src/x64/deoptimizer-x64.cc - fp2-dev/platform/external/v8 - Gitiles

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #if V8_TARGET_ARCH_X64

 #include "src/codegen.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
 #include "src/register-configuration.h"
 #include "src/safepoint-table.h"

 namespace v8 {
 namespace internal {


 const int Deoptimizer::table_entry_size_ = 10;


 int Deoptimizer::patch_size() {
   return Assembler::kCallSequenceLength;
 }


 void Deoptimizer::EnsureRelocSpaceForLazyDeoptimization(Handle<Code> code) {
   // Empty because there is no need for relocation information for the code
   // patching in Deoptimizer::PatchCodeForDeoptimization below.
 }


 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
   // Invalidate the relocation information, as it will become invalid by the
   // code patching below, and is not needed any more.
   code->InvalidateRelocation();

   if (FLAG_zap_code_space) {
     // Fail hard and early if we enter this code object again.
     byte* pointer = code->FindCodeAgeSequence();
     if (pointer != NULL) {
       pointer += kNoCodeAgeSequenceLength;
     } else {
       pointer = code->instruction_start();
     }
     CodePatcher patcher(isolate, pointer, 1);
     patcher.masm()->int3();

     DeoptimizationInputData* data =
         DeoptimizationInputData::cast(code->deoptimization_data());
     int osr_offset = data->OsrPcOffset()->value();
     if (osr_offset > 0) {
       CodePatcher osr_patcher(isolate, code->instruction_start() + osr_offset,
                               1);
       osr_patcher.masm()->int3();
     }
   }

   // For each LLazyBailout instruction insert a absolute call to the
   // corresponding deoptimization entry, or a short call to an absolute
   // jump if space is short. The absolute jumps are put in a table just
   // before the safepoint table (space was allocated there when the Code
   // object was created, if necessary).

   Address instruction_start = code->instruction_start();
 #ifdef DEBUG
   Address prev_call_address = NULL;
 #endif
   DeoptimizationInputData* deopt_data =
       DeoptimizationInputData::cast(code->deoptimization_data());
   deopt_data->SetSharedFunctionInfo(Smi::FromInt(0));
   // For each LLazyBailout instruction insert a call to the corresponding
   // deoptimization entry.
   for (int i = 0; i < deopt_data->DeoptCount(); i++) {
     if (deopt_data->Pc(i)->value() == -1) continue;
     // Position where Call will be patched in.
     Address call_address = instruction_start + deopt_data->Pc(i)->value();
     // There is room enough to write a long call instruction because we pad
     // LLazyBailout instructions with nops if necessary.
     CodePatcher patcher(isolate, call_address, Assembler::kCallSequenceLength);
     patcher.masm()->Call(GetDeoptimizationEntry(isolate, i, LAZY),
                          Assembler::RelocInfoNone());
     DCHECK(prev_call_address == NULL ||
            call_address >= prev_call_address + patch_size());
     DCHECK(call_address + patch_size() <= code->instruction_end());
 #ifdef DEBUG
     prev_call_address = call_address;
 #endif
   }
 }


 void Deoptimizer::SetPlatformCompiledStubRegisters(
     FrameDescription* output_frame, CodeStubDescriptor* descriptor) {
   intptr_t handler =
       reinterpret_cast<intptr_t>(descriptor->deoptimization_handler());
   int params = descriptor->GetHandlerParameterCount();
   output_frame->SetRegister(rax.code(), params);
   output_frame->SetRegister(rbx.code(), handler);
 }


 void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
   for (int i = 0; i < XMMRegister::kMaxNumRegisters; ++i) {
     double double_value = input_->GetDoubleRegister(i);
     output_frame->SetDoubleRegister(i, double_value);
   }
 }

 #define __ masm()->

 void Deoptimizer::TableEntryGenerator::Generate() {
   GeneratePrologue();

   // Save all general purpose registers before messing with them.
   const int kNumberOfRegisters = Register::kNumRegisters;

   const int kDoubleRegsSize = kDoubleSize * XMMRegister::kMaxNumRegisters;
   __ subp(rsp, Immediate(kDoubleRegsSize));

   const RegisterConfiguration* config = RegisterConfiguration::Crankshaft();
   for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
     int code = config->GetAllocatableDoubleCode(i);
     XMMRegister xmm_reg = XMMRegister::from_code(code);
     int offset = code * kDoubleSize;
     __ Movsd(Operand(rsp, offset), xmm_reg);
   }

