webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 53 insertions, 2 deletions

diff --git a/Source/JavaScriptCore/dfg/DFGThunks.cpp b/Source/JavaScriptCore/dfg/DFGThunks.cpp
index c0935b95a..38bdd11d1 100644
--- a/Source/JavaScriptCore/dfg/DFGThunks.cpp
+++ b/Source/JavaScriptCore/dfg/DFGThunks.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Apple Inc. All rights reserved.
+ * Copyright (C) 2011, 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
@@ -30,15 +30,22 @@
 
 #include "CCallHelpers.h"
 #include "DFGOSRExitCompiler.h"
+#include "DFGJITCode.h"
 #include "FPRInfo.h"
 #include "GPRInfo.h"
+#include "LinkBuffer.h"
 #include "MacroAssembler.h"
+#include "JSCInlines.h"
+#include "DFGOSRExitCompilerCommon.h"
 
 namespace JSC { namespace DFG {
 
 MacroAssemblerCodeRef osrExitGenerationThunkGenerator(VM* vm)
 {
     MacroAssembler jit;
+
+    // This needs to happen before we use the scratch buffer because this function also uses the scratch buffer.
+    adjustFrameAndStackInOSRExitCompilerThunk<DFG::JITCode>(jit, vm, JITCode::DFGJIT);
     
     size_t scratchSize = sizeof(EncodedJSValue) * (GPRInfo::numberOfRegisters + FPRInfo::numberOfRegisters);
     ScratchBuffer* scratchBuffer = vm->scratchBufferForSize(scratchSize);
@@ -86,13 +93,57 @@ MacroAssemblerCodeRef osrExitGenerationThunkGenerator(VM* vm)
     
     jit.jump(MacroAssembler::AbsoluteAddress(&vm->osrExitJumpDestination));
     
-    LinkBuffer patchBuffer(*vm, &jit, GLOBAL_THUNK_ID);
+    LinkBuffer patchBuffer(*vm, jit, GLOBAL_THUNK_ID);
     
     patchBuffer.link(functionCall, compileOSRExit);
     
     return FINALIZE_CODE(patchBuffer, ("DFG OSR exit generation thunk"));
 }
 
+MacroAssemblerCodeRef osrEntryThunkGenerator(VM* vm)
+{
+    AssemblyHelpers jit(vm, nullptr);
+
+    // We get passed the address of a scratch buffer. The first 8-byte slot of the buffer
+    // is the frame size. The second 8-byte slot is the pointer to where we are supposed to
+    // jump. The remaining bytes are the new call frame header followed by the locals.
+    
+    ptrdiff_t offsetOfFrameSize = 0; // This is the DFG frame count.
+    ptrdiff_t offsetOfTargetPC = offsetOfFrameSize + sizeof(EncodedJSValue);
+    ptrdiff_t offsetOfPayload = offsetOfTargetPC + sizeof(EncodedJSValue);
+    ptrdiff_t offsetOfLocals = offsetOfPayload + sizeof(Register) * CallFrame::headerSizeInRegisters;
+    
+    jit.move(GPRInfo::returnValueGPR2, GPRInfo::regT0);
+    jit.loadPtr(MacroAssembler::Address(GPRInfo::regT0, offsetOfFrameSize), GPRInfo::regT1); // Load the frame size.
+    jit.move(GPRInfo::regT1, GPRInfo::regT2);
+    jit.lshiftPtr(MacroAssembler::Imm32(3), GPRInfo::regT2);
+    jit.move(GPRInfo::callFrameRegister, MacroAssembler::stackPointerRegister);
+    jit.subPtr(GPRInfo::regT2, MacroAssembler::stackPointerRegister);
+    
+    MacroAssembler::Label loop = jit.label();
+    jit.subPtr(MacroAssembler::TrustedImm32(1), GPRInfo::regT1);
+    jit.move(GPRInfo::regT1, GPRInfo::regT4);
+    jit.negPtr(GPRInfo::regT4);
+    jit.load32(MacroAssembler::BaseIndex(GPRInfo::regT0, GPRInfo::regT1, MacroAssembler::TimesEight, offsetOfLocals), GPRInfo::regT2);
+    jit.load32(MacroAssembler::BaseIndex(GPRInfo::regT0, GPRInfo::regT1, MacroAssembler::TimesEight, offsetOfLocals + sizeof(int32_t)), GPRInfo::regT3);
+    jit.store32(GPRInfo::regT2, MacroAssembler::BaseIndex(GPRInfo::callFrameRegister, GPRInfo::regT4, MacroAssembler::TimesEight, -static_cast<intptr_t>(sizeof(Register))));
+    jit.store32(GPRInfo::regT3, MacroAssembler::BaseIndex(GPRInfo::callFrameRegister, GPRInfo::regT4, MacroAssembler::TimesEight, -static_cast<intptr_t>(sizeof(Register)) + static_cast<intptr_t>(sizeof(int32_t))));
+    jit.branchPtr(MacroAssembler::NotEqual, GPRInfo::regT1, MacroAssembler::TrustedImmPtr(bitwise_cast<void*>(-static_cast<intptr_t>(CallFrame::headerSizeInRegisters)))).linkTo(loop, &jit);
+    
+    jit.loadPtr(MacroAssembler::Address(GPRInfo::regT0, offsetOfTargetPC), GPRInfo::regT1);
+    MacroAssembler::Jump ok = jit.branchPtr(MacroAssembler::Above, GPRInfo::regT1, MacroAssembler::TrustedImmPtr(bitwise_cast<void*>(static_cast<intptr_t>(1000))));
+    jit.abortWithReason(DFGUnreasonableOSREntryJumpDestination);
+
+    ok.link(&jit);
+    jit.restoreCalleeSavesFromVMEntryFrameCalleeSavesBuffer();
+    jit.emitMaterializeTagCheckRegisters();
+
+    jit.jump(GPRInfo::regT1);
+    
+    LinkBuffer patchBuffer(*vm, jit, GLOBAL_THUNK_ID);
+    return FINALIZE_CODE(patchBuffer, ("DFG OSR entry thunk"));
+}
+
 } } // namespace JSC::DFG
 
 #endif // ENABLE(DFG_JIT)