mirrored from https://chromium.googlesource.com/v8/v8.git
/
code-stubs-hydrogen.cc
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code-stubs-hydrogen.cc
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// 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/v8.h"
#include "src/bailout-reason.h"
#include "src/code-stubs.h"
#include "src/field-index.h"
#include "src/hydrogen.h"
#include "src/ic/ic.h"
#include "src/lithium.h"
namespace v8 {
namespace internal {
static LChunk* OptimizeGraph(HGraph* graph) {
DisallowHeapAllocation no_allocation;
DisallowHandleAllocation no_handles;
DisallowHandleDereference no_deref;
DCHECK(graph != NULL);
BailoutReason bailout_reason = kNoReason;
if (!graph->Optimize(&bailout_reason)) {
FATAL(GetBailoutReason(bailout_reason));
}
LChunk* chunk = LChunk::NewChunk(graph);
if (chunk == NULL) {
FATAL(GetBailoutReason(graph->info()->bailout_reason()));
}
return chunk;
}
class CodeStubGraphBuilderBase : public HGraphBuilder {
public:
explicit CodeStubGraphBuilderBase(CompilationInfoWithZone* info)
: HGraphBuilder(info),
arguments_length_(NULL),
info_(info),
descriptor_(info->code_stub()),
context_(NULL) {
int parameter_count = descriptor_.GetEnvironmentParameterCount();
parameters_.Reset(new HParameter*[parameter_count]);
}
virtual bool BuildGraph();
protected:
virtual HValue* BuildCodeStub() = 0;
HParameter* GetParameter(int parameter) {
DCHECK(parameter < descriptor_.GetEnvironmentParameterCount());
return parameters_[parameter];
}
HValue* GetArgumentsLength() {
// This is initialized in BuildGraph()
DCHECK(arguments_length_ != NULL);
return arguments_length_;
}
CompilationInfo* info() { return info_; }
HydrogenCodeStub* stub() { return info_->code_stub(); }
HContext* context() { return context_; }
Isolate* isolate() { return info_->isolate(); }
HLoadNamedField* BuildLoadNamedField(HValue* object,
FieldIndex index);
void BuildStoreNamedField(HValue* object, HValue* value, FieldIndex index,
Representation representation,
bool transition_to_field);
enum ArgumentClass {
NONE,
SINGLE,
MULTIPLE
};
HValue* UnmappedCase(HValue* elements, HValue* key);
HValue* BuildArrayConstructor(ElementsKind kind,
AllocationSiteOverrideMode override_mode,
ArgumentClass argument_class);
HValue* BuildInternalArrayConstructor(ElementsKind kind,
ArgumentClass argument_class);
// BuildCheckAndInstallOptimizedCode emits code to install the optimized
// function found in the optimized code map at map_index in js_function, if
// the function at map_index matches the given native_context. Builder is
// left in the "Then()" state after the install.
void BuildCheckAndInstallOptimizedCode(HValue* js_function,
HValue* native_context,
IfBuilder* builder,
HValue* optimized_map,
HValue* map_index);
void BuildInstallCode(HValue* js_function, HValue* shared_info);
HInstruction* LoadFromOptimizedCodeMap(HValue* optimized_map,
HValue* iterator,
int field_offset);
void BuildInstallFromOptimizedCodeMap(HValue* js_function,
HValue* shared_info,
HValue* native_context);
// Tail calls handler found at array[map_index + 1].
void TailCallHandler(HValue* receiver, HValue* name, HValue* array,
HValue* map_index, HValue* slot, HValue* vector);
// Tail calls handler_code.
void TailCallHandler(HValue* receiver, HValue* name, HValue* slot,
HValue* vector, HValue* handler_code);
void TailCallMiss(HValue* receiver, HValue* name, HValue* slot,
HValue* vector, bool keyed_load);
// Handle MONOMORPHIC and POLYMORPHIC LoadIC and KeyedLoadIC cases.
void HandleArrayCases(HValue* array, HValue* receiver, HValue* name,
HValue* slot, HValue* vector, bool keyed_load);
private:
HValue* BuildArraySingleArgumentConstructor(JSArrayBuilder* builder);
HValue* BuildArrayNArgumentsConstructor(JSArrayBuilder* builder,
ElementsKind kind);
SmartArrayPointer<HParameter*> parameters_;
HValue* arguments_length_;
CompilationInfoWithZone* info_;
CodeStubDescriptor descriptor_;
HContext* context_;
};
bool CodeStubGraphBuilderBase::BuildGraph() {
// Update the static counter each time a new code stub is generated.
