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hydrogen.cc
// Copyright 2013 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following // disclaimer in the documentation and/or other materials provided // with the distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. #include "hydrogen.h" #include
#include "v8.h" #include "allocation-site-scopes.h" #include "codegen.h" #include "full-codegen.h" #include "hashmap.h" #include "hydrogen-bce.h" #include "hydrogen-bch.h" #include "hydrogen-canonicalize.h" #include "hydrogen-check-elimination.h" #include "hydrogen-dce.h" #include "hydrogen-dehoist.h" #include "hydrogen-environment-liveness.h" #include "hydrogen-escape-analysis.h" #include "hydrogen-infer-representation.h" #include "hydrogen-infer-types.h" #include "hydrogen-load-elimination.h" #include "hydrogen-gvn.h" #include "hydrogen-mark-deoptimize.h" #include "hydrogen-mark-unreachable.h" #include "hydrogen-minus-zero.h" #include "hydrogen-osr.h" #include "hydrogen-range-analysis.h" #include "hydrogen-redundant-phi.h" #include "hydrogen-removable-simulates.h" #include "hydrogen-representation-changes.h" #include "hydrogen-sce.h" #include "hydrogen-uint32-analysis.h" #include "lithium-allocator.h" #include "parser.h" #include "runtime.h" #include "scopeinfo.h" #include "scopes.h" #include "stub-cache.h" #include "typing.h" #if V8_TARGET_ARCH_IA32 #include "ia32/lithium-codegen-ia32.h" #elif V8_TARGET_ARCH_X64 #include "x64/lithium-codegen-x64.h" #elif V8_TARGET_ARCH_ARM #include "arm/lithium-codegen-arm.h" #elif V8_TARGET_ARCH_MIPS #include "mips/lithium-codegen-mips.h" #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) { } Isolate* HBasicBlock::isolate() const { return graph_->isolate(); } void HBasicBlock::MarkUnreachable() { is_reachable_ = false; } void HBasicBlock::AttachLoopInformation() { ASSERT(!IsLoopHeader()); loop_information_ = new(zone()) HLoopInformation(this, zone()); } void HBasicBlock::DetachLoopInformation() { ASSERT(IsLoopHeader()); loop_information_ = NULL; } void HBasicBlock::AddPhi(HPhi* phi) { ASSERT(!IsStartBlock()); phis_.Add(phi, zone()); phi->SetBlock(this); } void HBasicBlock::RemovePhi(HPhi* phi) { ASSERT(phi->block() == this); ASSERT(phis_.Contains(phi)); phi->Kill(); phis_.RemoveElement(phi); phi->SetBlock(NULL); } void HBasicBlock::AddInstruction(HInstruction* instr, int position) { ASSERT(!IsStartBlock() || !IsFinished()); ASSERT(!instr->IsLinked()); ASSERT(!IsFinished()); if (position != RelocInfo::kNoPosition) { instr->set_position(position); } if (first_ == NULL) { ASSERT(last_environment() != NULL); ASSERT(!last_environment()->ast_id().IsNone()); HBlockEntry* entry = new(zone()) HBlockEntry(); entry->InitializeAsFirst(this); if (position != RelocInfo::kNoPosition) { entry->set_position(position); } else { ASSERT(!FLAG_emit_opt_code_positions || !graph()->info()->IsOptimizing()); } 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) { ASSERT(HasEnvironment()); HEnvironment* environment = last_environment(); ASSERT(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, int position) { ASSERT(!IsFinished()); AddInstruction(end, position); end_ = end; for (HSuccessorIterator it(end); !it.Done(); it.Advance()) { it.Current()->RegisterPredecessor(this); } } void HBasicBlock::Goto(HBasicBlock* block, int position, FunctionState* state, bool add_simulate) { bool drop_extra = state != NULL && state->inlining_kind() == DROP_EXTRA_ON_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, int position) { HBasicBlock* target = state->function_return(); bool drop_extra = state->inlining_kind() == DROP_EXTRA_ON_RETURN; ASSERT(target->IsInlineReturnTarget()); ASSERT(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) { ASSERT(!HasEnvironment()); ASSERT(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(); ASSERT(length > 0); for (int i = 0; i < length; i++) { HBasicBlock* predecessor = predecessors_[i]; ASSERT(predecessor->end()->IsGoto()); HSimulate* simulate = HSimulate::cast(predecessor->end()->previous()); ASSERT(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; } 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) { ASSERT(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::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). ASSERT(IsLoopHeader() || first_ == NULL); HEnvironment* incoming_env = pred->last_environment(); if (IsLoopHeader()) { ASSERT(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()) { ASSERT(!IsLoopHeader()); SetInitialEnvironment(pred->last_environment()->Copy()); } predecessors_.Add(pred, zone()); } void HBasicBlock::AddDominatedBlock(HBasicBlock* block) { ASSERT(!