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// 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_IA32)
#include "codegen.h"
#include "deoptimizer.h"
#include "full-codegen.h"
#include "safepoint-table.h"
namespace v8 {
namespace internal {
int Deoptimizer::table_entry_size_ = 10;
void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
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.
unsigned last_pc_offset = 0;
SafepointTable table(function->code());
for (unsigned i = 0; i < table.length(); i++) {
unsigned pc_offset = table.GetPcOffset(i);
SafepointEntry safepoint_entry = table.GetEntry(i);
int deoptimization_index = safepoint_entry.deoptimization_index();
int gap_code_size = safepoint_entry.gap_code_size();
#ifdef DEBUG
// Destroy the code which is not supposed to run again.
unsigned instructions = pc_offset - last_pc_offset;
CodePatcher destroyer(code->instruction_start() + last_pc_offset,
instructions);
for (unsigned i = 0; i < instructions; i++) {
destroyer.masm()->int3();
}
#endif
last_pc_offset = pc_offset;
if (deoptimization_index != Safepoint::kNoDeoptimizationIndex) {
CodePatcher patcher(
code->instruction_start() + pc_offset + gap_code_size,
Assembler::kCallInstructionLength);
patcher.masm()->call(GetDeoptimizationEntry(deoptimization_index, LAZY),
RelocInfo::NONE);
last_pc_offset += gap_code_size + Assembler::kCallInstructionLength;
}
}
#ifdef DEBUG
// Destroy the code which is not supposed to run again.
unsigned instructions = code->safepoint_table_start() - last_pc_offset;
CodePatcher destroyer(code->instruction_start() + last_pc_offset,
instructions);
for (unsigned i = 0; i < instructions; i++) {
destroyer.masm()->int3();
}
#endif
// Add the deoptimizing code to the list.
DeoptimizingCodeListNode* node = new DeoptimizingCodeListNode(code);
node->set_next(deoptimizing_code_list_);
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(" / %x]\n", reinterpret_cast<uint32_t>(function));
}
}
void Deoptimizer::PatchStackCheckCode(RelocInfo* rinfo,
Code* replacement_code) {
// The stack check code matches the pattern:
//
// cmp esp, <limit>
// jae ok
// call <stack guard>
// test eax, <loop nesting depth>
// ok: ...
//
// We will patch away the branch so the code is:
//
// cmp esp, <limit> ;; Not changed
// nop
// nop
// call <on-stack replacment>
// test eax, <loop nesting depth>
// ok:
Address call_target_address = rinfo->pc();
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
rinfo->set_target_address(replacement_code->entry());
}
void Deoptimizer::RevertStackCheckCode(RelocInfo* rinfo, Code* check_code) {
// Replace the nops from patching (Deoptimizer::PatchStackCheckCode) to
// restore the conditional branch.
Address call_target_address = rinfo->pc();
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
rinfo->set_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 = 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 = 0; ok && i < 4; i++) {
uint32_t input_value = input_->GetFrameSlot(input_offset);
if (FLAG_trace_osr) {
PrintF(" [esp + %d] <- 0x%08x ; [esp + %d] (fixed part)\n",
output_offset,
input_value,
input_offset);
}
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<uint32_t>(from_));
} else {
// Setup the frame pointer and the context pointer.
output_[0]->SetRegister(ebp.code(), input_->GetRegister(ebp.code()));
output_[0]->SetRegister(esi.code(), input_->GetRegister(esi.code()));
unsigned pc_offset = data->OsrPcOffset()->value();
uint32_t pc = reinterpret_cast<uint32_t>(
optimized_code_->entry() + pc_offset);
output_[0]->SetPc(pc);
}
Code* continuation = Builtins::builtin(Builtins::NotifyOSR);
output_[0]->SetContinuation(
reinterpret_cast<uint32_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%0x]\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 = 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.
uint32_t top_address;
if (is_bottommost) {
// 2 = context and function in the frame.
top_address =
input_->GetRegister(ebp.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%08x: [top + %d] <- 0x%08x ; 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(ebp.code()) == fp_value);
output_frame->SetFp(fp_value);
if (is_topmost) output_frame->SetRegister(ebp.code(), fp_value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; caller's fp\n",
fp_value, output_offset, value);
}
// The context can be gotten from the function so long as we don't
// optimize functions that need local contexts.
