// 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"
#include "codegen.h"
#include "deoptimizer.h"
#include "full-codegen.h"
#include "safepoint-table.h"
namespace v8 {
namespace internal {
int Deoptimizer::patch_size() {
const int kCallInstructionSizeInWords = 4;
return kCallInstructionSizeInWords * Assembler::kInstrSize;
}
void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
HandleScope scope;
AssertNoAllocation no_allocation;
if (!function->IsOptimized()) return;
// Get the optimized code.
Code* code = function->code();
Address code_start_address = code->instruction_start();
// Invalidate the relocation information, as it will become invalid by the
// code patching below, and is not needed any more.
code->InvalidateRelocation();
// For each LLazyBailout instruction insert a call to the corresponding
// deoptimization entry.
DeoptimizationInputData* deopt_data =
DeoptimizationInputData::cast(code->deoptimization_data());
#ifdef DEBUG
Address prev_call_address = NULL;
#endif
for (int i = 0; i < deopt_data->DeoptCount(); i++) {
if (deopt_data->Pc(i)->value() == -1) continue;
Address call_address = code_start_address + deopt_data->Pc(i)->value();
Address deopt_entry = GetDeoptimizationEntry(i, LAZY);
int call_size_in_bytes = MacroAssembler::CallSize(deopt_entry,
RelocInfo::NONE);
int call_size_in_words = call_size_in_bytes / Assembler::kInstrSize;
ASSERT(call_size_in_bytes % Assembler::kInstrSize == 0);
ASSERT(call_size_in_bytes <= patch_size());
CodePatcher patcher(call_address, call_size_in_words);
patcher.masm()->Call(deopt_entry, RelocInfo::NONE);
ASSERT(prev_call_address == NULL ||
call_address >= prev_call_address + patch_size());
ASSERT(call_address + patch_size() <= code->instruction_end());
#ifdef DEBUG
prev_call_address = call_address;
#endif
}
Isolate* isolate = code->GetIsolate();
// Add the deoptimizing code to the list.
DeoptimizingCodeListNode* node = new DeoptimizingCodeListNode(code);
DeoptimizerData* data = isolate->deoptimizer_data();
node->set_next(data->deoptimizing_code_list_);
data->deoptimizing_code_list_ = node;
// We might be in the middle of incremental marking with compaction.
// Tell collector to treat this code object in a special way and
// ignore all slots that might have been recorded on it.
isolate->heap()->mark_compact_collector()->InvalidateCode(code);
// 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));
#ifdef DEBUG
if (FLAG_print_code) {
code->PrintLn();
}
#endif
}
}
void Deoptimizer::PatchStackCheckCodeAt(Code* unoptimized_code,
Address pc_after,
Code* check_code,
Code* replacement_code) {
const int kInstrSize = Assembler::kInstrSize;
// This structure comes from FullCodeGenerator::EmitStackCheck.
// The call of the stack guard check has the following form:
// sltu at, sp, t0 / slt at, a3, zero_reg (in case of count based interrupts)
// beq at, zero_reg, ok
// lui t9, <stack guard address> upper
// ori t9, <stack guard address> lower
// jalr t9
// nop
// ----- pc_after points here
ASSERT(Assembler::IsBeq(Assembler::instr_at(pc_after - 5 * kInstrSize)));
// Replace the sltu instruction with load-imm 1 to at, so beq is not taken.
CodePatcher patcher(pc_after - 6 * kInstrSize, 1);
patcher.masm()->addiu(at, zero_reg, 1);
// Replace the stack check address in the load-immediate (lui/ori pair)
// with the entry address of the replacement code.