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(); } ASSERT(first != NULL && second != NULL); } if (dominator_ != first) { ASSERT(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. ASSERT(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. ASSERT(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. ASSERT(IsFinished()); ASSERT(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) { ASSERT(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(); ASSERT(current != NULL && current->IsBlockEntry()); while (current != NULL) { ASSERT((current->next() == NULL) == current->IsControlInstruction()); ASSERT(current->block() == block); current->Verify(); current = current->next(); } // Check that successors are correctly set. HBasicBlock* first = block->end()->FirstSuccessor(); HBasicBlock* second = block->end()->SecondSuccessor(); ASSERT(second == NULL || first != NULL); // Check that the predecessor array is correct. if (first != NULL) { ASSERT(first->predecessors()->Contains(block)); if (second != NULL) { ASSERT(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); ASSERT(predecessor->end()->IsGoto() || predecessor->end()->IsDeoptimize()); ASSERT(predecessor->last_environment()->ast_id() == id); } } } // Check special property of first block to have no predecessors. ASSERT(blocks_.at(0)->predecessors()->is_empty()); if (do_full_verify) { // Check that the graph is fully connected. ReachabilityAnalyzer analyzer(entry_block_, blocks_.length(), NULL); ASSERT(analyzer.visited_count() == blocks_.length()); // Check that entry block dominator is NULL. ASSERT(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. ASSERT(i == 0); } else { // Assert that block is unreachable if dominator must not be visited. ReachabilityAnalyzer dominator_analyzer(entry_block_, blocks_.length(), block->dominator()); ASSERT(!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(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); } #define DEFINE_GET_CONSTANT(Name, name, htype, boolean_value) \ HConstant* HGraph::GetConstant##Name() { \ if (!constant_##name##_.is_set()) { \ HConstant* constant = new(zone()) HConstant( \ Unique
::CreateImmovable(isolate()->factory()->name##_value()), \ Representation::Tagged(), \ htype, \ false, \ true, \ false, \ boolean_value); \ constant->InsertAfter(entry_block()->first()); \ constant_##name##_.set(constant); \ } \ return ReinsertConstantIfNecessary(constant_##name##_.get()); \ } DEFINE_GET_CONSTANT(Undefined, undefined, HType::Tagged(), false) DEFINE_GET_CONSTANT(True, true, HType::Boolean(), true) DEFINE_GET_CONSTANT(False, false, HType::Boolean(), false) DEFINE_GET_CONSTANT(Hole, the_hole, HType::Tagged(), false) DEFINE_GET_CONSTANT(Null, null, HType::Tagged(), 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(HGraphBuilder* builder) : builder_(builder), finished_(false), did_then_(false), did_else_(false), did_else_if_(false), did_and_(false), did_or_(false), captured_(false), needs_compare_(true), 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) { HEnvironment* env = builder->environment(); first_true_block_ = builder->CreateBasicBlock(env->Copy()); first_false_block_ = builder->CreateBasicBlock(env->Copy()); } HGraphBuilder::IfBuilder::IfBuilder( HGraphBuilder* builder, HIfContinuation* continuation) : builder_(builder), finished_(false), did_then_(false), did_else_(false), did_else_if_(false), did_and_(false), did_or_(false), captured_(false), needs_compare_(false), pending_merge_block_(false), first_true_block_(NULL), first_false_block_(NULL), split_edge_merge_block_(NULL), merge_at_join_blocks_(NULL), normal_merge_at_join_block_count_(0), deopt_merge_at_join_block_count_(0) { continuation->Continue(&first_true_block_, &first_false_block_); } HControlInstruction* HGraphBuilder::IfBuilder::AddCompare( HControlInstruction* compare) { ASSERT(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() { ASSERT(!needs_compare_); ASSERT(!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() { ASSERT(!needs_compare_); ASSERT(!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) { ASSERT(!did_else_if_); ASSERT(!finished_); ASSERT(!captured_); HBasicBlock* true_block = NULL; HBasicBlock* false_block = NULL; Finish(&true_block, &false_block); ASSERT(true_block != NULL); ASSERT(false_block != NULL); continuation->Capture(true_block, false_block); captured_ = true; builder_->set_current_block(NULL); End(); } void HGraphBuilder::IfBuilder::JoinContinuation(HIfContinuation* continuation) { ASSERT(!did_else_if_); ASSERT(!finished_); ASSERT(!