v8/src/lithium.cc
ulan b79b985988 Use weak cells in dependent code.
BUG=

Review URL: https://codereview.chromium.org/871253005

Cr-Commit-Position: refs/heads/master@{#26614}
2015-02-12 13:21:13 +00:00

727 lines
23 KiB
C++

// Copyright 2012 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/lithium.h"
#include "src/v8.h"
#include "src/scopes.h"
#include "src/serialize.h"
#if V8_TARGET_ARCH_IA32
#include "src/ia32/lithium-ia32.h" // NOLINT
#include "src/ia32/lithium-codegen-ia32.h" // NOLINT
#elif V8_TARGET_ARCH_X64
#include "src/x64/lithium-x64.h" // NOLINT
#include "src/x64/lithium-codegen-x64.h" // NOLINT
#elif V8_TARGET_ARCH_ARM
#include "src/arm/lithium-arm.h" // NOLINT
#include "src/arm/lithium-codegen-arm.h" // NOLINT
#elif V8_TARGET_ARCH_PPC
#include "src/ppc/lithium-ppc.h" // NOLINT
#include "src/ppc/lithium-codegen-ppc.h" // NOLINT
#elif V8_TARGET_ARCH_MIPS
#include "src/mips/lithium-mips.h" // NOLINT
#include "src/mips/lithium-codegen-mips.h" // NOLINT
#elif V8_TARGET_ARCH_ARM64
#include "src/arm64/lithium-arm64.h" // NOLINT
#include "src/arm64/lithium-codegen-arm64.h" // NOLINT
#elif V8_TARGET_ARCH_MIPS64
#include "src/mips64/lithium-mips64.h" // NOLINT
#include "src/mips64/lithium-codegen-mips64.h" // NOLINT
#elif V8_TARGET_ARCH_X87
#include "src/x87/lithium-x87.h" // NOLINT
#include "src/x87/lithium-codegen-x87.h" // NOLINT
#else
#error "Unknown architecture."
#endif
namespace v8 {
namespace internal {
void LOperand::PrintTo(StringStream* stream) {
LUnallocated* unalloc = NULL;
switch (kind()) {
case INVALID:
stream->Add("(0)");
break;
case UNALLOCATED:
unalloc = LUnallocated::cast(this);
stream->Add("v%d", unalloc->virtual_register());
if (unalloc->basic_policy() == LUnallocated::FIXED_SLOT) {
stream->Add("(=%dS)", unalloc->fixed_slot_index());
break;
}
switch (unalloc->extended_policy()) {
case LUnallocated::NONE:
break;
case LUnallocated::FIXED_REGISTER: {
int reg_index = unalloc->fixed_register_index();
if (reg_index < 0 ||
reg_index >= Register::kMaxNumAllocatableRegisters) {
stream->Add("(=invalid_reg#%d)", reg_index);
} else {
const char* register_name =
Register::AllocationIndexToString(reg_index);
stream->Add("(=%s)", register_name);
}
break;
}
case LUnallocated::FIXED_DOUBLE_REGISTER: {
int reg_index = unalloc->fixed_register_index();
if (reg_index < 0 ||
reg_index >= DoubleRegister::kMaxNumAllocatableRegisters) {
stream->Add("(=invalid_double_reg#%d)", reg_index);
} else {
const char* double_register_name =
DoubleRegister::AllocationIndexToString(reg_index);
stream->Add("(=%s)", double_register_name);
}
break;
}
case LUnallocated::MUST_HAVE_REGISTER:
stream->Add("(R)");
break;
case LUnallocated::MUST_HAVE_DOUBLE_REGISTER:
stream->Add("(D)");
break;
case LUnallocated::WRITABLE_REGISTER:
stream->Add("(WR)");
break;
case LUnallocated::SAME_AS_FIRST_INPUT:
stream->Add("(1)");
break;
case LUnallocated::ANY:
stream->Add("(-)");
break;
}
break;
case CONSTANT_OPERAND:
stream->Add("[constant:%d]", index());
break;
case STACK_SLOT:
stream->Add("[stack:%d]", index());
break;
case DOUBLE_STACK_SLOT:
stream->Add("[double_stack:%d]", index());
break;
case REGISTER: {
int reg_index = index();
if (reg_index < 0 || reg_index >= Register::kMaxNumAllocatableRegisters) {
stream->Add("(=invalid_reg#%d|R)", reg_index);