isolate()->counters()->code_stubs()->Increment();
if (FLAG_trace_hydrogen_stubs) {
const char* name = CodeStub::MajorName(stub()->MajorKey(), false);
PrintF("-----------------------------------------------------------\n");
PrintF("Compiling stub %s using hydrogen\n", name);
isolate()->GetHTracer()->TraceCompilation(info());
}
int param_count = descriptor_.GetEnvironmentParameterCount();
HEnvironment* start_environment = graph()->start_environment();
HBasicBlock* next_block = CreateBasicBlock(start_environment);
Goto(next_block);
next_block->SetJoinId(BailoutId::StubEntry());
set_current_block(next_block);
bool runtime_stack_params = descriptor_.stack_parameter_count().is_valid();
HInstruction* stack_parameter_count = NULL;
for (int i = 0; i < param_count; ++i) {
Representation r = descriptor_.GetEnvironmentParameterRepresentation(i);
HParameter* param = Add<HParameter>(i,
HParameter::REGISTER_PARAMETER, r);
start_environment->Bind(i, param);
parameters_[i] = param;
if (descriptor_.IsEnvironmentParameterCountRegister(i)) {
param->set_type(HType::Smi());
stack_parameter_count = param;
arguments_length_ = stack_parameter_count;
}
}
DCHECK(!runtime_stack_params || arguments_length_ != NULL);
if (!runtime_stack_params) {
stack_parameter_count = graph()->GetConstantMinus1();
arguments_length_ = graph()->GetConstant0();
}
context_ = Add<HContext>();
start_environment->BindContext(context_);
Add<HSimulate>(BailoutId::StubEntry());
NoObservableSideEffectsScope no_effects(this);
HValue* return_value = BuildCodeStub();
// We might have extra expressions to pop from the stack in addition to the
// arguments above.
HInstruction* stack_pop_count = stack_parameter_count;
if (descriptor_.function_mode() == JS_FUNCTION_STUB_MODE) {
if (!stack_parameter_count->IsConstant() &&
descriptor_.hint_stack_parameter_count() < 0) {
HInstruction* constant_one = graph()->GetConstant1();
stack_pop_count = AddUncasted<HAdd>(stack_parameter_count, constant_one);
stack_pop_count->ClearFlag(HValue::kCanOverflow);
// TODO(mvstanton): verify that stack_parameter_count+1 really fits in a
// smi.
} else {
int count = descriptor_.hint_stack_parameter_count();
stack_pop_count = Add<HConstant>(count);
}
}
if (current_block() != NULL) {
HReturn* hreturn_instruction = New<HReturn>(return_value,
stack_pop_count);
FinishCurrentBlock(hreturn_instruction);
}
return true;
}
template <class Stub>
class CodeStubGraphBuilder: public CodeStubGraphBuilderBase {
public:
explicit CodeStubGraphBuilder(CompilationInfoWithZone* info)
: CodeStubGraphBuilderBase(info) {}
protected:
virtual HValue* BuildCodeStub() {
if (casted_stub()->IsUninitialized()) {
return BuildCodeUninitializedStub();
} else {
return BuildCodeInitializedStub();
}
}
virtual HValue* BuildCodeInitializedStub() {
UNIMPLEMENTED();
return NULL;
}
virtual HValue* BuildCodeUninitializedStub() {
// Force a deopt that falls back to the runtime.
HValue* undefined = graph()->GetConstantUndefined();
IfBuilder builder(this);
builder.IfNot<HCompareObjectEqAndBranch, HValue*>(undefined, undefined);
builder.Then();
builder.ElseDeopt("Forced deopt to runtime");
return undefined;
}
Stub* casted_stub() { return static_cast<Stub*>(stub()); }
};
Handle<Code> HydrogenCodeStub::GenerateLightweightMissCode(
ExternalReference miss) {
Factory* factory = isolate()->factory();
// Generate the new code.
MacroAssembler masm(isolate(), NULL, 256);
{
// Update the static counter each time a new code stub is generated.
isolate()->counters()->code_stubs()->Increment();
// Generate the code for the stub.
masm.set_generating_stub(true);
// TODO(yangguo): remove this once we can serialize IC stubs.
masm.enable_serializer();
NoCurrentFrameScope scope(&masm);
GenerateLightweightMiss(&masm, miss);
}
// Create the code object.
