// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * 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.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "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 THE COPYRIGHT
// OWNER 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 "v8.h"
#if defined(V8_TARGET_ARCH_X64)
#include "codegen.h"
#include "deoptimizer.h"
#include "full-codegen.h"
#include "safepoint-table.h"
namespace v8 {
namespace internal {
int Deoptimizer::table_entry_size_ = 10;
int Deoptimizer::patch_size() {
return MacroAssembler::kCallInstructionLength;
}
#ifdef DEBUG
// Overwrites code with int3 instructions.
static void ZapCodeRange(Address from, Address to) {
CHECK(from <= to);
int length = static_cast<int>(to - from);
CodePatcher destroyer(from, length);
while (length-- > 0) {
destroyer.masm()->int3();
}
}
#endif
// Iterate through the entries of a SafepointTable that corresponds to
// deoptimization points.
class SafepointTableDeoptimiztionEntryIterator {
public:
explicit SafepointTableDeoptimiztionEntryIterator(Code* code)
: code_(code), table_(code), index_(-1), limit_(table_.length()) {
FindNextIndex();
}
SafepointEntry Next(Address* pc) {
if (index_ >= limit_) {
*pc = NULL;
return SafepointEntry(); // Invalid entry.
}
*pc = code_->instruction_start() + table_.GetPcOffset(index_);
SafepointEntry entry = table_.GetEntry(index_);
FindNextIndex();
return entry;
}
private:
void FindNextIndex() {
ASSERT(index_ < limit_);
while (++index_ < limit_) {
if (table_.GetEntry(index_).deoptimization_index() !=
Safepoint::kNoDeoptimizationIndex) {
return;
}
}
}
Code* code_;
SafepointTable table_;
// Index of next deoptimization entry. If negative after calling
// FindNextIndex, there are no more, and Next will return an invalid
// SafepointEntry.
int index_;
// Table length.
int limit_;
};
void Deoptimizer::EnsureRelocSpaceForLazyDeoptimization(Handle<Code> code) {
// TODO(1276): Implement.
}
void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
HandleScope scope;
AssertNoAllocation no_allocation;
if (!function->IsOptimized()) return;
// Get the optimized code.
Code* code = function->code();
// Invalidate the relocation information, as it will become invalid by the
// code patching below, and is not needed any more.
code->InvalidateRelocation();
// For each return after a safepoint 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 = function->code()->instruction_start();
Address jump_table_address =
instruction_start + function->code()->safepoint_table_offset();
Address previous_pc = instruction_start;
SafepointTableDeoptimiztionEntryIterator deoptimizations(function->code());
Address entry_pc = NULL;
SafepointEntry current_entry = deoptimizations.Next(&entry_pc);
while (current_entry.is_valid()) {
int gap_code_size = current_entry.gap_code_size();
unsigned deoptimization_index = current_entry.deoptimization_index();
#ifdef DEBUG
// Destroy the code which is not supposed to run again.
ZapCodeRange(previous_pc, entry_pc);
#endif
// Position where Call will be patched in.
Address call_address = entry_pc + gap_code_size;
// End of call instruction, if using a direct call to a 64-bit address.
Address call_end_address =
call_address + MacroAssembler::kCallInstructionLength;
// Find next deoptimization entry, if any.
Address next_pc = NULL;
SafepointEntry next_entry = deoptimizations.Next(&next_pc);
if (!next_entry.is_valid() || next_pc >= call_end_address) {
// Room enough to write a long call instruction.
CodePatcher patcher(call_address, Assembler::kCallInstructionLength);
patcher.masm()->Call(GetDeoptimizationEntry(deoptimization_index, LAZY),
RelocInfo::NONE);
previous_pc = call_end_address;
} else {
// Not room enough for a long Call instruction. Write a short call
// instruction to a long jump placed elsewhere in the code.
Address short_call_end_address =
call_address + MacroAssembler::kShortCallInstructionLength;
ASSERT(next_pc >= short_call_end_address);
// Write jump in jump-table.
jump_table_address -= MacroAssembler::kJumpInstructionLength;
CodePatcher jump_patcher(jump_table_address,
MacroAssembler::kJumpInstructionLength);
jump_patcher.masm()->Jump(
GetDeoptimizationEntry(deoptimization_index, LAZY),
RelocInfo::NONE);
// Write call to jump at call_offset.