ASSERT(reinterpret_cast<uint32_t>(
Assembler::target_address_at(pc_after - 4 * kInstrSize)) ==
reinterpret_cast<uint32_t>(check_code->entry()));
Assembler::set_target_address_at(pc_after - 4 * kInstrSize,
replacement_code->entry());
// We patched the code to the following form:
// addiu at, zero_reg, 1
// beq at, zero_reg, ok ;; Not changed
// lui t9, <on-stack replacement address> upper
// ori t9, <on-stack replacement address> lower
// jalr t9 ;; Not changed
// nop ;; Not changed
// ----- pc_after points here
unoptimized_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
unoptimized_code, pc_after - 4 * kInstrSize, replacement_code);
}
void Deoptimizer::RevertStackCheckCodeAt(Code* unoptimized_code,
Address pc_after,
Code* check_code,
Code* replacement_code) {
// Exact opposite of the function above.
const int kInstrSize = Assembler::kInstrSize;
ASSERT(Assembler::IsAddImmediate(
Assembler::instr_at(pc_after - 6 * kInstrSize)));
ASSERT(Assembler::IsBeq(Assembler::instr_at(pc_after - 5 * kInstrSize)));
// Restore the sltu instruction so beq can be taken again.
CodePatcher patcher(pc_after - 6 * kInstrSize, 1);
if (FLAG_count_based_interrupts) {
patcher.masm()->slt(at, a3, zero_reg);
} else {
patcher.masm()->sltu(at, sp, t0);
}
// Replace the on-stack replacement address in the load-immediate (lui/ori
// pair) with the entry address of the normal stack-check code.
ASSERT(reinterpret_cast<uint32_t>(
Assembler::target_address_at(pc_after - 4 * kInstrSize)) ==
reinterpret_cast<uint32_t>(replacement_code->entry()));
Assembler::set_target_address_at(pc_after - 4 * kInstrSize,
check_code->entry());
check_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
unoptimized_code, pc_after - 4 * kInstrSize, check_code);
}
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();
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();
iterator.Skip(1); // Drop JS frame count.
ASSERT(count == 1);
USE(count);
opcode = static_cast<Translation::Opcode>(iterator.Next());
USE(opcode);
ASSERT(Translation::JS_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_);
output_[0]->SetFrameType(StackFrame::JAVA_SCRIPT);
// 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) {
uint32_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(" [sp + %d] <- 0x%08x ; [sp + %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<uint32_t>(from_));
} else {
// Set up the frame pointer and the context pointer.
output_[0]->SetRegister(fp.code(), input_->GetRegister(fp.code()));
output_[0]->SetRegister(cp.code(), input_->GetRegister(cp.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 = isolate_->builtins()->builtin(Builtins::kNotifyOSR);
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::DoComputeArgumentsAdaptorFrame(TranslationIterator* iterator,
int frame_index) {
JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
unsigned height = iterator->Next();
unsigned height_in_bytes = height * kPointerSize;
if (FLAG_trace_deopt) {
PrintF(" translating arguments adaptor => height=%d\n", height_in_bytes);
}
unsigned fixed_frame_size = ArgumentsAdaptorFrameConstants::kFrameSize;
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);
output_frame->SetFrameType(StackFrame::ARGUMENTS_ADAPTOR);
// Arguments adaptor can not be topmost or bottommost.
ASSERT(frame_index > 0 && frame_index < output_count_ - 1);
ASSERT(output_[frame_index] == NULL);
output_[frame_index] = output_frame;
// The top address of the frame is computed from the previous
// frame's top and this frame's size.
uint32_t top_address;
top_address = output_[frame_index - 1]->GetTop() - output_frame_size;
output_frame->SetTop(top_address);
// Compute the incoming parameter translation.
int parameter_count = height;
unsigned output_offset = output_frame_size;
for (int i = 0; i < parameter_count; ++i) {
output_offset -= kPointerSize;
DoTranslateCommand(iterator, frame_index, output_offset);
}
// Read caller's PC from the previous frame.
output_offset -= kPointerSize;
intptr_t callers_pc = output_[frame_index - 1]->GetPc();
output_frame->SetFrameSlot(output_offset, callers_pc);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; caller's pc\n",
top_address + output_offset, output_offset, callers_pc);
}
// Read caller's FP from the previous frame, and set this frame's FP.
output_offset -= kPointerSize;
intptr_t value = output_[frame_index - 1]->GetFp();
output_frame->SetFrameSlot(output_offset, value);
intptr_t fp_value = top_address + output_offset;
output_frame->SetFp(fp_value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; caller's fp\n",
fp_value, output_offset, value);
}
// A marker value is used in place of the context.