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()) { ASSERT(continuation->IsTrueReachable()); builder_->GotoNoSimulate(true_block, continuation->true_branch()); } if (false_block != NULL && !false_block->IsFinished()) { ASSERT(continuation->IsFalseReachable()); builder_->GotoNoSimulate(false_block, continuation->false_branch()); } captured_ = true; End(); } void HGraphBuilder::IfBuilder::Then() { ASSERT(!captured_); ASSERT(!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() { ASSERT(did_then_); ASSERT(!captured_); ASSERT(!finished_); AddMergeAtJoinBlock(false); builder_->set_current_block(first_false_block_); pending_merge_block_ = true; did_else_ = true; } void HGraphBuilder::IfBuilder::Deopt(const char* reason) { ASSERT(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(); ASSERT(block == NULL || !block->IsFinished()); MergeAtJoinBlock* record = new(builder_->zone()) MergeAtJoinBlock(block, deopt, merge_at_join_blocks_); merge_at_join_blocks_ = record; if (block != NULL) { ASSERT(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() { ASSERT(!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_; } ASSERT(then_record->next_ == NULL); } void HGraphBuilder::IfBuilder::End() { if (captured_) return; Finish(); int total_merged_blocks = normal_merge_at_join_block_count_ + deopt_merge_at_join_block_count_; ASSERT(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) { builder_->PadEnvironmentForContinuation(current->block_, merge_block); builder_->GotoNoSimulate(current->block_, merge_block); } current = current->next_; } builder_->set_current_block(merge_block); } HGraphBuilder::LoopBuilder::LoopBuilder(HGraphBuilder* builder, HValue* context, LoopBuilder::Direction direction) : builder_(builder), context_(context), direction_(direction), finished_(false) { header_block_ = builder->CreateLoopHeaderBlock(); body_block_ = NULL; exit_block_ = NULL; exit_trampoline_block_ = NULL; increment_amount_ = builder_->graph()->GetConstant1(); } HGraphBuilder::LoopBuilder::LoopBuilder(HGraphBuilder* builder, HValue* context, LoopBuilder::Direction direction, HValue* increment_amount) : builder_(builder), context_(context), direction_(direction), finished_(false) { header_block_ = builder->CreateLoopHeaderBlock(); body_block_ = NULL; exit_block_ = NULL; exit_trampoline_block_ = NULL; increment_amount_ = increment_amount; } HValue* HGraphBuilder::LoopBuilder::BeginBody( HValue* initial, HValue* terminating, Token::Value token) { 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) { HValue* one = builder_->graph()->GetConstant1(); if (direction_ == kPreIncrement) { increment_ = HAdd::New(zone(), context_, phi_, one); } else { increment_ = HSub::New(zone(), context_, phi_, one); } increment_->ClearFlag(HValue::kCanOverflow); builder_->AddInstruction(increment_); return increment_; } else { return phi_; } } void HGraphBuilder::LoopBuilder::Break() { if (exit_trampoline_block_ == NULL) { // Its the first time we saw a break. 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() { ASSERT(!finished_); if (direction_ == kPostIncrement || direction_ == kPostDecrement) { if (direction_ == kPostIncrement) { increment_ = HAdd::New(zone(), context_, phi_, increment_amount_); } else { increment_ = HSub::New(zone(), context_, phi_, increment_amount_); } increment_->ClearFlag(HValue::kCanOverflow); builder_->AddInstruction(increment_); } // 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) { ASSERT(current_block() != NULL); ASSERT(!FLAG_emit_opt_code_positions || position_ != RelocInfo::kNoPosition || !info_->IsOptimizing()); current_block()->AddInstruction(instr, position_); if (graph()->IsInsideNoSideEffectsScope()) { instr->SetFlag(HValue::kHasNoObservableSideEffects); } return instr; } void HGraphBuilder::FinishCurrentBlock(HControlInstruction* last) { ASSERT(!FLAG_emit_opt_code_positions || !info_->IsOptimizing() || position_ != RelocInfo::kNoPosition); current_block()->Finish(last, position_); if (last->IsReturn() || last->IsAbnormalExit()) { set_current_block(NULL); } } void HGraphBuilder::FinishExitCurrentBlock(HControlInstruction* instruction) { ASSERT(!FLAG_emit_opt_code_positions || !info_->IsOptimizing() || position_ != RelocInfo::kNoPosition); current_block()->FinishExit(instruction, 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, HObjectAccess::ForCounter()); HValue* new_value = AddUncasted
(old_value, graph()->GetConstant1()); new_value->ClearFlag(HValue::kCanOverflow); // Ignore counter overflow Add
(reference, HObjectAccess::ForCounter(), new_value); } } void HGraphBuilder::AddSimulate(BailoutId id, RemovableSimulate removable) { ASSERT(current_block() != NULL); ASSERT(!graph()->IsInsideNoSideEffectsScope()); current_block()->AddNewSimulate(id, 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::BuildCheckHeapObject(HValue* obj) { if (obj->type().IsHeapObject()) return obj; return Add