CodeDesc desc;
masm.GetCode(&desc);
// Copy the generated code into a heap object.
Code::Flags flags = Code::ComputeFlags(
GetCodeKind(),
GetICState(),
GetExtraICState(),
GetStubType());
Handle<Code> new_object = factory->NewCode(
desc, flags, masm.CodeObject(), NeedsImmovableCode());
return new_object;
}
template <class Stub>
static Handle<Code> DoGenerateCode(Stub* stub) {
Isolate* isolate = stub->isolate();
CodeStubDescriptor descriptor(stub);
// If we are uninitialized we can use a light-weight stub to enter
// the runtime that is significantly faster than using the standard
// stub-failure deopt mechanism.
if (stub->IsUninitialized() && descriptor.has_miss_handler()) {
DCHECK(!descriptor.stack_parameter_count().is_valid());
return stub->GenerateLightweightMissCode(descriptor.miss_handler());
}
base::ElapsedTimer timer;
if (FLAG_profile_hydrogen_code_stub_compilation) {
timer.Start();
}
CompilationInfoWithZone info(stub, isolate);
CodeStubGraphBuilder<Stub> builder(&info);
LChunk* chunk = OptimizeGraph(builder.CreateGraph());
Handle<Code> code = chunk->Codegen();
if (FLAG_profile_hydrogen_code_stub_compilation) {
OFStream os(stdout);
os << "[Lazy compilation of " << stub << " took "
<< timer.Elapsed().InMillisecondsF() << " ms]" << std::endl;
}
return code;
}
template <>
HValue* CodeStubGraphBuilder<NumberToStringStub>::BuildCodeStub() {
info()->MarkAsSavesCallerDoubles();
HValue* number = GetParameter(NumberToStringStub::kNumber);
return BuildNumberToString(number, Type::Number(zone()));
}
Handle<Code> NumberToStringStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<FastCloneShallowArrayStub>::BuildCodeStub() {
Factory* factory = isolate()->factory();
HValue* undefined = graph()->GetConstantUndefined();
AllocationSiteMode alloc_site_mode = casted_stub()->allocation_site_mode();
// This stub is very performance sensitive, the generated code must be tuned
// so that it doesn't build and eager frame.
info()->MarkMustNotHaveEagerFrame();
HInstruction* allocation_site =
Add<HLoadKeyed>(GetParameter(0), GetParameter(1), nullptr, FAST_ELEMENTS);
IfBuilder checker(this);
checker.IfNot<HCompareObjectEqAndBranch, HValue*>(allocation_site,
undefined);
checker.Then();
HObjectAccess access = HObjectAccess::ForAllocationSiteOffset(
AllocationSite::kTransitionInfoOffset);
HInstruction* boilerplate =
Add<HLoadNamedField>(allocation_site, nullptr, access);
HValue* elements = AddLoadElements(boilerplate);
HValue* capacity = AddLoadFixedArrayLength(elements);
IfBuilder zero_capacity(this);
zero_capacity.If<HCompareNumericAndBranch>(capacity, graph()->GetConstant0(),
Token::EQ);
zero_capacity.Then();
Push(BuildCloneShallowArrayEmpty(boilerplate,
allocation_site,
alloc_site_mode));
zero_capacity.Else();
IfBuilder if_fixed_cow(this);
if_fixed_cow.If<HCompareMap>(elements, factory->fixed_cow_array_map());
if_fixed_cow.Then();
Push(BuildCloneShallowArrayCow(boilerplate,
allocation_site,
alloc_site_mode,
FAST_ELEMENTS));
if_fixed_cow.Else();
IfBuilder if_fixed(this);
if_fixed.If<HCompareMap>(elements, factory->fixed_array_map());
if_fixed.Then();
Push(BuildCloneShallowArrayNonEmpty(boilerplate,
allocation_site,
alloc_site_mode,
FAST_ELEMENTS));
if_fixed.Else();
Push(BuildCloneShallowArrayNonEmpty(boilerplate,
allocation_site,
alloc_site_mode,
FAST_DOUBLE_ELEMENTS));
if_fixed.End();
if_fixed_cow.End();
zero_capacity.End();
checker.ElseDeopt("Uninitialized boilerplate literals");
checker.End();
return environment()->Pop();
}
Handle<Code> FastCloneShallowArrayStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<FastCloneShallowObjectStub>::BuildCodeStub() {
HValue* undefined = graph()->GetConstantUndefined();
HInstruction* allocation_site =
Add<HLoadKeyed>(GetParameter(0), GetParameter(1), nullptr, FAST_ELEMENTS);
IfBuilder checker(this);
checker.IfNot<HCompareObjectEqAndBranch, HValue*>(allocation_site,
undefined);
checker.And();
HObjectAccess access = HObjectAccess::ForAllocationSiteOffset(
AllocationSite::kTransitionInfoOffset);
HInstruction* boilerplate =
Add<HLoadNamedField>(allocation_site, nullptr, access);
int length = casted_stub()->length();
if (length == 0) {
// Empty objects have some slack added to them.