CodePatcher call_patcher(call_address,
MacroAssembler::kShortCallInstructionLength);
call_patcher.masm()->call(jump_table_address);
previous_pc = short_call_end_address;
}
// Continue with next deoptimization entry.
current_entry = next_entry;
entry_pc = next_pc;
}
#ifdef DEBUG
// Destroy the code which is not supposed to run again.
ZapCodeRange(previous_pc, jump_table_address);
#endif
// Add the deoptimizing code to the list.
DeoptimizingCodeListNode* node = new DeoptimizingCodeListNode(code);
DeoptimizerData* data = code->GetIsolate()->deoptimizer_data();
node->set_next(data->deoptimizing_code_list_);
data->deoptimizing_code_list_ = node;
// Set the code for the function to non-optimized version.
function->ReplaceCode(function->shared()->code());
if (FLAG_trace_deopt) {
PrintF("[forced deoptimization: ");
function->PrintName();
PrintF(" / %" V8PRIxPTR "]\n", reinterpret_cast<intptr_t>(function));
#ifdef DEBUG
if (FLAG_print_code) {
code->PrintLn();
}
#endif
}
}
void Deoptimizer::PatchStackCheckCodeAt(Address pc_after,
Code* check_code,
Code* replacement_code) {
Address call_target_address = pc_after - kIntSize;
ASSERT(check_code->entry() ==
Assembler::target_address_at(call_target_address));
// The stack check code matches the pattern:
//
// cmp rsp, <limit>
// jae ok
// call <stack guard>
// test rax, <loop nesting depth>
// ok: ...
//
// We will patch away the branch so the code is:
//
// cmp rsp, <limit> ;; Not changed
// nop
// nop
// call <on-stack replacment>
// test rax, <loop nesting depth>
// ok:
//
ASSERT(*(call_target_address - 3) == 0x73 && // jae
*(call_target_address - 2) == 0x07 && // offset
*(call_target_address - 1) == 0xe8); // call
*(call_target_address - 3) = 0x90; // nop
*(call_target_address - 2) = 0x90; // nop
Assembler::set_target_address_at(call_target_address,
replacement_code->entry());
}
void Deoptimizer::RevertStackCheckCodeAt(Address pc_after,
Code* check_code,
Code* replacement_code) {
Address call_target_address = pc_after - kIntSize;
ASSERT(replacement_code->entry() ==
Assembler::target_address_at(call_target_address));
// Replace the nops from patching (Deoptimizer::PatchStackCheckCode) to
// restore the conditional branch.
ASSERT(*(call_target_address - 3) == 0x90 && // nop
*(call_target_address - 2) == 0x90 && // nop
*(call_target_address - 1) == 0xe8); // call
*(call_target_address - 3) = 0x73; // jae
*(call_target_address - 2) = 0x07; // offset
Assembler::set_target_address_at(call_target_address,
check_code->entry());
}
static int LookupBailoutId(DeoptimizationInputData* data, unsigned ast_id) {
ByteArray* translations = data->TranslationByteArray();
int length = data->DeoptCount();
for (int i = 0; i < length; i++) {
if (static_cast<unsigned>(data->AstId(i)->value()) == ast_id) {
TranslationIterator it(translations, data->TranslationIndex(i)->value());
int value = it.Next();
ASSERT(Translation::BEGIN == static_cast<Translation::Opcode>(value));
// Read the number of frames.
value = it.Next();
if (value == 1) return i;
}
}
UNREACHABLE();
return -1;
}
void Deoptimizer::DoComputeOsrOutputFrame() {
DeoptimizationInputData* data = DeoptimizationInputData::cast(
optimized_code_->deoptimization_data());
unsigned ast_id = data->OsrAstId()->value();
// TODO(kasperl): This should not be the bailout_id_. It should be
// the ast id. Confusing.
