HELLO·Android
系统源代码
IT资讯
技术文章
我的收藏
注册
登录
-
我收藏的文章
创建代码块
我的代码块
我的账号
Nougat 7.0
|
7.0.0_r31
下载
查看原文件
收藏
根目录
external
v8
src
crankshaft
hydrogen.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/crankshaft/hydrogen.h" #include
#include "src/allocation-site-scopes.h" #include "src/ast/ast-numbering.h" #include "src/ast/scopeinfo.h" #include "src/code-factory.h" #include "src/crankshaft/hydrogen-bce.h" #include "src/crankshaft/hydrogen-bch.h" #include "src/crankshaft/hydrogen-canonicalize.h" #include "src/crankshaft/hydrogen-check-elimination.h" #include "src/crankshaft/hydrogen-dce.h" #include "src/crankshaft/hydrogen-dehoist.h" #include "src/crankshaft/hydrogen-environment-liveness.h" #include "src/crankshaft/hydrogen-escape-analysis.h" #include "src/crankshaft/hydrogen-gvn.h" #include "src/crankshaft/hydrogen-infer-representation.h" #include "src/crankshaft/hydrogen-infer-types.h" #include "src/crankshaft/hydrogen-load-elimination.h" #include "src/crankshaft/hydrogen-mark-deoptimize.h" #include "src/crankshaft/hydrogen-mark-unreachable.h" #include "src/crankshaft/hydrogen-osr.h" #include "src/crankshaft/hydrogen-range-analysis.h" #include "src/crankshaft/hydrogen-redundant-phi.h" #include "src/crankshaft/hydrogen-removable-simulates.h" #include "src/crankshaft/hydrogen-representation-changes.h" #include "src/crankshaft/hydrogen-sce.h" #include "src/crankshaft/hydrogen-store-elimination.h" #include "src/crankshaft/hydrogen-uint32-analysis.h" #include "src/crankshaft/lithium-allocator.h" #include "src/crankshaft/typing.h" #include "src/full-codegen/full-codegen.h" #include "src/ic/call-optimization.h" #include "src/ic/ic.h" // GetRootConstructor #include "src/ic/ic-inl.h" #include "src/isolate-inl.h" #include "src/parsing/parser.h" #include "src/runtime/runtime.h" #if V8_TARGET_ARCH_IA32 #include "src/crankshaft/ia32/lithium-codegen-ia32.h" // NOLINT #elif V8_TARGET_ARCH_X64 #include "src/crankshaft/x64/lithium-codegen-x64.h" // NOLINT #elif V8_TARGET_ARCH_ARM64 #include "src/crankshaft/arm64/lithium-codegen-arm64.h" // NOLINT #elif V8_TARGET_ARCH_ARM #include "src/crankshaft/arm/lithium-codegen-arm.h" // NOLINT #elif V8_TARGET_ARCH_PPC #include "src/crankshaft/ppc/lithium-codegen-ppc.h" // NOLINT #elif V8_TARGET_ARCH_MIPS #include "src/crankshaft/mips/lithium-codegen-mips.h" // NOLINT #elif V8_TARGET_ARCH_MIPS64 #include "src/crankshaft/mips64/lithium-codegen-mips64.h" // NOLINT #elif V8_TARGET_ARCH_X87 #include "src/crankshaft/x87/lithium-codegen-x87.h" // NOLINT #else #error Unsupported target architecture. #endif namespace v8 { namespace internal { HBasicBlock::HBasicBlock(HGraph* graph) : block_id_(graph->GetNextBlockID()), graph_(graph), phis_(4, graph->zone()), first_(NULL), last_(NULL), end_(NULL), loop_information_(NULL), predecessors_(2, graph->zone()), dominator_(NULL), dominated_blocks_(4, graph->zone()), last_environment_(NULL), argument_count_(-1), first_instruction_index_(-1), last_instruction_index_(-1), deleted_phis_(4, graph->zone()), parent_loop_header_(NULL), inlined_entry_block_(NULL), is_inline_return_target_(false), is_reachable_(true), dominates_loop_successors_(false), is_osr_entry_(false), is_ordered_(false) { } Isolate* HBasicBlock::isolate() const { return graph_->isolate(); } void HBasicBlock::MarkUnreachable() { is_reachable_ = false; } void HBasicBlock::AttachLoopInformation() { DCHECK(!IsLoopHeader()); loop_information_ = new(zone()) HLoopInformation(this, zone()); } void HBasicBlock::DetachLoopInformation() { DCHECK(IsLoopHeader()); loop_information_ = NULL; } void HBasicBlock::AddPhi(HPhi* phi) { DCHECK(!IsStartBlock()); phis_.Add(phi, zone()); phi->SetBlock(this); } void HBasicBlock::RemovePhi(HPhi* phi) { DCHECK(phi->block() == this); DCHECK(phis_.Contains(phi)); phi->Kill(); phis_.RemoveElement(phi); phi->SetBlock(NULL); } void HBasicBlock::AddInstruction(HInstruction* instr, SourcePosition position) { DCHECK(!IsStartBlock() || !IsFinished()); DCHECK(!instr->IsLinked()); DCHECK(!IsFinished()); if (!position.IsUnknown()) { instr->set_position(position); } if (first_ == NULL) { DCHECK(last_environment() != NULL); DCHECK(!last_environment()->ast_id().IsNone()); HBlockEntry* entry = new(zone()) HBlockEntry(); entry->InitializeAsFirst(this); if (!position.IsUnknown()) { entry->set_position(position); } else { DCHECK(!FLAG_hydrogen_track_positions || !graph()->info()->IsOptimizing() || instr->IsAbnormalExit()); } first_ = last_ = entry; } instr->InsertAfter(last_); } HPhi* HBasicBlock::AddNewPhi(int merged_index) { if (graph()->IsInsideNoSideEffectsScope()) { merged_index = HPhi::kInvalidMergedIndex; } HPhi* phi = new(zone()) HPhi(merged_index, zone()); AddPhi(phi); return phi; } HSimulate* HBasicBlock::CreateSimulate(BailoutId ast_id, RemovableSimulate removable) { DCHECK(HasEnvironment()); HEnvironment* environment = last_environment(); DCHECK(ast_id.IsNone() || ast_id == BailoutId::StubEntry() || environment->closure()->shared()->VerifyBailoutId(ast_id)); int push_count = environment->push_count(); int pop_count = environment->pop_count(); HSimulate* instr = new(zone()) HSimulate(ast_id, pop_count, zone(), removable); #ifdef DEBUG instr->set_closure(environment->closure()); #endif // Order of pushed values: newest (top of stack) first. This allows // HSimulate::MergeWith() to easily append additional pushed values // that are older (from further down the stack). for (int i = 0; i < push_count; ++i) { instr->AddPushedValue(environment->ExpressionStackAt(i)); } for (GrowableBitVector::Iterator it(environment->assigned_variables(), zone()); !it.Done(); it.Advance()) { int index = it.Current(); instr->AddAssignedValue(index, environment->Lookup(index)); } environment->ClearHistory(); return instr; } void HBasicBlock::Finish(HControlInstruction* end, SourcePosition position) { DCHECK(!IsFinished()); AddInstruction(end, position); end_ = end; for (HSuccessorIterator it(end); !it.Done(); it.Advance()) { it.Current()->RegisterPredecessor(this); } } void HBasicBlock::Goto(HBasicBlock* block, SourcePosition position, FunctionState* state, bool add_simulate) { bool drop_extra = state != NULL && state->inlining_kind() == NORMAL_RETURN; if (block->IsInlineReturnTarget()) { HEnvironment* env = last_environment(); int argument_count = env->arguments_environment()->parameter_count(); AddInstruction(new(zone()) HLeaveInlined(state->entry(), argument_count), position); UpdateEnvironment(last_environment()->DiscardInlined(drop_extra)); } if (add_simulate) AddNewSimulate(BailoutId::None(), position); HGoto* instr = new(zone()) HGoto(block); Finish(instr, position); } void HBasicBlock::AddLeaveInlined(HValue* return_value, FunctionState* state, SourcePosition position) { HBasicBlock* target = state->function_return(); bool drop_extra = state->inlining_kind() == NORMAL_RETURN; DCHECK(target->IsInlineReturnTarget()); DCHECK(return_value != NULL); HEnvironment* env = last_environment(); int argument_count = env->arguments_environment()->parameter_count(); AddInstruction(new(zone()) HLeaveInlined(state->entry(), argument_count), position); UpdateEnvironment(last_environment()->DiscardInlined(drop_extra)); last_environment()->Push(return_value); AddNewSimulate(BailoutId::None(), position); HGoto* instr = new(zone()) HGoto(target); Finish(instr, position); } void HBasicBlock::SetInitialEnvironment(HEnvironment* env) { DCHECK(!HasEnvironment()); DCHECK(first() == NULL); UpdateEnvironment(env); } void HBasicBlock::UpdateEnvironment(HEnvironment* env) { last_environment_ = env; graph()->update_maximum_environment_size(env->first_expression_index()); } void HBasicBlock::SetJoinId(BailoutId ast_id) { int length = predecessors_.length(); DCHECK(length > 0); for (int i = 0; i < length; i++) { HBasicBlock* predecessor = predecessors_[i]; DCHECK(predecessor->end()->IsGoto()); HSimulate* simulate = HSimulate::cast(predecessor->end()->previous()); DCHECK(i != 0 || (predecessor->last_environment()->closure().is_null() || predecessor->last_environment()->closure()->shared() ->VerifyBailoutId(ast_id))); simulate->set_ast_id(ast_id); predecessor->last_environment()->set_ast_id(ast_id); } } bool HBasicBlock::Dominates(HBasicBlock* other) const { HBasicBlock* current = other->dominator(); while (current != NULL) { if (current == this) return true; current = current->dominator(); } return false; } bool HBasicBlock::EqualToOrDominates(HBasicBlock* other) const { if (this == other) return true; return Dominates(other); } int HBasicBlock::LoopNestingDepth() const { const HBasicBlock* current = this; int result = (current->IsLoopHeader()) ? 