length = JSObject::kInitialGlobalObjectUnusedPropertiesCount;
}
int size = JSObject::kHeaderSize + length * kPointerSize;
int object_size = size;
if (FLAG_allocation_site_pretenuring) {
size += AllocationMemento::kSize;
}
HValue* boilerplate_map =
Add<HLoadNamedField>(boilerplate, nullptr, HObjectAccess::ForMap());
HValue* boilerplate_size = Add<HLoadNamedField>(
boilerplate_map, nullptr, HObjectAccess::ForMapInstanceSize());
HValue* size_in_words = Add<HConstant>(object_size >> kPointerSizeLog2);
checker.If<HCompareNumericAndBranch>(boilerplate_size,
size_in_words, Token::EQ);
checker.Then();
HValue* size_in_bytes = Add<HConstant>(size);
HInstruction* object = Add<HAllocate>(size_in_bytes, HType::JSObject(),
NOT_TENURED, JS_OBJECT_TYPE);
for (int i = 0; i < object_size; i += kPointerSize) {
HObjectAccess access = HObjectAccess::ForObservableJSObjectOffset(i);
Add<HStoreNamedField>(object, access,
Add<HLoadNamedField>(boilerplate, nullptr, access));
}
DCHECK(FLAG_allocation_site_pretenuring || (size == object_size));
if (FLAG_allocation_site_pretenuring) {
BuildCreateAllocationMemento(
object, Add<HConstant>(object_size), allocation_site);
}
environment()->Push(object);
checker.ElseDeopt("Uninitialized boilerplate in fast clone");
checker.End();
return environment()->Pop();
}
Handle<Code> FastCloneShallowObjectStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<CreateAllocationSiteStub>::BuildCodeStub() {
HValue* size = Add<HConstant>(AllocationSite::kSize);
HInstruction* object = Add<HAllocate>(size, HType::JSObject(), TENURED,
JS_OBJECT_TYPE);
// Store the map
Handle<Map> allocation_site_map = isolate()->factory()->allocation_site_map();
AddStoreMapConstant(object, allocation_site_map);
// Store the payload (smi elements kind)
HValue* initial_elements_kind = Add<HConstant>(GetInitialFastElementsKind());
Add<HStoreNamedField>(object,
HObjectAccess::ForAllocationSiteOffset(
AllocationSite::kTransitionInfoOffset),
initial_elements_kind);
// Unlike literals, constructed arrays don't have nested sites
Add<HStoreNamedField>(object,
HObjectAccess::ForAllocationSiteOffset(
AllocationSite::kNestedSiteOffset),
graph()->GetConstant0());
// Pretenuring calculation field.
Add<HStoreNamedField>(object,
HObjectAccess::ForAllocationSiteOffset(
AllocationSite::kPretenureDataOffset),
graph()->GetConstant0());
// Pretenuring memento creation count field.
Add<HStoreNamedField>(object,
HObjectAccess::ForAllocationSiteOffset(
AllocationSite::kPretenureCreateCountOffset),
graph()->GetConstant0());
// Store an empty fixed array for the code dependency.
HConstant* empty_fixed_array =
Add<HConstant>(isolate()->factory()->empty_fixed_array());
Add<HStoreNamedField>(
object,
HObjectAccess::ForAllocationSiteOffset(
AllocationSite::kDependentCodeOffset),
empty_fixed_array);
// Link the object to the allocation site list
HValue* site_list = Add<HConstant>(
ExternalReference::allocation_sites_list_address(isolate()));
HValue* site = Add<HLoadNamedField>(site_list, nullptr,
HObjectAccess::ForAllocationSiteList());
// TODO(mvstanton): This is a store to a weak pointer, which we may want to
// mark as such in order to skip the write barrier, once we have a unified
// system for weakness. For now we decided to keep it like this because having
// an initial write barrier backed store makes this pointer strong until the
// next GC, and allocation sites are designed to survive several GCs anyway.