(obj); } void HGraphBuilder::FinishExitWithHardDeoptimization( const char* reason, HBasicBlock* continuation) { PadEnvironmentForContinuation(current_block(), continuation); Add
(reason, Deoptimizer::EAGER); if (graph()->IsInsideNoSideEffectsScope()) { GotoNoSimulate(continuation); } else { Goto(continuation); } } void HGraphBuilder::PadEnvironmentForContinuation( HBasicBlock* from, HBasicBlock* continuation) { if (continuation->last_environment() != NULL) { // When merging from a deopt block to a continuation, resolve differences in // environment by pushing constant 0 and popping extra values so that the // environments match during the join. Push 0 since it has the most specific // representation, and will not influence representation inference of the // phi. int continuation_env_length = continuation->last_environment()->length(); while (continuation_env_length != from->last_environment()->length()) { if (continuation_env_length > from->last_environment()->length()) { from->last_environment()->Push(graph()->GetConstant0()); } else { from->last_environment()->Pop(); } } } else { ASSERT(continuation->predecessors()->length() == 0); } } HValue* HGraphBuilder::BuildCheckMap(HValue* obj, Handle
map) { return Add
(obj, map, top_info()); } HValue* HGraphBuilder::BuildCheckString(HValue* string) { if (!string->type().IsString()) { ASSERT(!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; return Add
(object, function); } HValue* HGraphBuilder::BuildCheckForCapacityGrow(HValue* object, HValue* elements, ElementsKind kind, HValue* length, HValue* key, bool is_js_array) { 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); IfBuilder capacity_checker(this); capacity_checker.If
(key, current_capacity, Token::GTE); capacity_checker.Then(); HValue* max_gap = Add
(static_cast
(JSObject::kMaxGap)); HValue* max_capacity = AddUncasted
(current_capacity, max_gap); IfBuilder key_checker(this); key_checker.If
(key, max_capacity, Token::LT); key_checker.Then(); key_checker.ElseDeopt("Key out of capacity range"); key_checker.End(); HValue* new_capacity = BuildNewElementsCapacity(key); HValue* new_elements = BuildGrowElementsCapacity(object, elements, kind, kind, length, new_capacity); environment()->Push(new_elements); capacity_checker.Else(); environment()->Push(elements); capacity_checker.End(); if (is_js_array) { HValue* new_length = AddUncasted
(key, graph_->GetConstant1()); new_length->ClearFlag(HValue::kCanOverflow); Add
(object, HObjectAccess::ForArrayLength(kind), new_length); } 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) { ASSERT(!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, 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); } HValue* HGraphBuilder::BuildUncheckedDictionaryElementLoadHelper( HValue* elements, HValue* key, HValue* hash, HValue* mask, int current_probe) { if (current_probe == kNumberDictionaryProbes) { return NULL; } int32_t offset = SeededNumberDictionary::GetProbeOffset(current_probe); HValue* raw_index = (current_probe == 0) ? hash : AddUncasted
(hash, Add
(offset)); raw_index = AddUncasted
(Token::BIT_AND, raw_index, mask); int32_t entry_size = SeededNumberDictionary::kEntrySize; raw_index = AddUncasted
(raw_index, Add
(entry_size)); raw_index->ClearFlag(HValue::kCanOverflow); int32_t base_offset = SeededNumberDictionary::kElementsStartIndex; HValue* key_index = AddUncasted
(raw_index, Add
(base_offset)); key_index->ClearFlag(HValue::kCanOverflow); HValue* candidate_key = Add
(elements, key_index, static_cast
(NULL), FAST_SMI_ELEMENTS); IfBuilder key_compare(this); key_compare.IfNot
(key, candidate_key); key_compare.Then(); { // Key at the current probe doesn't match, try at the next probe. HValue* result = BuildUncheckedDictionaryElementLoadHelper( elements, key, hash, mask, current_probe + 1); if (result == NULL) { key_compare.Deopt("probes exhausted in keyed load dictionary lookup"); result = graph()->GetConstantUndefined(); } else { Push(result); } } key_compare.Else(); { // Key at current probe matches. Details must be zero, otherwise the // dictionary element requires special handling. HValue* details_index = AddUncasted
( raw_index, Add
(base_offset + 2)); details_index->ClearFlag(HValue::kCanOverflow); HValue* details = Add
(elements, details_index, static_cast
(NULL), FAST_SMI_ELEMENTS); IfBuilder details_compare(this); details_compare.If