   // We push all registers onto the stack, even though we do not need
   // to restore all later.
   for (int i = 0; i < kNumberOfRegisters; i++) {
     Register r = Register::from_code(i);
     __ pushq(r);
   }

   const int kSavedRegistersAreaSize = kNumberOfRegisters * kRegisterSize +
                                       kDoubleRegsSize;

   __ Store(ExternalReference(Isolate::kCEntryFPAddress, isolate()), rbp);

   // We use this to keep the value of the fifth argument temporarily.
   // Unfortunately we can't store it directly in r8 (used for passing
   // this on linux), since it is another parameter passing register on windows.
   Register arg5 = r11;

   // Get the bailout id from the stack.
   __ movp(arg_reg_3, Operand(rsp, kSavedRegistersAreaSize));

   // Get the address of the location in the code object
   // and compute the fp-to-sp delta in register arg5.
   __ movp(arg_reg_4, Operand(rsp, kSavedRegistersAreaSize + 1 * kRegisterSize));
   __ leap(arg5, Operand(rsp, kSavedRegistersAreaSize + 1 * kRegisterSize +
                             kPCOnStackSize));

   __ subp(arg5, rbp);
   __ negp(arg5);

   // Allocate a new deoptimizer object.
   __ PrepareCallCFunction(6);
   __ movp(rax, Immediate(0));
   Label context_check;
   __ movp(rdi, Operand(rbp, CommonFrameConstants::kContextOrFrameTypeOffset));
   __ JumpIfSmi(rdi, &context_check);
   __ movp(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
   __ bind(&context_check);
   __ movp(arg_reg_1, rax);
   __ Set(arg_reg_2, type());
   // Args 3 and 4 are already in the right registers.

   // On windows put the arguments on the stack (PrepareCallCFunction
   // has created space for this). On linux pass the arguments in r8 and r9.
 #ifdef _WIN64
   __ movq(Operand(rsp, 4 * kRegisterSize), arg5);
   __ LoadAddress(arg5, ExternalReference::isolate_address(isolate()));
   __ movq(Operand(rsp, 5 * kRegisterSize), arg5);
 #else
   __ movp(r8, arg5);
   __ LoadAddress(r9, ExternalReference::isolate_address(isolate()));
 #endif

   { AllowExternalCallThatCantCauseGC scope(masm());
     __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6);
   }
   // Preserve deoptimizer object in register rax and get the input
   // frame descriptor pointer.
   __ movp(rbx, Operand(rax, Deoptimizer::input_offset()));

   // Fill in the input registers.
   for (int i = kNumberOfRegisters -1; i >= 0; i--) {
     int offset = (i * kPointerSize) + FrameDescription::registers_offset();
     __ PopQuad(Operand(rbx, offset));
   }

   // Fill in the double input registers.
   int double_regs_offset = FrameDescription::double_registers_offset();
   for (int i = 0; i < XMMRegister::kMaxNumRegisters; i++) {
     int dst_offset = i * kDoubleSize + double_regs_offset;
     __ popq(Operand(rbx, dst_offset));
   }

   // Remove the bailout id and return address from the stack.
   __ addp(rsp, Immediate(1 * kRegisterSize + kPCOnStackSize));

   // Compute a pointer to the unwinding limit in register rcx; that is
   // the first stack slot not part of the input frame.
   __ movp(rcx, Operand(rbx, FrameDescription::frame_size_offset()));
   __ addp(rcx, rsp);

   // Unwind the stack down to - but not including - the unwinding
   // limit and copy the contents of the activation frame to the input
   // frame description.
   __ leap(rdx, Operand(rbx, FrameDescription::frame_content_offset()));
   Label pop_loop_header;
   __ jmp(&pop_loop_header);
   Label pop_loop;
   __ bind(&pop_loop);
   __ Pop(Operand(rdx, 0));
   __ addp(rdx, Immediate(sizeof(intptr_t)));
   __ bind(&pop_loop_header);
   __ cmpp(rcx, rsp);
   __ j(not_equal, &pop_loop);