Add<HStoreNamedField>(
object,
HObjectAccess::ForAllocationSiteOffset(AllocationSite::kWeakNextOffset),
site);
Add<HStoreNamedField>(site_list, HObjectAccess::ForAllocationSiteList(),
object);
HInstruction* feedback_vector = GetParameter(0);
HInstruction* slot = GetParameter(1);
Add<HStoreKeyed>(feedback_vector, slot, object, FAST_ELEMENTS,
INITIALIZING_STORE);
return feedback_vector;
}
Handle<Code> CreateAllocationSiteStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<LoadScriptContextFieldStub>::BuildCodeStub() {
int context_index = casted_stub()->context_index();
int slot_index = casted_stub()->slot_index();
HValue* script_context = BuildGetScriptContext(context_index);
return Add<HLoadNamedField>(script_context, nullptr,
HObjectAccess::ForContextSlot(slot_index));
}
Handle<Code> LoadScriptContextFieldStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<StoreScriptContextFieldStub>::BuildCodeStub() {
int context_index = casted_stub()->context_index();
int slot_index = casted_stub()->slot_index();
HValue* script_context = BuildGetScriptContext(context_index);
Add<HStoreNamedField>(script_context,
HObjectAccess::ForContextSlot(slot_index),
GetParameter(2), STORE_TO_INITIALIZED_ENTRY);
return GetParameter(2);
}
Handle<Code> StoreScriptContextFieldStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<LoadFastElementStub>::BuildCodeStub() {
HInstruction* load = BuildUncheckedMonomorphicElementAccess(
GetParameter(LoadDescriptor::kReceiverIndex),
GetParameter(LoadDescriptor::kNameIndex), NULL,
casted_stub()->is_js_array(), casted_stub()->elements_kind(), LOAD,
NEVER_RETURN_HOLE, STANDARD_STORE);
return load;
}
Handle<Code> LoadFastElementStub::GenerateCode() {
return DoGenerateCode(this);
}
HLoadNamedField* CodeStubGraphBuilderBase::BuildLoadNamedField(
HValue* object, FieldIndex index) {
Representation representation = index.is_double()
? Representation::Double()
: Representation::Tagged();
int offset = index.offset();
HObjectAccess access = index.is_inobject()
? HObjectAccess::ForObservableJSObjectOffset(offset, representation)
: HObjectAccess::ForBackingStoreOffset(offset, representation);
if (index.is_double() &&
(!FLAG_unbox_double_fields || !index.is_inobject())) {
// Load the heap number.
object = Add<HLoadNamedField>(
object, nullptr, access.WithRepresentation(Representation::Tagged()));
// Load the double value from it.
access = HObjectAccess::ForHeapNumberValue();
}
return Add<HLoadNamedField>(object, nullptr, access);
}
template<>
HValue* CodeStubGraphBuilder<LoadFieldStub>::BuildCodeStub() {
return BuildLoadNamedField(GetParameter(0), casted_stub()->index());
}
Handle<Code> LoadFieldStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<LoadConstantStub>::BuildCodeStub() {
HValue* map = AddLoadMap(GetParameter(0), NULL);
HObjectAccess descriptors_access = HObjectAccess::ForObservableJSObjectOffset(
Map::kDescriptorsOffset, Representation::Tagged());
HValue* descriptors = Add<HLoadNamedField>(map, nullptr, descriptors_access);
HObjectAccess value_access = HObjectAccess::ForObservableJSObjectOffset(
DescriptorArray::GetValueOffset(casted_stub()->constant_index()));
return Add<HLoadNamedField>(descriptors, nullptr, value_access);
}
Handle<Code> LoadConstantStub::GenerateCode() { return DoGenerateCode(this); }
HValue* CodeStubGraphBuilderBase::UnmappedCase(HValue* elements, HValue* key) {
HValue* result;
HInstruction* backing_store =
Add<HLoadKeyed>(elements, graph()->GetConstant1(), nullptr, FAST_ELEMENTS,
ALLOW_RETURN_HOLE);
Add<HCheckMaps>(backing_store, isolate()->factory()->fixed_array_map());
HValue* backing_store_length = Add<HLoadNamedField>(
backing_store, nullptr, HObjectAccess::ForFixedArrayLength());
IfBuilder in_unmapped_range(this);
in_unmapped_range.If<HCompareNumericAndBranch>(key, backing_store_length,
Token::LT);
in_unmapped_range.Then();
{
result = Add<HLoadKeyed>(backing_store, key, nullptr, FAST_HOLEY_ELEMENTS,
NEVER_RETURN_HOLE);
}
in_unmapped_range.ElseDeopt("Outside of range");
in_unmapped_range.End();
return result;
}
template <>
HValue* CodeStubGraphBuilder<KeyedLoadSloppyArgumentsStub>::BuildCodeStub() {
HValue* receiver = GetParameter(LoadDescriptor::kReceiverIndex);
HValue* key = GetParameter(LoadDescriptor::kNameIndex);
// Mapped arguments are actual arguments. Unmapped arguments are values added
// to the arguments object after it was created for the call. Mapped arguments
// are stored in the context at indexes given by elements[key + 2]. Unmapped
// arguments are stored as regular indexed properties in the arguments array,
// held at elements[1]. See NewSloppyArguments() in runtime.cc for a detailed
// look at argument object construction.