} else {
stream->Add("[%s|R]", Register::AllocationIndexToString(reg_index));
}
break;
}
case DOUBLE_REGISTER: {
int reg_index = index();
if (reg_index < 0 ||
reg_index >= DoubleRegister::kMaxNumAllocatableRegisters) {
stream->Add("(=invalid_double_reg#%d|R)", reg_index);
} else {
stream->Add("[%s|R]",
DoubleRegister::AllocationIndexToString(reg_index));
}
break;
}
}
}
template<LOperand::Kind kOperandKind, int kNumCachedOperands>
LSubKindOperand<kOperandKind, kNumCachedOperands>*
LSubKindOperand<kOperandKind, kNumCachedOperands>::cache = NULL;
template<LOperand::Kind kOperandKind, int kNumCachedOperands>
void LSubKindOperand<kOperandKind, kNumCachedOperands>::SetUpCache() {
if (cache) return;
cache = new LSubKindOperand[kNumCachedOperands];
for (int i = 0; i < kNumCachedOperands; i++) {
cache[i].ConvertTo(kOperandKind, i);
}
}
template<LOperand::Kind kOperandKind, int kNumCachedOperands>
void LSubKindOperand<kOperandKind, kNumCachedOperands>::TearDownCache() {
delete[] cache;
cache = NULL;
}
void LOperand::SetUpCaches() {
#define LITHIUM_OPERAND_SETUP(name, type, number) L##name::SetUpCache();
LITHIUM_OPERAND_LIST(LITHIUM_OPERAND_SETUP)
#undef LITHIUM_OPERAND_SETUP
}
void LOperand::TearDownCaches() {
#define LITHIUM_OPERAND_TEARDOWN(name, type, number) L##name::TearDownCache();
LITHIUM_OPERAND_LIST(LITHIUM_OPERAND_TEARDOWN)
#undef LITHIUM_OPERAND_TEARDOWN
}
bool LParallelMove::IsRedundant() const {
for (int i = 0; i < move_operands_.length(); ++i) {
if (!move_operands_[i].IsRedundant()) return false;
}
return true;
}
void LParallelMove::PrintDataTo(StringStream* stream) const {
bool first = true;
for (int i = 0; i < move_operands_.length(); ++i) {
if (!move_operands_[i].IsEliminated()) {
LOperand* source = move_operands_[i].source();
LOperand* destination = move_operands_[i].destination();
if (!first) stream->Add(" ");
first = false;
if (source->Equals(destination)) {
destination->PrintTo(stream);
} else {
destination->PrintTo(stream);
stream->Add(" = ");
source->PrintTo(stream);
}
stream->Add(";");
}
}
}
void LEnvironment::PrintTo(StringStream* stream) {
stream->Add("[id=%d|", ast_id().ToInt());
if (deoptimization_index() != Safepoint::kNoDeoptimizationIndex) {
stream->Add("deopt_id=%d|", deoptimization_index());
}
stream->Add("parameters=%d|", parameter_count());
stream->Add("arguments_stack_height=%d|", arguments_stack_height());
for (int i = 0; i < values_.length(); ++i) {
if (i != 0) stream->Add(";");
if (values_[i] == NULL) {
stream->Add("[hole]");
} else {
values_[i]->PrintTo(stream);
}
}
stream->Add("]");
}
void LPointerMap::RecordPointer(LOperand* op, Zone* zone) {
// Do not record arguments as pointers.
if (op->IsStackSlot() && op->index() < 0) return;
DCHECK(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
pointer_operands_.Add(op, zone);
}
void LPointerMap::RemovePointer(LOperand* op) {
// Do not record arguments as pointers.
if (op->IsStackSlot() && op->index() < 0) return;
DCHECK(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
for (int i = 0; i < pointer_operands_.length(); ++i) {
if (pointer_operands_[i]->Equals(op)) {
pointer_operands_.Remove(i);
--i;
}
}
}
void LPointerMap::RecordUntagged(LOperand* op, Zone* zone) {
// Do not record arguments as pointers.