   // Compute the output frame in the deoptimizer.
   __ pushq(rax);
   __ PrepareCallCFunction(2);
   __ movp(arg_reg_1, rax);
   __ LoadAddress(arg_reg_2, ExternalReference::isolate_address(isolate()));
   {
     AllowExternalCallThatCantCauseGC scope(masm());
     __ CallCFunction(
         ExternalReference::compute_output_frames_function(isolate()), 2);
   }
   __ popq(rax);

   __ movp(rsp, Operand(rax, Deoptimizer::caller_frame_top_offset()));

   // Replace the current (input) frame with the output frames.
   Label outer_push_loop, inner_push_loop,
       outer_loop_header, inner_loop_header;
   // Outer loop state: rax = current FrameDescription**, rdx = one past the
   // last FrameDescription**.
   __ movl(rdx, Operand(rax, Deoptimizer::output_count_offset()));
   __ movp(rax, Operand(rax, Deoptimizer::output_offset()));
   __ leap(rdx, Operand(rax, rdx, times_pointer_size, 0));
   __ jmp(&outer_loop_header);
   __ bind(&outer_push_loop);
   // Inner loop state: rbx = current FrameDescription*, rcx = loop index.
   __ movp(rbx, Operand(rax, 0));
   __ movp(rcx, Operand(rbx, FrameDescription::frame_size_offset()));
   __ jmp(&inner_loop_header);
   __ bind(&inner_push_loop);
   __ subp(rcx, Immediate(sizeof(intptr_t)));
   __ Push(Operand(rbx, rcx, times_1, FrameDescription::frame_content_offset()));
   __ bind(&inner_loop_header);
   __ testp(rcx, rcx);
   __ j(not_zero, &inner_push_loop);
   __ addp(rax, Immediate(kPointerSize));
   __ bind(&outer_loop_header);
   __ cmpp(rax, rdx);
   __ j(below, &outer_push_loop);

   for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
     int code = config->GetAllocatableDoubleCode(i);
     XMMRegister xmm_reg = XMMRegister::from_code(code);
     int src_offset = code * kDoubleSize + double_regs_offset;
     __ Movsd(xmm_reg, Operand(rbx, src_offset));
   }

   // Push state, pc, and continuation from the last output frame.
   __ Push(Operand(rbx, FrameDescription::state_offset()));
   __ PushQuad(Operand(rbx, FrameDescription::pc_offset()));
   __ PushQuad(Operand(rbx, FrameDescription::continuation_offset()));

   // Push the registers from the last output frame.
   for (int i = 0; i < kNumberOfRegisters; i++) {
     int offset = (i * kPointerSize) + FrameDescription::registers_offset();
     __ PushQuad(Operand(rbx, offset));
   }

   // Restore the registers from the stack.
   for (int i = kNumberOfRegisters - 1; i >= 0 ; i--) {
     Register r = Register::from_code(i);
     // Do not restore rsp, simply pop the value into the next register
     // and overwrite this afterwards.
     if (r.is(rsp)) {
       DCHECK(i > 0);
       r = Register::from_code(i - 1);
     }
     __ popq(r);
   }

   // Set up the roots register.
   __ InitializeRootRegister();

   // Return to the continuation point.
   __ ret(0);
 }


 void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
   // Create a sequence of deoptimization entries.
   Label done;
   for (int i = 0; i < count(); i++) {
     int start = masm()->pc_offset();
     USE(start);
     __ pushq_imm32(i);
     __ jmp(&done);
     DCHECK(masm()->pc_offset() - start == table_entry_size_);
   }
   __ bind(&done);
 }


 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
   if (kPCOnStackSize == 2 * kPointerSize) {
     // Zero out the high-32 bit of PC for x32 port.
     SetFrameSlot(offset + kPointerSize, 0);
   }
   SetFrameSlot(offset, value);
 }


 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
   if (kFPOnStackSize == 2 * kPointerSize) {
     // Zero out the high-32 bit of FP for x32 port.
     SetFrameSlot(offset + kPointerSize, 0);
   }
   SetFrameSlot(offset, value);
 }


 void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
   // No embedded constant pool support.
   UNREACHABLE();
 }


 #undef __


 }  // namespace internal
 }  // namespace v8

 #endif  // V8_TARGET_ARCH_X64
	// Copyright 2012 the V8 project authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#if V8_TARGET_ARCH_X64