(details, graph()->GetConstant0(), Token::NE); details_compare.ThenDeopt("keyed load dictionary element not fast case"); details_compare.Else(); { // Key matches and details are zero --> fast case. Load and return the // value. HValue* result_index = AddUncasted
( raw_index, Add
(base_offset + 1)); result_index->ClearFlag(HValue::kCanOverflow); Push(Add
(elements, result_index, static_cast
(NULL), FAST_ELEMENTS)); } details_compare.End(); } key_compare.End(); return Pop(); } 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* key) { HValue* elements = AddLoadElements(receiver); HValue* hash = BuildElementIndexHash(key); HValue* capacity = Add
( elements, Add
(NameDictionary::kCapacityIndex), static_cast
(NULL), FAST_SMI_ELEMENTS); HValue* mask = AddUncasted
(capacity, graph()->GetConstant1()); mask->ChangeRepresentation(Representation::Integer32()); mask->ClearFlag(HValue::kCanOverflow); return BuildUncheckedDictionaryElementLoadHelper(elements, key, hash, mask, 0); } HValue* HGraphBuilder::BuildNumberToString(HValue* object, Handle
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, static_cast
(NULL), 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::Smi())) { if_objectissmi.Deopt("Expected smi"); } else { // Check if the object is a heap number. IfBuilder if_objectisnumber(this); 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, HObjectAccess::ForHeapNumberValueLowestBits()); HValue* high = Add
( object, 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, static_cast
(NULL), FAST_ELEMENTS, ALLOW_RETURN_HOLE); // Check if key is a heap number (the number string cache contains only // SMIs and heap number, so it is sufficient to do a SMI check here). IfBuilder if_keyisnotsmi(this); if_keyisnotsmi.IfNot
(key); if_keyisnotsmi.Then(); { // Check if values of key and object match. IfBuilder if_keyeqobject(this); if_keyeqobject.If
( Add
(key, HObjectAccess::ForHeapNumberValue()), Add
(object, HObjectAccess::ForHeapNumberValue()), Token::EQ); if_keyeqobject.Then(); { // Make the key_index available. Push(key_index); } if_keyeqobject.JoinContinuation(&found); } if_keyisnotsmi.JoinContinuation(&found); } if_objectisnumber.Else(); { if (type->Is(Type::Number())) { if_objectisnumber.Deopt("Expected heap number"); } } 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, static_cast
(NULL), FAST_ELEMENTS, ALLOW_RETURN_HOLE)); } if_found.Else(); { // Cache miss, fallback to runtime. Add
(object); Push(Add
( isolate()->factory()->empty_string(), Runtime::FunctionForId(Runtime::kNumberToStringSkipCache), 1)); } if_found.End(); return Pop(); } HValue* HGraphBuilder::BuildSeqStringSizeFor(HValue* length, String::Encoding encoding) { STATIC_ASSERT((SeqString::kHeaderSize & kObjectAlignmentMask) == 0); HValue* size = length; if (encoding == String::TWO_BYTE_ENCODING) { size = AddUncasted
(length, graph()->GetConstant1()); size->ClearFlag(HValue::kCanOverflow); size->SetFlag(HValue::kUint32); } size = AddUncasted
(size, Add
(static_cast
( SeqString::kHeaderSize + kObjectAlignmentMask))); size->ClearFlag(HValue::kCanOverflow); size = AddUncasted
( Token::BIT_AND, size, Add
(static_cast
( ~kObjectAlignmentMask))); return size; } void HGraphBuilder::BuildCopySeqStringChars(HValue* src, HValue* src_offset, String::Encoding src_encoding, HValue* dst, HValue* dst_offset, String::Encoding dst_encoding, HValue* length) { ASSERT(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::BuildUncheckedStringAdd(HValue* left, HValue* right, PretenureFlag pretenure_flag) { // Determine the string lengths. HValue* left_length = Add
( left, HObjectAccess::ForStringLength()); HValue* right_length = Add
( right, HObjectAccess::ForStringLength()); // Compute the combined string length. If the result is larger than the max // supported string length, we bailout to the runtime. This is done implicitly // when converting the result back to a smi in case the max string length // equals the max smi valie. Otherwise, for platforms with 32-bit smis, we do HValue* length = AddUncasted
(left_length, right_length); STATIC_ASSERT(String::kMaxLength <= Smi::kMaxValue); if (String::kMaxLength != Smi::kMaxValue) { IfBuilder if_nooverflow(this); if_nooverflow.If
( length, Add
(String::kMaxLength), Token::LTE); if_nooverflow.Then(); if_nooverflow.ElseDeopt("String length exceeds limit"); } // Determine the string instance types. HLoadNamedField* left_instance_type = Add
( Add
(left, HObjectAccess::ForMap()), HObjectAccess::ForMapInstanceType()); HLoadNamedField* right_instance_type = Add
( Add
(right, HObjectAccess::ForMap()), HObjectAccess::ForMapInstanceType()); // Compute difference of instance types. HValue* xored_instance_types = AddUncasted
