by
+        // operationPopulateNewObjectInOSR. We can't fill them in
+        // now, because they may not be available yet (typically
+        // because we have a cyclic dependency graph).
+
+        // We put a dummy value here in order to avoid super-subtle
+        // GC-and-OSR-exit crashes in case we have a bug and some
+        // field is, for any reason, not filled later.
+        // We use a random-ish number instead of a sensible value like
+        // undefined to make possible bugs easier to track.
+        for (PropertyMapEntry entry : structure->getPropertiesConcurrently())
+            result->putDirect(vm, entry.offset, jsNumber(19723));
+
+        return result;
+    }
+
+    case PhantomNewFunction:
+    case PhantomNewGeneratorFunction:
+    case PhantomNewAsyncFunction: {
+        // Figure out what the executable and activation are
+        FunctionExecutable* executable = nullptr;
+        JSScope* activation = nullptr;
+        for (unsigned i = materialization->properties().size(); i--;) {
+            const ExitPropertyValue& property = materialization->properties()[i];
+            if (property.location() == PromotedLocationDescriptor(FunctionExecutablePLoc)) {
+                RELEASE_ASSERT(JSValue::decode(values[i]).asCell()->inherits(vm, FunctionExecutable::info()));
+                executable = jsCast<FunctionExecutable*>(JSValue::decode(values[i]));
+            }
+            if (property.location() == PromotedLocationDescriptor(FunctionActivationPLoc)) {
+                RELEASE_ASSERT(JSValue::decode(values[i]).asCell()->inherits(vm, JSScope::info()));
+                activation = jsCast<JSScope*>(JSValue::decode(values[i]));
+            }
+        }
+        RELEASE_ASSERT(executable && activation);
+
+        if (materialization->type() == PhantomNewFunction)
+            return JSFunction::createWithInvalidatedReallocationWatchpoint(vm, executable, activation);
+        else if (materialization->type() == PhantomNewGeneratorFunction)
+            return JSGeneratorFunction::createWithInvalidatedReallocationWatchpoint(vm, executable, activation);    
+        ASSERT(materialization->type() == PhantomNewAsyncFunction);
+        return JSAsyncFunction::createWithInvalidatedReallocationWatchpoint(vm, executable, activation);
+    }
+
+    case PhantomCreateActivation: {
+        // Figure out what the scope and symbol table are
+        JSScope* scope = nullptr;
+        SymbolTable* table = nullptr;
+        for (unsigned i = materialization->properties().size(); i--;) {
+            const ExitPropertyValue& property = materialization->properties()[i];
+            if (property.location() == PromotedLocationDescriptor(ActivationScopePLoc)) {
+                RELEASE_ASSERT(JSValue::decode(values[i]).asCell()->inherits(vm, JSScope::info()));
+                scope = jsCast<JSScope*>(JSValue::decode(values[i]));
+            } else if (property.location() == PromotedLocationDescriptor(ActivationSymbolTablePLoc)) {
+                RELEASE_ASSERT(JSValue::decode(values[i]).asCell()->inherits(vm, SymbolTable::info()));
+                table = jsCast<SymbolTable*>(JSValue::decode(values[i]));
+            }
+        }
+        RELEASE_ASSERT(scope);
+        RELEASE_ASSERT(table);
+
+        CodeBlock* codeBlock = baselineCodeBlockForOriginAndBaselineCodeBlock(
+            materialization->origin(), exec->codeBlock());
+        Structure* structure = codeBlock->globalObject()->activationStructure();
+
+        // It doesn't matter what values we initialize as bottom values inside the activation constructor because
+        // activation sinking will set bottom values for each slot.
+        // FIXME: Slight optimization would be to create a constructor that doesn't initialize all slots.
+        JSLexicalEnvironment* result = JSLexicalEnvironment::create(vm, structure, scope, table, jsUndefined());
+
+        RELEASE_ASSERT(materialization->properties().size() - 2 == table->scopeSize());
+
+        // The real values will be put subsequently by
+        // operationPopulateNewObjectInOSR. See the PhantomNewObject
+        // case for details.
+        for (unsigned i = materialization->properties().size(); i--;) {
+            const ExitPropertyValue& property = materialization->properties()[i];
+            if (property.location().kind() != ClosureVarPLoc)
+                continue;
+
+            result->variableAt(ScopeOffset(property.location().info())).set(
+                exec->vm(), result, jsNumber(29834));
+        }
+
+        if (validationEnabled()) {
+            // Validate to make sure every slot in the scope has one value.
+            ConcurrentJSLocker locker(table->m_lock);
+            for (auto iter = table->begin(locker), end = table->end(locker); iter != end; ++iter) {
+                bool found = false;
+                for (unsigned i = materialization->properties().size(); i--;) {
+                    const ExitPropertyValue& property = materialization->properties()[i];
+                    if (property.location().kind() != ClosureVarPLoc)
+                        continue;
+                    if (ScopeOffset(property.location().info()) == iter->value.scopeOffset()) {
+                        found = true;
+                        break;
+                    }
+                }
+                ASSERT_UNUSED(found, found);
+            }
+            unsigned numberOfClosureVarPloc = 0;
+            for (unsigned i = materialization->properties().size(); i--;) {
+                const ExitPropertyValue& property = materialization->properties()[i];
+                if (property.location().kind() == ClosureVarPLoc)
+                    numberOfClosureVarPloc++;
+            }
+            ASSERT(numberOfClosureVarPloc == table->scopeSize());
+        }
+
+        return result;
+    }
+
+    case PhantomCreateRest:
+    case PhantomDirectArguments:
+    case PhantomClonedArguments: {
+        if (!materialization->origin().inlineCallFrame) {
+            switch (materialization->type()) {
+            case PhantomDirectArguments:
+                return DirectArguments::createByCopying(exec);
+            case PhantomClonedArguments:
+                return ClonedArguments::createWithMachineFrame(exec, exec, ArgumentsMode::Cloned);
+            case PhantomCreateRest: {
+                CodeBlock* codeBlock = baselineCodeBlockForOriginAndBaselineCodeBlock(
+                    materialization->origin(), exec->codeBlock());
+
+                unsigned numberOfArgumentsToSkip = codeBlock->numberOfArgumentsToSkip();
+                JSGlobalObject* globalObject = codeBlock->globalObject();
+                Structure* structure = globalObject->restParameterStructure();
+                JSValue* argumentsToCopyRegion = exec->addressOfArgumentsStart() + numberOfArgumentsToSkip;
+                unsigned arraySize = exec->argumentCount() > numberOfArgumentsToSkip ? exec->argumentCount() - numberOfArgumentsToSkip : 0;
+                return constructArray(exec, structure, argumentsToCopyRegion, arraySize);
+            }
+            default:
+                RELEASE_ASSERT_NOT_REACHED();
+                return nullptr;
+            }
+        }
+
+        // First figure out the argument count. If there isn't one then we represent the machine frame.
+        unsigned argumentCount = 0;
+        if (materialization->origin().inlineCallFrame->isVarargs()) {
+            for (unsigned i = materialization->properties().size(); i--;) {
+                const ExitPropertyValue& property = materialization->properties()[i];
+                if (property.location() != PromotedLocationDescriptor(ArgumentCountPLoc))
+                    continue;
+                argumentCount = JSValue::decode(values[i]).asUInt32();
+                break;
+            }
+        } else
+            argumentCount = materialization->origin().inlineCallFrame->arguments.size();
+        RELEASE_ASSERT(argumentCount);
+        
+        JSFunction* callee = nullptr;
+        if (materialization->origin().inlineCallFrame->isClosureCall) {
+            for (unsigned i = materialization->properties().size(); i--;) {
+                const ExitPropertyValue& property = materialization->properties()[i];
+                if (property.location() != PromotedLocationDescriptor(ArgumentsCalleePLoc))
+                    continue;
+                
+                callee = jsCast<JSFunction*>(JSValue::decode(values[i]));
+                break;
+            }
+        } else
+            callee = materialization->origin().inlineCallFrame->calleeConstant();
+        RELEASE_ASSERT(callee);
+        
+        CodeBlock* codeBlock = baselineCodeBlockForOriginAndBaselineCodeBlock(
+            materialization->origin(), exec->codeBlock());
+        
+        // We have an inline frame and we have all of the data we need to recreate it.
+        switch (materialization->type()) {
+        case PhantomDirectArguments: {
+            unsigned length = argumentCount - 1;
+            unsigned capacity = std::max(length, static_cast<unsigned>(codeBlock->numParameters() - 1));
+            DirectArguments* result = DirectArguments::create(
+                vm, codeBlock->globalObject()->directArgumentsStructure(), length, capacity);
+            result->callee().set(vm, result, callee);
+            for (unsigned i = materialization->properties().size(); i--;) {
+                const ExitPropertyValue& property = materialization->properties()[i];
+                if (property.location().kind() != ArgumentPLoc)
+                    continue;
+                
+                unsigned index = property.location().info();
+                if (index >= capacity)
+                    continue;
+                
+                // We don't want to use setIndexQuickly(), since that's only for the passed-in
+                // arguments but sometimes the number of named arguments is greater. For
+                // example:
+                //
+                // function foo(a, b, c) { ... }
+                // foo();
+                //
+                // setIndexQuickly() would fail for indices 0, 1, 2 - but we need to recover
+                // those here.
+                result->argument(DirectArgumentsOffset(index)).set(
+                    vm, result, JSValue::decode(values[i]));
+            }
+            return result;
+        }
+        case PhantomClonedArguments: {
+            unsigned length = argumentCount - 1;
+            ClonedArguments* result = ClonedArguments::createEmpty(
+                vm, codeBlock->globalObject()->clonedArgumentsStructure(), callee, length);
+            
+            for (unsigned i = materialization->properties().size(); i--;) {
+                const ExitPropertyValue& property = materialization->properties()[i];
+                if (property.location().kind() != ArgumentPLoc)
+                    continue;
+                
+                unsigned index = property.location().info();
+                if (index >= length)
+                    continue;
+                result->initializeIndex(vm, index, JSValue::decode(values[i]));
+            }
+            
+            return result;
+        }
+        case PhantomCreateRest: {
+            unsigned numberOfArgumentsToSkip = codeBlock->numberOfArgumentsToSkip();
+            JSGlobalObject* globalObject = codeBlock->globalObject();
+            Structure* structure = globalObject->restParameterStructure();
+            ASSERT(argumentCount > 0);
+            unsigned arraySize = (argumentCount - 1) > numberOfArgumentsToSkip ? argumentCount - 1 - numberOfArgumentsToSkip : 0;
+
+            // FIXME: we should throw an out of memory error here if tryCreateForInitializationPrivate() fails.
+            // https://bugs.webkit.org/show_bug.cgi?id=169784
+            JSArray* array = JSArray::tryCreateForInitializationPrivate(vm, structure, arraySize);
+            RELEASE_ASSERT(array);
+
+            for (unsigned i = materialization->properties().size(); i--;) {
+                const ExitPropertyValue& property = materialization->properties()[i];
+                if (property.location().kind() != ArgumentPLoc)
+                    continue;
+
+                unsigned argIndex = property.location().info();
+                if (numberOfArgumentsToSkip > argIndex)
+                    continue;
+                unsigned arrayIndex = argIndex - numberOfArgumentsToSkip;
+                if (arrayIndex >= arraySize)
+                    continue;
+                array->initializeIndex(vm, arrayIndex, JSValue::decode(values[i]));
+            }
+
+#if !ASSERT_DISABLED
+            // We avoid this O(n^2) loop when asserts are disabled, but the condition checked here
+            // must hold to ensure the correctness of the above loop because of how we allocate the array.
+            for (unsigned targetIndex = 0; targetIndex < arraySize; ++targetIndex) {
+                bool found = false;
+                for (unsigned i = materialization->properties().size(); i--;) {
+                    const ExitPropertyValue& property = materialization->properties()[i];
+                    if (property.location().kind() != ArgumentPLoc)
+                        continue;
+
+                    unsigned argIndex = property.location().info();
+                    if (numberOfArgumentsToSkip > argIndex)
+                        continue;
+                    unsigned arrayIndex = argIndex - numberOfArgumentsToSkip;
+                    if (arrayIndex >= arraySize)
+                        continue;
+                    if (arrayIndex == targetIndex) {
+                        found = true;
+                        break;
+                    }
+                }
+                ASSERT(found);
+            }
+#endif
+            return array;
+        }
+
+        default:
+            RELEASE_ASSERT_NOT_REACHED();
+            return nullptr;
+        }
+    }
+
+    case PhantomSpread: {
+        JSArray* array = nullptr;
+        for (unsigned i = materialization->properties().size(); i--;) {
+            const ExitPropertyValue& property = materialization->properties()[i];
+            if (property.location().kind() == SpreadPLoc) {
+                array = jsCast<JSArray*>(JSValue::decode(values[i]));
+                break;
+            }
+        }
+        RELEASE_ASSERT(array);
+
+        // Note: it is sound for JSFixedArray::createFromArray to call getDirectIndex here
+        // because we're guaranteed we won't be calling any getters. The reason for this is
+        // that we only support PhantomSpread over CreateRest, which is an array we create.
+        // Any attempts to put a getter on any indices on the rest array will escape the array.
+        JSFixedArray* fixedArray = JSFixedArray::createFromArray(exec, vm, array);
+        return fixedArray;
+    }
+
+    case PhantomNewArrayWithSpread: {
+        CodeBlock* codeBlock = baselineCodeBlockForOriginAndBaselineCodeBlock(
+            materialization->origin(), exec->codeBlock());
+        JSGlobalObject* globalObject = codeBlock->globalObject();
+        Structure* structure = globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithContiguous);
+
+        Checked<unsigned, RecordOverflow> checkedArraySize = 0;
+        unsigned numProperties = 0;
+        for (unsigned i = materialization->properties().size(); i--;) {
+            const ExitPropertyValue& property = materialization->properties()[i];
+            if (property.location().kind() == NewArrayWithSpreadArgumentPLoc) {
+                ++numProperties;
+                JSValue value = JSValue::decode(values[i]);
+                if (JSFixedArray* fixedArray = jsDynamicCast<JSFixedArray*>(vm, value))
+                    checkedArraySize += fixedArray->size();
+                else
+                    checkedArraySize += 1;
+            }
+        }
+
+        // FIXME: we should throw an out of memory error here if checkedArraySize has hasOverflowed() or tryCreateForInitializationPrivate() fails.
+        // https://bugs.webkit.org/show_bug.cgi?id=169784
+        unsigned arraySize = checkedArraySize.unsafeGet(); // Crashes if overflowed.
+        JSArray* result = JSArray::tryCreateForInitializationPrivate(vm, structure, arraySize);
+        RELEASE_ASSERT(result);
+
+#if !ASSERT_DISABLED
+        // Ensure we see indices for everything in the range: [0, numProperties)
+        for (unsigned i = 0; i < numProperties; ++i) {
+            bool found = false;
+            for (unsigned j = 0; j < materialization->properties().size(); ++j) {
+                const ExitPropertyValue& property = materialization->properties()[j];
+                if (property.location().kind() == NewArrayWithSpreadArgumentPLoc && property.location().info() == i) {
+                    found = true;
+                    break;
+                }
+            }
+            ASSERT(found);
+        }
+#endif
+
+        Vector<JSValue, 8> arguments;
+        arguments.grow(numProperties);
+
+        for (unsigned i = materialization->properties().size(); i--;) {
+            const ExitPropertyValue& property = materialization->properties()[i];
+            if (property.location().kind() == NewArrayWithSpreadArgumentPLoc) {
+                JSValue value = JSValue::decode(values[i]);
+                RELEASE_ASSERT(property.location().info() < numProperties);
+                arguments[property.location().info()] = value;
+            }
+        }
+
+        unsigned arrayIndex = 0;
+        for (JSValue value : arguments) {
+            if (JSFixedArray* fixedArray = jsDynamicCast<JSFixedArray*>(vm, value)) {
+                for (unsigned i = 0; i < fixedArray->size(); i++) {
+                    ASSERT(fixedArray->get(i));
+                    result->initializeIndex(vm, arrayIndex, fixedArray->get(i));
+                    ++arrayIndex;
+                }
+            } else {
+                // We are not spreading.
+                result->initializeIndex(vm, arrayIndex, value);
+                ++arrayIndex;
+            }
+        }
+
+        return result;
+    }
+
+        
+    default:
+        RELEASE_ASSERT_NOT_REACHED();
+        return nullptr;
+    }
+}
+
+extern "C" void* JIT_OPERATION compileFTLLazySlowPath(ExecState* exec, unsigned index)
+{
+    VM& vm = exec->vm();
+
+    // We cannot GC. We've got pointers in evil places.
+    DeferGCForAWhile deferGC(vm.heap);
+
+    CodeBlock* codeBlock = exec->codeBlock();
+    JITCode* jitCode = codeBlock->jitCode()->ftl();
+
+    LazySlowPath& lazySlowPath = *jitCode->lazySlowPaths[index];
+    lazySlowPath.generate(codeBlock);
+
+    return lazySlowPath.stub().code().executableAddress();
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLOperations.h b/Source/JavaScriptCore/ftl/FTLOperations.h
new file mode 100644
index 000000000..031840100
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLOperations.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+#include "DFGOperations.h"
+#include "FTLExitTimeObjectMaterialization.h"
+
+namespace JSC { namespace FTL {
+
+class LazySlowPath;
+
+extern "C" {
+
+JSCell* JIT_OPERATION operationMaterializeObjectInOSR(
+    ExecState*, ExitTimeObjectMaterialization*, EncodedJSValue*) WTF_INTERNAL;
+
+void JIT_OPERATION operationPopulateObjectInOSR(
+    ExecState*, ExitTimeObjectMaterialization*, EncodedJSValue*, EncodedJSValue*) WTF_INTERNAL;
+
+void* JIT_OPERATION compileFTLLazySlowPath(ExecState*, unsigned) WTF_INTERNAL;
+
+} // extern "C"
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLOutput.cpp b/Source/JavaScriptCore/ftl/FTLOutput.cpp
index fb2fc93b1..bd65e64e9 100644
--- a/Source/JavaScriptCore/ftl/FTLOutput.cpp
+++ b/Source/JavaScriptCore/ftl/FTLOutput.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -28,21 +28,803 @@
 