ASSERT(bailout_id_ == ast_id);
int bailout_id = LookupBailoutId(data, ast_id);
unsigned translation_index = data->TranslationIndex(bailout_id)->value();
ByteArray* translations = data->TranslationByteArray();
TranslationIterator iterator(translations, translation_index);
Translation::Opcode opcode =
static_cast<Translation::Opcode>(iterator.Next());
ASSERT(Translation::BEGIN == opcode);
USE(opcode);
int count = iterator.Next();
ASSERT(count == 1);
USE(count);
opcode = static_cast<Translation::Opcode>(iterator.Next());
USE(opcode);
ASSERT(Translation::FRAME == opcode);
unsigned node_id = iterator.Next();
USE(node_id);
ASSERT(node_id == ast_id);
JSFunction* function = JSFunction::cast(ComputeLiteral(iterator.Next()));
USE(function);
ASSERT(function == function_);
unsigned height = iterator.Next();
unsigned height_in_bytes = height * kPointerSize;
USE(height_in_bytes);
unsigned fixed_size = ComputeFixedSize(function_);
unsigned input_frame_size = static_cast<unsigned>(input_->GetFrameSize());
ASSERT(fixed_size + height_in_bytes == input_frame_size);
unsigned stack_slot_size = optimized_code_->stack_slots() * kPointerSize;
unsigned outgoing_height = data->ArgumentsStackHeight(bailout_id)->value();
unsigned outgoing_size = outgoing_height * kPointerSize;
unsigned output_frame_size = fixed_size + stack_slot_size + outgoing_size;
ASSERT(outgoing_size == 0); // OSR does not happen in the middle of a call.
if (FLAG_trace_osr) {
PrintF("[on-stack replacement: begin 0x%08" V8PRIxPTR " ",
reinterpret_cast<intptr_t>(function_));
function_->PrintName();
PrintF(" => node=%u, frame=%d->%d]\n",
ast_id,
input_frame_size,
output_frame_size);
}
// There's only one output frame in the OSR case.
output_count_ = 1;
output_ = new FrameDescription*[1];
output_[0] = new(output_frame_size) FrameDescription(
output_frame_size, function_);
// Clear the incoming parameters in the optimized frame to avoid
// confusing the garbage collector.
unsigned output_offset = output_frame_size - kPointerSize;
int parameter_count = function_->shared()->formal_parameter_count() + 1;
for (int i = 0; i < parameter_count; ++i) {
output_[0]->SetFrameSlot(output_offset, 0);
output_offset -= kPointerSize;
}
// Translate the incoming parameters. This may overwrite some of the
// incoming argument slots we've just cleared.
int input_offset = input_frame_size - kPointerSize;
bool ok = true;
int limit = input_offset - (parameter_count * kPointerSize);
while (ok && input_offset > limit) {
ok = DoOsrTranslateCommand(&iterator, &input_offset);
}
// There are no translation commands for the caller's pc and fp, the
// context, and the function. Set them up explicitly.
for (int i = StandardFrameConstants::kCallerPCOffset;
ok && i >= StandardFrameConstants::kMarkerOffset;
i -= kPointerSize) {
intptr_t input_value = input_->GetFrameSlot(input_offset);
if (FLAG_trace_osr) {
const char* name = "UNKNOWN";
switch (i) {
case StandardFrameConstants::kCallerPCOffset:
name = "caller's pc";
break;
case StandardFrameConstants::kCallerFPOffset:
name = "fp";
break;
case StandardFrameConstants::kContextOffset:
name = "context";
break;
case StandardFrameConstants::kMarkerOffset:
name = "function";
break;
}
PrintF(" [rsp + %d] <- 0x%08" V8PRIxPTR " ; [rsp + %d] "
"(fixed part - %s)\n",
output_offset,
input_value,
input_offset,
name);
}
output_[0]->SetFrameSlot(output_offset, input_->GetFrameSlot(input_offset));
input_offset -= kPointerSize;
output_offset -= kPointerSize;
}
// Translate the rest of the frame.
while (ok && input_offset >= 0) {
ok = DoOsrTranslateCommand(&iterator, &input_offset);
}
// If translation of any command failed, continue using the input frame.
if (!ok) {
delete output_[0];
output_[0] = input_;
output_[0]->SetPc(reinterpret_cast<intptr_t>(from_));
} else {
// Setup the frame pointer and the context pointer.
output_[0]->SetRegister(rbp.code(), input_->GetRegister(rbp.code()));
output_[0]->SetRegister(rsi.code(), input_->GetRegister(rsi.code()));
unsigned pc_offset = data->OsrPcOffset()->value();
intptr_t pc = reinterpret_cast<intptr_t>(
optimized_code_->entry() + pc_offset);
output_[0]->SetPc(pc);
}
Code* continuation =
function->GetIsolate()->builtins()->builtin(Builtins::kNotifyOSR);
output_[0]->SetContinuation(
reinterpret_cast<intptr_t>(continuation->entry()));
if (FLAG_trace_osr) {
PrintF("[on-stack replacement translation %s: 0x%08" V8PRIxPTR " ",
ok ? "finished" : "aborted",
reinterpret_cast<intptr_t>(function));
function->PrintName();
PrintF(" => pc=0x%0" V8PRIxPTR "]\n", output_[0]->GetPc());
}
}
void Deoptimizer::DoComputeFrame(TranslationIterator* iterator,
int frame_index) {
// Read the ast node id, function, and frame height for this output frame.