if (op->IsStackSlot() && op->index() < 0) return;
DCHECK(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
untagged_operands_.Add(op, zone);
}
void LPointerMap::PrintTo(StringStream* stream) {
stream->Add("{");
for (int i = 0; i < pointer_operands_.length(); ++i) {
if (i != 0) stream->Add(";");
pointer_operands_[i]->PrintTo(stream);
}
stream->Add("}");
}
int StackSlotOffset(int index) {
if (index >= 0) {
// Local or spill slot. Skip the frame pointer, function, and
// context in the fixed part of the frame.
return -(index + 1) * kPointerSize -
StandardFrameConstants::kFixedFrameSizeFromFp;
} else {
// Incoming parameter. Skip the return address.
return -(index + 1) * kPointerSize + kFPOnStackSize + kPCOnStackSize;
}
}
LChunk::LChunk(CompilationInfo* info, HGraph* graph)
: spill_slot_count_(0),
info_(info),
graph_(graph),
instructions_(32, info->zone()),
pointer_maps_(8, info->zone()),
inlined_closures_(1, info->zone()),
deprecation_dependencies_(MapLess(), MapAllocator(info->zone())),
stability_dependencies_(MapLess(), MapAllocator(info->zone())) {}
LLabel* LChunk::GetLabel(int block_id) const {
HBasicBlock* block = graph_->blocks()->at(block_id);
int first_instruction = block->first_instruction_index();
return LLabel::cast(instructions_[first_instruction]);
}
int LChunk::LookupDestination(int block_id) const {
LLabel* cur = GetLabel(block_id);
while (cur->replacement() != NULL) {
cur = cur->replacement();
}
return cur->block_id();
}
Label* LChunk::GetAssemblyLabel(int block_id) const {
LLabel* label = GetLabel(block_id);
DCHECK(!label->HasReplacement());
return label->label();
}
void LChunk::MarkEmptyBlocks() {
LPhase phase("L_Mark empty blocks", this);
for (int i = 0; i < graph()->blocks()->length(); ++i) {
HBasicBlock* block = graph()->blocks()->at(i);
int first = block->first_instruction_index();
int last = block->last_instruction_index();
LInstruction* first_instr = instructions()->at(first);
LInstruction* last_instr = instructions()->at(last);
LLabel* label = LLabel::cast(first_instr);
if (last_instr->IsGoto()) {
LGoto* goto_instr = LGoto::cast(last_instr);
if (label->IsRedundant() &&
!label->is_loop_header()) {
bool can_eliminate = true;
for (int i = first + 1; i < last && can_eliminate; ++i) {
LInstruction* cur = instructions()->at(i);
if (cur->IsGap()) {
LGap* gap = LGap::cast(cur);
if (!gap->IsRedundant()) {
can_eliminate = false;
}
} else {
can_eliminate = false;
}
}
if (can_eliminate) {
label->set_replacement(GetLabel(goto_instr->block_id()));
}
}
}
}
}
void LChunk::AddInstruction(LInstruction* instr, HBasicBlock* block) {
LInstructionGap* gap = new (zone()) LInstructionGap(block);
gap->set_hydrogen_value(instr->hydrogen_value());
int index = -1;
if (instr->IsControl()) {
instructions_.Add(gap, zone());
index = instructions_.length();
instructions_.Add(instr, zone());
} else {
index = instructions_.length();
instructions_.Add(instr, zone());
instructions_.Add(gap, zone());
}
if (instr->HasPointerMap()) {
pointer_maps_.Add(instr->pointer_map(), zone());
instr->pointer_map()->set_lithium_position(index);
}
}
LConstantOperand* LChunk::DefineConstantOperand(HConstant* constant) {
return LConstantOperand::Create(constant->id(), zone());
}
int LChunk::GetParameterStackSlot(int index) const {
// The receiver is at index 0, the first parameter at index 1, so we
// shift all parameter indexes down by the number of parameters, and
// make sure they end up negative so they are distinguishable from
// spill slots.
