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diff --git a/Source/JavaScriptCore/b3/B3Value.h b/Source/JavaScriptCore/b3/B3Value.h
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+/*
+ * 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. 
+ */
+
+#pragma once
+
+#if ENABLE(B3_JIT)
+
+#include "AirArg.h"
+#include "B3Effects.h"
+#include "B3FrequentedBlock.h"
+#include "B3Kind.h"
+#include "B3Origin.h"
+#include "B3SparseCollection.h"
+#include "B3Type.h"
+#include "B3ValueKey.h"
+#include <wtf/CommaPrinter.h>
+#include <wtf/FastMalloc.h>
+#include <wtf/Noncopyable.h>
+
+namespace JSC { namespace B3 {
+
+class BasicBlock;
+class CheckValue;
+class InsertionSet;
+class PhiChildren;
+class Procedure;
+
+class JS_EXPORT_PRIVATE Value {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    typedef Vector<Value*, 3> AdjacencyList;
+
+    static const char* const dumpPrefix;
+
+    static bool accepts(Kind) { return true; }
+
+    virtual ~Value();
+
+    unsigned index() const { return m_index; }
+    
+    // Note that the kind is immutable, except for replacing values with:
+    // Identity, Nop, Oops, Jump, and Phi. See below for replaceWithXXX() methods.
+    Kind kind() const { return m_kind; }
+    
+    Opcode opcode() const { return kind().opcode(); }
+    
+    // It's good practice to mirror Kind methods here, so you can say value->isBlah()
+    // instead of value->kind().isBlah().
+    bool isChill() const { return kind().isChill(); }
+    bool traps() const { return kind().traps(); }
+
+    Origin origin() const { return m_origin; }
+    void setOrigin(Origin origin) { m_origin = origin; }
+    
+    Value*& child(unsigned index) { return m_children[index]; }
+    Value* child(unsigned index) const { return m_children[index]; }
+
+    Value*& lastChild() { return m_children.last(); }
+    Value* lastChild() const { return m_children.last(); }
+
+    unsigned numChildren() const { return m_children.size(); }
+
+    Type type() const { return m_type; }
+    void setType(Type type) { m_type = type; }
+
+    // This is useful when lowering. Note that this is only valid for non-void values.
+    Air::Arg::Type airType() const { return Air::Arg::typeForB3Type(type()); }
+    Air::Arg::Width airWidth() const { return Air::Arg::widthForB3Type(type()); }
+
+    AdjacencyList& children() { return m_children; } 
+    const AdjacencyList& children() const { return m_children; }
+
+    // If you want to replace all uses of this value with a different value, then replace this
+    // value with Identity. Then do a pass of performSubstitution() on all of the values that use
+    // this one. Usually we do all of this in one pass in pre-order, which ensures that the
+    // X->replaceWithIdentity() calls happen before the performSubstitution() calls on X's users.
+    void replaceWithIdentity(Value*);
+    
+    // It's often necessary to kill a value. It's tempting to replace the value with Nop or to
+    // just remove it. But unless you are sure that the value is Void, you will probably still
+    // have other values that use this one. Sure, you may kill those later, or you might not. This
+    // method lets you kill a value safely. It will replace Void values with Nop and non-Void
+    // values with Identities on bottom constants. For this reason, this takes a callback that is
+    // responsible for creating bottoms. There's a utility for this, see B3BottomProvider.h. You
+    // can also access that utility using replaceWithBottom(InsertionSet&, size_t).
+    template<typename BottomProvider>
+    void replaceWithBottom(const BottomProvider&);
+    
+    void replaceWithBottom(InsertionSet&, size_t index);
+
+    // Use this if you want to kill a value and you are sure that the value is Void.
+    void replaceWithNop();
+    
+    // Use this if you want to kill a value and you are sure that nobody is using it anymore.
+    void replaceWithNopIgnoringType();
+    
+    void replaceWithPhi();
+    
+    // These transformations are only valid for terminals.
+    void replaceWithJump(BasicBlock* owner, FrequentedBlock);
+    void replaceWithOops(BasicBlock* owner);
+    
+    // You can use this form if owners are valid. They're usually not valid.
+    void replaceWithJump(FrequentedBlock);
+    void replaceWithOops();
+
+    void dump(PrintStream&) const;
+    void deepDump(const Procedure*, PrintStream&) const;
+    
+    virtual void dumpSuccessors(const BasicBlock*, PrintStream&) const;
+
+    // This is how you cast Values. For example, if you want to do something provided that we have a
+    // ArgumentRegValue, you can do:
+    //
+    // if (ArgumentRegValue* argumentReg = value->as<ArgumentRegValue>()) {
+    //     things
+    // }
+    //
+    // This will return null if this kind() != ArgumentReg. This works because this returns nullptr
+    // if T::accepts(kind()) returns false.