Translation::Opcode opcode =
static_cast<Translation::Opcode>(iterator->Next());
USE(opcode);
ASSERT(Translation::FRAME == opcode);
int node_id = iterator->Next();
JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
unsigned height = iterator->Next();
unsigned height_in_bytes = height * kPointerSize;
if (FLAG_trace_deopt) {
PrintF(" translating ");
function->PrintName();
PrintF(" => node=%d, height=%d\n", node_id, height_in_bytes);
}
// The 'fixed' part of the frame consists of the incoming parameters and
// the part described by JavaScriptFrameConstants.
unsigned fixed_frame_size = ComputeFixedSize(function);
unsigned input_frame_size = static_cast<unsigned>(input_->GetFrameSize());
unsigned output_frame_size = height_in_bytes + fixed_frame_size;
// Allocate and store the output frame description.
FrameDescription* output_frame =
new(output_frame_size) FrameDescription(output_frame_size, function);
bool is_bottommost = (0 == frame_index);
bool is_topmost = (output_count_ - 1 == frame_index);
ASSERT(frame_index >= 0 && frame_index < output_count_);
ASSERT(output_[frame_index] == NULL);
output_[frame_index] = output_frame;
// The top address for the bottommost output frame can be computed from
// the input frame pointer and the output frame's height. For all
// subsequent output frames, it can be computed from the previous one's
// top address and the current frame's size.
intptr_t top_address;
if (is_bottommost) {
// 2 = context and function in the frame.
top_address =
input_->GetRegister(rbp.code()) - (2 * kPointerSize) - height_in_bytes;
} else {
top_address = output_[frame_index - 1]->GetTop() - output_frame_size;
}
output_frame->SetTop(top_address);
// Compute the incoming parameter translation.
int parameter_count = function->shared()->formal_parameter_count() + 1;
unsigned output_offset = output_frame_size;
unsigned input_offset = input_frame_size;
for (int i = 0; i < parameter_count; ++i) {
output_offset -= kPointerSize;
DoTranslateCommand(iterator, frame_index, output_offset);
}
input_offset -= (parameter_count * kPointerSize);
// There are no translation commands for the caller's pc and fp, the
// context, and the function. Synthesize their values and set them up
// explicitly.
//
// The caller's pc for the bottommost output frame is the same as in the
// input frame. For all subsequent output frames, it can be read from the
// previous one. This frame's pc can be computed from the non-optimized
// function code and AST id of the bailout.
output_offset -= kPointerSize;
input_offset -= kPointerSize;
intptr_t value;
if (is_bottommost) {
value = input_->GetFrameSlot(input_offset);
} else {
value = output_[frame_index - 1]->GetPc();
}
output_frame->SetFrameSlot(output_offset, value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
V8PRIxPTR " ; caller's pc\n",
top_address + output_offset, output_offset, value);
}
// The caller's frame pointer for the bottommost output frame is the same
// as in the input frame. For all subsequent output frames, it can be
// read from the previous one. Also compute and set this frame's frame
// pointer.
output_offset -= kPointerSize;
input_offset -= kPointerSize;
if (is_bottommost) {
value = input_->GetFrameSlot(input_offset);
} else {
value = output_[frame_index - 1]->GetFp();
}
output_frame->SetFrameSlot(output_offset, value);
intptr_t fp_value = top_address + output_offset;
ASSERT(!is_bottommost || input_->GetRegister(rbp.code()) == fp_value);
output_frame->SetFp(fp_value);
if (is_topmost) output_frame->SetRegister(rbp.code(), fp_value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
V8PRIxPTR " ; caller's fp\n",
fp_value, output_offset, value);
}
// For the bottommost output frame the context can be gotten from the input
// frame. For all subsequent output frames it can be gotten from the function
// so long as we don't inline functions that need local contexts.