output_offset -= kPointerSize;
intptr_t context = reinterpret_cast<intptr_t>(
Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
output_frame->SetFrameSlot(output_offset, context);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; context (adaptor sentinel)\n",
top_address + output_offset, output_offset, context);
}
// The function was mentioned explicitly in the ARGUMENTS_ADAPTOR_FRAME.
output_offset -= kPointerSize;
value = reinterpret_cast<intptr_t>(function);
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);
}
// Number of incoming arguments.
output_offset -= kPointerSize;
value = reinterpret_cast<uint32_t>(Smi::FromInt(height - 1));
output_frame->SetFrameSlot(output_offset, value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; argc (%d)\n",
top_address + output_offset, output_offset, value, height - 1);
}
ASSERT(0 == output_offset);
Builtins* builtins = isolate_->builtins();
Code* adaptor_trampoline =
builtins->builtin(Builtins::kArgumentsAdaptorTrampoline);
uint32_t pc = reinterpret_cast<uint32_t>(
adaptor_trampoline->instruction_start() +
isolate_->heap()->arguments_adaptor_deopt_pc_offset()->value());
output_frame->SetPc(pc);
}
void Deoptimizer::DoComputeConstructStubFrame(TranslationIterator* iterator,
int frame_index) {
Builtins* builtins = isolate_->builtins();
Code* construct_stub = builtins->builtin(Builtins::kJSConstructStubGeneric);
JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
unsigned height = iterator->Next();
unsigned height_in_bytes = height * kPointerSize;
if (FLAG_trace_deopt) {
PrintF(" translating construct stub => height=%d\n", height_in_bytes);
}
unsigned fixed_frame_size = 8 * kPointerSize;
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);
output_frame->SetFrameType(StackFrame::CONSTRUCT);
// Construct stub can not be topmost or bottommost.
ASSERT(frame_index > 0 && frame_index < output_count_ - 1);
ASSERT(output_[frame_index] == NULL);
output_[frame_index] = output_frame;
// The top address of the frame is computed from the previous
// frame's top and this frame's size.
uint32_t top_address;
top_address = output_[frame_index - 1]->GetTop() - output_frame_size;
output_frame->SetTop(top_address);
// Compute the incoming parameter translation.
int parameter_count = height;
unsigned output_offset = output_frame_size;
for (int i = 0; i < parameter_count; ++i) {
output_offset -= kPointerSize;
DoTranslateCommand(iterator, frame_index, output_offset);
}
// Read caller's PC from the previous frame.
output_offset -= kPointerSize;
intptr_t callers_pc = output_[frame_index - 1]->GetPc();
output_frame->SetFrameSlot(output_offset, callers_pc);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; caller's pc\n",
top_address + output_offset, output_offset, callers_pc);
}
// Read caller's FP from the previous frame, and set this frame's FP.
output_offset -= kPointerSize;
intptr_t value = output_[frame_index - 1]->GetFp();
output_frame->SetFrameSlot(output_offset, value);
intptr_t fp_value = top_address + output_offset;
output_frame->SetFp(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 previous frame.
output_offset -= kPointerSize;
value = output_[frame_index - 1]->GetContext();
output_frame->SetFrameSlot(output_offset, value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; context\n",
top_address + output_offset, output_offset, value);
}
// A marker value is used in place of the function.
output_offset -= kPointerSize;
value = reinterpret_cast<intptr_t>(Smi::FromInt(StackFrame::CONSTRUCT));
output_frame->SetFrameSlot(output_offset, value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; function (construct sentinel)\n",
top_address + output_offset, output_offset, value);
}
// The output frame reflects a JSConstructStubGeneric frame.
output_offset -= kPointerSize;
value = reinterpret_cast<intptr_t>(construct_stub);
output_frame->SetFrameSlot(output_offset, value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; code object\n",
top_address + output_offset, output_offset, value);
}
// Number of incoming arguments.
output_offset -= kPointerSize;
value = reinterpret_cast<uint32_t>(Smi::FromInt(height - 1));
output_frame->SetFrameSlot(output_offset, value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; argc (%d)\n",
top_address + output_offset, output_offset, value, height - 1);
}
// Constructor function being invoked by the stub.