 #if ENABLE(FTL_JIT)
 
+#include "B3ArgumentRegValue.h"
+#include "B3BasicBlockInlines.h"
+#include "B3CCallValue.h"
+#include "B3Const32Value.h"
+#include "B3ConstPtrValue.h"
+#include "B3FenceValue.h"
+#include "B3MathExtras.h"
+#include "B3MemoryValue.h"
+#include "B3SlotBaseValue.h"
+#include "B3StackmapGenerationParams.h"
+#include "B3SwitchValue.h"
+#include "B3UpsilonValue.h"
+#include "B3ValueInlines.h"
+#include "SuperSampler.h"
+
 namespace JSC { namespace FTL {
 
-Output::Output(LContext context)
-    : IntrinsicRepository(context)
-    , m_function(0)
-    , m_heaps(0)
-    , m_builder(llvm->CreateBuilderInContext(m_context))
-    , m_block(0)
-    , m_nextBlock(0)
+using namespace B3;
+
+Output::Output(State& state)
+    : m_proc(*state.proc)
 {
 }
 
 Output::~Output()
 {
-    llvm->DisposeBuilder(m_builder);
+}
+
+void Output::initialize(AbstractHeapRepository& heaps)
+{
+    m_heaps = &heaps;
+}
+
+LBasicBlock Output::newBlock()
+{
+    LBasicBlock result = m_proc.addBlock(m_frequency);
+
+    if (!m_nextBlock)
+        m_blockOrder.append(result);
+    else
+        m_blockOrder.insertBefore(m_nextBlock, result);
+
+    return result;
+}
+
+void Output::applyBlockOrder()
+{
+    m_proc.setBlockOrder(m_blockOrder);
+}
+
+LBasicBlock Output::appendTo(LBasicBlock block, LBasicBlock nextBlock)
+{
+    appendTo(block);
+    return insertNewBlocksBefore(nextBlock);
+}
+
+void Output::appendTo(LBasicBlock block)
+{
+    m_block = block;
+}
+
+LValue Output::framePointer()
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::FramePointer, origin());
+}
+
+SlotBaseValue* Output::lockedStackSlot(size_t bytes)
+{
+    return m_block->appendNew<SlotBaseValue>(m_proc, origin(), m_proc.addStackSlot(bytes));
+}
+
+LValue Output::constBool(bool value)
+{
+    if (value)
+        return booleanTrue;
+    return booleanFalse;
+}
+
+LValue Output::constInt32(int32_t value)
+{
+    return m_block->appendNew<B3::Const32Value>(m_proc, origin(), value);
+}
+
+LValue Output::constInt64(int64_t value)
+{
+    return m_block->appendNew<B3::Const64Value>(m_proc, origin(), value);
+}
+
+LValue Output::constDouble(double value)
+{
+    return m_block->appendNew<B3::ConstDoubleValue>(m_proc, origin(), value);
+}
+
+LValue Output::phi(LType type)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Phi, type, origin());
+}
+
+LValue Output::add(LValue left, LValue right)
+{
+    if (Value* result = left->addConstant(m_proc, right)) {
+        m_block->append(result);
+        return result;
+    }
+    return m_block->appendNew<B3::Value>(m_proc, B3::Add, origin(), left, right);
+}
+
+LValue Output::sub(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Sub, origin(), left, right);
+}
+
+LValue Output::mul(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Mul, origin(), left, right);
+}
+
+LValue Output::div(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Div, origin(), left, right);
+}
+
+LValue Output::chillDiv(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, chill(B3::Div), origin(), left, right);
+}
+
+LValue Output::mod(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Mod, origin(), left, right);
+}
+
+LValue Output::chillMod(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, chill(B3::Mod), origin(), left, right);
+}
+
+LValue Output::neg(LValue value)
+{
+    return m_block->appendNew<Value>(m_proc, B3::Neg, origin(), value);
+}
+
+LValue Output::doubleAdd(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Add, origin(), left, right);
+}
+
+LValue Output::doubleSub(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Sub, origin(), left, right);
+}
+
+LValue Output::doubleMul(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Mul, origin(), left, right);
+}
+
+LValue Output::doubleDiv(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Div, origin(), left, right);
+}
+
+LValue Output::doubleMod(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Mod, origin(), left, right);
+}
+
+LValue Output::bitAnd(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::BitAnd, origin(), left, right);
+}
+
+LValue Output::bitOr(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::BitOr, origin(), left, right);
+}
+
+LValue Output::bitXor(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::BitXor, origin(), left, right);
+}
+
+LValue Output::shl(LValue left, LValue right)
+{
+    right = castToInt32(right);
+    if (Value* result = left->shlConstant(m_proc, right)) {
+        m_block->append(result);
+        return result;
+    }
+    return m_block->appendNew<B3::Value>(m_proc, B3::Shl, origin(), left, right);
+}
+
+LValue Output::aShr(LValue left, LValue right)
+{
+    right = castToInt32(right);
+    if (Value* result = left->sShrConstant(m_proc, right)) {
+        m_block->append(result);
+        return result;
+    }
+    return m_block->appendNew<B3::Value>(m_proc, B3::SShr, origin(), left, right);
+}
+
+LValue Output::lShr(LValue left, LValue right)
+{
+    right = castToInt32(right);
+    if (Value* result = left->zShrConstant(m_proc, right)) {
+        m_block->append(result);
+        return result;
+    }
+    return m_block->appendNew<B3::Value>(m_proc, B3::ZShr, origin(), left, right);
+}
+
+LValue Output::bitNot(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::BitXor, origin(),
+        value,
+        m_block->appendIntConstant(m_proc, origin(), value->type(), -1));
+}
+
+LValue Output::logicalNot(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Equal, origin(), value, int32Zero);
+}
+
+LValue Output::ctlz32(LValue operand)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Clz, origin(), operand);
+}
+
+LValue Output::doubleAbs(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Abs, origin(), value);
+}
+
+LValue Output::doubleCeil(LValue operand)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Ceil, origin(), operand);
+}
+
+LValue Output::doubleFloor(LValue operand)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Floor, origin(), operand);
+}
+
+LValue Output::doubleTrunc(LValue value)
+{
+    if (MacroAssembler::supportsFloatingPointRounding()) {
+        PatchpointValue* result = patchpoint(Double);
+        result->append(value, ValueRep::SomeRegister);
+        result->setGenerator(
+            [] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+                jit.roundTowardZeroDouble(params[1].fpr(), params[0].fpr());
+            });
+        result->effects = Effects::none();
+        return result;
+    }
+    double (*truncDouble)(double) = trunc;
+    return callWithoutSideEffects(Double, truncDouble, value);
+}
+
+LValue Output::doubleSin(LValue value)
+{
+    double (*sinDouble)(double) = sin;
+    return callWithoutSideEffects(B3::Double, sinDouble, value);
+}
+
+LValue Output::doubleCos(LValue value)
+{
+    double (*cosDouble)(double) = cos;
+    return callWithoutSideEffects(B3::Double, cosDouble, value);
+}
+
+LValue Output::doubleTan(LValue value)
+{
+    double (*tanDouble)(double) = tan;
+    return callWithoutSideEffects(B3::Double, tanDouble, value);
+}
+
+LValue Output::doublePow(LValue xOperand, LValue yOperand)
+{
+    double (*powDouble)(double, double) = pow;
+    return callWithoutSideEffects(B3::Double, powDouble, xOperand, yOperand);
+}
+
+LValue Output::doublePowi(LValue x, LValue y)
+{
+    // FIXME: powDoubleInt32() should be inlined here since Output knows about block layout and
+    // should be involved in any operation that creates blocks.
+    // https://bugs.webkit.org/show_bug.cgi?id=152223
+    auto result = powDoubleInt32(m_proc, m_block, origin(), x, y);
+    m_block = result.first;
+    return result.second;
+}
+
+LValue Output::doubleSqrt(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Sqrt, origin(), value);
+}
+
+LValue Output::doubleLog(LValue value)
+{
+    double (*logDouble)(double) = log;
+    return callWithoutSideEffects(B3::Double, logDouble, value);
+}
+
+LValue Output::doubleToInt(LValue value)
+{
+    PatchpointValue* result = patchpoint(Int32);
+    result->append(value, ValueRep::SomeRegister);
+    result->setGenerator(
+        [] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+            jit.truncateDoubleToInt32(params[1].fpr(), params[0].gpr());
+        });
+    result->effects = Effects::none();
+    return result;
+}
+
+LValue Output::doubleToUInt(LValue value)
+{
+    PatchpointValue* result = patchpoint(Int32);
+    result->append(value, ValueRep::SomeRegister);
+    result->setGenerator(
+        [] (CCallHelpers& jit, const StackmapGenerationParams& params) {
+            jit.truncateDoubleToUint32(params[1].fpr(), params[0].gpr());
+        });
+    result->effects = Effects::none();
+    return result;
+}
+
+LValue Output::signExt32To64(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::SExt32, origin(), value);
+}
+
+LValue Output::signExt32ToPtr(LValue value)
+{
+    return signExt32To64(value);
+}
+
+LValue Output::zeroExt(LValue value, LType type)
+{
+    if (value->type() == type)
+        return value;
+    if (value->hasInt32())
+        return m_block->appendIntConstant(m_proc, origin(), Int64, static_cast<uint64_t>(static_cast<uint32_t>(value->asInt32())));
+    return m_block->appendNew<B3::Value>(m_proc, B3::ZExt32, origin(), value);
+}
+
+LValue Output::intToDouble(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::IToD, origin(), value);
+}
+
+LValue Output::unsignedToDouble(LValue value)
+{
+    return intToDouble(zeroExt(value, Int64));
+}
+
+LValue Output::castToInt32(LValue value)
+{
+    if (value->type() == Int32)
+        return value;
+    if (value->hasInt64())
+        return constInt32(static_cast<int32_t>(value->asInt64()));
+    return m_block->appendNew<B3::Value>(m_proc, B3::Trunc, origin(), value);
+}
+
+LValue Output::doubleToFloat(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::DoubleToFloat, origin(), value);
+}
+
+LValue Output::floatToDouble(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::FloatToDouble, origin(), value);
+}
+
+LValue Output::load(TypedPointer pointer, LType type)
+{
+    LValue load = m_block->appendNew<MemoryValue>(m_proc, Load, type, origin(), pointer.value());
+    m_heaps->decorateMemory(pointer.heap(), load);
+    return load;
+}
+
+LValue Output::load8SignExt32(TypedPointer pointer)
+{
+    LValue load = m_block->appendNew<MemoryValue>(m_proc, Load8S, Int32, origin(), pointer.value());
+    m_heaps->decorateMemory(pointer.heap(), load);
+    return load;
+}
+
+LValue Output::load8ZeroExt32(TypedPointer pointer)
+{
+    LValue load = m_block->appendNew<MemoryValue>(m_proc, Load8Z, Int32, origin(), pointer.value());
+    m_heaps->decorateMemory(pointer.heap(), load);
+    return load;
+}
+
+LValue Output::load16SignExt32(TypedPointer pointer)
+{
+    LValue load = m_block->appendNew<MemoryValue>(m_proc, Load16S, Int32, origin(), pointer.value());
+    m_heaps->decorateMemory(pointer.heap(), load);
+    return load;
+}
+
+LValue Output::load16ZeroExt32(TypedPointer pointer)
+{
+    LValue load = m_block->appendNew<MemoryValue>(m_proc, Load16Z, Int32, origin(), pointer.value());
+    m_heaps->decorateMemory(pointer.heap(), load);
+    return load;
+}
+
+void Output::store(LValue value, TypedPointer pointer)
+{
+    LValue store = m_block->appendNew<MemoryValue>(m_proc, Store, origin(), value, pointer.value());
+    m_heaps->decorateMemory(pointer.heap(), store);
+}
+
+FenceValue* Output::fence(const AbstractHeap* read, const AbstractHeap* write)
+{
+    FenceValue* result = m_block->appendNew<FenceValue>(m_proc, origin());
+    m_heaps->decorateFenceRead(read, result);
+    m_heaps->decorateFenceWrite(write, result);
+    return result;
+}
+
+void Output::store32As8(LValue value, TypedPointer pointer)
+{
+    LValue store = m_block->appendNew<MemoryValue>(m_proc, Store8, origin(), value, pointer.value());
+    m_heaps->decorateMemory(pointer.heap(), store);
+}
+
+void Output::store32As16(LValue value, TypedPointer pointer)
+{
+    LValue store = m_block->appendNew<MemoryValue>(m_proc, Store16, origin(), value, pointer.value());
+    m_heaps->decorateMemory(pointer.heap(), store);
+}
+
+LValue Output::baseIndex(LValue base, LValue index, Scale scale, ptrdiff_t offset)
+{
+    LValue accumulatedOffset;
+        
+    switch (scale) {
+    case ScaleOne:
+        accumulatedOffset = index;
+        break;
+    case ScaleTwo:
+        accumulatedOffset = shl(index, intPtrOne);
+        break;
+    case ScaleFour:
+        accumulatedOffset = shl(index, intPtrTwo);
+        break;
+    case ScaleEight:
+    case ScalePtr:
+        accumulatedOffset = shl(index, intPtrThree);
+        break;
+    }
+        
+    if (offset)
+        accumulatedOffset = add(accumulatedOffset, constIntPtr(offset));
+        
+    return add(base, accumulatedOffset);
+}
+
+LValue Output::equal(LValue left, LValue right)
+{
+    TriState result = left->equalConstant(right);
+    if (result != MixedTriState)
+        return constBool(result == TrueTriState);
+    return m_block->appendNew<B3::Value>(m_proc, B3::Equal, origin(), left, right);
+}
+
+LValue Output::notEqual(LValue left, LValue right)
+{
+    TriState result = left->notEqualConstant(right);
+    if (result != MixedTriState)
+        return constBool(result == TrueTriState);
+    return m_block->appendNew<B3::Value>(m_proc, B3::NotEqual, origin(), left, right);
+}
+
+LValue Output::above(LValue left, LValue right)
+{
+    TriState result = left->aboveConstant(right);
+    if (result != MixedTriState)
+        return constBool(result == TrueTriState);
+    return m_block->appendNew<B3::Value>(m_proc, B3::Above, origin(), left, right);
+}
+
+LValue Output::aboveOrEqual(LValue left, LValue right)
+{
+    TriState result = left->aboveEqualConstant(right);
+    if (result != MixedTriState)
+        return constBool(result == TrueTriState);
+    return m_block->appendNew<B3::Value>(m_proc, B3::AboveEqual, origin(), left, right);
+}
+
+LValue Output::below(LValue left, LValue right)
+{
+    TriState result = left->belowConstant(right);
+    if (result != MixedTriState)
+        return constBool(result == TrueTriState);
+    return m_block->appendNew<B3::Value>(m_proc, B3::Below, origin(), left, right);
+}
+
+LValue Output::belowOrEqual(LValue left, LValue right)
+{
+    TriState result = left->belowEqualConstant(right);
+    if (result != MixedTriState)
+        return constBool(result == TrueTriState);
+    return m_block->appendNew<B3::Value>(m_proc, B3::BelowEqual, origin(), left, right);
+}
+
+LValue Output::greaterThan(LValue left, LValue right)
+{
+    TriState result = left->greaterThanConstant(right);
+    if (result != MixedTriState)
+        return constBool(result == TrueTriState);
+    return m_block->appendNew<B3::Value>(m_proc, B3::GreaterThan, origin(), left, right);
+}
+
+LValue Output::greaterThanOrEqual(LValue left, LValue right)
+{
+    TriState result = left->greaterEqualConstant(right);
+    if (result != MixedTriState)
+        return constBool(result == TrueTriState);
+    return m_block->appendNew<B3::Value>(m_proc, B3::GreaterEqual, origin(), left, right);
+}
+
+LValue Output::lessThan(LValue left, LValue right)
+{
+    TriState result = left->lessThanConstant(right);
+    if (result != MixedTriState)
+        return constBool(result == TrueTriState);
+    return m_block->appendNew<B3::Value>(m_proc, B3::LessThan, origin(), left, right);
+}
+
+LValue Output::lessThanOrEqual(LValue left, LValue right)
+{
+    TriState result = left->lessEqualConstant(right);
+    if (result != MixedTriState)
+        return constBool(result == TrueTriState);
+    return m_block->appendNew<B3::Value>(m_proc, B3::LessEqual, origin(), left, right);
+}
+
+LValue Output::doubleEqual(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Equal, origin(), left, right);
+}
+
+LValue Output::doubleEqualOrUnordered(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::EqualOrUnordered, origin(), left, right);
+}
+
+LValue Output::doubleNotEqualOrUnordered(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::NotEqual, origin(), left, right);
+}
+
+LValue Output::doubleLessThan(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::LessThan, origin(), left, right);
+}
+
+LValue Output::doubleLessThanOrEqual(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::LessEqual, origin(), left, right);
+}
+
+LValue Output::doubleGreaterThan(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::GreaterThan, origin(), left, right);
+}
+
+LValue Output::doubleGreaterThanOrEqual(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::GreaterEqual, origin(), left, right);
+}
+
+LValue Output::doubleNotEqualAndOrdered(LValue left, LValue right)
+{
+    return logicalNot(doubleEqualOrUnordered(left, right));
+}
+
+LValue Output::doubleLessThanOrUnordered(LValue left, LValue right)
+{
+    return logicalNot(doubleGreaterThanOrEqual(left, right));
+}
+
+LValue Output::doubleLessThanOrEqualOrUnordered(LValue left, LValue right)
+{
+    return logicalNot(doubleGreaterThan(left, right));
+}
+
+LValue Output::doubleGreaterThanOrUnordered(LValue left, LValue right)
+{
+    return logicalNot(doubleLessThanOrEqual(left, right));
+}
+
+LValue Output::doubleGreaterThanOrEqualOrUnordered(LValue left, LValue right)
+{
+    return logicalNot(doubleLessThan(left, right));
+}
+
+LValue Output::isZero32(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Equal, origin(), value, int32Zero);
+}
+
+LValue Output::notZero32(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::NotEqual, origin(), value, int32Zero);
+}
+
+LValue Output::isZero64(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::Equal, origin(), value, int64Zero);
+}
+
+LValue Output::notZero64(LValue value)
+{
+    return m_block->appendNew<B3::Value>(m_proc, B3::NotEqual, origin(), value, int64Zero);
+}
+
+LValue Output::select(LValue value, LValue taken, LValue notTaken)
+{
+    if (value->hasInt32()) {
+        if (value->asInt32())
+            return taken;
+        else
+            return notTaken;
+    }
+    return m_block->appendNew<B3::Value>(m_proc, B3::Select, origin(), value, taken, notTaken);
+}
+
+void Output::jump(LBasicBlock destination)
+{
+    m_block->appendNewControlValue(m_proc, B3::Jump, origin(), B3::FrequentedBlock(destination));
+}
+
+void Output::branch(LValue condition, LBasicBlock taken, Weight takenWeight, LBasicBlock notTaken, Weight notTakenWeight)
+{
+    m_block->appendNewControlValue(
+        m_proc, B3::Branch, origin(), condition,
+        FrequentedBlock(taken, takenWeight.frequencyClass()),
+        FrequentedBlock(notTaken, notTakenWeight.frequencyClass()));
+}
+
+void Output::check(LValue condition, WeightedTarget taken, Weight notTakenWeight)
+{
+    LBasicBlock continuation = newBlock();
+    branch(condition, taken, WeightedTarget(continuation, notTakenWeight));
+    appendTo(continuation);
+}
+
+void Output::check(LValue condition, WeightedTarget taken)
+{
+    check(condition, taken, taken.weight().inverse());
+}
+
+void Output::ret(LValue value)
+{
+    m_block->appendNewControlValue(m_proc, B3::Return, origin(), value);
+}
+
+void Output::unreachable()
+{
+    m_block->appendNewControlValue(m_proc, B3::Oops, origin());
+}
+
+void Output::appendSuccessor(WeightedTarget target)
+{
+    m_block->appendSuccessor(target.frequentedBlock());
+}
+
+CheckValue* Output::speculate(LValue value)
+{
+    return m_block->appendNew<B3::CheckValue>(m_proc, B3::Check, origin(), value);
+}
+
+CheckValue* Output::speculateAdd(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::CheckValue>(m_proc, B3::CheckAdd, origin(), left, right);
+}
+
+CheckValue* Output::speculateSub(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::CheckValue>(m_proc, B3::CheckSub, origin(), left, right);
+}
+
+CheckValue* Output::speculateMul(LValue left, LValue right)
+{
+    return m_block->appendNew<B3::CheckValue>(m_proc, B3::CheckMul, origin(), left, right);
+}
+
+PatchpointValue* Output::patchpoint(LType type)
+{
+    return m_block->appendNew<B3::PatchpointValue>(m_proc, type, origin());
+}
+
+void Output::trap()
+{
+    m_block->appendNewControlValue(m_proc, B3::Oops, origin());
+}
+
+ValueFromBlock Output::anchor(LValue value)
+{
+    B3::UpsilonValue* upsilon = m_block->appendNew<B3::UpsilonValue>(m_proc, origin(), value);
+    return ValueFromBlock(upsilon, m_block);
+}
+
+LValue Output::bitCast(LValue value, LType type)
+{
+    ASSERT_UNUSED(type, type == Int64 || type == Double);
+    return m_block->appendNew<B3::Value>(m_proc, B3::BitwiseCast, origin(), value);
+}
+
+LValue Output::fround(LValue doubleValue)
+{
+    return floatToDouble(doubleToFloat(doubleValue));
+}
+
+LValue Output::load(TypedPointer pointer, LoadType type)
+{
+    switch (type) {
+    case Load8SignExt32:
+        return load8SignExt32(pointer);
+    case Load8ZeroExt32:
+        return load8ZeroExt32(pointer);
+    case Load16SignExt32:
+        return load8SignExt32(pointer);
+    case Load16ZeroExt32:
+        return load8ZeroExt32(pointer);
+    case Load32:
+        return load32(pointer);
+    case Load64:
+        return load64(pointer);
+    case LoadPtr:
+        return loadPtr(pointer);
+    case LoadFloat:
+        return loadFloat(pointer);
+    case LoadDouble:
+        return loadDouble(pointer);
+    }
+    RELEASE_ASSERT_NOT_REACHED();
+    return nullptr;
+}
+
+void Output::store(LValue value, TypedPointer pointer, StoreType type)
+{
+    switch (type) {
+    case Store32As8:
+        store32As8(value, pointer);
+        return;
+    case Store32As16:
+        store32As16(value, pointer);
+        return;
+    case Store32:
+        store32(value, pointer);
+        return;
+    case Store64:
+        store64(value, pointer);
+        return;
+    case StorePtr:
+        storePtr(value, pointer);
+        return;
+    case StoreFloat:
+        storeFloat(value, pointer);
+        return;
+    case StoreDouble:
+        storeDouble(value, pointer);
+        return;
+    }
+    RELEASE_ASSERT_NOT_REACHED();
+}
+
+TypedPointer Output::absolute(const void* address)
+{
+    return TypedPointer(m_heaps->absolute[address], constIntPtr(address));
+}
+
+void Output::incrementSuperSamplerCount()
+{
+    TypedPointer counter = absolute(bitwise_cast<void*>(&g_superSamplerCount));
+    store32(add(load32(counter), int32One), counter);
+}
+
+void Output::decrementSuperSamplerCount()
+{
+    TypedPointer counter = absolute(bitwise_cast<void*>(&g_superSamplerCount));
+    store32(sub(load32(counter), int32One), counter);
+}
+
+void Output::addIncomingToPhi(LValue phi, ValueFromBlock value)
+{
+    if (value)
+        value.value()->as<B3::UpsilonValue>()->setPhi(phi);
 }
 