//
// The sloppy arguments elements array has a special format:
//
// 0: context
// 1: unmapped arguments array
// 2: mapped_index0,
// 3: mapped_index1,
// ...
//
// length is 2 + min(number_of_actual_arguments, number_of_formal_arguments).
// If key + 2 >= elements.length then attempt to look in the unmapped
// arguments array (given by elements[1]) and return the value at key, missing
// to the runtime if the unmapped arguments array is not a fixed array or if
// key >= unmapped_arguments_array.length.
//
// Otherwise, t = elements[key + 2]. If t is the hole, then look up the value
// in the unmapped arguments array, as described above. Otherwise, t is a Smi
// index into the context array given at elements[0]. Return the value at
// context[t].
key = AddUncasted<HForceRepresentation>(key, Representation::Smi());
IfBuilder positive_smi(this);
positive_smi.If<HCompareNumericAndBranch>(key, graph()->GetConstant0(),
Token::LT);
positive_smi.ThenDeopt("key is negative");
positive_smi.End();
HValue* constant_two = Add<HConstant>(2);
HValue* elements = AddLoadElements(receiver, nullptr);
HValue* elements_length = Add<HLoadNamedField>(
elements, nullptr, HObjectAccess::ForFixedArrayLength());
HValue* adjusted_length = AddUncasted<HSub>(elements_length, constant_two);
IfBuilder in_range(this);
in_range.If<HCompareNumericAndBranch>(key, adjusted_length, Token::LT);
in_range.Then();
{
HValue* index = AddUncasted<HAdd>(key, constant_two);
HInstruction* mapped_index = Add<HLoadKeyed>(
elements, index, nullptr, FAST_HOLEY_ELEMENTS, ALLOW_RETURN_HOLE);
IfBuilder is_valid(this);
is_valid.IfNot<HCompareObjectEqAndBranch>(mapped_index,
graph()->GetConstantHole());
is_valid.Then();
{
// TODO(mvstanton): I'd like to assert from this point, that if the
// mapped_index is not the hole that it is indeed, a smi. An unnecessary
// smi check is being emitted.
HValue* the_context = Add<HLoadKeyed>(elements, graph()->GetConstant0(),
nullptr, FAST_ELEMENTS);
STATIC_ASSERT(Context::kHeaderSize == FixedArray::kHeaderSize);
HValue* result = Add<HLoadKeyed>(the_context, mapped_index, nullptr,
FAST_ELEMENTS, ALLOW_RETURN_HOLE);
environment()->Push(result);
}
is_valid.Else();
{
HValue* result = UnmappedCase(elements, key);
environment()->Push(result);
}
is_valid.End();
}
in_range.Else();
{
HValue* result = UnmappedCase(elements, key);
environment()->Push(result);
}
in_range.End();
return environment()->Pop();
}
Handle<Code> KeyedLoadSloppyArgumentsStub::GenerateCode() {
return DoGenerateCode(this);
}
void CodeStubGraphBuilderBase::BuildStoreNamedField(
HValue* object, HValue* value, FieldIndex index,
Representation representation, bool transition_to_field) {
DCHECK(!index.is_double() || representation.IsDouble());
int offset = index.offset();
HObjectAccess access =
index.is_inobject()
? HObjectAccess::ForObservableJSObjectOffset(offset, representation)
: HObjectAccess::ForBackingStoreOffset(offset, representation);
if (representation.IsDouble()) {
if (!FLAG_unbox_double_fields || !index.is_inobject()) {
HObjectAccess heap_number_access =
access.WithRepresentation(Representation::Tagged());
if (transition_to_field) {
// The store requires a mutable HeapNumber to be allocated.