1 : 0; while (current->parent_loop_header() != NULL) { current = current->parent_loop_header(); result++; } return result; } void HBasicBlock::PostProcessLoopHeader(IterationStatement* stmt) { DCHECK(IsLoopHeader()); SetJoinId(stmt->EntryId()); if (predecessors()->length() == 1) { // This is a degenerated loop. DetachLoopInformation(); return; } // Only the first entry into the loop is from outside the loop. All other // entries must be back edges. for (int i = 1; i < predecessors()->length(); ++i) { loop_information()->RegisterBackEdge(predecessors()->at(i)); } } void HBasicBlock::MarkSuccEdgeUnreachable(int succ) { DCHECK(IsFinished()); HBasicBlock* succ_block = end()->SuccessorAt(succ); DCHECK(succ_block->predecessors()->length() == 1); succ_block->MarkUnreachable(); } void HBasicBlock::RegisterPredecessor(HBasicBlock* pred) { if (HasPredecessor()) { // Only loop header blocks can have a predecessor added after // instructions have been added to the block (they have phis for all // values in the environment, these phis may be eliminated later). DCHECK(IsLoopHeader() || first_ == NULL); HEnvironment* incoming_env = pred->last_environment(); if (IsLoopHeader()) { DCHECK_EQ(phis()->length(), incoming_env->length()); for (int i = 0; i < phis_.length(); ++i) { phis_[i]->AddInput(incoming_env->values()->at(i)); } } else { last_environment()->AddIncomingEdge(this, pred->last_environment()); } } else if (!HasEnvironment() && !IsFinished()) { DCHECK(!IsLoopHeader()); SetInitialEnvironment(pred->last_environment()->Copy()); } predecessors_.Add(pred, zone()); } void HBasicBlock::AddDominatedBlock(HBasicBlock* block) { DCHECK(!dominated_blocks_.Contains(block)); // Keep the list of dominated blocks sorted such that if there is two // succeeding block in this list, the predecessor is before the successor. int index = 0; while (index < dominated_blocks_.length() && dominated_blocks_[index]->block_id() < block->block_id()) { ++index; } dominated_blocks_.InsertAt(index, block, zone()); } void HBasicBlock::AssignCommonDominator(HBasicBlock* other) { if (dominator_ == NULL) { dominator_ = other; other->AddDominatedBlock(this); } else if (other->dominator() != NULL) { HBasicBlock* first = dominator_; HBasicBlock* second = other; while (first != second) { if (first->block_id() > second->block_id()) { first = first->dominator(); } else { second = second->dominator(); } DCHECK(first != NULL && second != NULL); } if (dominator_ != first) { DCHECK(dominator_->dominated_blocks_.Contains(this)); dominator_->dominated_blocks_.RemoveElement(this); dominator_ = first; first->AddDominatedBlock(this); } } } void HBasicBlock::AssignLoopSuccessorDominators() { // Mark blocks that dominate all subsequent reachable blocks inside their // loop. Exploit the fact that blocks are sorted in reverse post order. When // the loop is visited in increasing block id order, if the number of // non-loop-exiting successor edges at the dominator_candidate block doesn't // exceed the number of previously encountered predecessor edges, there is no // path from the loop header to any block with higher id that doesn't go // through the dominator_candidate block. In this case, the // dominator_candidate block is guaranteed to dominate all blocks reachable // from it with higher ids. HBasicBlock* last = loop_information()->GetLastBackEdge(); int outstanding_successors = 1; // one edge from the pre-header // Header always dominates everything. MarkAsLoopSuccessorDominator(); for (int j = block_id(); j <= last->block_id(); ++j) { HBasicBlock* dominator_candidate = graph_->blocks()->at(j); for (HPredecessorIterator it(dominator_candidate); !it.Done(); it.Advance()) { HBasicBlock* predecessor = it.Current(); // Don't count back edges. if (predecessor->block_id() < dominator_candidate->block_id()) { outstanding_successors--; } } // If more successors than predecessors have been seen in the loop up to // now, it's not possible to guarantee that the current block dominates // all of the blocks with higher IDs. In this case, assume conservatively // that those paths through loop that don't go through the current block // contain all of the loop's dependencies. Also be careful to record // dominator information about the current loop that's being processed, // and not nested loops, which will be processed when // AssignLoopSuccessorDominators gets called on their header. DCHECK(outstanding_successors >= 0); HBasicBlock* parent_loop_header = dominator_candidate->parent_loop_header(); if (outstanding_successors == 0 && (parent_loop_header == this && !dominator_candidate->IsLoopHeader())) { dominator_candidate->MarkAsLoopSuccessorDominator(); } HControlInstruction* end = dominator_candidate->end(); for (HSuccessorIterator it(end); !it.Done(); it.Advance()) { HBasicBlock* successor = it.Current(); // Only count successors that remain inside the loop and don't loop back // to a loop header. if (successor->block_id() > dominator_candidate->block_id() && successor->block_id() <= last->block_id()) { // Backwards edges must land on loop headers. DCHECK(successor->block_id() > dominator_candidate->block_id() || successor->IsLoopHeader()); outstanding_successors++; } } } } int HBasicBlock::PredecessorIndexOf(HBasicBlock* predecessor) const { for (int i = 0; i < predecessors_.length(); ++i) { if (predecessors_[i] == predecessor) return i; } UNREACHABLE(); return -1; } #ifdef DEBUG void HBasicBlock::Verify() { // Check that every block is finished. DCHECK(IsFinished()); DCHECK(block_id() >= 0); // Check that the incoming edges are in edge split form. if (predecessors_.length() > 1) { for (int i = 0; i < predecessors_.length(); ++i) { DCHECK(predecessors_[i]->end()->SecondSuccessor() == NULL); } } } #endif void HLoopInformation::RegisterBackEdge(HBasicBlock* block) { this->back_edges_.Add(block, block->zone()); AddBlock(block); } HBasicBlock* HLoopInformation::GetLastBackEdge() const { int max_id = -1; HBasicBlock* result = NULL; for (int i = 0; i < back_edges_.length(); ++i) { HBasicBlock* cur = back_edges_[i]; if (cur->block_id() > max_id) { max_id = cur->block_id(); result = cur; } } return result; } void HLoopInformation::AddBlock(HBasicBlock* block) { if (block == loop_header()) return; if (block->parent_loop_header() == loop_header()) return; if (block->parent_loop_header() != NULL) { AddBlock(block->parent_loop_header()); } else { block->set_parent_loop_header(loop_header()); blocks_.Add(block, block->zone()); for (int i = 0; i < block->predecessors()->length(); ++i) { AddBlock(block->predecessors()->at(i)); } } } #ifdef DEBUG // Checks reachability of the blocks in this graph and stores a bit in // the BitVector "reachable()" for every block that can be reached // from the start block of the graph. If "dont_visit" is non-null, the given // block is treated as if it would not be part of the graph. "visited_count()" // returns the number of reachable blocks. class ReachabilityAnalyzer BASE_EMBEDDED { public: ReachabilityAnalyzer(HBasicBlock* entry_block, int block_count, HBasicBlock* dont_visit) : visited_count_(0), stack_(16, entry_block->zone()), reachable_(block_count, entry_block->zone()), dont_visit_(dont_visit) { PushBlock(entry_block); Analyze(); } int visited_count() const { return visited_count_; } const BitVector* reachable() const { return &reachable_; } private: void PushBlock(HBasicBlock* block) { if (block != NULL && block != dont_visit_ && !reachable_.Contains(block->block_id())) { reachable_.Add(block->block_id()); stack_.Add(block, block->zone()); visited_count_++; } } void Analyze() { while (!stack_.is_empty()) { HControlInstruction* end = stack_.RemoveLast()->end(); for (HSuccessorIterator it(end); !it.Done(); it.Advance()) { PushBlock(it.Current()); } } } int visited_count_; ZoneList