( Token::BIT_XOR, left_instance_type, right_instance_type); // Check if we should create a cons string. IfBuilder if_createcons(this); if_createcons.If
( length, Add
(ConsString::kMinLength), Token::GTE); if_createcons.Then(); { // Allocate the cons string object. HAllocate does not care whether we // pass CONS_STRING_TYPE or CONS_ASCII_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. HAllocate* string = Add
(Add
(ConsString::kSize), HType::String(), pretenure_flag, CONS_STRING_TYPE); // Compute the intersection of instance types. HValue* anded_instance_types = AddUncasted
( Token::BIT_AND, 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. Handle
map = isolate()->factory()->cons_ascii_string_map(); AddStoreMapConstantNoWriteBarrier(string, map); } if_onebyte.Else(); { // We can safely skip the write barrier for storing the map here. Handle
map = isolate()->factory()->cons_string_map(); AddStoreMapConstantNoWriteBarrier(string, map); } if_onebyte.End(); // Initialize the cons string fields. Add
(string, HObjectAccess::ForStringHashField(), Add
(String::kEmptyHashField)); Add
(string, HObjectAccess::ForStringLength(), length); Add
(string, HObjectAccess::ForConsStringFirst(), left); Add
(string, HObjectAccess::ForConsStringSecond(), right); // Count the native string addition. AddIncrementCounter(isolate()->counters()->string_add_native()); // Cons string is result. Push(string); } if_createcons.Else(); { // Compute union of instance types. HValue* ored_instance_types = AddUncasted
( Token::BIT_OR, 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
(static_cast
(kStringEncodingMask))), graph()->GetConstant0(), Token::EQ); if_sameencodingandsequential.And(); STATIC_ASSERT(kSeqStringTag == 0); if_sameencodingandsequential.If
( AddUncasted
( Token::BIT_AND, ored_instance_types, Add
(static_cast
(kStringRepresentationMask))), graph()->GetConstant0(), Token::EQ); if_sameencodingandsequential.Then(); { // Check if the result is a one-byte string. IfBuilder if_onebyte(this); STATIC_ASSERT(kOneByteStringTag != 0); if_onebyte.If
( AddUncasted
( Token::BIT_AND, ored_instance_types, Add
(static_cast
(kStringEncodingMask))), graph()->GetConstant0(), Token::NE); if_onebyte.Then(); { // Calculate the number of bytes needed for the characters in the // string while observing object alignment. HValue* size = BuildSeqStringSizeFor( length, String::ONE_BYTE_ENCODING); // Allocate the ASCII string object. Handle
map = isolate()->factory()->ascii_string_map(); HAllocate* string = Add
(size, HType::String(), pretenure_flag, ASCII_STRING_TYPE); string->set_known_initial_map(map); // We can safely skip the write barrier for storing map here. AddStoreMapConstantNoWriteBarrier(string, map); // Length must be stored into the string before we copy characters to // make debug verification code happy. Add
(string, HObjectAccess::ForStringLength(), length); // Copy bytes from the left string. BuildCopySeqStringChars( left, graph()->GetConstant0(), String::ONE_BYTE_ENCODING, string, graph()->GetConstant0(), String::ONE_BYTE_ENCODING, left_length); // Copy bytes from the right string. BuildCopySeqStringChars( right, graph()->GetConstant0(), String::ONE_BYTE_ENCODING, string, left_length, String::ONE_BYTE_ENCODING, right_length); // Count the native string addition. AddIncrementCounter(isolate()->counters()->string_add_native()); // Return the string. Push(string); } if_onebyte.Else(); { // Calculate the number of bytes needed for the characters in the // string while observing object alignment. HValue* size = BuildSeqStringSizeFor( length, String::TWO_BYTE_ENCODING); // Allocate the two-byte string object. Handle
map = isolate()->factory()->string_map(); HAllocate* string = Add
(size, HType::String(), pretenure_flag, STRING_TYPE); string->set_known_initial_map(map); // We can safely skip the write barrier for storing map here. AddStoreMapConstantNoWriteBarrier(string, map); // Length must be stored into the string before we copy characters to // make debug verification code happy. Add
(string, HObjectAccess::ForStringLength(), length); // Copy bytes from the left string. BuildCopySeqStringChars( left, graph()->GetConstant0(), String::TWO_BYTE_ENCODING, string, graph()->GetConstant0(), String::TWO_BYTE_ENCODING, left_length); // Copy bytes from the right string. BuildCopySeqStringChars( right, graph()->GetConstant0(), String::TWO_BYTE_ENCODING, string, left_length, String::TWO_BYTE_ENCODING, right_length); // Return the string. Push(string); } if_onebyte.End(); // Initialize the (common) string fields. HValue* string = Pop(); Add
(string, HObjectAccess::ForStringHashField(), Add
