// Copyright 2012 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 {
const int Deoptimizer::table_entry_size_ = 16;
int Deoptimizer::patch_size() {
const int kCallInstructionSizeInWords = 3;
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));
}
}
static const int32_t kBranchBeforeStackCheck = 0x2a000001;
static const int32_t kBranchBeforeInterrupt = 0x5a000004;
void Deoptimizer::PatchStackCheckCodeAt(Code* unoptimized_code,
Address pc_after,
Code* check_code,
Code* replacement_code) {
const int kInstrSize = Assembler::kInstrSize;
// The call of the stack guard check has the following form:
// e1 5d 00 0c cmp sp, <limit>
// 2a 00 00 01 bcs ok
// e5 9f c? ?? ldr ip, [pc, <stack guard address>]
// e1 2f ff 3c blx ip
ASSERT(Memory::int32_at(pc_after - kInstrSize) == kBlxIp);
ASSERT(Assembler::IsLdrPcImmediateOffset(
Assembler::instr_at(pc_after - 2 * kInstrSize)));
if (FLAG_count_based_interrupts) {
ASSERT_EQ(kBranchBeforeInterrupt,
Memory::int32_at(pc_after - 3 * kInstrSize));
} else {
ASSERT_EQ(kBranchBeforeStackCheck,
Memory::int32_at(pc_after - 3 * kInstrSize));
}
// We patch the code to the following form:
// e1 5d 00 0c cmp sp, <limit>
// e1 a0 00 00 mov r0, r0 (NOP)
// e5 9f c? ?? ldr ip, [pc, <on-stack replacement address>]
// e1 2f ff 3c blx ip
// and overwrite the constant containing the
// address of the stack check stub.
// Replace conditional jump with NOP.
CodePatcher patcher(pc_after - 3 * kInstrSize, 1);
patcher.masm()->nop();
// Replace the stack check address in the constant pool
// with the entry address of the replacement code.
uint32_t stack_check_address_offset = Memory::uint16_at(pc_after -
2 * kInstrSize) & 0xfff;
Address stack_check_address_pointer = pc_after + stack_check_address_offset;
ASSERT(Memory::uint32_at(stack_check_address_pointer) ==
reinterpret_cast<uint32_t>(check_code->entry()));
Memory::uint32_at(stack_check_address_pointer) =
reinterpret_cast<uint32_t>(replacement_code->entry());
unoptimized_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
unoptimized_code, pc_after - 2 * kInstrSize, replacement_code);
}
void Deoptimizer::RevertStackCheckCodeAt(Code* unoptimized_code,
Address pc_after,
Code* check_code,
Code* replacement_code) {
const int kInstrSize = Assembler::kInstrSize;
ASSERT(Memory::int32_at(pc_after - kInstrSize) == kBlxIp);
ASSERT(Assembler::IsLdrPcImmediateOffset(
Assembler::instr_at(pc_after - 2 * kInstrSize)));
// Replace NOP with conditional jump.
CodePatcher patcher(pc_after - 3 * kInstrSize, 1);
if (FLAG_count_based_interrupts) {
patcher.masm()->b(+16, pl);
ASSERT_EQ(kBranchBeforeInterrupt,
Memory::int32_at(pc_after - 3 * kInstrSize));
} else {
patcher.masm()->b(+4, cs);
ASSERT_EQ(kBranchBeforeStackCheck,
Memory::int32_at(pc_after - 3 * kInstrSize));
}
// Replace the stack check address in the constant pool
// with the entry address of the replacement code.
uint32_t stack_check_address_offset = Memory::uint16_at(pc_after -
2 * kInstrSize) & 0xfff;
Address stack_check_address_pointer = pc_after + stack_check_address_offset;
ASSERT(Memory::uint32_at(stack_check_address_pointer) ==
reinterpret_cast<uint32_t>(replacement_code->entry()));
Memory::uint32_at(stack_check_address_pointer) =
reinterpret_cast<uint32_t>(check_code->entry());
check_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
unoptimized_code, pc_after - 2 * 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 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);
if (is_topmost) {
output_frame->SetRegister(pc.code(), 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(VFP3);
// Save all general purpose registers before messing with them.
const int kNumberOfRegisters = Register::kNumRegisters;
// Everything but pc, lr and ip which will be saved but not restored.