stack_; BitVector reachable_; HBasicBlock* dont_visit_; }; void HGraph::Verify(bool do_full_verify) const { Heap::RelocationLock relocation_lock(isolate()->heap()); AllowHandleDereference allow_deref; AllowDeferredHandleDereference allow_deferred_deref; for (int i = 0; i < blocks_.length(); i++) { HBasicBlock* block = blocks_.at(i); block->Verify(); // Check that every block contains at least one node and that only the last // node is a control instruction. HInstruction* current = block->first(); DCHECK(current != NULL && current->IsBlockEntry()); while (current != NULL) { DCHECK((current->next() == NULL) == current->IsControlInstruction()); DCHECK(current->block() == block); current->Verify(); current = current->next(); } // Check that successors are correctly set. HBasicBlock* first = block->end()->FirstSuccessor(); HBasicBlock* second = block->end()->SecondSuccessor(); DCHECK(second == NULL || first != NULL); // Check that the predecessor array is correct. if (first != NULL) { DCHECK(first->predecessors()->Contains(block)); if (second != NULL) { DCHECK(second->predecessors()->Contains(block)); } } // Check that phis have correct arguments. for (int j = 0; j < block->phis()->length(); j++) { HPhi* phi = block->phis()->at(j); phi->Verify(); } // Check that all join blocks have predecessors that end with an // unconditional goto and agree on their environment node id. if (block->predecessors()->length() >= 2) { BailoutId id = block->predecessors()->first()->last_environment()->ast_id(); for (int k = 0; k < block->predecessors()->length(); k++) { HBasicBlock* predecessor = block->predecessors()->at(k); DCHECK(predecessor->end()->IsGoto() || predecessor->end()->IsDeoptimize()); DCHECK(predecessor->last_environment()->ast_id() == id); } } } // Check special property of first block to have no predecessors. DCHECK(blocks_.at(0)->predecessors()->is_empty()); if (do_full_verify) { // Check that the graph is fully connected. ReachabilityAnalyzer analyzer(entry_block_, blocks_.length(), NULL); DCHECK(analyzer.visited_count() == blocks_.length()); // Check that entry block dominator is NULL. DCHECK(entry_block_->dominator() == NULL); // Check dominators. for (int i = 0; i < blocks_.length(); ++i) { HBasicBlock* block = blocks_.at(i); if (block->dominator() == NULL) { // Only start block may have no dominator assigned to. DCHECK(i == 0); } else { // Assert that block is unreachable if dominator must not be visited. ReachabilityAnalyzer dominator_analyzer(entry_block_, blocks_.length(), block->dominator()); DCHECK(!dominator_analyzer.reachable()->Contains(block->block_id())); } } } } #endif HConstant* HGraph::GetConstant(SetOncePointer
* pointer, int32_t value) { if (!pointer->is_set()) { // Can't pass GetInvalidContext() to HConstant::New, because that will // recursively call GetConstant HConstant* constant = HConstant::New(isolate(), zone(), NULL, value); constant->InsertAfter(entry_block()->first()); pointer->set(constant); return constant; } return ReinsertConstantIfNecessary(pointer->get()); } HConstant* HGraph::ReinsertConstantIfNecessary(HConstant* constant) { if (!constant->IsLinked()) { // The constant was removed from the graph. Reinsert. constant->ClearFlag(HValue::kIsDead); constant->InsertAfter(entry_block()->first()); } return constant; } HConstant* HGraph::GetConstant0() { return GetConstant(&constant_0_, 0); } HConstant* HGraph::GetConstant1() { return GetConstant(&constant_1_, 1); } HConstant* HGraph::GetConstantMinus1() { return GetConstant(&constant_minus1_, -1); } HConstant* HGraph::GetConstantBool(bool value) { return value ? GetConstantTrue() : GetConstantFalse(); } #define DEFINE_GET_CONSTANT(Name, name, type, htype, boolean_value) \ HConstant* HGraph::GetConstant##Name() { \ if (!constant_##name##_.is_set()) { \ HConstant* constant = new(zone()) HConstant( \ Unique
::CreateImmovable(isolate()->factory()->name##_value()), \ Unique
::CreateImmovable(isolate()->factory()->type##_map()), \ false, \ Representation::Tagged(), \ htype, \ true, \ boolean_value, \ false, \ ODDBALL_TYPE); \ constant->InsertAfter(entry_block()->first()); \ constant_##name##_.set(constant); \ } \ return ReinsertConstantIfNecessary(constant_##name##_.get()); \ } DEFINE_GET_CONSTANT(Undefined, undefined, undefined, HType::Undefined(), false) DEFINE_GET_CONSTANT(True, true, boolean, HType::Boolean(), true) DEFINE_GET_CONSTANT(False, false, boolean, HType::Boolean(), false) DEFINE_GET_CONSTANT(Hole, the_hole, the_hole, HType::None(), false) DEFINE_GET_CONSTANT(Null, null, null, HType::Null(), false) #undef DEFINE_GET_CONSTANT #define DEFINE_IS_CONSTANT(Name, name) \ bool HGraph::IsConstant##Name(HConstant* constant) { \ return constant_##name##_.is_set() && constant == constant_##name##_.get(); \ } DEFINE_IS_CONSTANT(Undefined, undefined) DEFINE_IS_CONSTANT(0, 0) DEFINE_IS_CONSTANT(1, 1) DEFINE_IS_CONSTANT(Minus1, minus1) DEFINE_IS_CONSTANT(True, true) DEFINE_IS_CONSTANT(False, false) DEFINE_IS_CONSTANT(Hole, the_hole) DEFINE_IS_CONSTANT(Null, null) #undef DEFINE_IS_CONSTANT HConstant* HGraph::GetInvalidContext() { return GetConstant(&constant_invalid_context_, 0xFFFFC0C7); } bool HGraph::IsStandardConstant(HConstant* constant) { if (IsConstantUndefined(constant)) return true; if (IsConstant0(constant)) return true; if (IsConstant1(constant)) return true; if (IsConstantMinus1(constant)) return true; if (IsConstantTrue(constant)) return true; if (IsConstantFalse(constant)) return true; if (IsConstantHole(constant)) return true; if (IsConstantNull(constant)) return true; return false; } HGraphBuilder::IfBuilder::IfBuilder() : builder_(NULL), needs_compare_(true) {} HGraphBuilder::IfBuilder::IfBuilder(HGraphBuilder* builder) : needs_compare_(true) { Initialize(builder); } HGraphBuilder::IfBuilder::IfBuilder(HGraphBuilder* builder, HIfContinuation* continuation) : needs_compare_(false), first_true_block_(NULL), first_false_block_(NULL) { InitializeDontCreateBlocks(builder); continuation->Continue(&first_true_block_, &first_false_block_); } void HGraphBuilder::IfBuilder::InitializeDontCreateBlocks( HGraphBuilder* builder) { builder_ = builder; finished_ = false; did_then_ = false; did_else_ = false; did_else_if_ = false; did_and_ = false; did_or_ = false; captured_ = false; pending_merge_block_ = false; split_edge_merge_block_ = NULL; merge_at_join_blocks_ = NULL; normal_merge_at_join_block_count_ = 0; deopt_merge_at_join_block_count_ = 0; } void HGraphBuilder::IfBuilder::Initialize(HGraphBuilder* builder) { InitializeDontCreateBlocks(builder); HEnvironment* env = builder->environment(); first_true_block_ = builder->CreateBasicBlock(env->Copy()); first_false_block_ = builder->CreateBasicBlock(env->Copy()); } HControlInstruction* HGraphBuilder::IfBuilder::AddCompare( HControlInstruction* compare) { DCHECK(did_then_ == did_else_); if (did_else_) { // Handle if-then-elseif did_else_if_ = true; did_else_ = false; did_then_ = false; did_and_ = false; did_or_ = false; pending_merge_block_ = false; split_edge_merge_block_ = NULL; HEnvironment* env = builder()->environment(); first_true_block_ = builder()->CreateBasicBlock(env->Copy()); first_false_block_ = builder()->CreateBasicBlock(env->Copy()); } if (split_edge_merge_block_ != NULL) { HEnvironment* env = first_false_block_->last_environment(); HBasicBlock* split_edge = builder()->CreateBasicBlock(env->Copy()); if (did_or_) { compare->SetSuccessorAt(0, split_edge); compare->SetSuccessorAt(1, first_false_block_); } else { compare->SetSuccessorAt(0, first_true_block_); compare->SetSuccessorAt(1, split_edge); } builder()->GotoNoSimulate(split_edge, split_edge_merge_block_); } else { compare->SetSuccessorAt(0, first_true_block_); compare->SetSuccessorAt(1, first_false_block_); } builder()->FinishCurrentBlock(compare); needs_compare_ = false; return compare; } void HGraphBuilder::IfBuilder::Or() { DCHECK(!needs_compare_); DCHECK(!did_and_); did_or_ = true; HEnvironment* env = first_false_block_->last_environment(); if (split_edge_merge_block_ == NULL) { split_edge_merge_block_ = builder()->CreateBasicBlock(env->Copy()); builder()->GotoNoSimulate(first_true_block_, split_edge_merge_block_); first_true_block_ = split_edge_merge_block_; } builder()->set_current_block(first_false_block_); first_false_block_ = builder()->CreateBasicBlock(env->Copy()); } void HGraphBuilder::IfBuilder::And() { DCHECK(!needs_compare_); DCHECK(!did_or_); did_and_ = true; HEnvironment* env = first_false_block_->last_environment(); if (split_edge_merge_block_ == NULL) { split_edge_merge_block_ = builder()->CreateBasicBlock(env->Copy()); builder()->GotoNoSimulate(first_false_block_, split_edge_merge_block_); first_false_block_ = split_edge_merge_block_; } builder()->set_current_block(first_true_block_); first_true_block_ = builder()->CreateBasicBlock(env->Copy()); } void HGraphBuilder::IfBuilder::CaptureContinuation( HIfContinuation* continuation) { DCHECK(!did_else_if_); DCHECK(!finished_); DCHECK(!captured_); HBasicBlock* true_block = NULL; HBasicBlock* false_block = NULL; Finish(&true_block, &false_block); DCHECK(true_block != NULL); DCHECK(false_block != NULL); continuation->Capture(true_block, false_block); captured_ = true; builder()->set_current_block(NULL); End(); } void HGraphBuilder::IfBuilder::JoinContinuation(HIfContinuation* continuation) { DCHECK(!did_else_if_); DCHECK(!finished_); DCHECK(!captured_); HBasicBlock* true_block = NULL; HBasicBlock* false_block = NULL; Finish(&true_block, &false_block); merge_at_join_blocks_ = NULL; if (true_block != NULL && !true_block->IsFinished()) { DCHECK(continuation->IsTrueReachable()); builder()->GotoNoSimulate(true_block, continuation->true_branch()); } if (false_block != NULL && !false_block->IsFinished()) { DCHECK(continuation->IsFalseReachable()); builder()->GotoNoSimulate(false_block, continuation->false_branch()); } captured_ = true; End(); } void HGraphBuilder::IfBuilder::Then() { DCHECK(!captured_); DCHECK(!finished_); did_then_ = true; if (needs_compare_) { // Handle if's without any expressions, they jump directly to the "else" // branch. However, we must pretend that the "then" branch is reachable, // so that the graph builder visits it and sees any live range extending // constructs within it. HConstant* constant_false = builder()->graph()->GetConstantFalse(); ToBooleanStub::Types boolean_type = ToBooleanStub::Types(); boolean_type.Add(ToBooleanStub::BOOLEAN); HBranch* branch = builder()->New
