deps/v8/src/compiler/code-generator.cc
// Copyright 2013 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/compiler/code-generator.h"
#include "src/compiler/code-generator-impl.h"
#include "src/compiler/linkage.h"
#include "src/compiler/pipeline.h"
namespace v8 {
namespace internal {
namespace compiler {
CodeGenerator::CodeGenerator(InstructionSequence* code)
: code_(code),
current_block_(NULL),
current_source_position_(SourcePosition::Invalid()),
masm_(code->zone()->isolate(), NULL, 0),
resolver_(this),
safepoints_(code->zone()),
lazy_deoptimization_entries_(
LazyDeoptimizationEntries::allocator_type(code->zone())),
deoptimization_states_(
DeoptimizationStates::allocator_type(code->zone())),
deoptimization_literals_(Literals::allocator_type(code->zone())),
translations_(code->zone()) {
deoptimization_states_.resize(code->GetDeoptimizationEntryCount(), NULL);
}
Handle<Code> CodeGenerator::GenerateCode() {
CompilationInfo* info = linkage()->info();
// Emit a code line info recording start event.
PositionsRecorder* recorder = masm()->positions_recorder();
LOG_CODE_EVENT(isolate(), CodeStartLinePosInfoRecordEvent(recorder));
// Place function entry hook if requested to do so.
if (linkage()->GetIncomingDescriptor()->IsJSFunctionCall()) {
ProfileEntryHookStub::MaybeCallEntryHook(masm());
}
// Architecture-specific, linkage-specific prologue.
info->set_prologue_offset(masm()->pc_offset());
AssemblePrologue();
// Assemble all instructions.
for (InstructionSequence::const_iterator i = code()->begin();
i != code()->end(); ++i) {
AssembleInstruction(*i);
}
FinishCode(masm());
safepoints()->Emit(masm(), frame()->GetSpillSlotCount());
// TODO(titzer): what are the right code flags here?
Code::Kind kind = Code::STUB;
if (linkage()->GetIncomingDescriptor()->IsJSFunctionCall()) {
kind = Code::OPTIMIZED_FUNCTION;
}
Handle<Code> result = v8::internal::CodeGenerator::MakeCodeEpilogue(
masm(), Code::ComputeFlags(kind), info);
result->set_is_turbofanned(true);
result->set_stack_slots(frame()->GetSpillSlotCount());
result->set_safepoint_table_offset(safepoints()->GetCodeOffset());
PopulateDeoptimizationData(result);
// Emit a code line info recording stop event.
void* line_info = recorder->DetachJITHandlerData();
LOG_CODE_EVENT(isolate(), CodeEndLinePosInfoRecordEvent(*result, line_info));
return result;
}
void CodeGenerator::RecordSafepoint(PointerMap* pointers, Safepoint::Kind kind,
int arguments,
Safepoint::DeoptMode deopt_mode) {
const ZoneList<InstructionOperand*>* operands =
pointers->GetNormalizedOperands();
Safepoint safepoint =
safepoints()->DefineSafepoint(masm(), kind, arguments, deopt_mode);
for (int i = 0; i < operands->length(); i++) {
InstructionOperand* pointer = operands->at(i);
if (pointer->IsStackSlot()) {
safepoint.DefinePointerSlot(pointer->index(), zone());
} else if (pointer->IsRegister() && (kind & Safepoint::kWithRegisters)) {
Register reg = Register::FromAllocationIndex(pointer->index());
safepoint.DefinePointerRegister(reg, zone());
}
}
}
void CodeGenerator::AssembleInstruction(Instruction* instr) {
if (instr->IsBlockStart()) {
// Bind a label for a block start and handle parallel moves.
BlockStartInstruction* block_start = BlockStartInstruction::cast(instr);
current_block_ = block_start->block();
if (FLAG_code_comments) {
// TODO(titzer): these code comments are a giant memory leak.
Vector<char> buffer = Vector<char>::New(32);
SNPrintF(buffer, "-- B%d start --", block_start->block()->id());
masm()->RecordComment(buffer.start());
}
masm()->bind(block_start->label());
}
if (instr->IsGapMoves()) {
// Handle parallel moves associated with the gap instruction.
AssembleGap(GapInstruction::cast(instr));
} else if (instr->IsSourcePosition()) {
AssembleSourcePosition(SourcePositionInstruction::cast(instr));
} else {
// Assemble architecture-specific code for the instruction.
AssembleArchInstruction(instr);
// Assemble branches or boolean materializations after this instruction.