RegList restored_regs = kJSCallerSaved | kCalleeSaved | ip.bit();
const int kDoubleRegsSize =
kDoubleSize * DwVfpRegister::kNumAllocatableRegisters;
// Save all VFP registers before messing with them.
DwVfpRegister first = DwVfpRegister::FromAllocationIndex(0);
DwVfpRegister last =
DwVfpRegister::FromAllocationIndex(
DwVfpRegister::kNumAllocatableRegisters - 1);
ASSERT(last.code() > first.code());
ASSERT((last.code() - first.code()) ==
(DwVfpRegister::kNumAllocatableRegisters - 1));
#ifdef DEBUG
for (int i = 0; i <= (DwVfpRegister::kNumAllocatableRegisters - 1); i++) {
ASSERT((DwVfpRegister::FromAllocationIndex(i).code() <= last.code()) &&
(DwVfpRegister::FromAllocationIndex(i).code() >= first.code()));
}
#endif
__ vstm(db_w, sp, first, last);
// Push all 16 registers (needed to populate FrameDescription::registers_).
// TODO(1588) Note that using pc with stm is deprecated, so we should perhaps
// handle this a bit differently.
__ stm(db_w, sp, restored_regs | sp.bit() | lr.bit() | pc.bit());
const int kSavedRegistersAreaSize =
(kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
// Get the bailout id from the stack.
__ ldr(r2, MemOperand(sp, kSavedRegistersAreaSize));
// Get the address of the location in the code object if possible (r3) (return
// address for lazy deoptimization) and compute the fp-to-sp delta in
// register r4.
if (type() == EAGER) {
__ mov(r3, Operand(0));
// Correct one word for bailout id.
__ add(r4, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
} else if (type() == OSR) {
__ mov(r3, lr);
// Correct one word for bailout id.
__ add(r4, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
} else {
__ mov(r3, lr);
// Correct two words for bailout id and return address.
__ add(r4, sp, Operand(kSavedRegistersAreaSize + (2 * kPointerSize)));
}
__ sub(r4, fp, r4);
// Allocate a new deoptimizer object.
// Pass four arguments in r0 to r3 and fifth argument on stack.
__ PrepareCallCFunction(6, r5);
__ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
__ mov(r1, Operand(type())); // bailout type,
// r2: bailout id already loaded.
// r3: code address or 0 already loaded.
__ str(r4, MemOperand(sp, 0 * kPointerSize)); // Fp-to-sp delta.
__ mov(r5, Operand(ExternalReference::isolate_address()));
__ str(r5, MemOperand(sp, 1 * kPointerSize)); // Isolate.
// Call Deoptimizer::New().
{
AllowExternalCallThatCantCauseGC scope(masm());
__ CallCFunction(ExternalReference::new_deoptimizer_function(isolate), 6);
}
// Preserve "deoptimizer" object in register r0 and get the input
// frame descriptor pointer to r1 (deoptimizer->input_);
__ ldr(r1, MemOperand(r0, 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();
__ ldr(r2, MemOperand(sp, i * kPointerSize));
__ str(r2, MemOperand(r1, offset));
}
// Copy VFP registers to
// double_registers_[DoubleRegister::kNumAllocatableRegisters]
int double_regs_offset = FrameDescription::double_registers_offset();
for (int i = 0; i < DwVfpRegister::kNumAllocatableRegisters; ++i) {
int dst_offset = i * kDoubleSize + double_regs_offset;
int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
__ vldr(d0, sp, src_offset);
__ vstr(d0, r1, dst_offset);
}
// Remove the bailout id, eventually return address, and the saved registers
// from the stack.
if (type() == EAGER || type() == OSR) {
__ add(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
} else {
__ add(sp, sp, Operand(kSavedRegistersAreaSize + (2 * kPointerSize)));
}
// Compute a pointer to the unwinding limit in register r2; that is
// the first stack slot not part of the input frame.