( constant_false, boolean_type, first_true_block_, first_false_block_); builder()->FinishCurrentBlock(branch); } builder()->set_current_block(first_true_block_); pending_merge_block_ = true; } void HGraphBuilder::IfBuilder::Else() { DCHECK(did_then_); DCHECK(!captured_); DCHECK(!finished_); AddMergeAtJoinBlock(false); builder()->set_current_block(first_false_block_); pending_merge_block_ = true; did_else_ = true; } void HGraphBuilder::IfBuilder::Deopt(Deoptimizer::DeoptReason reason) { DCHECK(did_then_); builder()->Add
(reason, Deoptimizer::EAGER); AddMergeAtJoinBlock(true); } void HGraphBuilder::IfBuilder::Return(HValue* value) { HValue* parameter_count = builder()->graph()->GetConstantMinus1(); builder()->FinishExitCurrentBlock( builder()->New
(value, parameter_count)); AddMergeAtJoinBlock(false); } void HGraphBuilder::IfBuilder::AddMergeAtJoinBlock(bool deopt) { if (!pending_merge_block_) return; HBasicBlock* block = builder()->current_block(); DCHECK(block == NULL || !block->IsFinished()); MergeAtJoinBlock* record = new (builder()->zone()) MergeAtJoinBlock(block, deopt, merge_at_join_blocks_); merge_at_join_blocks_ = record; if (block != NULL) { DCHECK(block->end() == NULL); if (deopt) { normal_merge_at_join_block_count_++; } else { deopt_merge_at_join_block_count_++; } } builder()->set_current_block(NULL); pending_merge_block_ = false; } void HGraphBuilder::IfBuilder::Finish() { DCHECK(!finished_); if (!did_then_) { Then(); } AddMergeAtJoinBlock(false); if (!did_else_) { Else(); AddMergeAtJoinBlock(false); } finished_ = true; } void HGraphBuilder::IfBuilder::Finish(HBasicBlock** then_continuation, HBasicBlock** else_continuation) { Finish(); MergeAtJoinBlock* else_record = merge_at_join_blocks_; if (else_continuation != NULL) { *else_continuation = else_record->block_; } MergeAtJoinBlock* then_record = else_record->next_; if (then_continuation != NULL) { *then_continuation = then_record->block_; } DCHECK(then_record->next_ == NULL); } void HGraphBuilder::IfBuilder::EndUnreachable() { if (captured_) return; Finish(); builder()->set_current_block(nullptr); } void HGraphBuilder::IfBuilder::End() { if (captured_) return; Finish(); int total_merged_blocks = normal_merge_at_join_block_count_ + deopt_merge_at_join_block_count_; DCHECK(total_merged_blocks >= 1); HBasicBlock* merge_block = total_merged_blocks == 1 ? NULL : builder()->graph()->CreateBasicBlock(); // Merge non-deopt blocks first to ensure environment has right size for // padding. MergeAtJoinBlock* current = merge_at_join_blocks_; while (current != NULL) { if (!current->deopt_ && current->block_ != NULL) { // If there is only one block that makes it through to the end of the // if, then just set it as the current block and continue rather then // creating an unnecessary merge block. if (total_merged_blocks == 1) { builder()->set_current_block(current->block_); return; } builder()->GotoNoSimulate(current->block_, merge_block); } current = current->next_; } // Merge deopt blocks, padding when necessary. current = merge_at_join_blocks_; while (current != NULL) { if (current->deopt_ && current->block_ != NULL) { current->block_->FinishExit( HAbnormalExit::New(builder()->isolate(), builder()->zone(), NULL), SourcePosition::Unknown()); } current = current->next_; } builder()->set_current_block(merge_block); } HGraphBuilder::LoopBuilder::LoopBuilder(HGraphBuilder* builder) { Initialize(builder, NULL, kWhileTrue, NULL); } HGraphBuilder::LoopBuilder::LoopBuilder(HGraphBuilder* builder, HValue* context, LoopBuilder::Direction direction) { Initialize(builder, context, direction, builder->graph()->GetConstant1()); } HGraphBuilder::LoopBuilder::LoopBuilder(HGraphBuilder* builder, HValue* context, LoopBuilder::Direction direction, HValue* increment_amount) { Initialize(builder, context, direction, increment_amount); increment_amount_ = increment_amount; } void HGraphBuilder::LoopBuilder::Initialize(HGraphBuilder* builder, HValue* context, Direction direction, HValue* increment_amount) { builder_ = builder; context_ = context; direction_ = direction; increment_amount_ = increment_amount; finished_ = false; header_block_ = builder->CreateLoopHeaderBlock(); body_block_ = NULL; exit_block_ = NULL; exit_trampoline_block_ = NULL; } HValue* HGraphBuilder::LoopBuilder::BeginBody( HValue* initial, HValue* terminating, Token::Value token) { DCHECK(direction_ != kWhileTrue); HEnvironment* env = builder_->environment(); phi_ = header_block_->AddNewPhi(env->values()->length()); phi_->AddInput(initial); env->Push(initial); builder_->GotoNoSimulate(header_block_); HEnvironment* body_env = env->Copy(); HEnvironment* exit_env = env->Copy(); // Remove the phi from the expression stack body_env->Pop(); exit_env->Pop(); body_block_ = builder_->CreateBasicBlock(body_env); exit_block_ = builder_->CreateBasicBlock(exit_env); builder_->set_current_block(header_block_); env->Pop(); builder_->FinishCurrentBlock(builder_->New
( phi_, terminating, token, body_block_, exit_block_)); builder_->set_current_block(body_block_); if (direction_ == kPreIncrement || direction_ == kPreDecrement) { Isolate* isolate = builder_->isolate(); HValue* one = builder_->graph()->GetConstant1(); if (direction_ == kPreIncrement) { increment_ = HAdd::New(isolate, zone(), context_, phi_, one); } else { increment_ = HSub::New(isolate, zone(), context_, phi_, one); } increment_->ClearFlag(HValue::kCanOverflow); builder_->AddInstruction(increment_); return increment_; } else { return phi_; } } void HGraphBuilder::LoopBuilder::BeginBody(int drop_count) { DCHECK(direction_ == kWhileTrue); HEnvironment* env = builder_->environment(); builder_->GotoNoSimulate(header_block_); builder_->set_current_block(header_block_); env->Drop(drop_count); } void HGraphBuilder::LoopBuilder::Break() { if (exit_trampoline_block_ == NULL) { // Its the first time we saw a break. if (direction_ == kWhileTrue) { HEnvironment* env = builder_->environment()->Copy(); exit_trampoline_block_ = builder_->CreateBasicBlock(env); } else { HEnvironment* env = exit_block_->last_environment()->Copy(); exit_trampoline_block_ = builder_->CreateBasicBlock(env); builder_->GotoNoSimulate(exit_block_, exit_trampoline_block_); } } builder_->GotoNoSimulate(exit_trampoline_block_); builder_->set_current_block(NULL); } void HGraphBuilder::LoopBuilder::EndBody() { DCHECK(!finished_); if (direction_ == kPostIncrement || direction_ == kPostDecrement) { Isolate* isolate = builder_->isolate(); if (direction_ == kPostIncrement) { increment_ = HAdd::New(isolate, zone(), context_, phi_, increment_amount_); } else { increment_ = HSub::New(isolate, zone(), context_, phi_, increment_amount_); } increment_->ClearFlag(HValue::kCanOverflow); builder_->AddInstruction(increment_); } if (direction_ != kWhileTrue) { // Push the new increment value on the expression stack to merge into // the phi. builder_->environment()->Push(increment_); } HBasicBlock* last_block = builder_->current_block(); builder_->GotoNoSimulate(last_block, header_block_); header_block_->loop_information()->RegisterBackEdge(last_block); if (exit_trampoline_block_ != NULL) { builder_->set_current_block(exit_trampoline_block_); } else { builder_->set_current_block(exit_block_); } finished_ = true; } HGraph* HGraphBuilder::CreateGraph() { graph_ = new(zone()) HGraph(info_); if (FLAG_hydrogen_stats) isolate()->GetHStatistics()->Initialize(info_); CompilationPhase phase("H_Block building", info_); set_current_block(graph()->entry_block()); if (!BuildGraph()) return NULL; graph()->FinalizeUniqueness(); return graph_; } HInstruction* HGraphBuilder::AddInstruction(HInstruction* instr) { DCHECK(current_block() != NULL); DCHECK(!FLAG_hydrogen_track_positions || !position_.IsUnknown() || !info_->IsOptimizing()); current_block()->AddInstruction(instr, source_position()); if (graph()->IsInsideNoSideEffectsScope()) { instr->SetFlag(HValue::kHasNoObservableSideEffects); } return instr; } void HGraphBuilder::FinishCurrentBlock(HControlInstruction* last) { DCHECK(!FLAG_hydrogen_track_positions || !info_->IsOptimizing() || !position_.IsUnknown()); current_block()->Finish(last, source_position()); if (last->IsReturn() || last->IsAbnormalExit()) { set_current_block(NULL); } } void HGraphBuilder::FinishExitCurrentBlock(HControlInstruction* instruction) { DCHECK(!FLAG_hydrogen_track_positions || !info_->IsOptimizing() || !position_.IsUnknown()); current_block()->FinishExit(instruction, source_position()); if (instruction->IsReturn() || instruction->IsAbnormalExit()) { set_current_block(NULL); } } void HGraphBuilder::AddIncrementCounter(StatsCounter* counter) { if (FLAG_native_code_counters && counter->Enabled()) { HValue* reference = Add