 } } // namespace JSC::FTL
diff --git a/Source/JavaScriptCore/ftl/FTLOutput.h b/Source/JavaScriptCore/ftl/FTLOutput.h
index 2ec873503..91e548c78 100644
--- a/Source/JavaScriptCore/ftl/FTLOutput.h
+++ b/Source/JavaScriptCore/ftl/FTLOutput.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -20,228 +20,260 @@
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef FTLOutput_h
-#define FTLOutput_h
+#pragma once
 
-#include <wtf/Platform.h>
+#include "DFGCommon.h"
 
 #if ENABLE(FTL_JIT)
 
-#include "DFGCommon.h"
-#include "FTLAbbreviations.h"
+#include "B3BasicBlockInlines.h"
+#include "B3CCallValue.h"
+#include "B3Compilation.h"
+#include "B3FrequentedBlock.h"
+#include "B3Procedure.h"
+#include "B3SwitchValue.h"
+#include "FTLAbbreviatedTypes.h"
 #include "FTLAbstractHeapRepository.h"
 #include "FTLCommonValues.h"
-#include "FTLIntrinsicRepository.h"
+#include "FTLState.h"
+#include "FTLSwitchCase.h"
 #include "FTLTypedPointer.h"
+#include "FTLValueFromBlock.h"
+#include "FTLWeight.h"
+#include "FTLWeightedTarget.h"
+#include "HeapCell.h"
+#include <wtf/OrderMaker.h>
 #include <wtf/StringPrintStream.h>
 
-namespace JSC { namespace FTL {
-
-// Idiomatic LLVM IR builder specifically designed for FTL. This uses our own lowering
-// terminology, and has some of its own notions:
-//
-// We say that a "reference" is what LLVM considers to be a "pointer". That is, it has
-// an element type and can be passed directly to memory access instructions. Note that
-// broadly speaking the users of FTL::Output should only use references for alloca'd
-// slots for mutable local variables.
-//
-// We say that a "pointer" is what LLVM considers to be a pointer-width integer.
-//
-// We say that a "typed pointer" is a pointer that carries TBAA meta-data (i.e. an
-// AbstractHeap). These should usually not have further computation performed on them
-// prior to access, though there are exceptions (like offsetting into the payload of
-// a typed pointer to a JSValue).
-//
-// We say that "get" and "set" are what LLVM considers to be "load" and "store". Get
-// and set take references.
-//
-// We say that "load" and "store" are operations that take a typed pointer. These
-// operations translate the pointer into a reference (or, a pointer in LLVM-speak),
-// emit get or set on the reference (or, load and store in LLVM-speak), and apply the
-// TBAA meta-data to the get or set.
+// FIXME: remove this once everything can be generated through B3.
+#if COMPILER(GCC_OR_CLANG)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-noreturn"
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+#endif // COMPILER(GCC_OR_CLANG)
+
+namespace JSC {
+
+namespace DFG {
+struct Node;
+} // namespace DFG
+
+namespace B3 {
+class FenceValue;
+class SlotBaseValue;
+} // namespace B3
+
+namespace FTL {
 
 enum Scale { ScaleOne, ScaleTwo, ScaleFour, ScaleEight, ScalePtr };
 