FlagsMode mode = FlagsModeField::decode(instr->opcode());
FlagsCondition condition = FlagsConditionField::decode(instr->opcode());
switch (mode) {
case kFlags_none:
return;
case kFlags_set:
return AssembleArchBoolean(instr, condition);
case kFlags_branch:
return AssembleArchBranch(instr, condition);
}
UNREACHABLE();
}
}
void CodeGenerator::AssembleSourcePosition(SourcePositionInstruction* instr) {
SourcePosition source_position = instr->source_position();
if (source_position == current_source_position_) return;
DCHECK(!source_position.IsInvalid());
if (!source_position.IsUnknown()) {
int code_pos = source_position.raw();
masm()->positions_recorder()->RecordPosition(source_position.raw());
masm()->positions_recorder()->WriteRecordedPositions();
if (FLAG_code_comments) {
Vector<char> buffer = Vector<char>::New(256);
CompilationInfo* info = linkage()->info();
int ln = Script::GetLineNumber(info->script(), code_pos);
int cn = Script::GetColumnNumber(info->script(), code_pos);
if (info->script()->name()->IsString()) {
Handle<String> file(String::cast(info->script()->name()));
base::OS::SNPrintF(buffer.start(), buffer.length(), "-- %s:%d:%d --",
file->ToCString().get(), ln, cn);
} else {
base::OS::SNPrintF(buffer.start(), buffer.length(),
"-- <unknown>:%d:%d --", ln, cn);
}
masm()->RecordComment(buffer.start());
}
}
current_source_position_ = source_position;
}
void CodeGenerator::AssembleGap(GapInstruction* instr) {
for (int i = GapInstruction::FIRST_INNER_POSITION;
i <= GapInstruction::LAST_INNER_POSITION; i++) {
GapInstruction::InnerPosition inner_pos =
static_cast<GapInstruction::InnerPosition>(i);
ParallelMove* move = instr->GetParallelMove(inner_pos);
if (move != NULL) resolver()->Resolve(move);
}
}
void CodeGenerator::PopulateDeoptimizationData(Handle<Code> code_object) {
CompilationInfo* info = linkage()->info();
int deopt_count = code()->GetDeoptimizationEntryCount();
int patch_count = static_cast<int>(lazy_deoptimization_entries_.size());
if (patch_count == 0 && deopt_count == 0) return;
Handle<DeoptimizationInputData> data = DeoptimizationInputData::New(
isolate(), deopt_count, patch_count, TENURED);
Handle<ByteArray> translation_array =
translations_.CreateByteArray(isolate()->factory());
data->SetTranslationByteArray(*translation_array);
data->SetInlinedFunctionCount(Smi::FromInt(0));
data->SetOptimizationId(Smi::FromInt(info->optimization_id()));
// TODO(jarin) The following code was copied over from Lithium, not sure
// whether the scope or the IsOptimizing condition are really needed.
if (info->IsOptimizing()) {
// Reference to shared function info does not change between phases.
AllowDeferredHandleDereference allow_handle_dereference;
data->SetSharedFunctionInfo(*info->shared_info());
} else {
data->SetSharedFunctionInfo(Smi::FromInt(0));
}
Handle<FixedArray> literals = isolate()->factory()->NewFixedArray(
static_cast<int>(deoptimization_literals_.size()), TENURED);
{
AllowDeferredHandleDereference copy_handles;
for (unsigned i = 0; i < deoptimization_literals_.size(); i++) {
literals->set(i, *deoptimization_literals_[i]);
}
data->SetLiteralArray(*literals);
}
// No OSR in Turbofan yet...
BailoutId osr_ast_id = BailoutId::None();
data->SetOsrAstId(Smi::FromInt(osr_ast_id.ToInt()));
data->SetOsrPcOffset(Smi::FromInt(-1));
// Populate deoptimization entries.
for (int i = 0; i < deopt_count; i++) {
FrameStateDescriptor* descriptor = code()->GetDeoptimizationEntry(i);
data->SetAstId(i, descriptor->bailout_id());
CHECK_NE(NULL, deoptimization_states_[i]);
data->SetTranslationIndex(
i, Smi::FromInt(deoptimization_states_[i]->translation_id_));
data->SetArgumentsStackHeight(i, Smi::FromInt(0));
data->SetPc(i, Smi::FromInt(-1));
}
// Populate the return address patcher entries.