+    template<typename T>
+    T* as();
+    template<typename T>
+    const T* as() const;
+
+    // What follows are a bunch of helpers for inspecting and modifying values. Note that we have a
+    // bunch of different idioms for implementing such helpers. You can use virtual methods, and
+    // override from the various Value subclasses. You can put the method inside Value and make it
+    // non-virtual, and the implementation can switch on kind. The method could be inline or not.
+    // If a method is specific to some Value subclass, you could put it in the subclass, or you could
+    // put it on Value anyway. It's fine to pick whatever feels right, and we shouldn't restrict
+    // ourselves to any particular idiom.
+
+    bool isConstant() const;
+    bool isInteger() const;
+    
+    virtual Value* negConstant(Procedure&) const;
+    virtual Value* addConstant(Procedure&, int32_t other) const;
+    virtual Value* addConstant(Procedure&, const Value* other) const;
+    virtual Value* subConstant(Procedure&, const Value* other) const;
+    virtual Value* mulConstant(Procedure&, const Value* other) const;
+    virtual Value* checkAddConstant(Procedure&, const Value* other) const;
+    virtual Value* checkSubConstant(Procedure&, const Value* other) const;
+    virtual Value* checkMulConstant(Procedure&, const Value* other) const;
+    virtual Value* checkNegConstant(Procedure&) const;
+    virtual Value* divConstant(Procedure&, const Value* other) const; // This chooses Div<Chill> semantics for integers.
+    virtual Value* uDivConstant(Procedure&, const Value* other) const;
+    virtual Value* modConstant(Procedure&, const Value* other) const; // This chooses Mod<Chill> semantics.
+    virtual Value* uModConstant(Procedure&, const Value* other) const;
+    virtual Value* bitAndConstant(Procedure&, const Value* other) const;
+    virtual Value* bitOrConstant(Procedure&, const Value* other) const;
+    virtual Value* bitXorConstant(Procedure&, const Value* other) const;
+    virtual Value* shlConstant(Procedure&, const Value* other) const;
+    virtual Value* sShrConstant(Procedure&, const Value* other) const;
+    virtual Value* zShrConstant(Procedure&, const Value* other) const;
+    virtual Value* rotRConstant(Procedure&, const Value* other) const;
+    virtual Value* rotLConstant(Procedure&, const Value* other) const;
+    virtual Value* bitwiseCastConstant(Procedure&) const;
+    virtual Value* iToDConstant(Procedure&) const;
+    virtual Value* iToFConstant(Procedure&) const;
+    virtual Value* doubleToFloatConstant(Procedure&) const;
+    virtual Value* floatToDoubleConstant(Procedure&) const;
+    virtual Value* absConstant(Procedure&) const;
+    virtual Value* ceilConstant(Procedure&) const;
+    virtual Value* floorConstant(Procedure&) const;
+    virtual Value* sqrtConstant(Procedure&) const;
+
+    virtual TriState equalConstant(const Value* other) const;
+    virtual TriState notEqualConstant(const Value* other) const;
+    virtual TriState lessThanConstant(const Value* other) const;
+    virtual TriState greaterThanConstant(const Value* other) const;
+    virtual TriState lessEqualConstant(const Value* other) const;
+    virtual TriState greaterEqualConstant(const Value* other) const;
+    virtual TriState aboveConstant(const Value* other) const;
+    virtual TriState belowConstant(const Value* other) const;
+    virtual TriState aboveEqualConstant(const Value* other) const;
+    virtual TriState belowEqualConstant(const Value* other) const;
+    virtual TriState equalOrUnorderedConstant(const Value* other) const;
+    
+    // If the value is a comparison then this returns the inverted form of that comparison, if
+    // possible. It can be impossible for double comparisons, where for example LessThan and
+    // GreaterEqual behave differently. If this returns a value, it is a new value, which must be
+    // either inserted into some block or deleted.
+    Value* invertedCompare(Procedure&) const;
+
+    bool hasInt32() const;
+    int32_t asInt32() const;
+    bool isInt32(int32_t) const;
+    
+    bool hasInt64() const;
+    int64_t asInt64() const;
+    bool isInt64(int64_t) const;
+
+    bool hasInt() const;
+    int64_t asInt() const;
+    bool isInt(int64_t value) const;
+
+    bool hasIntPtr() const;
+    intptr_t asIntPtr() const;
+    bool isIntPtr(intptr_t) const;
+
+    bool hasDouble() const;
+    double asDouble() const;
+    bool isEqualToDouble(double) const; // We say "isEqualToDouble" because "isDouble" would be a bit equality.