-class Output : public IntrinsicRepository {
+class Output : public CommonValues {
 public:
-    Output(LContext);
+    Output(State&);
     ~Output();
-    
-    void initialize(LModule module, LValue function, AbstractHeapRepository& heaps)
+
+    void initialize(AbstractHeapRepository&);
+
+    void setFrequency(double value)
     {
-        IntrinsicRepository::initialize(module);
-        m_function = function;
-        m_heaps = &heaps;
+        m_frequency = value;
     }
-    
+
+    LBasicBlock newBlock();
+
     LBasicBlock insertNewBlocksBefore(LBasicBlock nextBlock)
     {
         LBasicBlock lastNextBlock = m_nextBlock;
         m_nextBlock = nextBlock;
         return lastNextBlock;
     }
-    
-    LBasicBlock appendTo(LBasicBlock block, LBasicBlock nextBlock)
-    {
-        appendTo(block);
-        return insertNewBlocksBefore(nextBlock);
-    }
-    
-    void appendTo(LBasicBlock block)
+
+    void applyBlockOrder();
+
+    LBasicBlock appendTo(LBasicBlock, LBasicBlock nextBlock);
+    void appendTo(LBasicBlock);
+
+    void setOrigin(DFG::Node* node) { m_origin = node; }
+    B3::Origin origin() { return B3::Origin(m_origin); }
+
+    LValue framePointer();
+
+    B3::SlotBaseValue* lockedStackSlot(size_t bytes);
+
+    LValue constBool(bool value);
+    LValue constInt32(int32_t value);
+
+    LValue weakPointer(DFG::Graph& graph, JSCell* cell)
     {
-        m_block = block;
-        
-        llvm->PositionBuilderAtEnd(m_builder, block);
+        ASSERT(graph.m_plan.weakReferences.contains(cell));
+
+        if (sizeof(void*) == 8)
+            return constInt64(bitwise_cast<intptr_t>(cell));
+        return constInt32(bitwise_cast<intptr_t>(cell));
     }
-    LBasicBlock newBlock(const char* name = "")
+
+    LValue weakPointer(DFG::FrozenValue* value)
     {
-        if (!m_nextBlock)
-            return appendBasicBlock(m_context, m_function, name);
-        return insertBasicBlock(m_context, m_nextBlock, name);
+        RELEASE_ASSERT(value->value().isCell());
+
+        if (sizeof(void*) == 8)
+            return constInt64(bitwise_cast<intptr_t>(value->cell()));
+        return constInt32(bitwise_cast<intptr_t>(value->cell()));
     }
-    
-    LValue param(unsigned index) { return getParam(m_function, index); }
-    LValue constBool(bool value) { return constInt(boolean, value); }
-    LValue constInt8(int8_t value) { return constInt(int8, value); }
-    LValue constInt32(int32_t value) { return constInt(int32, value); }
-    template<typename T>
-    LValue constIntPtr(T* value) { return constInt(intPtr, bitwise_cast<intptr_t>(value)); }
+
     template<typename T>
-    LValue constIntPtr(T value) { return constInt(intPtr, static_cast<intptr_t>(value)); }
-    LValue constInt64(int64_t value) { return constInt(int64, value); }
-    LValue constDouble(double value) { return constReal(doubleType, value); }
-    
-    LValue phi(LType type) { return buildPhi(m_builder, type); }
-    LValue phi(LType type, ValueFromBlock value1)
+    LValue constIntPtr(T* value)
     {
-        return buildPhi(m_builder, type, value1);
+        static_assert(!std::is_base_of<HeapCell, T>::value, "To use a GC pointer, the graph must be aware of it. Use gcPointer instead and make sure the graph is aware of this reference.");
+        if (sizeof(void*) == 8)
+            return constInt64(bitwise_cast<intptr_t>(value));
+        return constInt32(bitwise_cast<intptr_t>(value));
     }
-    LValue phi(LType type, ValueFromBlock value1, ValueFromBlock value2)
+    template<typename T>
+    LValue constIntPtr(T value)
     {
-        return buildPhi(m_builder, type, value1, value2);
+        if (sizeof(void*) == 8)
+            return constInt64(static_cast<intptr_t>(value));
+        return constInt32(static_cast<intptr_t>(value));
     }
+    LValue constInt64(int64_t value);
+    LValue constDouble(double value);
+
+    LValue phi(LType);
+    template<typename... Params>
+    LValue phi(LType, ValueFromBlock, Params... theRest);
     template<typename VectorType>
-    LValue phi(LType type, const VectorType& vector)
-    {
-        LValue result = phi(type);
-        for (unsigned i = 0; i < vector.size(); ++i)
-            addIncoming(result, vector[i]);
-        return result;
-    }
-    
-    LValue add(LValue left, LValue right) { return buildAdd(m_builder, left, right); }
-    LValue sub(LValue left, LValue right) { return buildSub(m_builder, left, right); }
-    LValue mul(LValue left, LValue right) { return buildMul(m_builder, left, right); }
-    LValue div(LValue left, LValue right) { return buildDiv(m_builder, left, right); }
-    LValue rem(LValue left, LValue right) { return buildRem(m_builder, left, right); }
-    LValue neg(LValue value) { return buildNeg(m_builder, value); }
-
-    LValue doubleAdd(LValue left, LValue right) { return buildFAdd(m_builder, left, right); }
-    LValue doubleSub(LValue left, LValue right) { return buildFSub(m_builder, left, right); }
-    LValue doubleMul(LValue left, LValue right) { return buildFMul(m_builder, left, right); }
-    LValue doubleDiv(LValue left, LValue right) { return buildFDiv(m_builder, left, right); }
-    LValue doubleRem(LValue left, LValue right) { return buildFRem(m_builder, left, right); }
-    LValue doubleNeg(LValue value) { return buildFNeg(m_builder, value); }
-
-    LValue bitAnd(LValue left, LValue right) { return buildAnd(m_builder, left, right); }
-    LValue bitOr(LValue left, LValue right) { return buildOr(m_builder, left, right); }
-    LValue bitXor(LValue left, LValue right) { return buildXor(m_builder, left, right); }
-    LValue shl(LValue left, LValue right) { return buildShl(m_builder, left, right); }
-    LValue aShr(LValue left, LValue right) { return buildAShr(m_builder, left, right); }
-    LValue lShr(LValue left, LValue right) { return buildLShr(m_builder, left, right); }
-    LValue bitNot(LValue value) { return buildNot(m_builder, value); }
-    
-    LValue insertElement(LValue vector, LValue element, LValue index) { return buildInsertElement(m_builder, vector, element, index); }
-    
-    LValue addWithOverflow32(LValue left, LValue right)
-    {
-        return call(addWithOverflow32Intrinsic(), left, right);
-    }
-    LValue subWithOverflow32(LValue left, LValue right)
-    {
-        return call(subWithOverflow32Intrinsic(), left, right);
-    }
-    LValue mulWithOverflow32(LValue left, LValue right)
-    {
-        return call(mulWithOverflow32Intrinsic(), left, right);
-    }
-    LValue addWithOverflow64(LValue left, LValue right)
-    {
-        return call(addWithOverflow64Intrinsic(), left, right);
-    }
-    LValue subWithOverflow64(LValue left, LValue right)
-    {
-        return call(subWithOverflow64Intrinsic(), left, right);
-    }
-    LValue mulWithOverflow64(LValue left, LValue right)
+    LValue phi(LType, const VectorType&);
+    void addIncomingToPhi(LValue phi, ValueFromBlock);
+    template<typename... Params>
+    void addIncomingToPhi(LValue phi, ValueFromBlock, Params... theRest);
+
+    LValue add(LValue, LValue);
+    LValue sub(LValue, LValue);
+    LValue mul(LValue, LValue);
+    LValue div(LValue, LValue);
+    LValue chillDiv(LValue, LValue);
+    LValue mod(LValue, LValue);
+    LValue chillMod(LValue, LValue);
+    LValue neg(LValue);
+
+    LValue doubleAdd(LValue, LValue);
+    LValue doubleSub(LValue, LValue);
+    LValue doubleMul(LValue, LValue);
+    LValue doubleDiv(LValue, LValue);
+    LValue doubleMod(LValue, LValue);
+    LValue doubleNeg(LValue value) { return neg(value); }
+
+    LValue bitAnd(LValue, LValue);
+    LValue bitOr(LValue, LValue);
+    LValue bitXor(LValue, LValue);
+    LValue shl(LValue, LValue shiftAmount);
+    LValue aShr(LValue, LValue shiftAmount);
+    LValue lShr(LValue, LValue shiftAmount);
+    LValue bitNot(LValue);
+    LValue logicalNot(LValue);
+
+    LValue ctlz32(LValue);
+    LValue doubleAbs(LValue);
+    LValue doubleCeil(LValue);
+    LValue doubleFloor(LValue);
+    LValue doubleTrunc(LValue);
+
+    LValue doubleSin(LValue);
+    LValue doubleCos(LValue);
+    LValue doubleTan(LValue);
+
+    LValue doublePow(LValue base, LValue exponent);
+    LValue doublePowi(LValue base, LValue exponent);
+
+    LValue doubleSqrt(LValue);
+
+    LValue doubleLog(LValue);
+
+    LValue doubleToInt(LValue);
+    LValue doubleToUInt(LValue);
+
+    LValue signExt32To64(LValue);
+    LValue signExt32ToPtr(LValue);
+    LValue zeroExt(LValue, LType);
+    LValue zeroExtPtr(LValue value) { return zeroExt(value, B3::Int64); }
+    LValue intToDouble(LValue);
+    LValue unsignedToDouble(LValue);
+    LValue castToInt32(LValue);
+    LValue doubleToFloat(LValue);
+    LValue floatToDouble(LValue);
+    LValue bitCast(LValue, LType);
+    LValue fround(LValue);
+
+    LValue load(TypedPointer, LType);
+    void store(LValue, TypedPointer);
+    B3::FenceValue* fence(const AbstractHeap* read, const AbstractHeap* write);
+
+    LValue load8SignExt32(TypedPointer);
+    LValue load8ZeroExt32(TypedPointer);
+    LValue load16SignExt32(TypedPointer);
+    LValue load16ZeroExt32(TypedPointer);
+    LValue load32(TypedPointer pointer) { return load(pointer, B3::Int32); }
+    LValue load64(TypedPointer pointer) { return load(pointer, B3::Int64); }
+    LValue loadPtr(TypedPointer pointer) { return load(pointer, B3::pointerType()); }
+    LValue loadFloat(TypedPointer pointer) { return load(pointer, B3::Float); }
+    LValue loadDouble(TypedPointer pointer) { return load(pointer, B3::Double); }
+    void store32As8(LValue, TypedPointer);
+    void store32As16(LValue, TypedPointer);
+    void store32(LValue value, TypedPointer pointer)
     {
-        return call(mulWithOverflow64Intrinsic(), left, right);
+        ASSERT(value->type() == B3::Int32);
+        store(value, pointer);
     }
-    LValue doubleAbs(LValue value)
+    void store64(LValue value, TypedPointer pointer)
     {
-        return call(doubleAbsIntrinsic(), value);
+        ASSERT(value->type() == B3::Int64);
+        store(value, pointer);
     }
-    
-    static bool hasSensibleDoubleToInt() { return isX86(); }
-    LValue sensibleDoubleToInt(LValue value)
+    void storePtr(LValue value, TypedPointer pointer)
     {
-        RELEASE_ASSERT(isX86());
-        return call(
-            x86SSE2CvtTSD2SIIntrinsic(),
-            insertElement(
-                insertElement(getUndef(vectorType(doubleType, 2)), value, int32Zero),
-                doubleZero, int32One));
+        ASSERT(value->type() == B3::pointerType());
+        store(value, pointer);
     }
-    
-    LValue signExt(LValue value, LType type) { return buildSExt(m_builder, value, type); }
-    LValue zeroExt(LValue value, LType type) { return buildZExt(m_builder, value, type); }
-    LValue fpToInt(LValue value, LType type) { return buildFPToSI(m_builder, value, type); }
-    LValue fpToUInt(LValue value, LType type) { return buildFPToUI(m_builder, value, type); }
-    LValue fpToInt32(LValue value) { return fpToInt(value, int32); }
-    LValue fpToUInt32(LValue value) { return fpToUInt(value, int32); }
-    LValue intToFP(LValue value, LType type) { return buildSIToFP(m_builder, value, type); }
-    LValue intToDouble(LValue value) { return intToFP(value, doubleType); }
-    LValue unsignedToFP(LValue value, LType type) { return buildUIToFP(m_builder, value, type); }
-    LValue unsignedToDouble(LValue value) { return unsignedToFP(value, doubleType); }
-    LValue intCast(LValue value, LType type) { return buildIntCast(m_builder, value, type); }
-    LValue castToInt32(LValue value) { return intCast(value, int32); }
-    LValue fpCast(LValue value, LType type) { return buildFPCast(m_builder, value, type); }
-    LValue intToPtr(LValue value, LType type) { return buildIntToPtr(m_builder, value, type); }
-    LValue bitCast(LValue value, LType type) { return buildBitCast(m_builder, value, type); }
-    
-    LValue alloca(LType type) { return buildAlloca(m_builder, type); }
-    LValue get(LValue reference) { return buildLoad(m_builder, reference); }
-    LValue set(LValue value, LValue reference) { return buildStore(m_builder, value, reference); }
-    
-    LValue load(TypedPointer pointer, LType refType)
+    void storeFloat(LValue value, TypedPointer pointer)
     {
-        LValue result = get(intToPtr(pointer.value(), refType));
-        pointer.heap().decorateInstruction(result, *m_heaps);
-        return result;
+        ASSERT(value->type() == B3::Float);
+        store(value, pointer);
     }
-    void store(LValue value, TypedPointer pointer, LType refType)
+    void storeDouble(LValue value, TypedPointer pointer)
     {
-        LValue result = set(value, intToPtr(pointer.value(), refType));
-        pointer.heap().decorateInstruction(result, *m_heaps);
+        ASSERT(value->type() == B3::Double);
+        store(value, pointer);
     }
-    
-    LValue load8(TypedPointer pointer) { return load(pointer, ref8); }
-    LValue load16(TypedPointer pointer) { return load(pointer, ref16); }
-    LValue load32(TypedPointer pointer) { return load(pointer, ref32); }
-    LValue load64(TypedPointer pointer) { return load(pointer, ref64); }
-    LValue loadPtr(TypedPointer pointer) { return load(pointer, refPtr); }
-    LValue loadFloat(TypedPointer pointer) { return load(pointer, refFloat); }
-    LValue loadDouble(TypedPointer pointer) { return load(pointer, refDouble); }
-    void store8(LValue value, TypedPointer pointer) { store(value, pointer, ref8); }
-    void store16(LValue value, TypedPointer pointer) { store(value, pointer, ref16); }
-    void store32(LValue value, TypedPointer pointer) { store(value, pointer, ref32); }
-    void store64(LValue value, TypedPointer pointer) { store(value, pointer, ref64); }
-    void storePtr(LValue value, TypedPointer pointer) { store(value, pointer, refPtr); }
-    void storeFloat(LValue value, TypedPointer pointer) { store(value, pointer, refFloat); }
-    void storeDouble(LValue value, TypedPointer pointer) { store(value, pointer, refDouble); }
+
+    enum LoadType {
+        Load8SignExt32,
+        Load8ZeroExt32,
+        Load16SignExt32,
+        Load16ZeroExt32,
+        Load32,
+        Load64,
+        LoadPtr,
+        LoadFloat,
+        LoadDouble
+    };
+
+    LValue load(TypedPointer, LoadType);
+    
+    enum StoreType {
+        Store32As8,
+        Store32As16,
+        Store32,
+        Store64,
+        StorePtr,
+        StoreFloat,
+        StoreDouble
+    };
+
+    void store(LValue, TypedPointer, StoreType);
 
     LValue addPtr(LValue value, ptrdiff_t immediate = 0)
     {
@@ -249,7 +281,7 @@ public:
             return value;
         return add(value, constIntPtr(immediate));
     }
-    
+
     // Construct an address by offsetting base by the requested amount and ascribing
     // the requested abstract heap to it.
     TypedPointer address(const AbstractHeap& heap, LValue base, ptrdiff_t offset = 0)
@@ -259,36 +291,13 @@ public:
     // Construct an address by offsetting base by the amount specified by the field,
     // and optionally an additional amount (use this with care), and then creating
     // a TypedPointer with the given field as the heap.
-    TypedPointer address(LValue base, const AbstractField& field, ptrdiff_t offset = 0)
+    TypedPointer address(LValue base, const AbstractHeap& field, ptrdiff_t offset = 0)
     {
         return address(field, base, offset + field.offset());
     }
-    
-    LValue baseIndex(LValue base, LValue index, Scale scale, ptrdiff_t offset = 0)
-    {
-        LValue accumulatedOffset;
-        
-        switch (scale) {
-        case ScaleOne:
-            accumulatedOffset = index;
-            break;
-        case ScaleTwo:
-            accumulatedOffset = shl(index, intPtrOne);
-            break;
-        case ScaleFour:
-            accumulatedOffset = shl(index, intPtrTwo);
-            break;
-        case ScaleEight:
-        case ScalePtr:
-            accumulatedOffset = shl(index, intPtrThree);
-            break;
-        }
-        
-        if (offset)
-            accumulatedOffset = add(accumulatedOffset, constIntPtr(offset));
-        
-        return add(base, accumulatedOffset);
-    }
+
+    LValue baseIndex(LValue base, LValue index, Scale, ptrdiff_t offset = 0);
+
     TypedPointer baseIndex(const AbstractHeap& heap, LValue base, LValue index, Scale scale, ptrdiff_t offset = 0)
     {
         return TypedPointer(heap, baseIndex(base, index, scale, offset));
@@ -297,132 +306,183 @@ public:
     {
         return heap.baseIndex(*this, base, index, indexAsConstant, offset);
     }
-    
-    TypedPointer absolute(void* address)
-    {
-        return TypedPointer(m_heaps->absolute[address], constIntPtr(address));
-    }
-    
-    LValue load8(LValue base, const AbstractField& field) { return load8(address(base, field)); }
-    LValue load16(LValue base, const AbstractField& field) { return load16(address(base, field)); }
-    LValue load32(LValue base, const AbstractField& field) { return load32(address(base, field)); }
-    LValue load64(LValue base, const AbstractField& field) { return load64(address(base, field)); }
-    LValue loadPtr(LValue base, const AbstractField& field) { return loadPtr(address(base, field)); }
-    LValue loadDouble(LValue base, const AbstractField& field) { return loadDouble(address(base, field)); }
-    void store32(LValue value, LValue base, const AbstractField& field) { store32(value, address(base, field)); }
-    void store64(LValue value, LValue base, const AbstractField& field) { store64(value, address(base, field)); }
-    void storePtr(LValue value, LValue base, const AbstractField& field) { storePtr(value, address(base, field)); }
-    void storeDouble(LValue value, LValue base, const AbstractField& field) { storeDouble(value, address(base, field)); }
-    
-    LValue icmp(LIntPredicate cond, LValue left, LValue right) { return buildICmp(m_builder, cond, left, right); }
-    LValue equal(LValue left, LValue right) { return icmp(LLVMIntEQ, left, right); }
-    LValue notEqual(LValue left, LValue right) { return icmp(LLVMIntNE, left, right); }
-    LValue above(LValue left, LValue right) { return icmp(LLVMIntUGT, left, right); }
-    LValue aboveOrEqual(LValue left, LValue right) { return icmp(LLVMIntUGE, left, right); }
-    LValue below(LValue left, LValue right) { return icmp(LLVMIntULT, left, right); }
-    LValue belowOrEqual(LValue left, LValue right) { return icmp(LLVMIntULE, left, right); }
-    LValue greaterThan(LValue left, LValue right) { return icmp(LLVMIntSGT, left, right); }
-    LValue greaterThanOrEqual(LValue left, LValue right) { return icmp(LLVMIntSGE, left, right); }
-    LValue lessThan(LValue left, LValue right) { return icmp(LLVMIntSLT, left, right); }
-    LValue lessThanOrEqual(LValue left, LValue right) { return icmp(LLVMIntSLE, left, right); }
-    
-    LValue fcmp(LRealPredicate cond, LValue left, LValue right) { return buildFCmp(m_builder, cond, left, right); }
-    LValue doubleEqual(LValue left, LValue right) { return fcmp(LLVMRealOEQ, left, right); }
-    LValue doubleNotEqualOrUnordered(LValue left, LValue right) { return fcmp(LLVMRealUNE, left, right); }
-    LValue doubleLessThan(LValue left, LValue right) { return fcmp(LLVMRealOLT, left, right); }
-    LValue doubleLessThanOrEqual(LValue left, LValue right) { return fcmp(LLVMRealOLE, left, right); }
-    LValue doubleGreaterThan(LValue left, LValue right) { return fcmp(LLVMRealOGT, left, right); }
-    LValue doubleGreaterThanOrEqual(LValue left, LValue right) { return fcmp(LLVMRealOGE, left, right); }
-    LValue doubleEqualOrUnordered(LValue left, LValue right) { return fcmp(LLVMRealUEQ, left, right); }
-    LValue doubleNotEqual(LValue left, LValue right) { return fcmp(LLVMRealONE, left, right); }
-    LValue doubleLessThanOrUnordered(LValue left, LValue right) { return fcmp(LLVMRealULT, left, right); }
-    LValue doubleLessThanOrEqualOrUnordered(LValue left, LValue right) { return fcmp(LLVMRealULE, left, right); }
-    LValue doubleGreaterThanOrUnordered(LValue left, LValue right) { return fcmp(LLVMRealUGT, left, right); }
-    LValue doubleGreaterThanOrEqualOrUnordered(LValue left, LValue right) { return fcmp(LLVMRealUGE, left, right); }
-    
-    LValue isZero8(LValue value) { return equal(value, int8Zero); }
-    LValue notZero8(LValue value) { return notEqual(value, int8Zero); }
-    LValue isZero32(LValue value) { return equal(value, int32Zero); }
-    LValue notZero32(LValue value) { return notEqual(value, int32Zero); }
-    LValue isZero64(LValue value) { return equal(value, int64Zero); }
-    LValue notZero64(LValue value) { return notEqual(value, int64Zero); }
-    LValue isNull(LValue value) { return equal(value, intPtrZero); }
-    LValue notNull(LValue value) { return notEqual(value, intPtrZero); }
-    
-    LValue testIsZero8(LValue value, LValue mask) { return isZero8(bitAnd(value, mask)); }
-    LValue testNonZero8(LValue value, LValue mask) { return notZero8(bitAnd(value, mask)); }
+
+    TypedPointer absolute(const void* address);
+
+    LValue load8SignExt32(LValue base, const AbstractHeap& field) { return load8SignExt32(address(base, field)); }
+    LValue load8ZeroExt32(LValue base, const AbstractHeap& field) { return load8ZeroExt32(address(base, field)); }
+    LValue load16SignExt32(LValue base, const AbstractHeap& field) { return load16SignExt32(address(base, field)); }
+    LValue load16ZeroExt32(LValue base, const AbstractHeap& field) { return load16ZeroExt32(address(base, field)); }
+    LValue load32(LValue base, const AbstractHeap& field) { return load32(address(base, field)); }
+    LValue load64(LValue base, const AbstractHeap& field) { return load64(address(base, field)); }
+    LValue loadPtr(LValue base, const AbstractHeap& field) { return loadPtr(address(base, field)); }
+    LValue loadDouble(LValue base, const AbstractHeap& field) { return loadDouble(address(base, field)); }
+    void store32(LValue value, LValue base, const AbstractHeap& field) { store32(value, address(base, field)); }
+    void store64(LValue value, LValue base, const AbstractHeap& field) { store64(value, address(base, field)); }
+    void storePtr(LValue value, LValue base, const AbstractHeap& field) { storePtr(value, address(base, field)); }
+    void storeDouble(LValue value, LValue base, const AbstractHeap& field) { storeDouble(value, address(base, field)); }
+
+    // FIXME: Explore adding support for value range constraints to B3. Maybe it could be as simple as having
+    // a load instruction that guarantees that its result is non-negative.
+    // https://bugs.webkit.org/show_bug.cgi?id=151458
+    void ascribeRange(LValue, const ValueRange&) { }
+    LValue nonNegative32(LValue loadInstruction) { return loadInstruction; }
+    LValue load32NonNegative(TypedPointer pointer) { return load32(pointer); }
+    LValue load32NonNegative(LValue base, const AbstractHeap& field) { return load32(base, field); }
+
+    LValue equal(LValue, LValue);
+    LValue notEqual(LValue, LValue);
+    LValue above(LValue, LValue);
+    LValue aboveOrEqual(LValue, LValue);
+    LValue below(LValue, LValue);
+    LValue belowOrEqual(LValue, LValue);
+    LValue greaterThan(LValue, LValue);
+    LValue greaterThanOrEqual(LValue, LValue);
+    LValue lessThan(LValue, LValue);
+    LValue lessThanOrEqual(LValue, LValue);
+
+    LValue doubleEqual(LValue, LValue);
+    LValue doubleEqualOrUnordered(LValue, LValue);
+    LValue doubleNotEqualOrUnordered(LValue, LValue);
+    LValue doubleLessThan(LValue, LValue);
+    LValue doubleLessThanOrEqual(LValue, LValue);
+    LValue doubleGreaterThan(LValue, LValue);
+    LValue doubleGreaterThanOrEqual(LValue, LValue);
+    LValue doubleNotEqualAndOrdered(LValue, LValue);
+    LValue doubleLessThanOrUnordered(LValue, LValue);
+    LValue doubleLessThanOrEqualOrUnordered(LValue, LValue);
+    LValue doubleGreaterThanOrUnordered(LValue, LValue);
+    LValue doubleGreaterThanOrEqualOrUnordered(LValue, LValue);
+
+    LValue isZero32(LValue);
+    LValue notZero32(LValue);
+    LValue isZero64(LValue);
+    LValue notZero64(LValue);
+    LValue isNull(LValue value) { return isZero64(value); }
+    LValue notNull(LValue value) { return notZero64(value); }
+
     LValue testIsZero32(LValue value, LValue mask) { return isZero32(bitAnd(value, mask)); }
     LValue testNonZero32(LValue value, LValue mask) { return notZero32(bitAnd(value, mask)); }
     LValue testIsZero64(LValue value, LValue mask) { return isZero64(bitAnd(value, mask)); }
     LValue testNonZero64(LValue value, LValue mask) { return notZero64(bitAnd(value, mask)); }
-    
-    LValue select(LValue value, LValue taken, LValue notTaken) { return buildSelect(m_builder, value, taken, notTaken); }
-    LValue extractValue(LValue aggVal, unsigned index) { return buildExtractValue(m_builder, aggVal, index); }
-    
-    LValue fence(LAtomicOrdering ordering = LLVMAtomicOrderingSequentiallyConsistent, SynchronizationScope scope = CrossThread) { return buildFence(m_builder, ordering, scope); }
-    LValue fenceAcqRel() { return fence(LLVMAtomicOrderingAcquireRelease); }
-    
-    template<typename VectorType>
-    LValue call(LValue function, const VectorType& vector) { return buildCall(m_builder, function, vector); }
-    LValue call(LValue function) { return buildCall(m_builder, function); }
-    LValue call(LValue function, LValue arg1) { return buildCall(m_builder, function, arg1); }
-    LValue call(LValue function, LValue arg1, LValue arg2) { return buildCall(m_builder, function, arg1, arg2); }
-    LValue call(LValue function, LValue arg1, LValue arg2, LValue arg3) { return buildCall(m_builder, function, arg1, arg2, arg3); }
-    LValue call(LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4) { return buildCall(m_builder, function, arg1, arg2, arg3, arg4); }
-    LValue call(LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4, LValue arg5) { return buildCall(m_builder, function, arg1, arg2, arg3, arg4, arg5); }
-    LValue call(LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4, LValue arg5, LValue arg6) { return buildCall(m_builder, function, arg1, arg2, arg3, arg4, arg5, arg6); }
-    LValue call(LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4, LValue arg5, LValue arg6, LValue arg7) { return buildCall(m_builder, function, arg1, arg2, arg3, arg4, arg5, arg6, arg7); }
-    LValue call(LValue function, LValue arg1, LValue arg2, LValue arg3, LValue arg4, LValue arg5, LValue arg6, LValue arg7, LValue arg8) { return buildCall(m_builder, function, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8); }
-    
-    template<typename FunctionType>
-    LValue operation(FunctionType function)
-    {
-        return intToPtr(constIntPtr(function), pointerType(operationType(function)));
-    }
-    
-    void jump(LBasicBlock destination) { buildBr(m_builder, destination); }
-    void branch(LValue condition, LBasicBlock taken, LBasicBlock notTaken) { buildCondBr(m_builder, condition, taken, notTaken); }
+    LValue testIsZeroPtr(LValue value, LValue mask) { return isNull(bitAnd(value, mask)); }
+    LValue testNonZeroPtr(LValue value, LValue mask) { return notNull(bitAnd(value, mask)); }
+
+    LValue select(LValue value, LValue taken, LValue notTaken);
+
     template<typename VectorType>
-    void switchInstruction(LValue value, const VectorType& cases, LBasicBlock fallThrough) { buildSwitch(m_builder, value, cases, fallThrough); }
-    void ret(LValue value) { buildRet(m_builder, value); }
-    
-    void unreachable() { buildUnreachable(m_builder); }
-    
-    void trap()
+    LValue call(LType type, LValue function, const VectorType& vector)
     {
-        call(trapIntrinsic());
+        B3::CCallValue* result = m_block->appendNew<B3::CCallValue>(m_proc, type, origin(), function);
+        result->children().appendVector(vector);
+        return result;
     }
-    
-    void crashNonTerminal()
+    LValue call(LType type, LValue function) { return m_block->appendNew<B3::CCallValue>(m_proc, type, origin(), function); }
+    LValue call(LType type, LValue function, LValue arg1) { return m_block->appendNew<B3::CCallValue>(m_proc, type, origin(), function, arg1); }
+    template<typename... Args>
+    LValue call(LType type, LValue function, LValue arg1, Args... args) { return m_block->appendNew<B3::CCallValue>(m_proc, type, origin(), function, arg1, args...); }
+
+    template<typename Function, typename... Args>
+    LValue callWithoutSideEffects(B3::Type type, Function function, LValue arg1, Args... args)
     {
-        call(intToPtr(constIntPtr(abort), pointerType(functionType(voidType))));
+        return m_block->appendNew<B3::CCallValue>(m_proc, type, origin(), B3::Effects::none(),
+            constIntPtr(bitwise_cast<void*>(function)), arg1, args...);
     }
-    void crash()
+
+    template<typename FunctionType>
+    LValue operation(FunctionType function) { return constIntPtr(bitwise_cast<void*>(function)); }
+
+    void jump(LBasicBlock);
+    void branch(LValue condition, LBasicBlock taken, Weight takenWeight, LBasicBlock notTaken, Weight notTakenWeight);
+    void branch(LValue condition, WeightedTarget taken, WeightedTarget notTaken)
     {
-        crashNonTerminal();
-        unreachable();
+        branch(condition, taken.target(), taken.weight(), notTaken.target(), notTaken.weight());
     }
+
+    // Branches to an already-created handler if true, "falls through" if false. Fall-through is
+    // simulated by creating a continuation for you.
+    void check(LValue condition, WeightedTarget taken, Weight notTakenWeight);
     
