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// 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_IA32
#include "src/assembler-inl.h"
#include "src/deoptimizer.h"
#include "src/frame-constants.h"
#include "src/register-configuration.h"
#include "src/safepoint-table.h"
namespace v8 {
namespace internal {
const int Deoptimizer::table_entry_size_ = 10;
#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::kNumRegisters;
__ sub(esp, Immediate(kDoubleRegsSize));
const RegisterConfiguration* config = RegisterConfiguration::Default();
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(esp, offset), xmm_reg);
}
STATIC_ASSERT(kFloatSize == kPointerSize);
const int kFloatRegsSize = kFloatSize * XMMRegister::kNumRegisters;
__ sub(esp, Immediate(kFloatRegsSize));
for (int i = 0; i < config->num_allocatable_float_registers(); ++i) {
int code = config->GetAllocatableFloatCode(i);
XMMRegister xmm_reg = XMMRegister::from_code(code);
int offset = code * kFloatSize;
__ movss(Operand(esp, offset), xmm_reg);
}
__ pushad();
ExternalReference c_entry_fp_address =
ExternalReference::Create(IsolateAddressId::kCEntryFPAddress, isolate());
__ mov(masm()->StaticVariable(c_entry_fp_address), ebp);
const int kSavedRegistersAreaSize =
kNumberOfRegisters * kPointerSize + kDoubleRegsSize + kFloatRegsSize;
// Get the bailout id from the stack.
__ mov(ebx, Operand(esp, kSavedRegistersAreaSize));
// Get the address of the location in the code object
// and compute the fp-to-sp delta in register edx.
__ mov(ecx, Operand(esp, kSavedRegistersAreaSize + 1 * kPointerSize));
__ lea(edx, Operand(esp, kSavedRegistersAreaSize + 2 * kPointerSize));
__ sub(edx, ebp);
__ neg(edx);
// Allocate a new deoptimizer object.
__ PrepareCallCFunction(6, eax);
__ mov(eax, Immediate(0));
Label context_check;
__ mov(edi, Operand(ebp, CommonFrameConstants::kContextOrFrameTypeOffset));
__ JumpIfSmi(edi, &context_check);
__ mov(eax, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
__ bind(&context_check);
__ mov(Operand(esp, 0 * kPointerSize), eax); // Function.
__ mov(Operand(esp, 1 * kPointerSize),
Immediate(static_cast<int>(deopt_kind())));
__ mov(Operand(esp, 2 * kPointerSize), ebx); // Bailout id.
__ mov(Operand(esp, 3 * kPointerSize), ecx); // Code address or 0.
__ mov(Operand(esp, 4 * kPointerSize), edx); // Fp-to-sp delta.
__ mov(Operand(esp, 5 * kPointerSize),
Immediate(ExternalReference::isolate_address(isolate())));
{
AllowExternalCallThatCantCauseGC scope(masm());
__ CallCFunction(ExternalReference::new_deoptimizer_function(), 6);
}
// Preserve deoptimizer object in register eax and get the input
// frame descriptor pointer.
__ mov(ebx, Operand(eax, Deoptimizer::input_offset()));
// Fill in the input registers.
for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
int offset = (i * kPointerSize) + FrameDescription::registers_offset();
__ pop(Operand(ebx, offset));
}
int float_regs_offset = FrameDescription::float_registers_offset();
// Fill in the float input registers.
for (int i = 0; i < XMMRegister::kNumRegisters; i++) {
int dst_offset = i * kFloatSize + float_regs_offset;
__ pop(Operand(ebx, dst_offset));
}
int double_regs_offset = FrameDescription::double_registers_offset();
// Fill in the double input registers.
for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
int code = config->GetAllocatableDoubleCode(i);
int dst_offset = code * kDoubleSize + double_regs_offset;
int src_offset = code * kDoubleSize;
__ movsd(xmm0, Operand(esp, src_offset));
__ movsd(Operand(ebx, dst_offset), xmm0);
}
// Clear FPU all exceptions.
// TODO(ulan): Find out why the TOP register is not zero here in some cases,
// and check that the generated code never deoptimizes with unbalanced stack.
__ fnclex();
// Remove the bailout id, return address and the double registers.
__ add(esp, Immediate(kDoubleRegsSize + 2 * kPointerSize));
// Compute a pointer to the unwinding limit in register ecx; that is
// the first stack slot not part of the input frame.
__ mov(ecx, Operand(ebx, FrameDescription::frame_size_offset()));
__ add(ecx, esp);
// Unwind the stack down to - but not including - the unwinding
// limit and copy the contents of the activation frame to the input
// frame description.
__ lea(edx, Operand(ebx, FrameDescription::frame_content_offset()));
Label pop_loop_header;
__ jmp(&pop_loop_header);
Label pop_loop;
__ bind(&pop_loop);
__ pop(Operand(edx, 0));
__ add(edx, Immediate(sizeof(uint32_t)));
__ bind(&pop_loop_header);
__ cmp(ecx, esp);
__ j(not_equal, &pop_loop);
// Compute the output frame in the deoptimizer.
__ push(eax);
__ PrepareCallCFunction(1, ebx);
__ mov(Operand(esp, 0 * kPointerSize), eax);
{
AllowExternalCallThatCantCauseGC scope(masm());
__ CallCFunction(ExternalReference::compute_output_frames_function(), 1);
}
__ pop(eax);
__ mov(esp, Operand(eax, 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: eax = current FrameDescription**, edx = one past the
// last FrameDescription**.
__ mov(edx, Operand(eax, Deoptimizer::output_count_offset()));
__ mov(eax, Operand(eax, Deoptimizer::output_offset()));
__ lea(edx, Operand(eax, edx, times_4, 0));
__ jmp(&outer_loop_header);
__ bind(&outer_push_loop);
// Inner loop state: ebx = current FrameDescription*, ecx = loop index.
__ mov(ebx, Operand(eax, 0));
__ mov(ecx, Operand(ebx, FrameDescription::frame_size_offset()));
__ jmp(&inner_loop_header);
__ bind(&inner_push_loop);
__ sub(ecx, Immediate(sizeof(uint32_t)));
__ push(Operand(ebx, ecx, times_1, FrameDescription::frame_content_offset()));
__ bind(&inner_loop_header);
__ test(ecx, ecx);
__ j(not_zero, &inner_push_loop);
__ add(eax, Immediate(kPointerSize));
__ bind(&outer_loop_header);
__ cmp(eax, edx);
__ j(below, &outer_push_loop);
// In case of a failed STUB, we have to restore the XMM registers.
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(ebx, src_offset));
}
// Push pc and continuation from the last output frame.
__ push(Operand(ebx, FrameDescription::pc_offset()));
__ push(Operand(ebx, 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();
__ push(Operand(ebx, offset));
}
// Restore the registers from the stack.
__ popad();
// 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);
__ push_imm32(i);
__ jmp(&done);
DCHECK(masm()->pc_offset() - start == table_entry_size_);
}
__ bind(&done);
}
bool Deoptimizer::PadTopOfStackRegister() { return false; }
void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
SetFrameSlot(offset, value);
}
void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
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_IA32
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