int result = index - info()->num_parameters() - 1;
DCHECK(result < 0);
return result;
}
// A parameter relative to ebp in the arguments stub.
int LChunk::ParameterAt(int index) {
DCHECK(-1 <= index); // -1 is the receiver.
return (1 + info()->scope()->num_parameters() - index) *
kPointerSize;
}
LGap* LChunk::GetGapAt(int index) const {
return LGap::cast(instructions_[index]);
}
bool LChunk::IsGapAt(int index) const {
return instructions_[index]->IsGap();
}
int LChunk::NearestGapPos(int index) const {
while (!IsGapAt(index)) index--;
return index;
}
void LChunk::AddGapMove(int index, LOperand* from, LOperand* to) {
GetGapAt(index)->GetOrCreateParallelMove(
LGap::START, zone())->AddMove(from, to, zone());
}
HConstant* LChunk::LookupConstant(LConstantOperand* operand) const {
return HConstant::cast(graph_->LookupValue(operand->index()));
}
Representation LChunk::LookupLiteralRepresentation(
LConstantOperand* operand) const {
return graph_->LookupValue(operand->index())->representation();
}
static void AddWeakObjectToCodeDependency(Isolate* isolate,
Handle<HeapObject> object,
Handle<Code> code) {
Handle<WeakCell> cell = Code::WeakCellFor(code);
Heap* heap = isolate->heap();
Handle<DependentCode> dep(heap->LookupWeakObjectToCodeDependency(object));
dep = DependentCode::InsertWeakCode(dep, DependentCode::kWeakCodeGroup, cell);
heap->AddWeakObjectToCodeDependency(object, dep);
}
void LChunk::RegisterWeakObjectsInOptimizedCode(Handle<Code> code) const {
DCHECK(code->is_optimized_code());
ZoneList<Handle<Map> > maps(1, zone());
ZoneList<Handle<HeapObject> > objects(1, zone());
int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
RelocInfo::ModeMask(RelocInfo::CELL);
for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
RelocInfo::Mode mode = it.rinfo()->rmode();
if (mode == RelocInfo::CELL &&
code->IsWeakObjectInOptimizedCode(it.rinfo()->target_cell())) {
objects.Add(Handle<HeapObject>(it.rinfo()->target_cell()), zone());
} else if (mode == RelocInfo::EMBEDDED_OBJECT &&
code->IsWeakObjectInOptimizedCode(it.rinfo()->target_object())) {
if (it.rinfo()->target_object()->IsMap()) {
Handle<Map> map(Map::cast(it.rinfo()->target_object()));
maps.Add(map, zone());
} else {
Handle<HeapObject> object(
HeapObject::cast(it.rinfo()->target_object()));
objects.Add(object, zone());
}
}
}
for (int i = 0; i < maps.length(); i++) {
Map::AddDependentCode(maps.at(i), DependentCode::kWeakCodeGroup, code);
}
for (int i = 0; i < objects.length(); i++) {
AddWeakObjectToCodeDependency(isolate(), objects.at(i), code);
}
if (FLAG_enable_ool_constant_pool) {
code->constant_pool()->set_weak_object_state(
ConstantPoolArray::WEAK_OBJECTS_IN_OPTIMIZED_CODE);
}
code->set_can_have_weak_objects(true);
}
void LChunk::CommitDependencies(Handle<Code> code) const {
if (!code->is_optimized_code()) return;
HandleScope scope(isolate());
for (MapSet::const_iterator it = deprecation_dependencies_.begin(),
iend = deprecation_dependencies_.end(); it != iend; ++it) {
Handle<Map> map = *it;
DCHECK(!map->is_deprecated());
DCHECK(map->CanBeDeprecated());
Map::AddDependentCode(map, DependentCode::kTransitionGroup, code);
}
for (MapSet::const_iterator it = stability_dependencies_.begin(),
iend = stability_dependencies_.end(); it != iend; ++it) {
Handle<Map> map = *it;
DCHECK(map->is_stable());
DCHECK(map->CanTransition());
Map::AddDependentCode(map, DependentCode::kPrototypeCheckGroup, code);
}
info_->CommitDependencies(code);
RegisterWeakObjectsInOptimizedCode(code);
}
LChunk* LChunk::NewChunk(HGraph* graph) {
DisallowHandleAllocation no_handles;
DisallowHeapAllocation no_gc;
graph->DisallowAddingNewValues();
int values = graph->GetMaximumValueID();
CompilationInfo* info = graph->info();
if (values > LUnallocated::kMaxVirtualRegisters) {
info->AbortOptimization(kNotEnoughVirtualRegistersForValues);
return NULL;
}
LAllocator allocator(values, graph);
LChunkBuilder builder(info, graph, &allocator);