-    ValueFromBlock anchor(LValue value)
+    // Same as check(), but uses Weight::inverse() to compute the notTakenWeight.
+    void check(LValue condition, WeightedTarget taken);
+    
+    template<typename VectorType>
+    void switchInstruction(LValue value, const VectorType& cases, LBasicBlock fallThrough, Weight fallThroughWeight)
     {
-        return ValueFromBlock(value, m_block);
+        B3::SwitchValue* switchValue = m_block->appendNew<B3::SwitchValue>(m_proc, origin(), value);
+        switchValue->setFallThrough(B3::FrequentedBlock(fallThrough));
+        for (const SwitchCase& switchCase : cases) {
+            int64_t value = switchCase.value()->asInt();
+            B3::FrequentedBlock target(switchCase.target(), switchCase.weight().frequencyClass());
+            switchValue->appendCase(B3::SwitchCase(value, target));
+        }
     }
+
+    void ret(LValue);
+
+    void unreachable();
     
-    LValue m_function;
+    void appendSuccessor(WeightedTarget);
+
+    B3::CheckValue* speculate(LValue);
+    B3::CheckValue* speculateAdd(LValue, LValue);
+    B3::CheckValue* speculateSub(LValue, LValue);
+    B3::CheckValue* speculateMul(LValue, LValue);
+
+    B3::PatchpointValue* patchpoint(LType);
+
+    void trap();
+
+    ValueFromBlock anchor(LValue);
+
+    void incrementSuperSamplerCount();
+    void decrementSuperSamplerCount();
+
+#if PLATFORM(COCOA)
+#pragma mark - States
+#endif
+    B3::Procedure& m_proc;
+
+    DFG::Node* m_origin { nullptr };
+    LBasicBlock m_block { nullptr };
+    LBasicBlock m_nextBlock { nullptr };
+
     AbstractHeapRepository* m_heaps;
-    LBuilder m_builder;
-    LBasicBlock m_block;
-    LBasicBlock m_nextBlock;
+
+    double m_frequency { 1 };
+
+private:
+    OrderMaker<LBasicBlock> m_blockOrder;
 };
 
-#define FTL_NEW_BLOCK(output, nameArguments) \
-    (LIKELY(!::JSC::DFG::verboseCompilationEnabled()) \
-    ? (output).newBlock() \
-    : (output).newBlock((toCString nameArguments).data()))
+template<typename... Params>
+inline LValue Output::phi(LType type, ValueFromBlock value, Params... theRest)
+{
+    LValue phiNode = phi(type);
+    addIncomingToPhi(phiNode, value, theRest...);
+    return phiNode;
+}
 
-} } // namespace JSC::FTL
+template<typename VectorType>
+inline LValue Output::phi(LType type, const VectorType& vector)
+{
+    LValue phiNode = phi(type);
+    for (const ValueFromBlock& valueFromBlock : vector)
+        addIncomingToPhi(phiNode, valueFromBlock);
+    return phiNode;
+}
 
-#endif // ENABLE(FTL_JIT)
+template<typename... Params>
+inline void Output::addIncomingToPhi(LValue phi, ValueFromBlock value, Params... theRest)
+{
+    addIncomingToPhi(phi, value);
+    addIncomingToPhi(phi, theRest...);
+}
+
+#if COMPILER(GCC_OR_CLANG)
+#pragma GCC diagnostic pop
+#endif // COMPILER(GCC_OR_CLANG)
 