	#include "src/codegen.h"
	#include "src/deoptimizer.h"
	#include "src/full-codegen/full-codegen.h"
	#include "src/register-configuration.h"
	#include "src/safepoint-table.h"

	namespace v8 {
	namespace internal {


	const int Deoptimizer::table_entry_size_ = 10;


	int Deoptimizer::patch_size() {
	return Assembler::kCallSequenceLength;
	}


	void Deoptimizer::EnsureRelocSpaceForLazyDeoptimization(Handle<Code> code) {
	// Empty because there is no need for relocation information for the code
	// patching in Deoptimizer::PatchCodeForDeoptimization below.
	}


	void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
	// Invalidate the relocation information, as it will become invalid by the
	// code patching below, and is not needed any more.
	code->InvalidateRelocation();

	if (FLAG_zap_code_space) {
	// Fail hard and early if we enter this code object again.
	byte* pointer = code->FindCodeAgeSequence();
	if (pointer != NULL) {
	pointer += kNoCodeAgeSequenceLength;
	} else {
	pointer = code->instruction_start();
	}
	CodePatcher patcher(isolate, pointer, 1);
	patcher.masm()->int3();

	DeoptimizationInputData* data =
	DeoptimizationInputData::cast(code->deoptimization_data());
	int osr_offset = data->OsrPcOffset()->value();
	if (osr_offset > 0) {
	CodePatcher osr_patcher(isolate, code->instruction_start() + osr_offset,
	1);
	osr_patcher.masm()->int3();
	}
	}

	// For each LLazyBailout instruction insert a absolute call to the
	// corresponding deoptimization entry, or a short call to an absolute
	// jump if space is short. The absolute jumps are put in a table just
	// before the safepoint table (space was allocated there when the Code
	// object was created, if necessary).

	Address instruction_start = code->instruction_start();
	#ifdef DEBUG
	Address prev_call_address = NULL;
	#endif
	DeoptimizationInputData* deopt_data =
	DeoptimizationInputData::cast(code->deoptimization_data());
	deopt_data->SetSharedFunctionInfo(Smi::FromInt(0));
	// For each LLazyBailout instruction insert a call to the corresponding
	// deoptimization entry.
	for (int i = 0; i < deopt_data->DeoptCount(); i++) {
	if (deopt_data->Pc(i)->value() == -1) continue;
	// Position where Call will be patched in.
	Address call_address = instruction_start + deopt_data->Pc(i)->value();
	// There is room enough to write a long call instruction because we pad
	// LLazyBailout instructions with nops if necessary.
	CodePatcher patcher(isolate, call_address, Assembler::kCallSequenceLength);
	patcher.masm()->Call(GetDeoptimizationEntry(isolate, i, LAZY),
	Assembler::RelocInfoNone());
	DCHECK(prev_call_address == NULL \|\|
	call_address >= prev_call_address + patch_size());
	DCHECK(call_address + patch_size() <= code->instruction_end());
	#ifdef DEBUG
	prev_call_address = call_address;
	#endif
	}
	}


	void Deoptimizer::SetPlatformCompiledStubRegisters(
	FrameDescription* output_frame, CodeStubDescriptor* descriptor) {
	intptr_t handler =
	reinterpret_cast<intptr_t>(descriptor->deoptimization_handler());
	int params = descriptor->GetHandlerParameterCount();
	output_frame->SetRegister(rax.code(), params);
	output_frame->SetRegister(rbx.code(), handler);
	}


	void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
	for (int i = 0; i < XMMRegister::kMaxNumRegisters; ++i) {
	double double_value = input_->GetDoubleRegister(i);
	output_frame->SetDoubleRegister(i, double_value);
	}
	}

	#define __ masm()->

	void Deoptimizer::TableEntryGenerator::Generate() {
	GeneratePrologue();

	// Save all general purpose registers before messing with them.
	const int kNumberOfRegisters = Register::kNumRegisters;

	const int kDoubleRegsSize = kDoubleSize * XMMRegister::kMaxNumRegisters;
	__ subp(rsp, Immediate(kDoubleRegsSize));

	const RegisterConfiguration* config = RegisterConfiguration::Crankshaft();
	for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
	int code = config->GetAllocatableDoubleCode(i);
	XMMRegister xmm_reg = XMMRegister::from_code(code);
	int offset = code * kDoubleSize;
	__ Movsd(Operand(rsp, offset), xmm_reg);
	}