LChunk* chunk = builder.Build();
if (chunk == NULL) return NULL;
if (!allocator.Allocate(chunk)) {
info->AbortOptimization(kNotEnoughVirtualRegistersRegalloc);
return NULL;
}
chunk->set_allocated_double_registers(
allocator.assigned_double_registers());
return chunk;
}
Handle<Code> LChunk::Codegen() {
MacroAssembler assembler(info()->isolate(), NULL, 0);
LOG_CODE_EVENT(info()->isolate(),
CodeStartLinePosInfoRecordEvent(
assembler.positions_recorder()));
// Code serializer only takes unoptimized code.
DCHECK(!info()->will_serialize());
LCodeGen generator(this, &assembler, info());
MarkEmptyBlocks();
if (generator.GenerateCode()) {
generator.CheckEnvironmentUsage();
CodeGenerator::MakeCodePrologue(info(), "optimized");
Code::Flags flags = info()->flags();
Handle<Code> code =
CodeGenerator::MakeCodeEpilogue(&assembler, flags, info());
generator.FinishCode(code);
CommitDependencies(code);
code->set_is_crankshafted(true);
void* jit_handler_data =
assembler.positions_recorder()->DetachJITHandlerData();
LOG_CODE_EVENT(info()->isolate(),
CodeEndLinePosInfoRecordEvent(*code, jit_handler_data));
CodeGenerator::PrintCode(code, info());
DCHECK(!(info()->isolate()->serializer_enabled() &&
info()->GetMustNotHaveEagerFrame() &&
generator.NeedsEagerFrame()));
return code;
}
assembler.AbortedCodeGeneration();
return Handle<Code>::null();
}
void LChunk::set_allocated_double_registers(BitVector* allocated_registers) {
allocated_double_registers_ = allocated_registers;
BitVector* doubles = allocated_double_registers();
BitVector::Iterator iterator(doubles);
while (!iterator.Done()) {
if (info()->saves_caller_doubles()) {
if (kDoubleSize == kPointerSize * 2) {
spill_slot_count_ += 2;
} else {
spill_slot_count_++;
}
}
iterator.Advance();
}
}
void LChunkBuilderBase::Abort(BailoutReason reason) {
info()->AbortOptimization(reason);
status_ = ABORTED;
}
void LChunkBuilderBase::Retry(BailoutReason reason) {
info()->RetryOptimization(reason);
status_ = ABORTED;
}
LEnvironment* LChunkBuilderBase::CreateEnvironment(
HEnvironment* hydrogen_env, int* argument_index_accumulator,
ZoneList<HValue*>* objects_to_materialize) {
if (hydrogen_env == NULL) return NULL;
LEnvironment* outer =
CreateEnvironment(hydrogen_env->outer(), argument_index_accumulator,
objects_to_materialize);
BailoutId ast_id = hydrogen_env->ast_id();
DCHECK(!ast_id.IsNone() ||
hydrogen_env->frame_type() != JS_FUNCTION);
int omitted_count = (hydrogen_env->frame_type() == JS_FUNCTION)
? 0
: hydrogen_env->specials_count();
int value_count = hydrogen_env->length() - omitted_count;
LEnvironment* result =
new(zone()) LEnvironment(hydrogen_env->closure(),
hydrogen_env->frame_type(),
ast_id,
hydrogen_env->parameter_count(),
argument_count_,
value_count,
outer,
hydrogen_env->entry(),
zone());
int argument_index = *argument_index_accumulator;
// Store the environment description into the environment
// (with holes for nested objects)
for (int i = 0; i < hydrogen_env->length(); ++i) {
if (hydrogen_env->is_special_index(i) &&
hydrogen_env->frame_type() != JS_FUNCTION) {
continue;
}
LOperand* op;
HValue* value = hydrogen_env->values()->at(i);
CHECK(!value->IsPushArguments()); // Do not deopt outgoing arguments
if (value->IsArgumentsObject() || value->IsCapturedObject()) {
op = LEnvironment::materialization_marker();
} else {
op = UseAny(value);
}
result->AddValue(op,
value->representation(),
value->CheckFlag(HInstruction::kUint32));
}
// Recursively store the nested objects into the environment
for (int i = 0; i < hydrogen_env->length(); ++i) {
if (hydrogen_env->is_special_index(i)) continue;
HValue* value = hydrogen_env->values()->at(i);
if (value->IsArgumentsObject() || value->IsCapturedObject()) {
AddObjectToMaterialize(value, objects_to_materialize, result);
}
}
if (hydrogen_env->frame_type() == JS_FUNCTION) {
*argument_index_accumulator = argument_index;
}
return result;
}
// Add an object to the supplied environment and object materialization list.