-#endif // FTLOutput_h
+} } // namespace JSC::FTL
 
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLPatchpointExceptionHandle.cpp b/Source/JavaScriptCore/ftl/FTLPatchpointExceptionHandle.cpp
new file mode 100644
index 000000000..6dcc5ee87
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLPatchpointExceptionHandle.cpp
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLPatchpointExceptionHandle.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "B3StackmapGenerationParams.h"
+#include "FTLExceptionTarget.h"
+#include "FTLOSRExit.h"
+#include "FTLOSRExitHandle.h"
+#include "FTLState.h"
+
+namespace JSC { namespace FTL {
+
+using namespace DFG;
+
+RefPtr<PatchpointExceptionHandle> PatchpointExceptionHandle::create(
+    State& state, OSRExitDescriptor* descriptor, NodeOrigin origin, unsigned offset,
+    const HandlerInfo& handler)
+{
+    return adoptRef(new PatchpointExceptionHandle(state, descriptor, origin, offset, handler));
+}
+
+RefPtr<PatchpointExceptionHandle> PatchpointExceptionHandle::defaultHandle(State& state)
+{
+    if (!state.defaultExceptionHandle) {
+        state.defaultExceptionHandle = adoptRef(
+            new PatchpointExceptionHandle(state, nullptr, NodeOrigin(), 0, HandlerInfo()));
+    }
+    return state.defaultExceptionHandle;
+}
+
+PatchpointExceptionHandle::~PatchpointExceptionHandle()
+{
+}
+
+RefPtr<ExceptionTarget> PatchpointExceptionHandle::scheduleExitCreation(
+    const B3::StackmapGenerationParams& params)
+{
+    if (!m_descriptor) {
+        // NOTE: This object could be a singleton, however usually we toss the ExceptionHandler
+        // object shortly after creation.
+        bool isDefaultHandler = true;
+        return adoptRef(
+            new ExceptionTarget(isDefaultHandler, m_state.exceptionHandler, nullptr));
+    }
+    bool isDefaultHandler = false;
+    return adoptRef(new ExceptionTarget(isDefaultHandler, { }, createHandle(ExceptionCheck, params)));
+}
+
+void PatchpointExceptionHandle::scheduleExitCreationForUnwind(
+    const B3::StackmapGenerationParams& params, CallSiteIndex callSiteIndex)
+{
+    if (!m_descriptor)
+        return;
+    
+    RefPtr<OSRExitHandle> handle = createHandle(GenericUnwind, params);
+
+    handle->exit.m_exceptionHandlerCallSiteIndex = callSiteIndex;
+
+    HandlerInfo handler = m_handler;
+    params.addLatePath(
+        [handle, handler, callSiteIndex] (CCallHelpers& jit) {
+            CodeBlock* codeBlock = jit.codeBlock();
+            jit.addLinkTask(
+                [=] (LinkBuffer& linkBuffer) {
+                    HandlerInfo newHandler = handler;
+                    newHandler.start = callSiteIndex.bits();
+                    newHandler.end = callSiteIndex.bits() + 1;
+                    newHandler.nativeCode = linkBuffer.locationOf(handle->label);
+                    codeBlock->appendExceptionHandler(newHandler);
+                });
+        });
+}
+
+PatchpointExceptionHandle::PatchpointExceptionHandle(
+    State& state, OSRExitDescriptor* descriptor, NodeOrigin origin, unsigned offset,
+    const HandlerInfo& handler)
+    : m_state(state)
+    , m_descriptor(descriptor)
+    , m_origin(origin)
+    , m_offset(offset)
+    , m_handler(handler)
+{
+}
+
+RefPtr<OSRExitHandle> PatchpointExceptionHandle::createHandle(
+    ExitKind kind, const B3::StackmapGenerationParams& params)
+{
+    return m_descriptor->emitOSRExitLater(
+        m_state, kind, m_origin, params, m_offset);
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLPatchpointExceptionHandle.h b/Source/JavaScriptCore/ftl/FTLPatchpointExceptionHandle.h
new file mode 100644
index 000000000..523369ba3
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLPatchpointExceptionHandle.h
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#include "DFGCommon.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "DFGNodeOrigin.h"
+#include "ExitKind.h"
+#include "HandlerInfo.h"
+#include <wtf/Ref.h>
+#include <wtf/ThreadSafeRefCounted.h>
+
+namespace JSC {
+
+namespace B3 {
+class StackmapGenerationParams;
+} // namespace B3
+
+namespace FTL {
+
+class ExceptionTarget;
+class State;
+struct OSRExitDescriptor;
+struct OSRExitHandle;
+
+class PatchpointExceptionHandle : public ThreadSafeRefCounted<PatchpointExceptionHandle> {
+public:
+    static RefPtr<PatchpointExceptionHandle> create(
+        State&, OSRExitDescriptor*, DFG::NodeOrigin, unsigned offset, const HandlerInfo&);
+
+    static RefPtr<PatchpointExceptionHandle> defaultHandle(State&);
+    
+    ~PatchpointExceptionHandle();
+
+    // Note that you can use this handle to schedule any number of exits. This capability is here for
+    // two reasons:
+    // 
+    // - B3 code duplication. B3 could take a patchpoint and turn it into multiple patchpoints if it
+    //   duplicates code. Duplicating code is legal since you can do it without changing the behavior
+    //   of the program. One example is tail duplication. Another is jump threading. Yet another is
+    //   path specialization. You will have one PatchpointExceptionHandle per patchpoint you create
+    //   during DFG->B3 lowering, and that patchpoint will have a generator that calls
+    //   handle->scheduleBlah(). That generator will be called multiple times if your patchpoint got
+    //   duplicated.
+    //
+    // - Combination of unwind and non-unwind exception handlers inside one patchpoint. A GetById may
+    //   need both an exception handler that serves as an unwind target and an exception handler that
+    //   is branched to directly for operation calls emitted inside the patchpoint. In that case,
+    //   you'll call both scheduleExitCreation() and scheduleExitCreationForUnwind() on the same
+    //   handle.
+
+    // Schedules the creation of an OSR exit jump destination. You don't know when this will be
+    // created, but it will happen before linking. You can link jumps to it during link time. That's
+    // why this returns an ExceptionTarget. That will contain the jump destination (target->label())
+    // at link time. This function should be used for exceptions from C calls.
+    RefPtr<ExceptionTarget> scheduleExitCreation(const B3::StackmapGenerationParams&);
+
+    // Schedules the creation of an OSR exit jump destination, and ensures that it gets associated
+    // with the handler for some callsite index. This function should be used for exceptions from JS.
+    void scheduleExitCreationForUnwind(const B3::StackmapGenerationParams&, CallSiteIndex);
+
+private:
+    PatchpointExceptionHandle(
+        State&, OSRExitDescriptor*, DFG::NodeOrigin, unsigned offset, const HandlerInfo&);
+
+    RefPtr<OSRExitHandle> createHandle(ExitKind, const B3::StackmapGenerationParams&);
+
+    State& m_state;
+    OSRExitDescriptor* m_descriptor;
+    DFG::NodeOrigin m_origin;
+    unsigned m_offset;
+    HandlerInfo m_handler;
+};
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLRecoveryOpcode.cpp b/Source/JavaScriptCore/ftl/FTLRecoveryOpcode.cpp
new file mode 100644
index 000000000..70770dd81
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLRecoveryOpcode.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLRecoveryOpcode.h"
+
+#if ENABLE(FTL_JIT)
+
+#include <wtf/PrintStream.h>
+
+namespace WTF {
+
+void printInternal(PrintStream& out, JSC::FTL::RecoveryOpcode opcode)
+{
+    switch (opcode) {
+    case JSC::FTL::AddRecovery:
+        out.print("Add");
+        return;
+    case JSC::FTL::SubRecovery:
+        out.print("Sub");
+        return;
+    }
+    RELEASE_ASSERT_NOT_REACHED();
+}
+
+} // namespace WTF
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLRecoveryOpcode.h b/Source/JavaScriptCore/ftl/FTLRecoveryOpcode.h
new file mode 100644
index 000000000..70e7e4ee6
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLRecoveryOpcode.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+namespace JSC { namespace FTL {
+
+enum RecoveryOpcode {
+    AddRecovery,
+    SubRecovery
+};
+
+} } // namespace JSC::FTL
+
+namespace WTF {
+
+class PrintStream;
+void printInternal(PrintStream&, JSC::FTL::RecoveryOpcode);
+
+} // namespace WTF
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLSaveRestore.cpp b/Source/JavaScriptCore/ftl/FTLSaveRestore.cpp
new file mode 100644
index 000000000..c752fd22f
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLSaveRestore.cpp
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2013, 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLSaveRestore.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "FPRInfo.h"
+#include "GPRInfo.h"
+#include "MacroAssembler.h"
+#include "RegisterSet.h"
+
+namespace JSC { namespace FTL {
+
+static size_t bytesForGPRs()
+{
+    return MacroAssembler::numberOfRegisters() * sizeof(int64_t);
+}
+
+static size_t bytesForFPRs()
+{
+    // FIXME: It might be worthwhile saving the full state of the FP registers, at some point.
+    // Right now we don't need this since we only do the save/restore just prior to OSR exit, and
+    // OSR exit will be guaranteed to only need the double portion of the FP registers.
+    return MacroAssembler::numberOfFPRegisters() * sizeof(double);
+}
+
+size_t requiredScratchMemorySizeInBytes()
+{
+    return bytesForGPRs() + bytesForFPRs();
+}
+
+size_t offsetOfGPR(GPRReg reg)
+{
+    return MacroAssembler::registerIndex(reg) * sizeof(int64_t);
+}
+
+size_t offsetOfFPR(FPRReg reg)
+{
+    return bytesForGPRs() + MacroAssembler::fpRegisterIndex(reg) * sizeof(double);
+}
+
+size_t offsetOfReg(Reg reg)
+{
+    if (reg.isGPR())
+        return offsetOfGPR(reg.gpr());
+    return offsetOfFPR(reg.fpr());
+}
+
+namespace {
+
+struct Regs {
+    Regs()
+    {
+        special = RegisterSet::stackRegisters();
+        special.merge(RegisterSet::reservedHardwareRegisters());
+        
+        first = MacroAssembler::firstRegister();
+        while (special.get(first))
+            first = MacroAssembler::nextRegister(first);
+        second = MacroAssembler::nextRegister(first);
+        while (special.get(second))
+            second = MacroAssembler::nextRegister(second);
+    }
+    
+    RegisterSet special;
+    GPRReg first;
+    GPRReg second;
+};
+
+} // anonymous namespace
+
+void saveAllRegisters(MacroAssembler& jit, char* scratchMemory)
+{
+    Regs regs;
+    
+    // Get the first register out of the way, so that we can use it as a pointer.
+    jit.poke64(regs.first, 0);
+    jit.move(MacroAssembler::TrustedImmPtr(scratchMemory), regs.first);
+    
+    // Get all of the other GPRs out of the way.
+    for (MacroAssembler::RegisterID reg = regs.second; reg <= MacroAssembler::lastRegister(); reg = MacroAssembler::nextRegister(reg)) {
+        if (regs.special.get(reg))
+            continue;
+        jit.store64(reg, MacroAssembler::Address(regs.first, offsetOfGPR(reg)));
+    }
+    
+    // Restore the first register into the second one and save it.
+    jit.peek64(regs.second, 0);
+    jit.store64(regs.second, MacroAssembler::Address(regs.first, offsetOfGPR(regs.first)));
+    
+    // Finally save all FPR's.
+    for (MacroAssembler::FPRegisterID reg = MacroAssembler::firstFPRegister(); reg <= MacroAssembler::lastFPRegister(); reg = MacroAssembler::nextFPRegister(reg)) {
+        if (regs.special.get(reg))
+            continue;
+        jit.storeDouble(reg, MacroAssembler::Address(regs.first, offsetOfFPR(reg)));
+    }
+}
+
+void restoreAllRegisters(MacroAssembler& jit, char* scratchMemory)
+{
+    Regs regs;
+    
+    // Give ourselves a pointer to the scratch memory.
+    jit.move(MacroAssembler::TrustedImmPtr(scratchMemory), regs.first);
+    
+    // Restore all FPR's.
+    for (MacroAssembler::FPRegisterID reg = MacroAssembler::firstFPRegister(); reg <= MacroAssembler::lastFPRegister(); reg = MacroAssembler::nextFPRegister(reg)) {
+        if (regs.special.get(reg))
+            continue;
+        jit.loadDouble(MacroAssembler::Address(regs.first, offsetOfFPR(reg)), reg);
+    }
+    
+    for (MacroAssembler::RegisterID reg = regs.second; reg <= MacroAssembler::lastRegister(); reg = MacroAssembler::nextRegister(reg)) {
+        if (regs.special.get(reg))
+            continue;
+        jit.load64(MacroAssembler::Address(regs.first, offsetOfGPR(reg)), reg);
+    }
+    
+    jit.load64(MacroAssembler::Address(regs.first, offsetOfGPR(regs.first)), regs.first);
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLSaveRestore.h b/Source/JavaScriptCore/ftl/FTLSaveRestore.h
new file mode 100644
index 000000000..c624641c7
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLSaveRestore.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2013 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+#include "FPRInfo.h"
+#include "GPRInfo.h"
+#include "Reg.h"
+
+namespace JSC {
+
+class MacroAssembler;
+
+namespace FTL {
+
+size_t requiredScratchMemorySizeInBytes();
+
+size_t offsetOfReg(Reg);
+size_t offsetOfGPR(GPRReg);
+size_t offsetOfFPR(FPRReg);
+
+// Assumes that top-of-stack can be used as a pointer-sized scratchpad. Saves all of
+// the registers into the scratch buffer such that RegisterID * sizeof(int64_t) is the
+// offset of every register.
+void saveAllRegisters(MacroAssembler& jit, char* scratchMemory);
+
+void restoreAllRegisters(MacroAssembler& jit, char* scratchMemory);
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLSlowPathCall.cpp b/Source/JavaScriptCore/ftl/FTLSlowPathCall.cpp
new file mode 100644
index 000000000..eeba48274
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLSlowPathCall.cpp
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLSlowPathCall.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "CCallHelpers.h"
+#include "FTLState.h"
+#include "FTLThunks.h"
+#include "GPRInfo.h"
+#include "JSCInlines.h"
+
+namespace JSC { namespace FTL {
+
+// This code relies on us being 64-bit. FTL is currently always 64-bit.
+static const size_t wordSize = 8;
+
+SlowPathCallContext::SlowPathCallContext(
+    RegisterSet usedRegisters, CCallHelpers& jit, unsigned numArgs, GPRReg returnRegister)
+    : m_jit(jit)
+    , m_numArgs(numArgs)
+    , m_returnRegister(returnRegister)
+{
+    // We don't care that you're using callee-save, stack, or hardware registers.
+    usedRegisters.exclude(RegisterSet::stackRegisters());
+    usedRegisters.exclude(RegisterSet::reservedHardwareRegisters());
+    usedRegisters.exclude(RegisterSet::calleeSaveRegisters());
+        
+    // The return register doesn't need to be saved.
+    if (m_returnRegister != InvalidGPRReg)
+        usedRegisters.clear(m_returnRegister);
+        
+    size_t stackBytesNeededForReturnAddress = wordSize;
+        
+    m_offsetToSavingArea =
+        (std::max(m_numArgs, NUMBER_OF_ARGUMENT_REGISTERS) - NUMBER_OF_ARGUMENT_REGISTERS) * wordSize;
+        
+    for (unsigned i = std::min(NUMBER_OF_ARGUMENT_REGISTERS, numArgs); i--;)
+        m_argumentRegisters.set(GPRInfo::toArgumentRegister(i));
+    m_callingConventionRegisters.merge(m_argumentRegisters);
+    if (returnRegister != InvalidGPRReg)
+        m_callingConventionRegisters.set(GPRInfo::returnValueGPR);
+    m_callingConventionRegisters.filter(usedRegisters);
+        
+    unsigned numberOfCallingConventionRegisters =
+        m_callingConventionRegisters.numberOfSetRegisters();
+        
+    size_t offsetToThunkSavingArea =
+        m_offsetToSavingArea +
+        numberOfCallingConventionRegisters * wordSize;
+        
+    m_stackBytesNeeded =
+        offsetToThunkSavingArea +
+        stackBytesNeededForReturnAddress +
+        (usedRegisters.numberOfSetRegisters() - numberOfCallingConventionRegisters) * wordSize;
+        
+    m_stackBytesNeeded = (m_stackBytesNeeded + stackAlignmentBytes() - 1) & ~(stackAlignmentBytes() - 1);
+        
+    m_jit.subPtr(CCallHelpers::TrustedImm32(m_stackBytesNeeded), CCallHelpers::stackPointerRegister);
+
+    m_thunkSaveSet = usedRegisters;
+        
+    // This relies on all calling convention registers also being temp registers.
+    unsigned stackIndex = 0;
+    for (unsigned i = GPRInfo::numberOfRegisters; i--;) {
+        GPRReg reg = GPRInfo::toRegister(i);
+        if (!m_callingConventionRegisters.get(reg))
+            continue;
+        m_jit.storePtr(reg, CCallHelpers::Address(CCallHelpers::stackPointerRegister, m_offsetToSavingArea + (stackIndex++) * wordSize));
+        m_thunkSaveSet.clear(reg);
+    }
+        
+    m_offset = offsetToThunkSavingArea;
+}
+    
+SlowPathCallContext::~SlowPathCallContext()
+{
+    if (m_returnRegister != InvalidGPRReg)
+        m_jit.move(GPRInfo::returnValueGPR, m_returnRegister);
+    
+    unsigned stackIndex = 0;
+    for (unsigned i = GPRInfo::numberOfRegisters; i--;) {
+        GPRReg reg = GPRInfo::toRegister(i);
+        if (!m_callingConventionRegisters.get(reg))
+            continue;
+        m_jit.loadPtr(CCallHelpers::Address(CCallHelpers::stackPointerRegister, m_offsetToSavingArea + (stackIndex++) * wordSize), reg);
+    }
+    
+    m_jit.addPtr(CCallHelpers::TrustedImm32(m_stackBytesNeeded), CCallHelpers::stackPointerRegister);
+}
+
+SlowPathCallKey SlowPathCallContext::keyWithTarget(void* callTarget) const
+{
+    return SlowPathCallKey(m_thunkSaveSet, callTarget, m_argumentRegisters, m_offset);
+}
+
+SlowPathCall SlowPathCallContext::makeCall(void* callTarget)
+{
+    SlowPathCall result = SlowPathCall(m_jit.call(), keyWithTarget(callTarget));
+
+    m_jit.addLinkTask(
+        [result] (LinkBuffer& linkBuffer) {
+            VM& vm = linkBuffer.vm();
+
+            MacroAssemblerCodeRef thunk =
+                vm.ftlThunks->getSlowPathCallThunk(vm, result.key());
+
+            linkBuffer.link(result.call(), CodeLocationLabel(thunk.code()));
+        });
+    
+    return result;
+}
+
+CallSiteIndex callSiteIndexForCodeOrigin(State& state, CodeOrigin codeOrigin)
+{
+    if (codeOrigin)
+        return state.jitCode->common.addCodeOrigin(codeOrigin);
+    return CallSiteIndex();
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
+
diff --git a/Source/JavaScriptCore/ftl/FTLSlowPathCall.h b/Source/JavaScriptCore/ftl/FTLSlowPathCall.h
new file mode 100644
index 000000000..1d6eb9623
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLSlowPathCall.h
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+#include "CCallHelpers.h"
+#include "FTLSlowPathCallKey.h"
+#include "JITOperations.h"
+
+namespace JSC { namespace FTL {
+
+class State;
+
+class SlowPathCall {
+public:
+    SlowPathCall() { }
+    
+    SlowPathCall(MacroAssembler::Call call, const SlowPathCallKey& key)
+        : m_call(call)
+        , m_key(key)
+    {
+    }
+    
+    MacroAssembler::Call call() const { return m_call; }
+    SlowPathCallKey key() const { return m_key; }
+    
+private:
+    MacroAssembler::Call m_call;
+    SlowPathCallKey m_key;
+};
+
+// This will be an RAII thingy that will set up the necessary stack sizes and offsets and such.
+class SlowPathCallContext {
+public:
+    SlowPathCallContext(RegisterSet usedRegisters, CCallHelpers&, unsigned numArgs, GPRReg returnRegister);
+    ~SlowPathCallContext();
+
+    // NOTE: The call that this returns is already going to be linked by the JIT using addLinkTask(),
+    // so there is no need for you to link it yourself.
+    SlowPathCall makeCall(void* callTarget);
+
+private:
+    SlowPathCallKey keyWithTarget(void* callTarget) const;
+    
+    RegisterSet m_argumentRegisters;
+    RegisterSet m_callingConventionRegisters;
+    CCallHelpers& m_jit;
+    unsigned m_numArgs;
+    GPRReg m_returnRegister;
+    size_t m_offsetToSavingArea;
+    size_t m_stackBytesNeeded;
+    RegisterSet m_thunkSaveSet;
+    ptrdiff_t m_offset;
+};
+
+template<typename... ArgumentTypes>
+SlowPathCall callOperation(
+    const RegisterSet& usedRegisters, CCallHelpers& jit, CCallHelpers::JumpList* exceptionTarget,
+    FunctionPtr function, GPRReg resultGPR, ArgumentTypes... arguments)
+{
+    SlowPathCall call;
+    {
+        SlowPathCallContext context(usedRegisters, jit, sizeof...(ArgumentTypes) + 1, resultGPR);
+        jit.setupArgumentsWithExecState(arguments...);
+        call = context.makeCall(function.value());
+    }
+    if (exceptionTarget)
+        exceptionTarget->append(jit.emitExceptionCheck());
+    return call;
+}
+
+template<typename... ArgumentTypes>
+SlowPathCall callOperation(
+    const RegisterSet& usedRegisters, CCallHelpers& jit, CallSiteIndex callSiteIndex,
+    CCallHelpers::JumpList* exceptionTarget, FunctionPtr function, GPRReg resultGPR,
+    ArgumentTypes... arguments)
+{
+    if (callSiteIndex) {
+        jit.store32(
+            CCallHelpers::TrustedImm32(callSiteIndex.bits()),
+            CCallHelpers::tagFor(CallFrameSlot::argumentCount));
+    }
+    return callOperation(usedRegisters, jit, exceptionTarget, function, resultGPR, arguments...);
+}
+
+CallSiteIndex callSiteIndexForCodeOrigin(State&, CodeOrigin);
+
+template<typename... ArgumentTypes>
+SlowPathCall callOperation(
+    State& state, const RegisterSet& usedRegisters, CCallHelpers& jit, CodeOrigin codeOrigin,
+    CCallHelpers::JumpList* exceptionTarget, FunctionPtr function, GPRReg result, ArgumentTypes... arguments)
+{
+    return callOperation(
+        usedRegisters, jit, callSiteIndexForCodeOrigin(state, codeOrigin), exceptionTarget, function,
+        result, arguments...);
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLOSRExitCompilationInfo.h b/Source/JavaScriptCore/ftl/FTLSlowPathCallKey.cpp
index 796c9d691..4cc835d82 100644
--- a/Source/JavaScriptCore/ftl/FTLOSRExitCompilationInfo.h
+++ b/Source/JavaScriptCore/ftl/FTLSlowPathCallKey.cpp
@@ -23,33 +23,19 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLOSRExitCompilationInfo_h
-#define FTLOSRExitCompilationInfo_h
-
-#include <wtf/Platform.h>
+#include "config.h"
+#include "FTLSlowPathCallKey.h"
 