output_offset -= kPointerSize;
value = reinterpret_cast<intptr_t>(function);
output_frame->SetFrameSlot(output_offset, value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; constructor function\n",
top_address + output_offset, output_offset, value);
}
// The newly allocated object was passed as receiver in the artificial
// constructor stub environment created by HEnvironment::CopyForInlining().
output_offset -= kPointerSize;
value = output_frame->GetFrameSlot(output_frame_size - kPointerSize);
output_frame->SetFrameSlot(output_offset, value);
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; allocated receiver\n",
top_address + output_offset, output_offset, value);
}
ASSERT(0 == output_offset);
uint32_t pc = reinterpret_cast<uint32_t>(
construct_stub->instruction_start() +
isolate_->heap()->construct_stub_deopt_pc_offset()->value());
output_frame->SetPc(pc);
}
// This code is very similar to ia32/arm code, but relies on register names
// (fp, sp) and how the frame is laid out.
void Deoptimizer::DoComputeJSFrame(TranslationIterator* iterator,
int frame_index) {
// Read the ast node id, function, and frame height for this output frame.
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);
output_frame->SetFrameType(StackFrame::JAVA_SCRIPT);
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(fp.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(fp.code()) == fp_value);
output_frame->SetFp(fp_value);
if (is_topmost) {
output_frame->SetRegister(fp.code(), fp_value);
}
if (FLAG_trace_deopt) {
PrintF(" 0x%08x: [top + %d] <- 0x%08x ; 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);
output_frame->SetContext(value);
if (is_topmost) output_frame->SetRegister(cp.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 && bailout_type_ != DEBUGGER) {
Builtins* builtins = isolate_->builtins();
Code* continuation = (bailout_type_ == EAGER)
? builtins->builtin(Builtins::kNotifyDeoptimized)
: builtins->builtin(Builtins::kNotifyLazyDeoptimized);
output_frame->SetContinuation(
reinterpret_cast<uint32_t>(continuation->entry()));
}
}
void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
// Set the register values. The values are not important as there are no
// callee saved registers in JavaScript frames, so all registers are
// spilled. Registers fp and sp are set to the correct values though.
for (int i = 0; i < Register::kNumRegisters; i++) {
input_->SetRegister(i, i * 4);
}
input_->SetRegister(sp.code(), reinterpret_cast<intptr_t>(frame->sp()));
input_->SetRegister(fp.code(), reinterpret_cast<intptr_t>(frame->fp()));
for (int i = 0; i < DoubleRegister::kNumAllocatableRegisters; i++) {
input_->SetDoubleRegister(i, 0.0);
}
// Fill the frame content from the actual data on the frame.
for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
input_->SetFrameSlot(i, Memory::uint32_at(tos + i));
}
}
#define __ masm()->
// This code tries to be close to ia32 code so that any changes can be
// easily ported.
void Deoptimizer::EntryGenerator::Generate() {
GeneratePrologue();
Isolate* isolate = masm()->isolate();
CpuFeatures::Scope scope(FPU);
// Unlike on ARM we don't save all the registers, just the useful ones.
// For the rest, there are gaps on the stack, so the offsets remain the same.
const int kNumberOfRegisters = Register::kNumRegisters;
RegList restored_regs = kJSCallerSaved | kCalleeSaved;
RegList saved_regs = restored_regs | sp.bit() | ra.bit();
const int kDoubleRegsSize =
kDoubleSize * FPURegister::kNumAllocatableRegisters;
// Save all FPU registers before messing with them.
__ Subu(sp, sp, Operand(kDoubleRegsSize));
for (int i = 0; i < FPURegister::kNumAllocatableRegisters; ++i) {
FPURegister fpu_reg = FPURegister::FromAllocationIndex(i);
int offset = i * kDoubleSize;
__ sdc1(fpu_reg, MemOperand(sp, offset));
}
// Push saved_regs (needed to populate FrameDescription::registers_).
// Leave gaps for other registers.
__ Subu(sp, sp, kNumberOfRegisters * kPointerSize);
for (int16_t i = kNumberOfRegisters - 1; i >= 0; i--) {
if ((saved_regs & (1 << i)) != 0) {
__ sw(ToRegister(i), MemOperand(sp, kPointerSize * i));
}
}
const int kSavedRegistersAreaSize =
(kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
// Get the bailout id from the stack.