(ExternalReference(counter)); HValue* old_value = Add
(reference, nullptr, HObjectAccess::ForCounter()); HValue* new_value = AddUncasted
(old_value, graph()->GetConstant1()); new_value->ClearFlag(HValue::kCanOverflow); // Ignore counter overflow Add
(reference, HObjectAccess::ForCounter(), new_value, STORE_TO_INITIALIZED_ENTRY); } } void HGraphBuilder::AddSimulate(BailoutId id, RemovableSimulate removable) { DCHECK(current_block() != NULL); DCHECK(!graph()->IsInsideNoSideEffectsScope()); current_block()->AddNewSimulate(id, source_position(), removable); } HBasicBlock* HGraphBuilder::CreateBasicBlock(HEnvironment* env) { HBasicBlock* b = graph()->CreateBasicBlock(); b->SetInitialEnvironment(env); return b; } HBasicBlock* HGraphBuilder::CreateLoopHeaderBlock() { HBasicBlock* header = graph()->CreateBasicBlock(); HEnvironment* entry_env = environment()->CopyAsLoopHeader(header); header->SetInitialEnvironment(entry_env); header->AttachLoopInformation(); return header; } HValue* HGraphBuilder::BuildGetElementsKind(HValue* object) { HValue* map = Add
(object, nullptr, HObjectAccess::ForMap()); HValue* bit_field2 = Add
(map, nullptr, HObjectAccess::ForMapBitField2()); return BuildDecodeField
(bit_field2); } HValue* HGraphBuilder::BuildCheckHeapObject(HValue* obj) { if (obj->type().IsHeapObject()) return obj; return Add
(obj); } void HGraphBuilder::FinishExitWithHardDeoptimization( Deoptimizer::DeoptReason reason) { Add
(reason, Deoptimizer::EAGER); FinishExitCurrentBlock(New
()); } HValue* HGraphBuilder::BuildCheckString(HValue* string) { if (!string->type().IsString()) { DCHECK(!string->IsConstant() || !HConstant::cast(string)->HasStringValue()); BuildCheckHeapObject(string); return Add
(string, HCheckInstanceType::IS_STRING); } return string; } HValue* HGraphBuilder::BuildWrapReceiver(HValue* object, HValue* function) { if (object->type().IsJSObject()) return object; if (function->IsConstant() && HConstant::cast(function)->handle(isolate())->IsJSFunction()) { Handle
f = Handle
::cast( HConstant::cast(function)->handle(isolate())); SharedFunctionInfo* shared = f->shared(); if (is_strict(shared->language_mode()) || shared->native()) return object; } return Add
(object, function); } HValue* HGraphBuilder::BuildCheckAndGrowElementsCapacity( HValue* object, HValue* elements, ElementsKind kind, HValue* length, HValue* capacity, HValue* key) { HValue* max_gap = Add
(static_cast
(JSObject::kMaxGap)); HValue* max_capacity = AddUncasted
(capacity, max_gap); Add
(key, max_capacity); HValue* new_capacity = BuildNewElementsCapacity(key); HValue* new_elements = BuildGrowElementsCapacity(object, elements, kind, kind, length, new_capacity); return new_elements; } HValue* HGraphBuilder::BuildCheckForCapacityGrow( HValue* object, HValue* elements, ElementsKind kind, HValue* length, HValue* key, bool is_js_array, PropertyAccessType access_type) { IfBuilder length_checker(this); Token::Value token = IsHoleyElementsKind(kind) ? Token::GTE : Token::EQ; length_checker.If
(key, length, token); length_checker.Then(); HValue* current_capacity = AddLoadFixedArrayLength(elements); if (top_info()->IsStub()) { IfBuilder capacity_checker(this); capacity_checker.If
(key, current_capacity, Token::GTE); capacity_checker.Then(); HValue* new_elements = BuildCheckAndGrowElementsCapacity( object, elements, kind, length, current_capacity, key); environment()->Push(new_elements); capacity_checker.Else(); environment()->Push(elements); capacity_checker.End(); } else { HValue* result = Add
( object, elements, key, current_capacity, is_js_array, kind); environment()->Push(result); } if (is_js_array) { HValue* new_length = AddUncasted
(key, graph_->GetConstant1()); new_length->ClearFlag(HValue::kCanOverflow); Add
(object, HObjectAccess::ForArrayLength(kind), new_length); } if (access_type == STORE && kind == FAST_SMI_ELEMENTS) { HValue* checked_elements = environment()->Top(); // Write zero to ensure that the new element is initialized with some smi. Add
(checked_elements, key, graph()->GetConstant0(), nullptr, kind); } length_checker.Else(); Add
(key, length); environment()->Push(elements); length_checker.End(); return environment()->Pop(); } HValue* HGraphBuilder::BuildCopyElementsOnWrite(HValue* object, HValue* elements, ElementsKind kind, HValue* length) { Factory* factory = isolate()->factory(); IfBuilder cow_checker(this); cow_checker.If
(elements, factory->fixed_cow_array_map()); cow_checker.Then(); HValue* capacity = AddLoadFixedArrayLength(elements); HValue* new_elements = BuildGrowElementsCapacity(object, elements, kind, kind, length, capacity); environment()->Push(new_elements); cow_checker.Else(); environment()->Push(elements); cow_checker.End(); return environment()->Pop(); } void HGraphBuilder::BuildTransitionElementsKind(HValue* object, HValue* map, ElementsKind from_kind, ElementsKind to_kind, bool is_jsarray) { DCHECK(!IsFastHoleyElementsKind(from_kind) || IsFastHoleyElementsKind(to_kind)); if (AllocationSite::GetMode(from_kind, to_kind) == TRACK_ALLOCATION_SITE) { Add
(object); } if (!IsSimpleMapChangeTransition(from_kind, to_kind)) { HInstruction* elements = AddLoadElements(object); HInstruction* empty_fixed_array = Add
( isolate()->factory()->empty_fixed_array()); IfBuilder if_builder(this); if_builder.IfNot
(elements, empty_fixed_array); if_builder.Then(); HInstruction* elements_length = AddLoadFixedArrayLength(elements); HInstruction* array_length = is_jsarray ? Add
(object, nullptr, HObjectAccess::ForArrayLength(from_kind)) : elements_length; BuildGrowElementsCapacity(object, elements, from_kind, to_kind, array_length, elements_length); if_builder.End(); } Add
(object, HObjectAccess::ForMap(), map); } void HGraphBuilder::BuildJSObjectCheck(HValue* receiver, int bit_field_mask) { // Check that the object isn't a smi. Add
(receiver); // Get the map of the receiver. HValue* map = Add
(receiver, nullptr, HObjectAccess::ForMap()); // Check the instance type and if an access check is needed, this can be // done with a single load, since both bytes are adjacent in the map. HObjectAccess access(HObjectAccess::ForMapInstanceTypeAndBitField()); HValue* instance_type_and_bit_field = Add
(map, nullptr, access); HValue* mask = Add
(0x00FF | (bit_field_mask << 8)); HValue* and_result = AddUncasted
(Token::BIT_AND, instance_type_and_bit_field, mask); HValue* sub_result = AddUncasted
(and_result, Add
(JS_OBJECT_TYPE)); Add
(sub_result, Add
(LAST_JS_OBJECT_TYPE + 1 - JS_OBJECT_TYPE)); } void HGraphBuilder::BuildKeyedIndexCheck(HValue* key, HIfContinuation* join_continuation) { // The sometimes unintuitively backward ordering of the ifs below is // convoluted, but necessary. All of the paths must guarantee that the // if-true of the continuation returns a smi element index and the if-false of // the continuation returns either a symbol or a unique string key. All other // object types cause a deopt to fall back to the runtime. IfBuilder key_smi_if(this); key_smi_if.If
(key); key_smi_if.Then(); { Push(key); // Nothing to do, just continue to true of continuation. } key_smi_if.Else(); { HValue* map = Add
(key, nullptr, HObjectAccess::ForMap()); HValue* instance_type = Add
(map, nullptr, HObjectAccess::ForMapInstanceType()); // Non-unique string, check for a string with a hash code that is actually // an index. STATIC_ASSERT(LAST_UNIQUE_NAME_TYPE == FIRST_NONSTRING_TYPE); IfBuilder not_string_or_name_if(this); not_string_or_name_if.If
( instance_type, Add
(LAST_UNIQUE_NAME_TYPE), Token::GT); not_string_or_name_if.Then(); { // Non-smi, non-Name, non-String: Try to convert to smi in case of // HeapNumber. // TODO(danno): This could call some variant of ToString Push(AddUncasted
(key, Representation::Smi())); } not_string_or_name_if.Else(); { // String or Name: check explicitly for Name, they can short-circuit // directly to unique non-index key path. IfBuilder not_symbol_if(this); not_symbol_if.If