 #if ENABLE(FTL_JIT)
 
-#include "FTLAbbreviations.h"
-#include "MacroAssembler.h"
-
 namespace JSC { namespace FTL {
 
-struct OSRExitCompilationInfo {
-    OSRExitCompilationInfo()
-        : m_isInvalidationPoint(false)
-    {
-    }
-    
-    MacroAssembler::Label m_thunkLabel;
-    MacroAssembler::PatchableJump m_thunkJump;
-    CodeLocationLabel m_thunkAddress;
-    bool m_isInvalidationPoint;
-};
+void SlowPathCallKey::dump(PrintStream& out) const
+{
+    out.print("<usedRegisters = ", m_usedRegisters, ", offset = ", m_offset, ", callTarget = ", RawPointer(m_callTarget), ", argumentRegisters = ", m_argumentRegisters, ">");
+}
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
 
-#endif // FTLOSRExitCompilationInfo_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLSlowPathCallKey.h b/Source/JavaScriptCore/ftl/FTLSlowPathCallKey.h
new file mode 100644
index 000000000..f1161fbb2
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLSlowPathCallKey.h
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2013 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+#include "RegisterSet.h"
+
+namespace JSC { namespace FTL {
+
+// This is used for creating some sanity in slow-path calls out of the FTL's inline
+// caches. The idea is that we don't want all of the register save/restore stuff to
+// be generated at each IC site. Instead, the IC slow path call site will just save
+// the registers needed for the arguments. It will arrange for there to be enough
+// space on top of stack to save the remaining registers and the return PC. Then it
+// will call a shared thunk that will save the remaining registers. That thunk needs
+// to know the stack offset at which things get saved along with the call target.
+
+// Note that the offset is *not including* the return PC that would be pushed on X86.
+
+class SlowPathCallKey {
+public:
+    SlowPathCallKey()
+        : m_callTarget(0)
+        , m_offset(0)
+    {
+    }
+    
+    SlowPathCallKey(
+        const RegisterSet& set, void* callTarget, const RegisterSet& argumentRegisters,
+        ptrdiff_t offset)
+        : m_usedRegisters(set)
+        , m_callTarget(callTarget)
+        , m_argumentRegisters(argumentRegisters)
+        , m_offset(offset)
+    {
+    }
+    
+    const RegisterSet& usedRegisters() const { return m_usedRegisters; }
+    void* callTarget() const { return m_callTarget; }
+    const RegisterSet& argumentRegisters() const { return m_argumentRegisters; }
+    ptrdiff_t offset() const { return m_offset; }
+    
+    SlowPathCallKey withCallTarget(void* callTarget)
+    {
+        return SlowPathCallKey(usedRegisters(), callTarget, argumentRegisters(), offset());
+    }
+    
+    void dump(PrintStream&) const;
+    
+    enum EmptyValueTag { EmptyValue };
+    enum DeletedValueTag { DeletedValue };
+    
+    SlowPathCallKey(EmptyValueTag)
+        : m_usedRegisters(RegisterSet::EmptyValue)
+        , m_callTarget(0)
+        , m_offset(0)
+    {
+    }
+    
+    SlowPathCallKey(DeletedValueTag)
+        : m_usedRegisters(RegisterSet::DeletedValue)
+        , m_callTarget(0)
+        , m_offset(0)
+    {
+    }
+    
+    bool isEmptyValue() const { return m_usedRegisters.isEmptyValue(); }
+    bool isDeletedValue() const { return m_usedRegisters.isDeletedValue(); }
+    
+    bool operator==(const SlowPathCallKey& other) const
+    {
+        return m_usedRegisters == other.m_usedRegisters
+            && m_callTarget == other.m_callTarget
+            && m_offset == other.m_offset;
+    }
+    unsigned hash() const
+    {
+        return m_usedRegisters.hash() + PtrHash<void*>::hash(m_callTarget) + m_offset;
+    }
+
+private:
+    RegisterSet m_usedRegisters;
+    void* m_callTarget;
+    RegisterSet m_argumentRegisters;
+    ptrdiff_t m_offset;
+};
+
+struct SlowPathCallKeyHash {
+    static unsigned hash(const SlowPathCallKey& key) { return key.hash(); }
+    static bool equal(const SlowPathCallKey& a, const SlowPathCallKey& b) { return a == b; }
+    static const bool safeToCompareToEmptyOrDeleted = false;
+};
+
+} } // namespace JSC::FTL
+
+namespace WTF {
+
+template<typename T> struct DefaultHash;
+template<> struct DefaultHash<JSC::FTL::SlowPathCallKey> {
+    typedef JSC::FTL::SlowPathCallKeyHash Hash;
+};
+
+template<typename T> struct HashTraits;
+template<> struct HashTraits<JSC::FTL::SlowPathCallKey> : public CustomHashTraits<JSC::FTL::SlowPathCallKey> { };
+
+} // namespace WTF
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLExitArgumentList.h b/Source/JavaScriptCore/ftl/FTLStackmapArgumentList.h
index a466edc46..bbbfb641f 100644
--- a/Source/JavaScriptCore/ftl/FTLExitArgumentList.h
+++ b/Source/JavaScriptCore/ftl/FTLStackmapArgumentList.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,23 +23,17 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLExitArgumentList_h
-#define FTLExitArgumentList_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
-#include "FTLAbbreviations.h"
+#include "FTLAbbreviatedTypes.h"
 #include <wtf/Vector.h>
 
 namespace JSC { namespace FTL {
 
-typedef Vector<LValue, 16> ExitArgumentList;
+typedef Vector<LValue, 16> StackmapArgumentList;
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLExitArgumentList_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLState.cpp b/Source/JavaScriptCore/ftl/FTLState.cpp
index c263b264b..d62433700 100644
--- a/Source/JavaScriptCore/ftl/FTLState.cpp
+++ b/Source/JavaScriptCore/ftl/FTLState.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2015-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -32,16 +32,16 @@
 #include "FTLForOSREntryJITCode.h"
 #include "FTLJITCode.h"
 #include "FTLJITFinalizer.h"
+#include "FTLPatchpointExceptionHandle.h"
+#include <stdio.h>
 
 namespace JSC { namespace FTL {
 
+using namespace B3;
 using namespace DFG;
 
 State::State(Graph& graph)
     : graph(graph)
-    , context(llvm->ContextCreate())
-    , module(0)
-    , function(0)
     , generatedFunction(0)
 {
     switch (graph.m_plan.mode) {
@@ -51,7 +51,7 @@ State::State(Graph& graph)
     }
     case FTLForOSREntryMode: {
         RefPtr<ForOSREntryJITCode> code = adoptRef(new ForOSREntryJITCode());
-        code->initializeEntryBuffer(graph.m_vm, graph.m_profiledBlock->m_numCalleeRegisters);
+        code->initializeEntryBuffer(graph.m_vm, graph.m_profiledBlock->m_numCalleeLocals);
         code->setBytecodeIndex(graph.m_plan.osrEntryBytecodeIndex);
         jitCode = code;
         break;
@@ -60,20 +60,22 @@ State::State(Graph& graph)
         RELEASE_ASSERT_NOT_REACHED();
         break;
     }
-    
-    finalizer = new JITFinalizer(graph.m_plan);
-    graph.m_plan.finalizer = adoptPtr(finalizer);
-}
 
-State::~State()
-{
-    llvm->ContextDispose(context);
+    graph.m_plan.finalizer = std::make_unique<JITFinalizer>(graph.m_plan);
+    finalizer = static_cast<JITFinalizer*>(graph.m_plan.finalizer.get());
+
+    proc = std::make_unique<Procedure>();
+
+    proc->setOriginPrinter(
+        [this] (PrintStream& out, B3::Origin origin) {
+            out.print("DFG:", bitwise_cast<Node*>(origin.data()));
+        });
+
+    proc->setFrontendData(&graph);
 }
 
-void State::dumpState(const char* when)
+State::~State()
 {
-    dataLog("LLVM IR for ", CodeBlockWithJITType(graph.m_codeBlock, FTL::JITCode::FTLJIT), " ", when, ":\n");
-    dumpModule(module);
 }
 
 } } // namespace JSC::FTL
diff --git a/Source/JavaScriptCore/ftl/FTLState.h b/Source/JavaScriptCore/ftl/FTLState.h
index c82db6728..bc434304d 100644
--- a/Source/JavaScriptCore/ftl/FTLState.h
+++ b/Source/JavaScriptCore/ftl/FTLState.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,23 +23,40 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLState_h
-#define FTLState_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
+#include "B3Procedure.h"
+#include "DFGCommon.h"
 #include "DFGGraph.h"
-#include "FTLAbbreviations.h"
+#include "FTLAbbreviatedTypes.h"
 #include "FTLGeneratedFunction.h"
-#include "FTLInlineCacheDescriptor.h"
 #include "FTLJITCode.h"
 #include "FTLJITFinalizer.h"
-#include "FTLStackMaps.h"
+#include <wtf/Box.h>
 #include <wtf/Noncopyable.h>
 
-namespace JSC { namespace FTL {
+namespace JSC {
+
+namespace B3 {
+class PatchpointValue;
+class StackSlot;
+} // namespace B3
+
+namespace FTL {
+
+class PatchpointExceptionHandle;
+
+inline bool verboseCompilationEnabled()
+{
+    return DFG::verboseCompilationEnabled(DFG::FTLMode);
+}
+
+inline bool shouldDumpDisassembly()
+{
+    return DFG::shouldDumpDisassembly(DFG::FTLMode);
+}
 
 class State {
     WTF_MAKE_NONCOPYABLE(State);
@@ -51,24 +68,18 @@ public:
     // None of these things is owned by State. It is the responsibility of
     // FTL phases to properly manage the lifecycle of the module and function.
     DFG::Graph& graph;
-    LContext context;
-    LModule module;
-    LValue function;
+    std::unique_ptr<B3::Procedure> proc;
+    bool allocationFailed { false }; // Throw out the compilation once B3 returns.
     RefPtr<JITCode> jitCode;
     GeneratedFunction generatedFunction;
     JITFinalizer* finalizer;
-    SegmentedVector<GetByIdDescriptor> getByIds;
-    SegmentedVector<PutByIdDescriptor> putByIds;
-    Vector<CString> codeSectionNames;
-    Vector<CString> dataSectionNames;
-    RefCountedArray<LSectionWord> stackmapsSection;
-    
-    void dumpState(const char* when);
+    // Top-level exception handler. Jump here if you know that you have to genericUnwind() and there
+    // are no applicable catch blocks anywhere in the Graph.
+    RefPtr<PatchpointExceptionHandle> defaultExceptionHandle;
+    Box<CCallHelpers::Label> exceptionHandler { Box<CCallHelpers::Label>::create() };
+    B3::StackSlot* capturedValue { nullptr };
 };
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLState_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLSwitchCase.h b/Source/JavaScriptCore/ftl/FTLSwitchCase.h
index e9f17d010..948e7462f 100644
--- a/Source/JavaScriptCore/ftl/FTLSwitchCase.h
+++ b/Source/JavaScriptCore/ftl/FTLSwitchCase.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,36 +23,40 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLSwitchCase_h
-#define FTLSwitchCase_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
 #include "FTLAbbreviatedTypes.h"
+#include "FTLWeight.h"
 
 namespace JSC { namespace FTL {
 
 class SwitchCase {
 public:
-    SwitchCase(LValue value, LBasicBlock target)
+    SwitchCase()
+        : m_value(nullptr)
+        , m_target(nullptr)
+    {
+    }
+
+    SwitchCase(LValue value, LBasicBlock target, Weight weight = Weight())
         : m_value(value)
         , m_target(target)
+        , m_weight(weight)
     {
     }
 
     LValue value() const { return m_value; }
     LBasicBlock target() const { return m_target; }
+    Weight weight() const { return m_weight; }
 
 private:
     LValue m_value;
     LBasicBlock m_target;
+    Weight m_weight;
 };
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLSwitchCase_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLThunks.cpp b/Source/JavaScriptCore/ftl/FTLThunks.cpp
index bf04af02a..cfbc75b7c 100644
--- a/Source/JavaScriptCore/ftl/FTLThunks.cpp
+++ b/Source/JavaScriptCore/ftl/FTLThunks.cpp
@@ -29,8 +29,10 @@
 #if ENABLE(FTL_JIT)
 
 #include "AssemblyHelpers.h"
+#include "DFGOSRExitCompilerCommon.h"
 #include "FPRInfo.h"
 #include "FTLOSRExitCompiler.h"
+#include "FTLOperations.h"
 #include "FTLSaveRestore.h"
 #include "GPRInfo.h"
 #include "LinkBuffer.h"
@@ -39,29 +41,51 @@ namespace JSC { namespace FTL {
 
 using namespace DFG;
 
-MacroAssemblerCodeRef osrExitGenerationThunkGenerator(VM& vm, const Location& location)
+enum class FrameAndStackAdjustmentRequirement {
+    Needed, 
+    NotNeeded 
+};
+
+static MacroAssemblerCodeRef genericGenerationThunkGenerator(
+    VM* vm, FunctionPtr generationFunction, const char* name, unsigned extraPopsToRestore, FrameAndStackAdjustmentRequirement frameAndStackAdjustmentRequirement)
 {
-    AssemblyHelpers jit(&vm, 0);
+    AssemblyHelpers jit(vm, 0);
+
+    if (frameAndStackAdjustmentRequirement == FrameAndStackAdjustmentRequirement::Needed) {
+        // This needs to happen before we use the scratch buffer because this function also uses the scratch buffer.
+        adjustFrameAndStackInOSRExitCompilerThunk<FTL::JITCode>(jit, vm, JITCode::FTLJIT);
+    }
     
-    // Note that the "return address" will be the OSR exit ID.
+    // Note that the "return address" will be the ID that we pass to the generation function.
+    
+    ptrdiff_t stackMisalignment = MacroAssembler::pushToSaveByteOffset();
     
     // Pretend that we're a C call frame.
-    jit.push(MacroAssembler::framePointerRegister);
+    jit.pushToSave(MacroAssembler::framePointerRegister);
     jit.move(MacroAssembler::stackPointerRegister, MacroAssembler::framePointerRegister);
-    jit.push(GPRInfo::regT0);
-    jit.push(GPRInfo::regT0);
+    stackMisalignment += MacroAssembler::pushToSaveByteOffset();
+    
+    // Now create ourselves enough stack space to give saveAllRegisters() a scratch slot.
+    unsigned numberOfRequiredPops = 0;
+    do {
+        jit.pushToSave(GPRInfo::regT0);
+        stackMisalignment += MacroAssembler::pushToSaveByteOffset();
+        numberOfRequiredPops++;
+    } while (stackMisalignment % stackAlignmentBytes());
     
-    ScratchBuffer* scratchBuffer = vm.scratchBufferForSize(requiredScratchMemorySizeInBytes());
+    ScratchBuffer* scratchBuffer = vm->scratchBufferForSize(requiredScratchMemorySizeInBytes());
     char* buffer = static_cast<char*>(scratchBuffer->dataBuffer());
     
     saveAllRegisters(jit, buffer);
     
     // Tell GC mark phase how much of the scratch buffer is active during call.
-    jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->activeLengthPtr()), GPRInfo::nonArgGPR1);
-    jit.storePtr(MacroAssembler::TrustedImmPtr(requiredScratchMemorySizeInBytes()), GPRInfo::nonArgGPR1);
+    jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->activeLengthPtr()), GPRInfo::nonArgGPR0);
+    jit.storePtr(MacroAssembler::TrustedImmPtr(requiredScratchMemorySizeInBytes()), GPRInfo::nonArgGPR0);
 
-    location.restoreInto(jit, buffer, GPRInfo::argumentGPR0, 1);
-    jit.peek(GPRInfo::argumentGPR1, 3);
+    jit.loadPtr(GPRInfo::callFrameRegister, GPRInfo::argumentGPR0);
+    jit.peek(
+        GPRInfo::argumentGPR1,
+        (stackMisalignment - MacroAssembler::pushToSaveByteOffset()) / sizeof(void*));
     MacroAssembler::Call functionCall = jit.call();
     
     // At this point we want to make a tail call to what was returned to us in the
@@ -71,24 +95,73 @@ MacroAssemblerCodeRef osrExitGenerationThunkGenerator(VM& vm, const Location& lo
     
     jit.move(GPRInfo::returnValueGPR, GPRInfo::regT0);
     
-    // Prepare for tail call.
-    jit.pop(GPRInfo::regT1);
-    jit.pop(GPRInfo::regT1);
-    jit.pop(MacroAssembler::framePointerRegister);
-    
-    // At this point we're sitting on the return address - so if we did a jump right now, the
-    // tail-callee would be happy. Instead we'll stash the callee in the return address and then
-    // restore all registers.
+    // Make sure we tell the GC that we're not using the scratch buffer anymore.
+    jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->activeLengthPtr()), GPRInfo::regT1);
+    jit.storePtr(MacroAssembler::TrustedImmPtr(0), GPRInfo::regT1);
     