	// We push all registers onto the stack, even though we do not need
	// to restore all later.
	for (int i = 0; i < kNumberOfRegisters; i++) {
	Register r = Register::from_code(i);
	__ pushq(r);
	}

	const int kSavedRegistersAreaSize = kNumberOfRegisters * kRegisterSize +
	kDoubleRegsSize;

	__ Store(ExternalReference(Isolate::kCEntryFPAddress, isolate()), rbp);

	// We use this to keep the value of the fifth argument temporarily.
	// Unfortunately we can't store it directly in r8 (used for passing
	// this on linux), since it is another parameter passing register on windows.
	Register arg5 = r11;

	// Get the bailout id from the stack.
	__ movp(arg_reg_3, Operand(rsp, kSavedRegistersAreaSize));

	// Get the address of the location in the code object
	// and compute the fp-to-sp delta in register arg5.
	__ movp(arg_reg_4, Operand(rsp, kSavedRegistersAreaSize + 1 * kRegisterSize));
	__ leap(arg5, Operand(rsp, kSavedRegistersAreaSize + 1 * kRegisterSize +
	kPCOnStackSize));

	__ subp(arg5, rbp);
	__ negp(arg5);

	// Allocate a new deoptimizer object.
	__ PrepareCallCFunction(6);
	__ movp(rax, Immediate(0));
	Label context_check;
	__ movp(rdi, Operand(rbp, CommonFrameConstants::kContextOrFrameTypeOffset));
	__ JumpIfSmi(rdi, &context_check);
	__ movp(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
	__ bind(&context_check);
	__ movp(arg_reg_1, rax);
	__ Set(arg_reg_2, type());
	// Args 3 and 4 are already in the right registers.

	// On windows put the arguments on the stack (PrepareCallCFunction
	// has created space for this). On linux pass the arguments in r8 and r9.
	#ifdef _WIN64
	__ movq(Operand(rsp, 4 * kRegisterSize), arg5);
	__ LoadAddress(arg5, ExternalReference::isolate_address(isolate()));
	__ movq(Operand(rsp, 5 * kRegisterSize), arg5);
	#else
	__ movp(r8, arg5);
	__ LoadAddress(r9, ExternalReference::isolate_address(isolate()));
	#endif

	{ AllowExternalCallThatCantCauseGC scope(masm());
	__ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6);
	}
	// Preserve deoptimizer object in register rax and get the input
	// frame descriptor pointer.
	__ movp(rbx, Operand(rax, Deoptimizer::input_offset()));

	// Fill in the input registers.
	for (int i = kNumberOfRegisters -1; i >= 0; i--) {
	int offset = (i * kPointerSize) + FrameDescription::registers_offset();
	__ PopQuad(Operand(rbx, offset));
	}

	// Fill in the double input registers.
	int double_regs_offset = FrameDescription::double_registers_offset();
	for (int i = 0; i < XMMRegister::kMaxNumRegisters; i++) {
	int dst_offset = i * kDoubleSize + double_regs_offset;
	__ popq(Operand(rbx, dst_offset));
	}

	// Remove the bailout id and return address from the stack.
	__ addp(rsp, Immediate(1 * kRegisterSize + kPCOnStackSize));

	// Compute a pointer to the unwinding limit in register rcx; that is
	// the first stack slot not part of the input frame.
	__ movp(rcx, Operand(rbx, FrameDescription::frame_size_offset()));
	__ addp(rcx, rsp);

	// Unwind the stack down to - but not including - the unwinding
	// limit and copy the contents of the activation frame to the input
	// frame description.
	__ leap(rdx, Operand(rbx, FrameDescription::frame_content_offset()));
	Label pop_loop_header;
	__ jmp(&pop_loop_header);
	Label pop_loop;
	__ bind(&pop_loop);
	__ Pop(Operand(rdx, 0));
	__ addp(rdx, Immediate(sizeof(intptr_t)));
	__ bind(&pop_loop_header);
	__ cmpp(rcx, rsp);
	__ j(not_equal, &pop_loop);