+
+    bool hasFloat() const;
+    float asFloat() const;
+
+    bool hasNumber() const;
+    template<typename T> bool isRepresentableAs() const;
+    template<typename T> T asNumber() const;
+
+    // Booleans in B3 are Const32(0) or Const32(1). So this is true if the type is Int32 and the only
+    // possible return values are 0 or 1. It's OK for this method to conservatively return false.
+    bool returnsBool() const;
+
+    bool isNegativeZero() const;
+
+    bool isRounded() const;
+
+    TriState asTriState() const;
+    bool isLikeZero() const { return asTriState() == FalseTriState; }
+    bool isLikeNonZero() const { return asTriState() == TrueTriState; }
+
+    Effects effects() const;
+
+    // This returns a ValueKey that describes that this Value returns when it executes. Returns an
+    // empty ValueKey if this Value is impure. Note that an operation that returns Void could still
+    // have a non-empty ValueKey. This happens for example with Check operations.
+    ValueKey key() const;
+
+    // Makes sure that none of the children are Identity's. If a child points to Identity, this will
+    // repoint it at the Identity's child. For simplicity, this will follow arbitrarily long chains
+    // of Identity's.
+    void performSubstitution();
+    
+    // Free values are those whose presence is guaranteed not to hurt code. We consider constants,
+    // Identities, and Nops to be free. Constants are free because we hoist them to an optimal place.
+    // Identities and Nops are free because we remove them.
+    bool isFree() const;
+
+    // Walk the ancestors of this value (i.e. the graph of things it transitively uses). This
+    // either walks phis or not, depending on whether PhiChildren is null. Your callback gets
+    // called with the signature:
+    //
+    //     (Value*) -> WalkStatus
+    enum WalkStatus {
+        Continue,
+        IgnoreChildren,
+        Stop
+    };
+    template<typename Functor>
+    void walk(const Functor& functor, PhiChildren* = nullptr);
+
+protected:
+    virtual Value* cloneImpl() const;
+    
+    virtual void dumpChildren(CommaPrinter&, PrintStream&) const;
+    virtual void dumpMeta(CommaPrinter&, PrintStream&) const;
+
+private:
+    friend class Procedure;
+    friend class SparseCollection<Value>;
+
+    // Checks that this kind is valid for use with B3::Value.
+    ALWAYS_INLINE static void checkKind(Kind kind, unsigned numArgs)
+    {
+        switch (kind.opcode()) {
+        case FramePointer:
+        case Nop:
+        case Phi:
+        case Jump:
+        case Oops:
+        case EntrySwitch:
+            if (UNLIKELY(numArgs))
+                badKind(kind, numArgs);
+            break;
+        case Return:
+            if (UNLIKELY(numArgs > 1))
+                badKind(kind, numArgs);
+            break;
+        case Identity:
+        case Neg:
+        case Clz:
+        case Abs:
+        case Ceil:
+        case Floor:
+        case Sqrt:
+        case SExt8:
+        case SExt16:
+        case Trunc:
+        case SExt32:
+        case ZExt32:
+        case FloatToDouble:
+        case IToD:
+        case DoubleToFloat:
+        case IToF:
+        case BitwiseCast:
+        case Branch:
+            if (UNLIKELY(numArgs != 1))
+                badKind(kind, numArgs);
+            break;
+        case Add:
+        case Sub:
+        case Mul:
+        case Div:
+        case UDiv:
+        case Mod:
+        case UMod:
+        case BitAnd:
+        case BitOr:
+        case BitXor:
+        case Shl:
+        case SShr:
+        case ZShr:
+        case RotR:
+        case RotL:
+        case Equal:
+        case NotEqual:
+        case LessThan:
+        case GreaterThan:
+        case LessEqual:
+        case GreaterEqual:
+        case Above:
+        case Below:
+        case AboveEqual:
+        case BelowEqual:
+        case EqualOrUnordered:
+            if (UNLIKELY(numArgs != 2))
+                badKind(kind, numArgs);
+            break;
+        case Select:
+            if (UNLIKELY(numArgs != 3))
+                badKind(kind, numArgs);
+            break;
+        default:
+            badKind(kind, numArgs);
+            break;
+        }
+    }
+
+protected:
+    enum CheckedOpcodeTag { CheckedOpcode };
+
+    Value(const Value&) = default;
+    Value& operator=(const Value&) = default;
+    
+    // Instantiate values via Procedure.