(String::kEmptyHashField)); // Count the native string addition. AddIncrementCounter(isolate()->counters()->string_add_native()); Push(string); } if_sameencodingandsequential.Else(); { // Fallback to the runtime to add the two strings. Add
(left); Add
(right); Push(Add
(isolate()->factory()->empty_string(), Runtime::FunctionForId(Runtime::kStringAdd), 2)); } if_sameencodingandsequential.End(); } if_createcons.End(); return Pop(); } HValue* HGraphBuilder::BuildStringAdd(HValue* left, HValue* right, PretenureFlag pretenure_flag) { // Determine the string lengths. HValue* left_length = Add
( left, HObjectAccess::ForStringLength()); HValue* right_length = Add
( right, HObjectAccess::ForStringLength()); // Check if left string is empty. IfBuilder if_leftisempty(this); if_leftisempty.If
( left_length, graph()->GetConstant0(), Token::EQ); if_leftisempty.Then(); { // Count the native string addition. AddIncrementCounter(isolate()->counters()->string_add_native()); // Just return the right string. Push(right); } if_leftisempty.Else(); { // Check if right string is empty. IfBuilder if_rightisempty(this); if_rightisempty.If
( right_length, graph()->GetConstant0(), Token::EQ); if_rightisempty.Then(); { // Count the native string addition. AddIncrementCounter(isolate()->counters()->string_add_native()); // Just return the left string. Push(left); } if_rightisempty.Else(); { // Concatenate the two non-empty strings. Push(BuildUncheckedStringAdd(left, right, pretenure_flag)); } if_rightisempty.End(); } if_leftisempty.End(); return Pop(); } HInstruction* HGraphBuilder::BuildUncheckedMonomorphicElementAccess( HValue* checked_object, HValue* key, HValue* val, bool is_js_array, ElementsKind elements_kind, bool is_store, LoadKeyedHoleMode load_mode, KeyedAccessStoreMode store_mode) { ASSERT(!IsExternalArrayElementsKind(elements_kind) || !is_js_array); // No GVNFlag is necessary for ElementsKind if there is an explicit dependency // on a HElementsTransition instruction. The flag can also be removed if the // map to check has FAST_HOLEY_ELEMENTS, since there can be no further // ElementsKind transitions. Finally, the dependency can be removed for stores // for FAST_ELEMENTS, since a transition to HOLEY elements won't change the // generated store code. if ((elements_kind == FAST_HOLEY_ELEMENTS) || (elements_kind == FAST_ELEMENTS && is_store)) { checked_object->ClearGVNFlag(kDependsOnElementsKind); } bool fast_smi_only_elements = IsFastSmiElementsKind(elements_kind); bool fast_elements = IsFastObjectElementsKind(elements_kind); HValue* elements = AddLoadElements(checked_object); if (is_store && (fast_elements || fast_smi_only_elements) && store_mode != STORE_NO_TRANSITION_HANDLE_COW) { HCheckMaps* check_cow_map = Add
( elements, isolate()->factory()->fixed_array_map(), top_info()); check_cow_map->ClearGVNFlag(kDependsOnElementsKind); } HInstruction* length = NULL; if (is_js_array) { length = Add
( checked_object, HObjectAccess::ForArrayLength(elements_kind)); } else { length = AddLoadFixedArrayLength(elements); } length->set_type(HType::Smi()); HValue* checked_key = NULL; if (IsExternalArrayElementsKind(elements_kind)) { if (store_mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) { NoObservableSideEffectsScope no_effects(this); HLoadExternalArrayPointer* external_elements = Add
(elements); IfBuilder length_checker(this); length_checker.If
(key, length, Token::LT); length_checker.Then(); IfBuilder negative_checker(this); HValue* bounds_check = negative_checker.If
( key, graph()->GetConstant0(), Token::GTE); negative_checker.Then(); HInstruction* result = AddElementAccess( external_elements, key, val, bounds_check, elements_kind, is_store); negative_checker.ElseDeopt("Negative key encountered"); negative_checker.End(); length_checker.End(); return result; } else { ASSERT(store_mode == STANDARD_STORE); checked_key = Add
(key, length); HLoadExternalArrayPointer* external_elements = Add
(elements); return AddElementAccess( external_elements, checked_key, val, checked_object, elements_kind, is_store); } } ASSERT(fast_smi_only_elements || fast_elements || IsFastDoubleElementsKind(elements_kind)); // In case val is stored into a fast smi array, assure that the value is a smi // before manipulating the backing store. Otherwise the actual store may // deopt, leaving the backing store in an invalid state. if (is_store && IsFastSmiElementsKind(elements_kind) && !val->type().IsSmi()) { val = AddUncasted
(val, Representation::Smi()); } if (IsGrowStoreMode(store_mode)) { NoObservableSideEffectsScope no_effects(this); elements = BuildCheckForCapacityGrow(checked_object, elements, elements_kind, length, key, is_js_array); checked_key = key; } else { checked_key = Add