__ lw(a2, MemOperand(sp, kSavedRegistersAreaSize));
// Get the address of the location in the code object if possible (a3) (return
// address for lazy deoptimization) and compute the fp-to-sp delta in
// register t0.
if (type() == EAGER) {
__ mov(a3, zero_reg);
// Correct one word for bailout id.
__ Addu(t0, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
} else if (type() == OSR) {
__ mov(a3, ra);
// Correct one word for bailout id.
__ Addu(t0, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
} else {
__ mov(a3, ra);
// Correct two words for bailout id and return address.
__ Addu(t0, sp, Operand(kSavedRegistersAreaSize + (2 * kPointerSize)));
}
__ Subu(t0, fp, t0);
// Allocate a new deoptimizer object.
// Pass four arguments in a0 to a3 and fifth & sixth arguments on stack.
__ PrepareCallCFunction(6, t1);
__ lw(a0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
__ li(a1, Operand(type())); // bailout type,
// a2: bailout id already loaded.
// a3: code address or 0 already loaded.
__ sw(t0, CFunctionArgumentOperand(5)); // Fp-to-sp delta.
__ li(t1, Operand(ExternalReference::isolate_address()));
__ sw(t1, CFunctionArgumentOperand(6)); // Isolate.
// Call Deoptimizer::New().
{
AllowExternalCallThatCantCauseGC scope(masm());
__ CallCFunction(ExternalReference::new_deoptimizer_function(isolate), 6);
}
// Preserve "deoptimizer" object in register v0 and get the input
// frame descriptor pointer to a1 (deoptimizer->input_);
// Move deopt-obj to a0 for call to Deoptimizer::ComputeOutputFrames() below.
__ mov(a0, v0);
__ lw(a1, MemOperand(v0, Deoptimizer::input_offset()));
// Copy core registers into FrameDescription::registers_[kNumRegisters].
ASSERT(Register::kNumRegisters == kNumberOfRegisters);
for (int i = 0; i < kNumberOfRegisters; i++) {
int offset = (i * kPointerSize) + FrameDescription::registers_offset();
if ((saved_regs & (1 << i)) != 0) {
__ lw(a2, MemOperand(sp, i * kPointerSize));
__ sw(a2, MemOperand(a1, offset));
} else if (FLAG_debug_code) {
__ li(a2, kDebugZapValue);
__ sw(a2, MemOperand(a1, offset));
}
}
// Copy FPU registers to
// double_registers_[DoubleRegister::kNumAllocatableRegisters]
int double_regs_offset = FrameDescription::double_registers_offset();
for (int i = 0; i < FPURegister::kNumAllocatableRegisters; ++i) {
int dst_offset = i * kDoubleSize + double_regs_offset;
int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
__ ldc1(f0, MemOperand(sp, src_offset));
__ sdc1(f0, MemOperand(a1, dst_offset));
}
// Remove the bailout id, eventually return address, and the saved registers
// from the stack.
if (type() == EAGER || type() == OSR) {
__ Addu(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
} else {
__ Addu(sp, sp, Operand(kSavedRegistersAreaSize + (2 * kPointerSize)));
}
// Compute a pointer to the unwinding limit in register a2; that is
// the first stack slot not part of the input frame.
__ lw(a2, MemOperand(a1, FrameDescription::frame_size_offset()));
__ Addu(a2, a2, sp);
// Unwind the stack down to - but not including - the unwinding
// limit and copy the contents of the activation frame to the input
// frame description.
__ Addu(a3, a1, Operand(FrameDescription::frame_content_offset()));
Label pop_loop;
__ bind(&pop_loop);
__ pop(t0);
__ sw(t0, MemOperand(a3, 0));
__ Branch(USE_DELAY_SLOT, &pop_loop, ne, a2, Operand(sp));
__ addiu(a3, a3, sizeof(uint32_t)); // In delay slot.
// Compute the output frame in the deoptimizer.
__ push(a0); // Preserve deoptimizer object across call.
// a0: deoptimizer object; a1: scratch.