output_offset -= kPointerSize;
input_offset -= kPointerSize;
if (is_bottommost) {
value = input_->GetFrameSlot(input_offset);
} else {
value = reinterpret_cast<intptr_t>(function->context());
}
output_frame->SetFrameSlot(output_offset, value);
if (is_topmost) output_frame->SetRegister(rsi.code(), value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
V8PRIxPTR "; context\n",
top_address + output_offset, output_offset, value);
}
// The function was mentioned explicitly in the BEGIN_FRAME.
output_offset -= kPointerSize;
input_offset -= kPointerSize;
value = reinterpret_cast<intptr_t>(function);
// The function for the bottommost output frame should also agree with the
// input frame.
ASSERT(!is_bottommost || input_->GetFrameSlot(input_offset) == value);
output_frame->SetFrameSlot(output_offset, value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
V8PRIxPTR "; function\n",
top_address + output_offset, output_offset, value);
}
// Translate the rest of the frame.
for (unsigned i = 0; i < height; ++i) {
output_offset -= kPointerSize;
DoTranslateCommand(iterator, frame_index, output_offset);
}
ASSERT(0 == output_offset);
// Compute this frame's PC, state, and continuation.
Code* non_optimized_code = function->shared()->code();
FixedArray* raw_data = non_optimized_code->deoptimization_data();
DeoptimizationOutputData* data = DeoptimizationOutputData::cast(raw_data);
Address start = non_optimized_code->instruction_start();
unsigned pc_and_state = GetOutputInfo(data, node_id, function->shared());
unsigned pc_offset = FullCodeGenerator::PcField::decode(pc_and_state);
intptr_t pc_value = reinterpret_cast<intptr_t>(start + pc_offset);
output_frame->SetPc(pc_value);
FullCodeGenerator::State state =
FullCodeGenerator::StateField::decode(pc_and_state);
output_frame->SetState(Smi::FromInt(state));
// Set the continuation for the topmost frame.
if (is_topmost) {
Code* continuation = (bailout_type_ == EAGER)
? isolate_->builtins()->builtin(Builtins::kNotifyDeoptimized)
: isolate_->builtins()->builtin(Builtins::kNotifyLazyDeoptimized);
output_frame->SetContinuation(
reinterpret_cast<intptr_t>(continuation->entry()));
}
if (output_count_ - 1 == frame_index) iterator->Done();
}
#define __ masm()->
void Deoptimizer::EntryGenerator::Generate() {
GeneratePrologue();
// Save all general purpose registers before messing with them.
const int kNumberOfRegisters = Register::kNumRegisters;
const int kDoubleRegsSize = kDoubleSize *
XMMRegister::kNumAllocatableRegisters;
__ subq(rsp, Immediate(kDoubleRegsSize));
for (int i = 0; i < XMMRegister::kNumAllocatableRegisters; ++i) {
XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i);
int offset = i * 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::toRegister(i);
__ push(r);
}
const int kSavedRegistersAreaSize = kNumberOfRegisters * kPointerSize +
kDoubleRegsSize;
// When calling new_deoptimizer_function we need to pass the last argument
// on the stack on windows and in r8 on linux. The remaining arguments are
// all passed in registers (different ones on linux and windows though).
#ifdef _WIN64
Register arg4 = r9;
Register arg3 = r8;
Register arg2 = rdx;
Register arg1 = rcx;
#else
Register arg4 = rcx;
Register arg3 = rdx;
Register arg2 = rsi;
Register arg1 = rdi;
#endif
// 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.
__ movq(arg3, Operand(rsp, kSavedRegistersAreaSize));
// Get the address of the location in the code object if possible
// and compute the fp-to-sp delta in register arg5.
if (type() == EAGER) {
__ Set(arg4, 0);
__ lea(arg5, Operand(rsp, kSavedRegistersAreaSize + 1 * kPointerSize));
} else {
__ movq(arg4, Operand(rsp, kSavedRegistersAreaSize + 1 * kPointerSize));
__ lea(arg5, Operand(rsp, kSavedRegistersAreaSize + 2 * kPointerSize));
}
__ subq(arg5, rbp);
__ neg(arg5);
// Allocate a new deoptimizer object.