( instance_type, Add
(SYMBOL_TYPE), Token::NE); not_symbol_if.Then(); { // String: check whether the String is a String of an index. If it is, // extract the index value from the hash. HValue* hash = Add
(key, nullptr, HObjectAccess::ForNameHashField()); HValue* not_index_mask = Add
(static_cast
( String::kContainsCachedArrayIndexMask)); HValue* not_index_test = AddUncasted
( Token::BIT_AND, hash, not_index_mask); IfBuilder string_index_if(this); string_index_if.If
(not_index_test, graph()->GetConstant0(), Token::EQ); string_index_if.Then(); { // String with index in hash: extract string and merge to index path. Push(BuildDecodeField
(hash)); } string_index_if.Else(); { // Key is a non-index String, check for uniqueness/internalization. // If it's not internalized yet, internalize it now. HValue* not_internalized_bit = AddUncasted
( Token::BIT_AND, instance_type, Add
(static_cast
(kIsNotInternalizedMask))); IfBuilder internalized(this); internalized.If
(not_internalized_bit, graph()->GetConstant0(), Token::EQ); internalized.Then(); Push(key); internalized.Else(); Add
(key); HValue* intern_key = Add
( Runtime::FunctionForId(Runtime::kInternalizeString), 1); Push(intern_key); internalized.End(); // Key guaranteed to be a unique string } string_index_if.JoinContinuation(join_continuation); } not_symbol_if.Else(); { Push(key); // Key is symbol } not_symbol_if.JoinContinuation(join_continuation); } not_string_or_name_if.JoinContinuation(join_continuation); } key_smi_if.JoinContinuation(join_continuation); } void HGraphBuilder::BuildNonGlobalObjectCheck(HValue* receiver) { // Get the the instance type of the receiver, and make sure that it is // not one of the global object types. HValue* map = Add
(receiver, nullptr, HObjectAccess::ForMap()); HValue* instance_type = Add
(map, nullptr, HObjectAccess::ForMapInstanceType()); HValue* global_type = Add
(JS_GLOBAL_OBJECT_TYPE); IfBuilder if_global_object(this); if_global_object.If
(instance_type, global_type, Token::EQ); if_global_object.ThenDeopt(Deoptimizer::kReceiverWasAGlobalObject); if_global_object.End(); } void HGraphBuilder::BuildTestForDictionaryProperties( HValue* object, HIfContinuation* continuation) { HValue* properties = Add
( object, nullptr, HObjectAccess::ForPropertiesPointer()); HValue* properties_map = Add
(properties, nullptr, HObjectAccess::ForMap()); HValue* hash_map = Add
(Heap::kHashTableMapRootIndex); IfBuilder builder(this); builder.If
(properties_map, hash_map); builder.CaptureContinuation(continuation); } HValue* HGraphBuilder::BuildKeyedLookupCacheHash(HValue* object, HValue* key) { // Load the map of the receiver, compute the keyed lookup cache hash // based on 32 bits of the map pointer and the string hash. HValue* object_map = Add
(object, nullptr, HObjectAccess::ForMapAsInteger32()); HValue* shifted_map = AddUncasted
( object_map, Add
(KeyedLookupCache::kMapHashShift)); HValue* string_hash = Add
(key, nullptr, HObjectAccess::ForStringHashField()); HValue* shifted_hash = AddUncasted
( string_hash, Add
(String::kHashShift)); HValue* xor_result = AddUncasted
(Token::BIT_XOR, shifted_map, shifted_hash); int mask = (KeyedLookupCache::kCapacityMask & KeyedLookupCache::kHashMask); return AddUncasted
(Token::BIT_AND, xor_result, Add
(mask)); } HValue* HGraphBuilder::BuildElementIndexHash(HValue* index) { int32_t seed_value = static_cast
(isolate()->heap()->HashSeed()); HValue* seed = Add
(seed_value); HValue* hash = AddUncasted
(Token::BIT_XOR, index, seed); // hash = ~hash + (hash << 15); HValue* shifted_hash = AddUncasted
(hash, Add
(15)); HValue* not_hash = AddUncasted
(Token::BIT_XOR, hash, graph()->GetConstantMinus1()); hash = AddUncasted
(shifted_hash, not_hash); // hash = hash ^ (hash >> 12); shifted_hash = AddUncasted
(hash, Add
(12)); hash = AddUncasted
(Token::BIT_XOR, hash, shifted_hash); // hash = hash + (hash << 2); shifted_hash = AddUncasted
(hash, Add
(2)); hash = AddUncasted
(hash, shifted_hash); // hash = hash ^ (hash >> 4); shifted_hash = AddUncasted
(hash, Add
(4)); hash = AddUncasted
(Token::BIT_XOR, hash, shifted_hash); // hash = hash * 2057; hash = AddUncasted
(hash, Add
(2057)); hash->ClearFlag(HValue::kCanOverflow); // hash = hash ^ (hash >> 16); shifted_hash = AddUncasted
(hash, Add
(16)); return AddUncasted
(Token::BIT_XOR, hash, shifted_hash); } HValue* HGraphBuilder::BuildUncheckedDictionaryElementLoad( HValue* receiver, HValue* elements, HValue* key, HValue* hash, LanguageMode language_mode) { HValue* capacity = Add
(elements, Add
(NameDictionary::kCapacityIndex), nullptr, nullptr, FAST_ELEMENTS); HValue* mask = AddUncasted
(capacity, graph()->GetConstant1()); mask->ChangeRepresentation(Representation::Integer32()); mask->ClearFlag(HValue::kCanOverflow); HValue* entry = hash; HValue* count = graph()->GetConstant1(); Push(entry); Push(count); HIfContinuation return_or_loop_continuation(graph()->CreateBasicBlock(), graph()->CreateBasicBlock()); HIfContinuation found_key_match_continuation(graph()->CreateBasicBlock(), graph()->CreateBasicBlock()); LoopBuilder probe_loop(this); probe_loop.BeginBody(2); // Drop entry, count from last environment to // appease live range building without simulates. count = Pop(); entry = Pop(); entry = AddUncasted
(Token::BIT_AND, entry, mask); int entry_size = SeededNumberDictionary::kEntrySize; HValue* base_index = AddUncasted
(entry, Add
(entry_size)); base_index->ClearFlag(HValue::kCanOverflow); int start_offset = SeededNumberDictionary::kElementsStartIndex; HValue* key_index = AddUncasted
(base_index, Add
(start_offset)); key_index->ClearFlag(HValue::kCanOverflow); HValue* candidate_key = Add
(elements, key_index, nullptr, nullptr, FAST_ELEMENTS); IfBuilder if_undefined(this); if_undefined.If
(candidate_key, graph()->GetConstantUndefined()); if_undefined.Then(); { // element == undefined means "not found". Call the runtime. // TODO(jkummerow): walk the prototype chain instead. Add
(receiver, key); Push(Add
( Runtime::FunctionForId(is_strong(language_mode) ? Runtime::kKeyedGetPropertyStrong : Runtime::kKeyedGetProperty), 2)); } if_undefined.Else(); { IfBuilder if_match(this); if_match.If
(candidate_key, key); if_match.Then(); if_match.Else(); // Update non-internalized string in the dictionary with internalized key? IfBuilder if_update_with_internalized(this); HValue* smi_check = if_update_with_internalized.IfNot
(candidate_key); if_update_with_internalized.And(); HValue* map = AddLoadMap(candidate_key, smi_check); HValue* instance_type = Add
(map, nullptr, HObjectAccess::ForMapInstanceType()); HValue* not_internalized_bit = AddUncasted
( Token::BIT_AND, instance_type, Add
(static_cast
(kIsNotInternalizedMask))); if_update_with_internalized.If
( not_internalized_bit, graph()->GetConstant0(), Token::NE); if_update_with_internalized.And(); if_update_with_internalized.IfNot
( candidate_key, graph()->GetConstantHole()); if_update_with_internalized.AndIf
(candidate_key, key, Token::EQ); if_update_with_internalized.Then(); // Replace a key that is a non-internalized string by the equivalent // internalized string for faster further lookups. Add
(elements, key_index, key, nullptr, FAST_ELEMENTS); if_update_with_internalized.Else(); if_update_with_internalized.JoinContinuation(&found_key_match_continuation); if_match.JoinContinuation(&found_key_match_continuation); IfBuilder found_key_match(this, &found_key_match_continuation); found_key_match.Then(); // Key at current probe matches. Relevant bits in the |details| field must // be zero, otherwise the dictionary element requires special handling. HValue* details_index = AddUncasted
(base_index, Add
(start_offset + 2)); details_index->ClearFlag(HValue::kCanOverflow); HValue* details = Add
(elements, details_index, nullptr, nullptr, FAST_ELEMENTS); int details_mask = PropertyDetails::TypeField::kMask; details = AddUncasted
(Token::BIT_AND, details, Add
(details_mask)); IfBuilder details_compare(this); details_compare.If
( details, graph()->GetConstant0(), Token::EQ); details_compare.Then(); HValue* result_index = AddUncasted
(base_index, Add
(start_offset + 1)); result_index->ClearFlag(HValue::kCanOverflow); Push(Add
(elements, result_index, nullptr, nullptr, FAST_ELEMENTS)); details_compare.Else(); Add
(receiver, key); Push(Add
( Runtime::FunctionForId(is_strong(language_mode) ? Runtime::kKeyedGetPropertyStrong : Runtime::kKeyedGetProperty), 2)); details_compare.End(); found_key_match.Else(); found_key_match.JoinContinuation(&return_or_loop_continuation); } if_undefined.JoinContinuation(&return_or_loop_continuation); IfBuilder return_or_loop(this, &return_or_loop_continuation); return_or_loop.Then(); probe_loop.Break(); return_or_loop.Else(); entry = AddUncasted