__ PrepareCallCFunction(1, a1);
// Call Deoptimizer::ComputeOutputFrames().
{
AllowExternalCallThatCantCauseGC scope(masm());
__ CallCFunction(
ExternalReference::compute_output_frames_function(isolate), 1);
}
__ pop(a0); // Restore deoptimizer object (class Deoptimizer).
// Replace the current (input) frame with the output frames.
Label outer_push_loop, inner_push_loop;
// Outer loop state: a0 = current "FrameDescription** output_",
// a1 = one past the last FrameDescription**.
__ lw(a1, MemOperand(a0, Deoptimizer::output_count_offset()));
__ lw(a0, MemOperand(a0, Deoptimizer::output_offset())); // a0 is output_.
__ sll(a1, a1, kPointerSizeLog2); // Count to offset.
__ addu(a1, a0, a1); // a1 = one past the last FrameDescription**.
__ bind(&outer_push_loop);
// Inner loop state: a2 = current FrameDescription*, a3 = loop index.
__ lw(a2, MemOperand(a0, 0)); // output_[ix]
__ lw(a3, MemOperand(a2, FrameDescription::frame_size_offset()));
__ bind(&inner_push_loop);
__ Subu(a3, a3, Operand(sizeof(uint32_t)));
__ Addu(t2, a2, Operand(a3));
__ lw(t3, MemOperand(t2, FrameDescription::frame_content_offset()));
__ push(t3);
__ Branch(&inner_push_loop, ne, a3, Operand(zero_reg));
__ Addu(a0, a0, Operand(kPointerSize));
__ Branch(&outer_push_loop, lt, a0, Operand(a1));
// Push state, pc, and continuation from the last output frame.
if (type() != OSR) {
__ lw(t2, MemOperand(a2, FrameDescription::state_offset()));
__ push(t2);
}
__ lw(t2, MemOperand(a2, FrameDescription::pc_offset()));
__ push(t2);
__ lw(t2, MemOperand(a2, FrameDescription::continuation_offset()));
__ push(t2);
// Technically restoring 'at' should work unless zero_reg is also restored
// but it's safer to check for this.
ASSERT(!(at.bit() & restored_regs));
// Restore the registers from the last output frame.
__ mov(at, a2);
for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
int offset = (i * kPointerSize) + FrameDescription::registers_offset();
if ((restored_regs & (1 << i)) != 0) {
__ lw(ToRegister(i), MemOperand(at, offset));
}
}
__ InitializeRootRegister();
__ pop(at); // Get continuation, leave pc on stack.
__ pop(ra);
__ Jump(at);
__ stop("Unreachable.");
}
// Maximum size of a table entry generated below.
const int Deoptimizer::table_entry_size_ = 9 * Assembler::kInstrSize;
void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm());
// Create a sequence of deoptimization entries. Note that any
// registers may be still live.
Label table_start;
__ bind(&table_start);
for (int i = 0; i < count(); i++) {
Label start;
__ bind(&start);
if (type() != EAGER) {
// Emulate ia32 like call by pushing return address to stack.
__ addiu(sp, sp, -2 * kPointerSize);
__ sw(ra, MemOperand(sp, 1 * kPointerSize));
} else {
__ addiu(sp, sp, -1 * kPointerSize);
}
// Jump over the remaining deopt entries (including this one).
// This code is always reached by calling Jump, which puts the target (label
// start) into t9.
const int remaining_entries = (count() - i) * table_entry_size_;
__ Addu(t9, t9, remaining_entries);
// 'at' was clobbered so we can only load the current entry value here.
__ li(at, i);
__ jr(t9); // Expose delay slot.
__ sw(at, MemOperand(sp, 0 * kPointerSize)); // In the delay slot.
// Pad the rest of the code.
while (table_entry_size_ > (masm()->SizeOfCodeGeneratedSince(&start))) {
__ nop();
}
ASSERT_EQ(table_entry_size_, masm()->SizeOfCodeGeneratedSince(&start));
}
ASSERT_EQ(masm()->SizeOfCodeGeneratedSince(&table_start),
count() * table_entry_size_);
}
#undef __
} } // namespace v8::internal