__ PrepareCallCFunction(6);
__ movq(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
__ movq(arg1, rax);
__ Set(arg2, 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 * kPointerSize), arg5);
__ LoadAddress(arg5, ExternalReference::isolate_address());
__ movq(Operand(rsp, 5 * kPointerSize), arg5);
#else
__ movq(r8, arg5);
__ LoadAddress(r9, ExternalReference::isolate_address());
#endif
Isolate* isolate = masm()->isolate();
__ CallCFunction(ExternalReference::new_deoptimizer_function(isolate), 6);
// Preserve deoptimizer object in register rax and get the input
// frame descriptor pointer.
__ movq(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();
__ pop(Operand(rbx, offset));
}
// Fill in the double input registers.
int double_regs_offset = FrameDescription::double_registers_offset();
for (int i = 0; i < XMMRegister::kNumAllocatableRegisters; i++) {
int dst_offset = i * kDoubleSize + double_regs_offset;
__ pop(Operand(rbx, dst_offset));
}
// Remove the bailout id from the stack.
if (type() == EAGER) {
__ addq(rsp, Immediate(kPointerSize));
} else {
__ addq(rsp, Immediate(2 * kPointerSize));
}
// Compute a pointer to the unwinding limit in register rcx; that is
// the first stack slot not part of the input frame.
__ movq(rcx, Operand(rbx, FrameDescription::frame_size_offset()));
__ addq(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.
__ lea(rdx, Operand(rbx, FrameDescription::frame_content_offset()));
Label pop_loop;
__ bind(&pop_loop);
__ pop(Operand(rdx, 0));
__ addq(rdx, Immediate(sizeof(intptr_t)));
__ cmpq(rcx, rsp);
__ j(not_equal, &pop_loop);
// Compute the output frame in the deoptimizer.
__ push(rax);
__ PrepareCallCFunction(2);
__ movq(arg1, rax);
__ LoadAddress(arg2, ExternalReference::isolate_address());
__ CallCFunction(
ExternalReference::compute_output_frames_function(isolate), 2);
__ pop(rax);
// Replace the current frame with the output frames.
Label outer_push_loop, inner_push_loop;
// Outer loop state: rax = current FrameDescription**, rdx = one past the
// last FrameDescription**.
__ movl(rdx, Operand(rax, Deoptimizer::output_count_offset()));
__ movq(rax, Operand(rax, Deoptimizer::output_offset()));
__ lea(rdx, Operand(rax, rdx, times_8, 0));
__ bind(&outer_push_loop);
// Inner loop state: rbx = current FrameDescription*, rcx = loop index.
__ movq(rbx, Operand(rax, 0));
__ movq(rcx, Operand(rbx, FrameDescription::frame_size_offset()));
__ bind(&inner_push_loop);
__ subq(rcx, Immediate(sizeof(intptr_t)));
__ push(Operand(rbx, rcx, times_1, FrameDescription::frame_content_offset()));
__ testq(rcx, rcx);
__ j(not_zero, &inner_push_loop);
__ addq(rax, Immediate(kPointerSize));
__ cmpq(rax, rdx);
__ j(below, &outer_push_loop);
// In case of OSR, we have to restore the XMM registers.
if (type() == OSR) {
for (int i = 0; i < XMMRegister::kNumAllocatableRegisters; ++i) {
XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i);
int src_offset = i * kDoubleSize + double_regs_offset;
__ movsd(xmm_reg, Operand(rbx, src_offset));
}
}
// Push state, pc, and continuation from the last output frame.
if (type() != OSR) {
__ push(Operand(rbx, FrameDescription::state_offset()));
}
__ push(Operand(rbx, FrameDescription::pc_offset()));
__ push(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();
__ push(Operand(rbx, offset));
}
// Restore the registers from the stack.
for (int i = kNumberOfRegisters - 1; i >= 0 ; i--) {
Register r = Register::toRegister(i);
// Do not restore rsp, simply pop the value into the next register
// and overwrite this afterwards.
if (r.is(rsp)) {
ASSERT(i > 0);
r = Register::toRegister(i - 1);
}
__ pop(r);
}
// Set up the roots register.
__ InitializeRootRegister();
__ InitializeSmiConstantRegister();
// 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);
ASSERT(masm()->pc_offset() - start == table_entry_size_);
}
__ bind(&done);
}
#undef __
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_X64