NoObservableSideEffectsScope no_side_effects(this);
HInstruction* heap_number_size = Add<HConstant>(HeapNumber::kSize);
// TODO(hpayer): Allocation site pretenuring support.
HInstruction* heap_number =
Add<HAllocate>(heap_number_size, HType::HeapObject(), NOT_TENURED,
MUTABLE_HEAP_NUMBER_TYPE);
AddStoreMapConstant(heap_number,
isolate()->factory()->mutable_heap_number_map());
Add<HStoreNamedField>(heap_number, HObjectAccess::ForHeapNumberValue(),
value);
// Store the new mutable heap number into the object.
access = heap_number_access;
value = heap_number;
} else {
// Load the heap number.
object = Add<HLoadNamedField>(object, nullptr, heap_number_access);
// Store the double value into it.
access = HObjectAccess::ForHeapNumberValue();
}
}
} else if (representation.IsHeapObject()) {
BuildCheckHeapObject(value);
}
Add<HStoreNamedField>(object, access, value, INITIALIZING_STORE);
}
template <>
HValue* CodeStubGraphBuilder<StoreFieldStub>::BuildCodeStub() {
BuildStoreNamedField(GetParameter(0), GetParameter(2), casted_stub()->index(),
casted_stub()->representation(), false);
return GetParameter(2);
}
Handle<Code> StoreFieldStub::GenerateCode() { return DoGenerateCode(this); }
template <>
HValue* CodeStubGraphBuilder<StoreTransitionStub>::BuildCodeStub() {
HValue* object = GetParameter(StoreTransitionDescriptor::kReceiverIndex);
switch (casted_stub()->store_mode()) {
case StoreTransitionStub::ExtendStorageAndStoreMapAndValue: {
HValue* properties = Add<HLoadNamedField>(
object, nullptr, HObjectAccess::ForPropertiesPointer());
HValue* length = AddLoadFixedArrayLength(properties);
HValue* delta =
Add<HConstant>(static_cast<int32_t>(JSObject::kFieldsAdded));
HValue* new_capacity = AddUncasted<HAdd>(length, delta);
// Grow properties array.
ElementsKind kind = FAST_ELEMENTS;
Add<HBoundsCheck>(new_capacity,
Add<HConstant>((Page::kMaxRegularHeapObjectSize -
FixedArray::kHeaderSize) >>
ElementsKindToShiftSize(kind)));
// Reuse this code for properties backing store allocation.
HValue* new_properties =
BuildAllocateAndInitializeArray(kind, new_capacity);
BuildCopyProperties(properties, new_properties, length, new_capacity);
Add<HStoreNamedField>(object, HObjectAccess::ForPropertiesPointer(),
new_properties);
}
// Fall through.
case StoreTransitionStub::StoreMapAndValue:
// Store the new value into the "extended" object.
BuildStoreNamedField(
object, GetParameter(StoreTransitionDescriptor::kValueIndex),
casted_stub()->index(), casted_stub()->representation(), true);
// Fall through.
case StoreTransitionStub::StoreMapOnly:
// And finally update the map.