	// Compute the output frame in the deoptimizer.
	__ pushq(rax);
	__ PrepareCallCFunction(2);
	__ movp(arg_reg_1, rax);
	__ LoadAddress(arg_reg_2, ExternalReference::isolate_address(isolate()));
	{
	AllowExternalCallThatCantCauseGC scope(masm());
	__ CallCFunction(
	ExternalReference::compute_output_frames_function(isolate()), 2);
	}
	__ popq(rax);

	__ movp(rsp, Operand(rax, Deoptimizer::caller_frame_top_offset()));

	// Replace the current (input) frame with the output frames.
	Label outer_push_loop, inner_push_loop,
	outer_loop_header, inner_loop_header;
	// Outer loop state: rax = current FrameDescription**, rdx = one past the
	// last FrameDescription**.
	__ movl(rdx, Operand(rax, Deoptimizer::output_count_offset()));
	__ movp(rax, Operand(rax, Deoptimizer::output_offset()));
	__ leap(rdx, Operand(rax, rdx, times_pointer_size, 0));
	__ jmp(&outer_loop_header);
	__ bind(&outer_push_loop);
	// Inner loop state: rbx = current FrameDescription*, rcx = loop index.
	__ movp(rbx, Operand(rax, 0));
	__ movp(rcx, Operand(rbx, FrameDescription::frame_size_offset()));
	__ jmp(&inner_loop_header);
	__ bind(&inner_push_loop);
	__ subp(rcx, Immediate(sizeof(intptr_t)));
	__ Push(Operand(rbx, rcx, times_1, FrameDescription::frame_content_offset()));
	__ bind(&inner_loop_header);
	__ testp(rcx, rcx);
	__ j(not_zero, &inner_push_loop);
	__ addp(rax, Immediate(kPointerSize));
	__ bind(&outer_loop_header);
	__ cmpp(rax, rdx);
	__ j(below, &outer_push_loop);

	for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
	int code = config->GetAllocatableDoubleCode(i);
	XMMRegister xmm_reg = XMMRegister::from_code(code);
	int src_offset = code * kDoubleSize + double_regs_offset;
	__ Movsd(xmm_reg, Operand(rbx, src_offset));
	}

	// Push state, pc, and continuation from the last output frame.
	__ Push(Operand(rbx, FrameDescription::state_offset()));
	__ PushQuad(Operand(rbx, FrameDescription::pc_offset()));
	__ PushQuad(Operand(rbx, FrameDescription::continuation_offset()));

	// Push the registers from the last output frame.
	for (int i = 0; i < kNumberOfRegisters; i++) {
	int offset = (i * kPointerSize) + FrameDescription::registers_offset();
	__ PushQuad(Operand(rbx, offset));
	}

	// Restore the registers from the stack.
	for (int i = kNumberOfRegisters - 1; i >= 0 ; i--) {
	Register r = Register::from_code(i);
	// Do not restore rsp, simply pop the value into the next register
	// and overwrite this afterwards.
	if (r.is(rsp)) {
	DCHECK(i > 0);
	r = Register::from_code(i - 1);
	}
	__ popq(r);
	}

	// Set up the roots register.
	__ InitializeRootRegister();

	// Return to the continuation point.
	__ ret(0);
	}


	void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
	// Create a sequence of deoptimization entries.
	Label done;
	for (int i = 0; i < count(); i++) {
	int start = masm()->pc_offset();
	USE(start);
	__ pushq_imm32(i);
	__ jmp(&done);
	DCHECK(masm()->pc_offset() - start == table_entry_size_);
	}
	__ bind(&done);
	}


	void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
	if (kPCOnStackSize == 2 * kPointerSize) {
	// Zero out the high-32 bit of PC for x32 port.
	SetFrameSlot(offset + kPointerSize, 0);
	}
	SetFrameSlot(offset, value);
	}


	void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
	if (kFPOnStackSize == 2 * kPointerSize) {
	// Zero out the high-32 bit of FP for x32 port.
	SetFrameSlot(offset + kPointerSize, 0);
	}
	SetFrameSlot(offset, value);
	}


	void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
	// No embedded constant pool support.
	UNREACHABLE();
	}


	#undef __


	} // namespace internal
	} // namespace v8

	#endif // V8_TARGET_ARCH_X64