__ ldr(r2, MemOperand(r1, FrameDescription::frame_size_offset()));
__ add(r2, r2, 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.
__ add(r3, r1, Operand(FrameDescription::frame_content_offset()));
Label pop_loop;
__ bind(&pop_loop);
__ pop(r4);
__ str(r4, MemOperand(r3, 0));
__ add(r3, r3, Operand(sizeof(uint32_t)));
__ cmp(r2, sp);
__ b(ne, &pop_loop);
// Compute the output frame in the deoptimizer.
__ push(r0); // Preserve deoptimizer object across call.
// r0: deoptimizer object; r1: scratch.
__ PrepareCallCFunction(1, r1);
// Call Deoptimizer::ComputeOutputFrames().
{
AllowExternalCallThatCantCauseGC scope(masm());
__ CallCFunction(
ExternalReference::compute_output_frames_function(isolate), 1);
}
__ pop(r0); // Restore deoptimizer object (class Deoptimizer).
// Replace the current (input) frame with the output frames.
Label outer_push_loop, inner_push_loop;
// Outer loop state: r0 = current "FrameDescription** output_",
// r1 = one past the last FrameDescription**.
__ ldr(r1, MemOperand(r0, Deoptimizer::output_count_offset()));
__ ldr(r0, MemOperand(r0, Deoptimizer::output_offset())); // r0 is output_.
__ add(r1, r0, Operand(r1, LSL, 2));
__ bind(&outer_push_loop);
// Inner loop state: r2 = current FrameDescription*, r3 = loop index.
__ ldr(r2, MemOperand(r0, 0)); // output_[ix]
__ ldr(r3, MemOperand(r2, FrameDescription::frame_size_offset()));
__ bind(&inner_push_loop);
__ sub(r3, r3, Operand(sizeof(uint32_t)));
__ add(r6, r2, Operand(r3));
__ ldr(r7, MemOperand(r6, FrameDescription::frame_content_offset()));
__ push(r7);
__ cmp(r3, Operand(0));
__ b(ne, &inner_push_loop); // test for gt?
__ add(r0, r0, Operand(kPointerSize));
__ cmp(r0, r1);
__ b(lt, &outer_push_loop);
// Push state, pc, and continuation from the last output frame.
if (type() != OSR) {
__ ldr(r6, MemOperand(r2, FrameDescription::state_offset()));
__ push(r6);
}
__ ldr(r6, MemOperand(r2, FrameDescription::pc_offset()));
__ push(r6);
__ ldr(r6, MemOperand(r2, FrameDescription::continuation_offset()));
__ push(r6);
// Push the registers from the last output frame.
for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
int offset = (i * kPointerSize) + FrameDescription::registers_offset();
__ ldr(r6, MemOperand(r2, offset));
__ push(r6);
}
// Restore the registers from the stack.
__ ldm(ia_w, sp, restored_regs); // all but pc registers.
__ pop(ip); // remove sp
__ pop(ip); // remove lr
__ InitializeRootRegister();
__ pop(ip); // remove pc
__ pop(r7); // get continuation, leave pc on stack
__ pop(lr);
__ Jump(r7);
__ stop("Unreachable.");
}
void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
// Create a sequence of deoptimization entries. Note that any
// registers may be still live.
Label done;
for (int i = 0; i < count(); i++) {
int start = masm()->pc_offset();
USE(start);
if (type() == EAGER) {
__ nop();
} else {
// Emulate ia32 like call by pushing return address to stack.
__ push(lr);
}
__ mov(ip, Operand(i));
__ push(ip);
__ b(&done);
ASSERT(masm()->pc_offset() - start == table_entry_size_);
}
__ bind(&done);
}
#undef __
} } // namespace v8::internal