(entry, count); entry->ClearFlag(HValue::kCanOverflow); count = AddUncasted
(count, graph()->GetConstant1()); count->ClearFlag(HValue::kCanOverflow); Push(entry); Push(count); probe_loop.EndBody(); return_or_loop.End(); return Pop(); } HValue* HGraphBuilder::BuildCreateIterResultObject(HValue* value, HValue* done) { NoObservableSideEffectsScope scope(this); // Allocate the JSIteratorResult object. HValue* result = Add
(Add
(JSIteratorResult::kSize), HType::JSObject(), NOT_TENURED, JS_ITERATOR_RESULT_TYPE); // Initialize the JSIteratorResult object. HValue* native_context = BuildGetNativeContext(); HValue* map = Add
( native_context, nullptr, HObjectAccess::ForContextSlot(Context::ITERATOR_RESULT_MAP_INDEX)); Add
(result, HObjectAccess::ForMap(), map); HValue* empty_fixed_array = Add
(Heap::kEmptyFixedArrayRootIndex); Add
(result, HObjectAccess::ForPropertiesPointer(), empty_fixed_array); Add
(result, HObjectAccess::ForElementsPointer(), empty_fixed_array); Add
(result, HObjectAccess::ForObservableJSObjectOffset( JSIteratorResult::kValueOffset), value); Add
(result, HObjectAccess::ForObservableJSObjectOffset( JSIteratorResult::kDoneOffset), done); STATIC_ASSERT(JSIteratorResult::kSize == 5 * kPointerSize); return result; } HValue* HGraphBuilder::BuildRegExpConstructResult(HValue* length, HValue* index, HValue* input) { NoObservableSideEffectsScope scope(this); HConstant* max_length = Add
(JSArray::kInitialMaxFastElementArray); Add
(length, max_length); // Generate size calculation code here in order to make it dominate // the JSRegExpResult allocation. ElementsKind elements_kind = FAST_ELEMENTS; HValue* size = BuildCalculateElementsSize(elements_kind, length); // Allocate the JSRegExpResult and the FixedArray in one step. HValue* result = Add
( Add
(JSRegExpResult::kSize), HType::JSArray(), NOT_TENURED, JS_ARRAY_TYPE); // Initialize the JSRegExpResult header. HValue* native_context = Add
( context(), nullptr, HObjectAccess::ForContextSlot(Context::NATIVE_CONTEXT_INDEX)); Add
( result, HObjectAccess::ForMap(), Add
( native_context, nullptr, HObjectAccess::ForContextSlot(Context::REGEXP_RESULT_MAP_INDEX))); HConstant* empty_fixed_array = Add
(isolate()->factory()->empty_fixed_array()); Add
( result, HObjectAccess::ForJSArrayOffset(JSArray::kPropertiesOffset), empty_fixed_array); Add
( result, HObjectAccess::ForJSArrayOffset(JSArray::kElementsOffset), empty_fixed_array); Add
( result, HObjectAccess::ForJSArrayOffset(JSArray::kLengthOffset), length); // Initialize the additional fields. Add
( result, HObjectAccess::ForJSArrayOffset(JSRegExpResult::kIndexOffset), index); Add
( result, HObjectAccess::ForJSArrayOffset(JSRegExpResult::kInputOffset), input); // Allocate and initialize the elements header. HAllocate* elements = BuildAllocateElements(elements_kind, size); BuildInitializeElementsHeader(elements, elements_kind, length); if (!elements->has_size_upper_bound()) { HConstant* size_in_bytes_upper_bound = EstablishElementsAllocationSize( elements_kind, max_length->Integer32Value()); elements->set_size_upper_bound(size_in_bytes_upper_bound); } Add
( result, HObjectAccess::ForJSArrayOffset(JSArray::kElementsOffset), elements); // Initialize the elements contents with undefined. BuildFillElementsWithValue( elements, elements_kind, graph()->GetConstant0(), length, graph()->GetConstantUndefined()); return result; } HValue* HGraphBuilder::BuildNumberToString(HValue* object, Type* type) { NoObservableSideEffectsScope scope(this); // Convert constant numbers at compile time. if (object->IsConstant() && HConstant::cast(object)->HasNumberValue()) { Handle
number = HConstant::cast(object)->handle(isolate()); Handle
result = isolate()->factory()->NumberToString(number); return Add
(result); } // Create a joinable continuation. HIfContinuation found(graph()->CreateBasicBlock(), graph()->CreateBasicBlock()); // Load the number string cache. HValue* number_string_cache = Add
(Heap::kNumberStringCacheRootIndex); // Make the hash mask from the length of the number string cache. It // contains two elements (number and string) for each cache entry. HValue* mask = AddLoadFixedArrayLength(number_string_cache); mask->set_type(HType::Smi()); mask = AddUncasted
(mask, graph()->GetConstant1()); mask = AddUncasted
(mask, graph()->GetConstant1()); // Check whether object is a smi. IfBuilder if_objectissmi(this); if_objectissmi.If
(object); if_objectissmi.Then(); { // Compute hash for smi similar to smi_get_hash(). HValue* hash = AddUncasted
(Token::BIT_AND, object, mask); // Load the key. HValue* key_index = AddUncasted
(hash, graph()->GetConstant1()); HValue* key = Add
(number_string_cache, key_index, nullptr, nullptr, FAST_ELEMENTS, ALLOW_RETURN_HOLE); // Check if object == key. IfBuilder if_objectiskey(this); if_objectiskey.If
(object, key); if_objectiskey.Then(); { // Make the key_index available. Push(key_index); } if_objectiskey.JoinContinuation(&found); } if_objectissmi.Else(); { if (type->Is(Type::SignedSmall())) { if_objectissmi.Deopt(Deoptimizer::kExpectedSmi); } else { // Check if the object is a heap number. IfBuilder if_objectisnumber(this); HValue* objectisnumber = if_objectisnumber.If
( object, isolate()->factory()->heap_number_map()); if_objectisnumber.Then(); { // Compute hash for heap number similar to double_get_hash(). HValue* low = Add
( object, objectisnumber, HObjectAccess::ForHeapNumberValueLowestBits()); HValue* high = Add
( object, objectisnumber, HObjectAccess::ForHeapNumberValueHighestBits()); HValue* hash = AddUncasted
(Token::BIT_XOR, low, high); hash = AddUncasted
(Token::BIT_AND, hash, mask); // Load the key. HValue* key_index = AddUncasted
(hash, graph()->GetConstant1()); HValue* key = Add
(number_string_cache, key_index, nullptr, nullptr, FAST_ELEMENTS, ALLOW_RETURN_HOLE); // Check if the key is a heap number and compare it with the object. IfBuilder if_keyisnotsmi(this); HValue* keyisnotsmi = if_keyisnotsmi.IfNot
(key); if_keyisnotsmi.Then(); { IfBuilder if_keyisheapnumber(this); if_keyisheapnumber.If
( key, isolate()->factory()->heap_number_map()); if_keyisheapnumber.Then(); { // Check if values of key and object match. IfBuilder if_keyeqobject(this); if_keyeqobject.If
( Add
(key, keyisnotsmi, HObjectAccess::ForHeapNumberValue()), Add
(object, objectisnumber, HObjectAccess::ForHeapNumberValue()), Token::EQ); if_keyeqobject.Then(); { // Make the key_index available. Push(key_index); } if_keyeqobject.JoinContinuation(&found); } if_keyisheapnumber.JoinContinuation(&found); } if_keyisnotsmi.JoinContinuation(&found); } if_objectisnumber.Else(); { if (type->Is(Type::Number())) { if_objectisnumber.Deopt(Deoptimizer::kExpectedHeapNumber); } } if_objectisnumber.JoinContinuation(&found); } } if_objectissmi.JoinContinuation(&found); // Check for cache hit. IfBuilder if_found(this, &found); if_found.Then(); { // Count number to string operation in native code. AddIncrementCounter(isolate()->counters()->number_to_string_native()); // Load the value in case of cache hit. HValue* key_index = Pop(); HValue* value_index = AddUncasted
(key_index, graph()->GetConstant1()); Push(Add
(number_string_cache, value_index, nullptr, nullptr, FAST_ELEMENTS, ALLOW_RETURN_HOLE)); } if_found.Else(); { // Cache miss, fallback to runtime. Add
(object); Push(Add
( Runtime::FunctionForId(Runtime::kNumberToStringSkipCache), 1)); } if_found.End(); return Pop(); } HValue* HGraphBuilder::BuildToObject(HValue* receiver) { NoObservableSideEffectsScope scope(this); // Create a joinable continuation. HIfContinuation wrap(graph()->CreateBasicBlock(), graph()->CreateBasicBlock()); // Determine the proper global constructor function required to wrap // {receiver} into a JSValue, unless {receiver} is already a {JSReceiver}, in // which case we just return it. Deopts to Runtime::kToObject if {receiver} // is undefined or null. IfBuilder receiver_is_smi(this); receiver_is_smi.If
(receiver); receiver_is_smi.Then(); { // Use global Number function. Push(Add
(Context::NUMBER_FUNCTION_INDEX)); } receiver_is_smi.Else(); { // Determine {receiver} map and instance type. HValue* receiver_map = Add
(receiver, nullptr, HObjectAccess::ForMap()); HValue* receiver_instance_type = Add
( receiver_map, nullptr, HObjectAccess::ForMapInstanceType()); // First check whether {receiver} is already a spec object (fast case). IfBuilder receiver_is_not_spec_object(this); receiver_is_not_spec_object.If
( receiver_instance_type, Add
(FIRST_JS_RECEIVER_TYPE), Token::LT); receiver_is_not_spec_object.Then(); { // Load the constructor function index from the {receiver} map. HValue* constructor_function_index = Add