//
// Notes:
//
// We are building three lists here:
//
// 1. In the result->object_mapping_ list (added to by the
// LEnvironment::Add*Object methods), we store the lengths (number
// of fields) of the captured objects in depth-first traversal order, or
// in case of duplicated objects, we store the index to the duplicate object
// (with a tag to differentiate between captured and duplicated objects).
//
// 2. The object fields are stored in the result->values_ list
// (added to by the LEnvironment.AddValue method) sequentially as lists
// of fields with holes for nested objects (the holes will be expanded
// later by LCodegen::AddToTranslation according to the
// LEnvironment.object_mapping_ list).
//
// 3. The auxiliary objects_to_materialize array stores the hydrogen values
// in the same order as result->object_mapping_ list. This is used
// to detect duplicate values and calculate the corresponding object index.
void LChunkBuilderBase::AddObjectToMaterialize(HValue* value,
ZoneList<HValue*>* objects_to_materialize, LEnvironment* result) {
int object_index = objects_to_materialize->length();
// Store the hydrogen value into the de-duplication array
objects_to_materialize->Add(value, zone());
// Find out whether we are storing a duplicated value
int previously_materialized_object = -1;
for (int prev = 0; prev < object_index; ++prev) {
if (objects_to_materialize->at(prev) == value) {
previously_materialized_object = prev;
break;
}
}
// Store the captured object length (or duplicated object index)
// into the environment. For duplicated objects, we stop here.
int length = value->OperandCount();
bool is_arguments = value->IsArgumentsObject();
if (previously_materialized_object >= 0) {
result->AddDuplicateObject(previously_materialized_object);
return;
} else {
result->AddNewObject(is_arguments ? length - 1 : length, is_arguments);
}
// Store the captured object's fields into the environment
for (int i = is_arguments ? 1 : 0; i < length; ++i) {
LOperand* op;
HValue* arg_value = value->OperandAt(i);
if (arg_value->IsArgumentsObject() || arg_value->IsCapturedObject()) {
// Insert a hole for nested objects
op = LEnvironment::materialization_marker();
} else {
DCHECK(!arg_value->IsPushArguments());
// For ordinary values, tell the register allocator we need the value
// to be alive here
op = UseAny(arg_value);
}
result->AddValue(op,
arg_value->representation(),
arg_value->CheckFlag(HInstruction::kUint32));
}
// Recursively store all the nested captured objects into the environment
for (int i = is_arguments ? 1 : 0; i < length; ++i) {
HValue* arg_value = value->OperandAt(i);
if (arg_value->IsArgumentsObject() || arg_value->IsCapturedObject()) {
AddObjectToMaterialize(arg_value, objects_to_materialize, result);
}
}
}
LPhase::~LPhase() {
if (ShouldProduceTraceOutput()) {
isolate()->GetHTracer()->TraceLithium(name(), chunk_);
}
}
} } // namespace v8::internal