Add<HStoreNamedField>(object, HObjectAccess::ForMap(),
GetParameter(StoreTransitionDescriptor::kMapIndex));
break;
}
return GetParameter(StoreTransitionDescriptor::kValueIndex);
}
Handle<Code> StoreTransitionStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<StringLengthStub>::BuildCodeStub() {
HValue* string = BuildLoadNamedField(GetParameter(0),
FieldIndex::ForInObjectOffset(JSValue::kValueOffset));
return BuildLoadNamedField(string,
FieldIndex::ForInObjectOffset(String::kLengthOffset));
}
Handle<Code> StringLengthStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<StoreFastElementStub>::BuildCodeStub() {
BuildUncheckedMonomorphicElementAccess(
GetParameter(StoreDescriptor::kReceiverIndex),
GetParameter(StoreDescriptor::kNameIndex),
GetParameter(StoreDescriptor::kValueIndex), casted_stub()->is_js_array(),
casted_stub()->elements_kind(), STORE, NEVER_RETURN_HOLE,
casted_stub()->store_mode());
return GetParameter(2);
}
Handle<Code> StoreFastElementStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<TransitionElementsKindStub>::BuildCodeStub() {
info()->MarkAsSavesCallerDoubles();
BuildTransitionElementsKind(GetParameter(0),
GetParameter(1),
casted_stub()->from_kind(),
casted_stub()->to_kind(),
casted_stub()->is_js_array());
return GetParameter(0);
}
Handle<Code> TransitionElementsKindStub::GenerateCode() {
return DoGenerateCode(this);
}
template <>
HValue* CodeStubGraphBuilder<AllocateHeapNumberStub>::BuildCodeStub() {
HValue* result =
Add<HAllocate>(Add<HConstant>(HeapNumber::kSize), HType::HeapNumber(),
NOT_TENURED, HEAP_NUMBER_TYPE);
AddStoreMapConstant(result, isolate()->factory()->heap_number_map());
return result;
}
Handle<Code> AllocateHeapNumberStub::GenerateCode() {
return DoGenerateCode(this);
}
HValue* CodeStubGraphBuilderBase::BuildArrayConstructor(
ElementsKind kind,
AllocationSiteOverrideMode override_mode,
ArgumentClass argument_class) {
HValue* constructor = GetParameter(ArrayConstructorStubBase::kConstructor);
HValue* alloc_site = GetParameter(ArrayConstructorStubBase::kAllocationSite);
JSArrayBuilder array_builder(this, kind, alloc_site, constructor,
override_mode);
HValue* result = NULL;
switch (argument_class) {
case NONE:
// This stub is very performance sensitive, the generated code must be
// tuned so that it doesn't build and eager frame.
info()->MarkMustNotHaveEagerFrame();
result = array_builder.AllocateEmptyArray();
break;
case SINGLE:
result = BuildArraySingleArgumentConstructor(&array_builder);
break;
case MULTIPLE:
result = BuildArrayNArgumentsConstructor(&array_builder, kind);
break;
}
return result;
}
HValue* CodeStubGraphBuilderBase::BuildInternalArrayConstructor(
ElementsKind kind, ArgumentClass argument_class) {
HValue* constructor = GetParameter(
InternalArrayConstructorStubBase::kConstructor);
JSArrayBuilder array_builder(this, kind, constructor);
HValue* result = NULL;
switch (argument_class) {
case NONE:
// This stub is very performance sensitive, the generated code must be
// tuned so that it doesn't build and eager frame.
info()->MarkMustNotHaveEagerFrame();
result = array_builder.AllocateEmptyArray();
break;
case SINGLE:
result = BuildArraySingleArgumentConstructor(&array_builder);
break;
case MULTIPLE:
result = BuildArrayNArgumentsConstructor(&array_builder, kind);
break;
}
return result;
}
HValue* CodeStubGraphBuilderBase::BuildArraySingleArgumentConstructor(
JSArrayBuilder* array_builder) {
// Smi check and range check on the input arg.
HValue* constant_one = graph()->GetConstant1();
HValue* constant_zero = graph()->GetConstant0();
HInstruction* elements = Add<HArgumentsElements>(false);
HInstruction* argument = Add<HAccessArgumentsAt>(
elements, constant_one, constant_zero);
return BuildAllocateArrayFromLength(array_builder, argument);
}
HValue* CodeStubGraphBuilderBase::BuildArrayNArgumentsConstructor(
JSArrayBuilder* array_builder, ElementsKind kind) {
// Insert a bounds check because the number of arguments might exceed
// the kInitialMaxFastElementArray limit. This cannot happen for code
// that was parsed, but calling via Array.apply(thisArg, [...]) might
// trigger it.
HValue* length = GetArgumentsLength();
HConstant* max_alloc_length =
Add<HConstant>(JSObject::kInitialMaxFastElementArray);
HValue* checked_length = Add<HBoundsCheck>(length, max_alloc_length);
// We need to fill with the hole if it's a smi array in the multi-argument
// case because we might have to bail out while copying arguments into
// the array because they aren't compatible with a smi array.
// If it's a double array, no problem, and if it's fast then no
// problem either because doubles are boxed.
//
// TODO(mvstanton): consider an instruction to memset fill the array
// with zero in this case instead.
JSArrayBuilder::FillMode fill_mode = IsFastSmiElementsKind(kind)
? JSArrayBuilder::FILL_WITH_HOLE
: JSArrayBuilder::DONT_FILL_WITH_HOLE;
HValue* new_object = array_builder->AllocateArray(checked_length,
max_alloc_length,
checked_length,
fill_mode);
HValue* elements = array_builder->GetElementsLocation();