( receiver_map, nullptr, HObjectAccess::ForMapInObjectPropertiesOrConstructorFunctionIndex()); // Check if {receiver} has a constructor (null and undefined have no // constructors, so we deoptimize to the runtime to throw an exception). IfBuilder constructor_function_index_is_invalid(this); constructor_function_index_is_invalid.If
( constructor_function_index, Add
(Map::kNoConstructorFunctionIndex), Token::EQ); constructor_function_index_is_invalid.ThenDeopt( Deoptimizer::kUndefinedOrNullInToObject); constructor_function_index_is_invalid.End(); // Use the global constructor function. Push(constructor_function_index); } receiver_is_not_spec_object.JoinContinuation(&wrap); } receiver_is_smi.JoinContinuation(&wrap); // Wrap the receiver if necessary. IfBuilder if_wrap(this, &wrap); if_wrap.Then(); { // Grab the constructor function index. HValue* constructor_index = Pop(); // Load native context. HValue* native_context = BuildGetNativeContext(); // Determine the initial map for the global constructor. HValue* constructor = Add
(native_context, constructor_index, nullptr, nullptr, FAST_ELEMENTS); HValue* constructor_initial_map = Add
( constructor, nullptr, HObjectAccess::ForPrototypeOrInitialMap()); // Allocate and initialize a JSValue wrapper. HValue* value = BuildAllocate(Add
(JSValue::kSize), HType::JSObject(), JS_VALUE_TYPE, HAllocationMode()); Add
(value, HObjectAccess::ForMap(), constructor_initial_map); HValue* empty_fixed_array = Add
(Heap::kEmptyFixedArrayRootIndex); Add
(value, HObjectAccess::ForPropertiesPointer(), empty_fixed_array); Add
(value, HObjectAccess::ForElementsPointer(), empty_fixed_array); Add
(value, HObjectAccess::ForObservableJSObjectOffset( JSValue::kValueOffset), receiver); Push(value); } if_wrap.Else(); { Push(receiver); } if_wrap.End(); return Pop(); } HAllocate* HGraphBuilder::BuildAllocate( HValue* object_size, HType type, InstanceType instance_type, HAllocationMode allocation_mode) { // Compute the effective allocation size. HValue* size = object_size; if (allocation_mode.CreateAllocationMementos()) { size = AddUncasted
(size, Add
(AllocationMemento::kSize)); size->ClearFlag(HValue::kCanOverflow); } // Perform the actual allocation. HAllocate* object = Add
( size, type, allocation_mode.GetPretenureMode(), instance_type, allocation_mode.feedback_site()); // Setup the allocation memento. if (allocation_mode.CreateAllocationMementos()) { BuildCreateAllocationMemento( object, object_size, allocation_mode.current_site()); } return object; } HValue* HGraphBuilder::BuildAddStringLengths(HValue* left_length, HValue* right_length) { // Compute the combined string length and check against max string length. HValue* length = AddUncasted
(left_length, right_length); // Check that length <= kMaxLength <=> length < MaxLength + 1. HValue* max_length = Add
(String::kMaxLength + 1); Add
(length, max_length); return length; } HValue* HGraphBuilder::BuildCreateConsString( HValue* length, HValue* left, HValue* right, HAllocationMode allocation_mode) { // Determine the string instance types. HInstruction* left_instance_type = AddLoadStringInstanceType(left); HInstruction* right_instance_type = AddLoadStringInstanceType(right); // Allocate the cons string object. HAllocate does not care whether we // pass CONS_STRING_TYPE or CONS_ONE_BYTE_STRING_TYPE here, so we just use // CONS_STRING_TYPE here. Below we decide whether the cons string is // one-byte or two-byte and set the appropriate map. DCHECK(HAllocate::CompatibleInstanceTypes(CONS_STRING_TYPE, CONS_ONE_BYTE_STRING_TYPE)); HAllocate* result = BuildAllocate(Add
(ConsString::kSize), HType::String(), CONS_STRING_TYPE, allocation_mode); // Compute intersection and difference of instance types. HValue* anded_instance_types = AddUncasted
( Token::BIT_AND, left_instance_type, right_instance_type); HValue* xored_instance_types = AddUncasted
( Token::BIT_XOR, left_instance_type, right_instance_type); // We create a one-byte cons string if // 1. both strings are one-byte, or // 2. at least one of the strings is two-byte, but happens to contain only // one-byte characters. // To do this, we check // 1. if both strings are one-byte, or if the one-byte data hint is set in // both strings, or // 2. if one of the strings has the one-byte data hint set and the other // string is one-byte. IfBuilder if_onebyte(this); STATIC_ASSERT(kOneByteStringTag != 0); STATIC_ASSERT(kOneByteDataHintMask != 0); if_onebyte.If
( AddUncasted
( Token::BIT_AND, anded_instance_types, Add
(static_cast
( kStringEncodingMask | kOneByteDataHintMask))), graph()->GetConstant0(), Token::NE); if_onebyte.Or(); STATIC_ASSERT(kOneByteStringTag != 0 && kOneByteDataHintTag != 0 && kOneByteDataHintTag != kOneByteStringTag); if_onebyte.If
( AddUncasted
( Token::BIT_AND, xored_instance_types, Add
(static_cast
( kOneByteStringTag | kOneByteDataHintTag))), Add
(static_cast
( kOneByteStringTag | kOneByteDataHintTag)), Token::EQ); if_onebyte.Then(); { // We can safely skip the write barrier for storing the map here. Add
( result, HObjectAccess::ForMap(), Add
(isolate()->factory()->cons_one_byte_string_map())); } if_onebyte.Else(); { // We can safely skip the write barrier for storing the map here. Add
( result, HObjectAccess::ForMap(), Add
(isolate()->factory()->cons_string_map())); } if_onebyte.End(); // Initialize the cons string fields. Add
(result, HObjectAccess::ForStringHashField(), Add
(String::kEmptyHashField)); Add
(result, HObjectAccess::ForStringLength(), length); Add
(result, HObjectAccess::ForConsStringFirst(), left); Add
(result, HObjectAccess::ForConsStringSecond(), right); // Count the native string addition. AddIncrementCounter(isolate()->counters()->string_add_native()); return result; } void HGraphBuilder::BuildCopySeqStringChars(HValue* src, HValue* src_offset, String::Encoding src_encoding, HValue* dst, HValue* dst_offset, String::Encoding dst_encoding, HValue* length) { DCHECK(dst_encoding != String::ONE_BYTE_ENCODING || src_encoding == String::ONE_BYTE_ENCODING); LoopBuilder loop(this, context(), LoopBuilder::kPostIncrement); HValue* index = loop.BeginBody(graph()->GetConstant0(), length, Token::LT); { HValue* src_index = AddUncasted
(src_offset, index); HValue* value = AddUncasted
(src_encoding, src, src_index); HValue* dst_index = AddUncasted
(dst_offset, index); Add
(dst_encoding, dst, dst_index, value); } loop.EndBody(); } HValue* HGraphBuilder::BuildObjectSizeAlignment( HValue* unaligned_size, int header_size) { DCHECK((header_size & kObjectAlignmentMask) == 0); HValue* size = AddUncasted
( unaligned_size, Add
(static_cast
( header_size + kObjectAlignmentMask))); size->ClearFlag(HValue::kCanOverflow); return AddUncasted
( Token::BIT_AND, size, Add
(static_cast
( ~kObjectAlignmentMask))); } HValue* HGraphBuilder::BuildUncheckedStringAdd( HValue* left, HValue* right, HAllocationMode allocation_mode) { // Determine the string lengths. HValue* left_length = AddLoadStringLength(left); HValue* right_length = AddLoadStringLength(right); // Compute the combined string length. HValue* length = BuildAddStringLengths(left_length, right_length); // Do some manual constant folding here. if (left_length->IsConstant()) { HConstant* c_left_length = HConstant::cast(left_length); DCHECK_NE(0, c_left_length->Integer32Value()); if (c_left_length->Integer32Value() + 1 >= ConsString::kMinLength) { // The right string contains at least one character. return BuildCreateConsString(length, left, right, allocation_mode); } } else if (right_length->IsConstant()) { HConstant* c_right_length = HConstant::cast(right_length); DCHECK_NE(0, c_right_length->Integer32Value()); if (c_right_length->Integer32Value() + 1 >= ConsString::kMinLength) { // The left string contains at least one character. return BuildCreateConsString(length, left, right, allocation_mode); } } // Check if we should create a cons string. IfBuilder if_createcons(this); if_createcons.If
( length, Add
(ConsString::kMinLength), Token::GTE); if_createcons.Then(); { // Create a cons string. Push(BuildCreateConsString(length, left, right, allocation_mode)); } if_createcons.Else(); { // Determine the string instance types. HValue* left_instance_type = AddLoadStringInstanceType(left); HValue* right_instance_type = AddLoadStringInstanceType(right); // Compute union and difference of instance types. HValue* ored_instance_types = AddUncasted
( Token::BIT_OR, left_instance_type, right_instance_type); HValue* xored_instance_types = AddUncasted
( Token::BIT_XOR, left_instance_type, right_instance_type); // Check if both strings have the same encoding and both are // sequential. IfBuilder if_sameencodingandsequential(this); if_sameencodingandsequential.If
( AddUncasted
( Token::BIT_AND, xored_instance_types, Add