for (int i = 0; i < patch_count; ++i) {
LazyDeoptimizationEntry entry = lazy_deoptimization_entries_[i];
DCHECK(entry.position_after_call() == entry.continuation()->pos() ||
IsNopForSmiCodeInlining(code_object, entry.position_after_call(),
entry.continuation()->pos()));
data->SetReturnAddressPc(i, Smi::FromInt(entry.position_after_call()));
data->SetPatchedAddressPc(i, Smi::FromInt(entry.deoptimization()->pos()));
}
code_object->set_deoptimization_data(*data);
}
void CodeGenerator::RecordLazyDeoptimizationEntry(Instruction* instr) {
InstructionOperandConverter i(this, instr);
Label after_call;
masm()->bind(&after_call);
// The continuation and deoptimization are the last two inputs:
BasicBlock* cont_block =
i.InputBlock(static_cast<int>(instr->InputCount()) - 2);
BasicBlock* deopt_block =
i.InputBlock(static_cast<int>(instr->InputCount()) - 1);
Label* cont_label = code_->GetLabel(cont_block);
Label* deopt_label = code_->GetLabel(deopt_block);
lazy_deoptimization_entries_.push_back(
LazyDeoptimizationEntry(after_call.pos(), cont_label, deopt_label));
}
int CodeGenerator::DefineDeoptimizationLiteral(Handle<Object> literal) {
int result = static_cast<int>(deoptimization_literals_.size());
for (unsigned i = 0; i < deoptimization_literals_.size(); ++i) {
if (deoptimization_literals_[i].is_identical_to(literal)) return i;
}
deoptimization_literals_.push_back(literal);
return result;
}
void CodeGenerator::BuildTranslation(Instruction* instr,
int deoptimization_id) {
// We should build translation only once.
DCHECK_EQ(NULL, deoptimization_states_[deoptimization_id]);
FrameStateDescriptor* descriptor =
code()->GetDeoptimizationEntry(deoptimization_id);
Translation translation(&translations_, 1, 1, zone());
translation.BeginJSFrame(descriptor->bailout_id(),
Translation::kSelfLiteralId,
descriptor->size() - descriptor->parameters_count());
for (int i = 0; i < descriptor->size(); i++) {
AddTranslationForOperand(&translation, instr, instr->InputAt(i));
}
deoptimization_states_[deoptimization_id] =
new (zone()) DeoptimizationState(translation.index());
}
void CodeGenerator::AddTranslationForOperand(Translation* translation,
Instruction* instr,
InstructionOperand* op) {
if (op->IsStackSlot()) {
translation->StoreStackSlot(op->index());
} else if (op->IsDoubleStackSlot()) {
translation->StoreDoubleStackSlot(op->index());
} else if (op->IsRegister()) {
InstructionOperandConverter converter(this, instr);
translation->StoreRegister(converter.ToRegister(op));
} else if (op->IsDoubleRegister()) {
InstructionOperandConverter converter(this, instr);
translation->StoreDoubleRegister(converter.ToDoubleRegister(op));
} else if (op->IsImmediate()) {
InstructionOperandConverter converter(this, instr);
Constant constant = converter.ToConstant(op);
Handle<Object> constant_object;
switch (constant.type()) {
case Constant::kInt32:
constant_object =
isolate()->factory()->NewNumberFromInt(constant.ToInt32());
break;
case Constant::kFloat64:
constant_object =
isolate()->factory()->NewHeapNumber(constant.ToFloat64());
break;
case Constant::kHeapObject:
constant_object = constant.ToHeapObject();
break;
default:
UNREACHABLE();
}
int literal_id = DefineDeoptimizationLiteral(constant_object);
translation->StoreLiteral(literal_id);
} else {
UNREACHABLE();
}
}
#if !V8_TURBOFAN_BACKEND
void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
UNIMPLEMENTED();
}
void CodeGenerator::AssembleArchBranch(Instruction* instr,
FlagsCondition condition) {
UNIMPLEMENTED();
}
void CodeGenerator::AssembleArchBoolean(Instruction* instr,
FlagsCondition condition) {
UNIMPLEMENTED();
}
void CodeGenerator::AssemblePrologue() { UNIMPLEMENTED(); }
void CodeGenerator::AssembleReturn() { UNIMPLEMENTED(); }
void CodeGenerator::AssembleMove(InstructionOperand* source,
InstructionOperand* destination) {
UNIMPLEMENTED();
}
void CodeGenerator::AssembleSwap(InstructionOperand* source,
InstructionOperand* destination) {
UNIMPLEMENTED();
}
void CodeGenerator::AddNopForSmiCodeInlining() { UNIMPLEMENTED(); }
#ifdef DEBUG
bool CodeGenerator::IsNopForSmiCodeInlining(Handle<Code> code, int start_pc,
int end_pc) {
UNIMPLEMENTED();
return false;
}
#endif
#endif // !V8_TURBOFAN_BACKEND
} // namespace compiler
} // namespace internal
} // namespace v8