+    // This form requires specifying the type explicitly:
+    template<typename... Arguments>
+    explicit Value(CheckedOpcodeTag, Kind kind, Type type, Origin origin, Value* firstChild, Arguments... arguments)
+        : m_kind(kind)
+        , m_type(type)
+        , m_origin(origin)
+        , m_children{ firstChild, arguments... }
+    {
+    }
+    // This form is for specifying the type explicitly when the opcode has no children:
+    explicit Value(CheckedOpcodeTag, Kind kind, Type type, Origin origin)
+        : m_kind(kind)
+        , m_type(type)
+        , m_origin(origin)
+    {
+    }
+    // This form is for those opcodes that can infer their type from the opcode and first child:
+    template<typename... Arguments>
+    explicit Value(CheckedOpcodeTag, Kind kind, Origin origin, Value* firstChild)
+        : m_kind(kind)
+        , m_type(typeFor(kind, firstChild))
+        , m_origin(origin)
+        , m_children{ firstChild }
+    {
+    }
+    // This form is for those opcodes that can infer their type from the opcode and first and second child:
+    template<typename... Arguments>
+    explicit Value(CheckedOpcodeTag, Kind kind, Origin origin, Value* firstChild, Value* secondChild, Arguments... arguments)
+        : m_kind(kind)
+        , m_type(typeFor(kind, firstChild, secondChild))
+        , m_origin(origin)
+        , m_children{ firstChild, secondChild, arguments... }
+    {
+    }
+    // This form is for those opcodes that can infer their type from the opcode alone, and that don't
+    // take any arguments:
+    explicit Value(CheckedOpcodeTag, Kind kind, Origin origin)
+        : m_kind(kind)
+        , m_type(typeFor(kind, nullptr))
+        , m_origin(origin)
+    {
+    }
+    // Use this form for varargs.
+    explicit Value(CheckedOpcodeTag, Kind kind, Type type, Origin origin, const AdjacencyList& children)
+        : m_kind(kind)
+        , m_type(type)
+        , m_origin(origin)
+        , m_children(children)
+    {
+    }
+    explicit Value(CheckedOpcodeTag, Kind kind, Type type, Origin origin, AdjacencyList&& children)
+        : m_kind(kind)
+        , m_type(type)
+        , m_origin(origin)
+        , m_children(WTFMove(children))
+    {
+    }
+
+    // This is the constructor you end up actually calling, if you're instantiating Value
+    // directly.
+    template<typename... Arguments>
+        explicit Value(Kind kind, Type type, Origin origin)
+        : Value(CheckedOpcode, kind, type, origin)
+    {
+        checkKind(kind, 0);
+    }
+    template<typename... Arguments>
+        explicit Value(Kind kind, Type type, Origin origin, Value* firstChild, Arguments&&... arguments)
+        : Value(CheckedOpcode, kind, type, origin, firstChild, std::forward<Arguments>(arguments)...)
+    {
+        checkKind(kind, 1 + sizeof...(arguments));
+    }
+    template<typename... Arguments>
+        explicit Value(Kind kind, Type type, Origin origin, const AdjacencyList& children)
+        : Value(CheckedOpcode, kind, type, origin, children)
+    {
+        checkKind(kind, children.size());
+    }
+    template<typename... Arguments>
+        explicit Value(Kind kind, Type type, Origin origin, AdjacencyList&& children)
+        : Value(CheckedOpcode, kind, type, origin, WTFMove(children))
+    {
+        checkKind(kind, m_children.size());
+    }
+    template<typename... Arguments>
+        explicit Value(Kind kind, Origin origin, Arguments&&... arguments)
+        : Value(CheckedOpcode, kind, origin, std::forward<Arguments>(arguments)...)
+    {
+        checkKind(kind, sizeof...(arguments));
+    }
+
+private:
+    friend class CheckValue; // CheckValue::convertToAdd() modifies m_kind.
+    
+    static Type typeFor(Kind, Value* firstChild, Value* secondChild = nullptr);
+
+    // This group of fields is arranged to fit in 64 bits.
+protected:
+    unsigned m_index { UINT_MAX };
+private:
+    Kind m_kind;
+    Type m_type;
+    
+    Origin m_origin;
+    AdjacencyList m_children;
+
+    JS_EXPORT_PRIVATE NO_RETURN_DUE_TO_CRASH static void badKind(Kind, unsigned);
+
+public:
+    BasicBlock* owner { nullptr }; // computed by Procedure::resetValueOwners().
+};
+
+class DeepValueDump {
+public:
+    DeepValueDump(const Procedure* proc, const Value* value)
+        : m_proc(proc)
+        , m_value(value)
+    {
+    }
+
+    void dump(PrintStream& out) const
+    {
+        if (m_value)
+            m_value->deepDump(m_proc, out);
+        else
+            out.print("<null>");
+    }
+
+private:
+    const Procedure* m_proc;
+    const Value* m_value;
+};
+
+inline DeepValueDump deepDump(const Procedure& proc, const Value* value)
+{
+    return DeepValueDump(&proc, value);
+}
+inline DeepValueDump deepDump(const Value* value)
+{
+    return DeepValueDump(nullptr, value);
+}
+
+} } // namespace JSC::B3
+
+#endif // ENABLE(B3_JIT)