+    // Prepare for tail call.
+    while (numberOfRequiredPops--)
+        jit.popToRestore(GPRInfo::regT1);
+    jit.popToRestore(MacroAssembler::framePointerRegister);
+
+    // When we came in here, there was an additional thing pushed to the stack. Some clients want it
+    // popped before proceeding.
+    while (extraPopsToRestore--)
+        jit.popToRestore(GPRInfo::regT1);
+
+    // Put the return address wherever the return instruction wants it. On all platforms, this
+    // ensures that the return address is out of the way of register restoration.
     jit.restoreReturnAddressBeforeReturn(GPRInfo::regT0);
-    
+
     restoreAllRegisters(jit, buffer);
 
     jit.ret();
     
-    LinkBuffer patchBuffer(vm, &jit, GLOBAL_THUNK_ID);
-    patchBuffer.link(functionCall, compileFTLOSRExit);
-    return FINALIZE_CODE(patchBuffer, ("FTL OSR exit generation thunk for callFrame at %s", toCString(location).data()));
+    LinkBuffer patchBuffer(*vm, jit, GLOBAL_THUNK_ID);
+    patchBuffer.link(functionCall, generationFunction);
+    return FINALIZE_CODE(patchBuffer, ("%s", name));
+}
+
+MacroAssemblerCodeRef osrExitGenerationThunkGenerator(VM* vm)
+{
+    unsigned extraPopsToRestore = 0;
+    return genericGenerationThunkGenerator(
+        vm, compileFTLOSRExit, "FTL OSR exit generation thunk", extraPopsToRestore, FrameAndStackAdjustmentRequirement::Needed);
+}
+
+MacroAssemblerCodeRef lazySlowPathGenerationThunkGenerator(VM* vm)
+{
+    unsigned extraPopsToRestore = 1;
+    return genericGenerationThunkGenerator(
+        vm, compileFTLLazySlowPath, "FTL lazy slow path generation thunk", extraPopsToRestore, FrameAndStackAdjustmentRequirement::NotNeeded);
+}
+
+static void registerClobberCheck(AssemblyHelpers& jit, RegisterSet dontClobber)
+{
+    if (!Options::clobberAllRegsInFTLICSlowPath())
+        return;
+    
+    RegisterSet clobber = RegisterSet::allRegisters();
+    clobber.exclude(RegisterSet::reservedHardwareRegisters());
+    clobber.exclude(RegisterSet::stackRegisters());
+    clobber.exclude(RegisterSet::calleeSaveRegisters());
+    clobber.exclude(dontClobber);
+    
+    GPRReg someGPR;
+    for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {
+        if (!clobber.get(reg) || !reg.isGPR())
+            continue;
+        
+        jit.move(AssemblyHelpers::TrustedImm32(0x1337beef), reg.gpr());
+        someGPR = reg.gpr();
+    }
+    
+    for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {
+        if (!clobber.get(reg) || !reg.isFPR())
+            continue;
+        
+        jit.move64ToDouble(someGPR, reg.fpr());
+    }
 }
 
 MacroAssemblerCodeRef slowPathCallThunkGenerator(VM& vm, const SlowPathCallKey& key)
@@ -122,8 +195,10 @@ MacroAssemblerCodeRef slowPathCallThunkGenerator(VM& vm, const SlowPathCallKey&
     jit.preserveReturnAddressAfterCall(GPRInfo::nonArgGPR0);
     jit.storePtr(GPRInfo::nonArgGPR0, AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, key.offset()));
     
-    JITCompiler::Call call = jit.call();
+    registerClobberCheck(jit, key.argumentRegisters());
     
+    AssemblyHelpers::Call call = jit.call();
+
     jit.loadPtr(AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, key.offset()), GPRInfo::nonPreservedNonReturnGPR);
     jit.restoreReturnAddressBeforeReturn(GPRInfo::nonPreservedNonReturnGPR);
     
@@ -147,7 +222,7 @@ MacroAssemblerCodeRef slowPathCallThunkGenerator(VM& vm, const SlowPathCallKey&
     
     jit.ret();
 
-    LinkBuffer patchBuffer(vm, &jit, GLOBAL_THUNK_ID);
+    LinkBuffer patchBuffer(vm, jit, GLOBAL_THUNK_ID);
     patchBuffer.link(call, FunctionPtr(key.callTarget()));
     return FINALIZE_CODE(patchBuffer, ("FTL slow path call thunk for %s", toCString(key).data()));
 }
diff --git a/Source/JavaScriptCore/ftl/FTLThunks.h b/Source/JavaScriptCore/ftl/FTLThunks.h
index bbcdbddc9..33e3b021b 100644
--- a/Source/JavaScriptCore/ftl/FTLThunks.h
+++ b/Source/JavaScriptCore/ftl/FTLThunks.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLThunks_h
-#define FTLThunks_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -41,7 +38,8 @@ class VM;
 
 namespace FTL {
 
-MacroAssemblerCodeRef osrExitGenerationThunkGenerator(VM&, const Location&);
+MacroAssemblerCodeRef osrExitGenerationThunkGenerator(VM*);
+MacroAssemblerCodeRef lazySlowPathGenerationThunkGenerator(VM*);
 MacroAssemblerCodeRef slowPathCallThunkGenerator(VM&, const SlowPathCallKey&);
 
 template<typename KeyTypeArgument>
@@ -78,12 +76,6 @@ typename MapType::KeyType keyForThunk(MapType& map, MacroAssemblerCodePtr ptr)
 
 class Thunks {
 public:
-    MacroAssemblerCodeRef getOSRExitGenerationThunk(VM& vm, const Location& location)
-    {
-        return generateIfNecessary(
-            vm, m_osrExitThunks, location, osrExitGenerationThunkGenerator);
-    }
-    
     MacroAssemblerCodeRef getSlowPathCallThunk(VM& vm, const SlowPathCallKey& key)
     {
         return generateIfNecessary(
@@ -96,12 +88,9 @@ public:
     }
     
 private:
-    ThunkMap<Location> m_osrExitThunks;
     ThunkMap<SlowPathCallKey> m_slowPathCallThunks;
 };
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLTHunks_h
diff --git a/Source/JavaScriptCore/ftl/FTLTypedPointer.h b/Source/JavaScriptCore/ftl/FTLTypedPointer.h
index fbee5a3ec..8c0cbae5f 100644
--- a/Source/JavaScriptCore/ftl/FTLTypedPointer.h
+++ b/Source/JavaScriptCore/ftl/FTLTypedPointer.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2016 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,14 +23,11 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLTypedPointer_h
-#define FTLTypedPointer_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
-#include "FTLAbbreviations.h"
+#include "FTLAbbreviatedTypes.h"
 #include "FTLAbstractHeap.h"
 
 namespace JSC { namespace FTL {
@@ -49,13 +46,13 @@ public:
     {
     }
     
-    bool operator!() const
+    explicit operator bool() const
     {
         ASSERT(!m_heap == !m_value);
-        return !m_heap;
+        return !!m_heap;
     }
     
-    const AbstractHeap& heap() const { return *m_heap; }
+    const AbstractHeap* heap() const { return m_heap; }
     LValue value() const { return m_value; }
 
 private:
@@ -66,6 +63,3 @@ private:
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLTypedPointer_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLValueFormat.cpp b/Source/JavaScriptCore/ftl/FTLValueFormat.cpp
deleted file mode 100644
index 5a89d6a49..000000000
--- a/Source/JavaScriptCore/ftl/FTLValueFormat.cpp
+++ /dev/null
@@ -1,123 +0,0 @@
-/*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
- */
-
-#include "config.h"
-#include "FTLValueFormat.h"
-
-#if ENABLE(FTL_JIT)
-
-#include "AssemblyHelpers.h"
-
-namespace JSC { namespace FTL {
-
-void reboxAccordingToFormat(
-    ValueFormat format, AssemblyHelpers& jit, GPRReg value, GPRReg scratch1, GPRReg scratch2)
-{
-    switch (format) {
-    case ValueFormatInt32: {
-        jit.zeroExtend32ToPtr(value, value);
-        jit.or64(GPRInfo::tagTypeNumberRegister, value);
-        break;
-    }
-    
-    case ValueFormatInt52: {
-        jit.rshift64(AssemblyHelpers::TrustedImm32(JSValue::int52ShiftAmount), value);
-        jit.moveDoubleTo64(FPRInfo::fpRegT0, scratch2);
-        jit.boxInt52(value, value, scratch1, FPRInfo::fpRegT0);
-        jit.move64ToDouble(scratch2, FPRInfo::fpRegT0);
-        break;
-    }
-    
-    case ValueFormatStrictInt52: {
-        jit.moveDoubleTo64(FPRInfo::fpRegT0, scratch2);
-        jit.boxInt52(value, value, scratch1, FPRInfo::fpRegT0);
-        jit.move64ToDouble(scratch2, FPRInfo::fpRegT0);
-        break;
-    }
-    
-    case ValueFormatBoolean: {
-        jit.zeroExtend32ToPtr(value, value);
-        jit.or32(MacroAssembler::TrustedImm32(ValueFalse), value);
-        break;
-    }
-    
-    case ValueFormatJSValue: {
-        // Done already!
-        break;
-    }
-    
-    case ValueFormatDouble: {
-        jit.moveDoubleTo64(FPRInfo::fpRegT0, scratch1);
-        jit.move64ToDouble(value, FPRInfo::fpRegT0);
-        jit.boxDouble(FPRInfo::fpRegT0, value);
-        jit.move64ToDouble(scratch1, FPRInfo::fpRegT0);
-        break;
-    }
-    
-    default:
-        RELEASE_ASSERT_NOT_REACHED();
-        break;
-    }
-}
-
-} } // namespace JSC::FTL
-
-namespace WTF {
-
-using namespace JSC::FTL;
-
-void printInternal(PrintStream& out, ValueFormat format)
-{
-    switch (format) {
-    case InvalidValueFormat:
-        out.print("Invalid");
-        return;
-    case ValueFormatInt32:
-        out.print("Int32");
-        return;
-    case ValueFormatInt52:
-        out.print("Int52");
-        return;
-    case ValueFormatStrictInt52:
-        out.print("StrictInt52");
-        return;
-    case ValueFormatBoolean:
-        out.print("Boolean");
-        return;
-    case ValueFormatJSValue:
-        out.print("JSValue");
-        return;
-    case ValueFormatDouble:
-        out.print("Double");
-        return;
-    }
-    
-    RELEASE_ASSERT_NOT_REACHED();
-}
-
-} // namespace WTF
-
-#endif // ENABLE(FTL_JIT)
-
diff --git a/Source/JavaScriptCore/ftl/FTLValueFromBlock.h b/Source/JavaScriptCore/ftl/FTLValueFromBlock.h
index fec0a1b37..5bd14ca62 100644
--- a/Source/JavaScriptCore/ftl/FTLValueFromBlock.h
+++ b/Source/JavaScriptCore/ftl/FTLValueFromBlock.h
@@ -23,10 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLValueFromBlock_h
-#define FTLValueFromBlock_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
@@ -47,6 +44,8 @@ public:
         , m_block(block)
     {
     }
+    
+    explicit operator bool() const { return m_value || m_block; }
 
     LValue value() const { return m_value; }
     LBasicBlock block() const { return m_block; }
@@ -59,6 +58,3 @@ private:
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLValueFromBlock_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLValueRange.cpp b/Source/JavaScriptCore/ftl/FTLValueRange.cpp
new file mode 100644
index 000000000..d46ddafc1
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLValueRange.cpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLValueRange.h"
+
+#if ENABLE(FTL_JIT)
+
+namespace JSC { namespace FTL {
+
+void ValueRange::decorateInstruction(LValue loadInstruction, unsigned rangeKind) const
+{
+    UNUSED_PARAM(loadInstruction);
+    UNUSED_PARAM(rangeKind);
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
diff --git a/Source/JavaScriptCore/ftl/FTLExitThunkGenerator.h b/Source/JavaScriptCore/ftl/FTLValueRange.h
index 56936b518..3ae3dcbf9 100644
--- a/Source/JavaScriptCore/ftl/FTLExitThunkGenerator.h
+++ b/Source/JavaScriptCore/ftl/FTLValueRange.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2014 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,38 +23,38 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef FTLExitThunkGenerator_h
-#define FTLExitThunkGenerator_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
-#include "CCallHelpers.h"
+#include "FTLAbbreviatedTypes.h"
 
 namespace JSC { namespace FTL {
 
-class State;
-struct OSRExitCompilationInfo;
-
-class ExitThunkGenerator : public CCallHelpers {
+class ValueRange {
 public:
-    ExitThunkGenerator(State& state);
-    ~ExitThunkGenerator();
+    ValueRange()
+        : m_begin(0)
+        , m_end(0)
+    {
+    }
     
-    void emitThunk(unsigned index);
-    void emitThunks();
+    ValueRange(LValue begin, LValue end)
+        : m_begin(begin)
+        , m_end(end)
+    {
+    }
+    
+    LValue begin() const { return m_begin; }
+    LValue end() const { return m_end; }
+    
+    void decorateInstruction(LValue loadInstruction, unsigned rangeKind) const;
     
-    bool didThings() const { return m_didThings; }
-
 private:
-    State& m_state;
-    bool m_didThings;
+    LValue m_begin;
+    LValue m_end;
 };
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
-#endif // FTLExitThunkGenerator_h
-
diff --git a/Source/JavaScriptCore/ftl/FTLExitThunkGenerator.cpp b/Source/JavaScriptCore/ftl/FTLWeight.h
index 86c872307..cde23070b 100644
--- a/Source/JavaScriptCore/ftl/FTLExitThunkGenerator.cpp
+++ b/Source/JavaScriptCore/ftl/FTLWeight.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2014 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,47 +23,49 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#include "config.h"
-#include "FTLExitThunkGenerator.h"
+#pragma once
 
 #if ENABLE(FTL_JIT)
 
-#include "FTLOSRExitCompilationInfo.h"
-#include "FTLState.h"
+#include "B3FrequencyClass.h"
+#include <wtf/MathExtras.h>
+#include <wtf/StdLibExtras.h>
 
 namespace JSC { namespace FTL {
 
-using namespace JSC::DFG;
-
-ExitThunkGenerator::ExitThunkGenerator(State& state)
-    : CCallHelpers(&state.graph.m_vm, state.graph.m_codeBlock)
-    , m_state(state)
-    , m_didThings(false)
-{
-}
-
-ExitThunkGenerator::~ExitThunkGenerator()
-{
-}
-
-void ExitThunkGenerator::emitThunk(unsigned index)
-{
-    OSRExitCompilationInfo& info = m_state.finalizer->osrExit[index];
+class Weight {
+public:
+    Weight()
+        : m_value(std::numeric_limits<float>::quiet_NaN())
+    {
+    }
+    
+    explicit Weight(float value)
+        : m_value(value)
+    {
+    }
     
-    info.m_thunkLabel = label();
-    push(TrustedImm32(index));
-    info.m_thunkJump = patchableJump();
+    bool isSet() const { return m_value == m_value; }
+    bool operator!() const { return !isSet(); }
     
-    m_didThings = true;
-}
+    float value() const { return m_value; }
 
-void ExitThunkGenerator::emitThunks()
-{
-    for (unsigned i = 0; i < m_state.finalizer->osrExit.size(); ++i)
-        emitThunk(i);
-}
+    B3::FrequencyClass frequencyClass() const { return value() ? B3::FrequencyClass::Normal : B3::FrequencyClass::Rare; }
+    
+    // Inverse weight for a two-target branch.
+    Weight inverse() const
+    {
+        if (!isSet())
+            return Weight();
+        if (value())
+            return Weight(0);
+        return Weight(1);
+    }
+    
+private:
+    float m_value;
+};
 
 } } // namespace JSC::FTL
 
 #endif // ENABLE(FTL_JIT)
-
diff --git a/Source/JavaScriptCore/ftl/FTLWeightedTarget.h b/Source/JavaScriptCore/ftl/FTLWeightedTarget.h
new file mode 100644
index 000000000..5ed2968e4
--- /dev/null
+++ b/Source/JavaScriptCore/ftl/FTLWeightedTarget.h
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2014, 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#if ENABLE(FTL_JIT)
+
+#include "FTLAbbreviatedTypes.h"
+#include "FTLWeight.h"
+
+namespace JSC { namespace FTL {
+
+class WeightedTarget {
+public:
+    WeightedTarget()
+        : m_target(nullptr)
+    {
+    }
+    
+    WeightedTarget(LBasicBlock target, Weight weight)
+        : m_target(target)
+        , m_weight(weight)
+    {
+    }
+    
+    WeightedTarget(LBasicBlock target, float weight)
+        : m_target(target)
+        , m_weight(weight)
+    {
+    }
+    
+    LBasicBlock target() const { return m_target; }
+    Weight weight() const { return m_weight; }
+    
+    B3::FrequentedBlock frequentedBlock() const
+    {
+        return B3::FrequentedBlock(target(), weight().frequencyClass());
+    }
+    
+private:
+    LBasicBlock m_target;
+    Weight m_weight;
+};
+
+// Helpers for creating weighted targets for statically known (or unknown) branch
+// profiles.
+
+inline WeightedTarget usually(LBasicBlock block)
+{
+    return WeightedTarget(block, 1);
+}
+
+inline WeightedTarget rarely(LBasicBlock block)
+{
+    return WeightedTarget(block, 0);
+}
+
+// Currently in B3 this is the equivalent of "usually", but we like to make the distinction in
+// case we ever make B3 support proper branch weights. We used to do that in LLVM.
+inline WeightedTarget unsure(LBasicBlock block)
+{
+    return WeightedTarget(block, Weight());
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)