output_offset -= kPointerSize;
input_offset -= kPointerSize;
value = reinterpret_cast<uint32_t>(function->context());
// The context 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 (is_topmost) output_frame->SetRegister(esi.code(), value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; 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<uint32_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%08x: [top + %d] <- 0x%08x ; 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);
uint32_t pc_value = reinterpret_cast<uint32_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)
? Builtins::builtin(Builtins::NotifyDeoptimized)
: Builtins::builtin(Builtins::NotifyLazyDeoptimized);
output_frame->SetContinuation(
reinterpret_cast<uint32_t>(continuation->entry()));
}
if (output_count_ - 1 == frame_index) iterator->Done();
}
#define __ masm()->
void Deoptimizer::EntryGenerator::Generate() {
GeneratePrologue();
CpuFeatures::Scope scope(SSE2);
// Save all general purpose registers before messing with them.
const int kNumberOfRegisters = Register::kNumRegisters;
const int kDoubleRegsSize = kDoubleSize *
XMMRegister::kNumAllocatableRegisters;
__ sub(Operand(esp), Immediate(kDoubleRegsSize));
for (int i = 0; i < XMMRegister::kNumAllocatableRegisters; ++i) {
XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i);
int offset = i * kDoubleSize;
__ movdbl(Operand(esp, offset), xmm_reg);
}
__ pushad();
const int kSavedRegistersAreaSize = kNumberOfRegisters * kPointerSize +
kDoubleRegsSize;
// Get the bailout id from the stack.
__ mov(ebx, Operand(esp, kSavedRegistersAreaSize));
// Get the address of the location in the code object if possible
// and compute the fp-to-sp delta in register edx.
if (type() == EAGER) {
__ Set(ecx, Immediate(0));
__ lea(edx, Operand(esp, kSavedRegistersAreaSize + 1 * kPointerSize));
} else {
__ mov(ecx, Operand(esp, kSavedRegistersAreaSize + 1 * kPointerSize));
__ lea(edx, Operand(esp, kSavedRegistersAreaSize + 2 * kPointerSize));
}
__ sub(edx, Operand(ebp));
__ neg(edx);
// Allocate a new deoptimizer object.
__ PrepareCallCFunction(5, eax);
__ mov(eax, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
__ mov(Operand(esp, 0 * kPointerSize), eax); // Function.
__ mov(Operand(esp, 1 * kPointerSize), Immediate(type())); // Bailout type.
__ 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.
__ CallCFunction(ExternalReference::new_deoptimizer_function(), 5);
// 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 = 0; i < kNumberOfRegisters; i++) {
int offset = (i * kIntSize) + FrameDescription::registers_offset();
__ mov(ecx, Operand(esp, (kNumberOfRegisters - 1 - i) * kPointerSize));
__ mov(Operand(ebx, offset), ecx);
}
// 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;
int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
__ movdbl(xmm0, Operand(esp, src_offset));
__ movdbl(Operand(ebx, dst_offset), xmm0);
}
// Remove the bailout id and the general purpose registers from the stack.
if (type() == EAGER) {
__ add(Operand(esp), Immediate(kSavedRegistersAreaSize + kPointerSize));
} else {
__ add(Operand(esp), Immediate(kSavedRegistersAreaSize + 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, Operand(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;
__ bind(&pop_loop);
__ pop(Operand(edx, 0));
__ add(Operand(edx), Immediate(sizeof(uint32_t)));
__ cmp(ecx, Operand(esp));
__ j(not_equal, &pop_loop);
// Compute the output frame in the deoptimizer.
__ push(eax);
__ PrepareCallCFunction(1, ebx);
__ mov(Operand(esp, 0 * kPointerSize), eax);
__ CallCFunction(ExternalReference::compute_output_frames_function(), 1);
__ pop(eax);
// Replace the current frame with the output frames.
Label outer_push_loop, inner_push_loop;
// 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));
__ 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()));
__ bind(&inner_push_loop);
__ sub(Operand(ecx), Immediate(sizeof(uint32_t)));
__ push(Operand(ebx, ecx, times_1, FrameDescription::frame_content_offset()));
__ test(ecx, Operand(ecx));
__ j(not_zero, &inner_push_loop);
__ add(Operand(eax), Immediate(kPointerSize));
__ cmp(eax, Operand(edx));
__ 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;
__ movdbl(xmm_reg, Operand(ebx, src_offset));
}
}
// Push state, pc, and continuation from the last output frame.
if (type() != OSR) {
__ push(Operand(ebx, FrameDescription::state_offset()));
}
__ 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 * kIntSize) + 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);
ASSERT(masm()->pc_offset() - start == table_entry_size_);
}
__ bind(&done);
}
#undef __
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_IA32