(key, length); if (is_store && (fast_elements || fast_smi_only_elements)) { if (store_mode == STORE_NO_TRANSITION_HANDLE_COW) { NoObservableSideEffectsScope no_effects(this); elements = BuildCopyElementsOnWrite(checked_object, elements, elements_kind, length); } else { HCheckMaps* check_cow_map = Add
( elements, isolate()->factory()->fixed_array_map(), top_info()); check_cow_map->ClearGVNFlag(kDependsOnElementsKind); } } } return AddElementAccess(elements, checked_key, val, checked_object, elements_kind, is_store, load_mode); } HValue* HGraphBuilder::BuildAllocateArrayFromLength( JSArrayBuilder* array_builder, HValue* length_argument) { if (length_argument->IsConstant() && HConstant::cast(length_argument)->HasSmiValue()) { int array_length = HConstant::cast(length_argument)->Integer32Value(); HValue* new_object = array_length == 0 ? array_builder->AllocateEmptyArray() : array_builder->AllocateArray(length_argument, length_argument); return new_object; } HValue* constant_zero = graph()->GetConstant0(); HConstant* max_alloc_length = Add
(JSObject::kInitialMaxFastElementArray); HInstruction* checked_length = Add
(length_argument, max_alloc_length); IfBuilder if_builder(this); if_builder.If
(checked_length, constant_zero, Token::EQ); if_builder.Then(); const int initial_capacity = JSArray::kPreallocatedArrayElements; HConstant* initial_capacity_node = Add
(initial_capacity); Push(initial_capacity_node); // capacity Push(constant_zero); // length if_builder.Else(); if (!(top_info()->IsStub()) && IsFastPackedElementsKind(array_builder->kind())) { // We'll come back later with better (holey) feedback. if_builder.Deopt("Holey array despite packed elements_kind feedback"); } else { Push(checked_length); // capacity Push(checked_length); // length } if_builder.End(); // Figure out total size HValue* length = Pop(); HValue* capacity = Pop(); return array_builder->AllocateArray(capacity, length); } HValue* HGraphBuilder::BuildAllocateElements(ElementsKind kind, HValue* capacity) { int elements_size; InstanceType instance_type; if (IsFastDoubleElementsKind(kind)) { elements_size = kDoubleSize; instance_type = FIXED_DOUBLE_ARRAY_TYPE; } else { elements_size = kPointerSize; instance_type = FIXED_ARRAY_TYPE; } HConstant* elements_size_value = Add
(elements_size); HValue* mul = AddUncasted
(capacity, elements_size_value); mul->ClearFlag(HValue::kCanOverflow); HConstant* header_size = Add
(FixedArray::kHeaderSize); HValue* total_size = AddUncasted
(mul, header_size); total_size->ClearFlag(HValue::kCanOverflow); return Add
(total_size, HType::JSArray(), isolate()->heap()->GetPretenureMode(), instance_type); } void HGraphBuilder::BuildInitializeElementsHeader(HValue* elements, ElementsKind kind, HValue* capacity) { Factory* factory = isolate()->factory(); Handle
map = IsFastDoubleElementsKind(kind) ? factory->fixed_double_array_map() : factory->fixed_array_map(); AddStoreMapConstant(elements, map); Add
(elements, HObjectAccess::ForFixedArrayLength(), capacity); } HValue* HGraphBuilder::BuildAllocateElementsAndInitializeElementsHeader( ElementsKind kind, HValue* capacity) { // The HForceRepresentation is to prevent possible deopt on int-smi // conversion after allocation but before the new object fields are set. capacity = AddUncasted
(capacity, Representation::Smi()); HValue* new_elements = BuildAllocateElements(kind, capacity); BuildInitializeElementsHeader(new_elements, kind, capacity); return new_elements; } HInnerAllocatedObject* HGraphBuilder::BuildJSArrayHeader(HValue* array, HValue* array_map, AllocationSiteMode mode, ElementsKind elements_kind, HValue* allocation_site_payload, HValue* length_field) { Add
(array, HObjectAccess::ForMap(), array_map); HConstant* empty_fixed_array = Add
(isolate()->factory()->empty_fixed_array()); HObjectAccess access = HObjectAccess::ForPropertiesPointer(); Add
(array, access, empty_fixed_array); Add
(array, HObjectAccess::ForArrayLength(elements_kind), length_field); if (mode == TRACK_ALLOCATION_SITE) { BuildCreateAllocationMemento( array, Add
(JSArray::kSize), allocation_site_payload); } int elements_location = JSArray::kSize; if (mode == TRACK_ALLOCATION_SITE) { elements_location += AllocationMemento::kSize; } HInnerAllocatedObject* elements = Add
( array, Add
(elements_location)); Add
(array, HObjectAccess::ForElementsPointer(), elements); return elements; } HInstruction* HGraphBuilder::AddElementAccess( HValue* elements, HValue* checked_key, HValue* val, HValue* dependency, ElementsKind elements_kind, bool is_store, LoadKeyedHoleMode load_mode) { if (is_store) { ASSERT(val != NULL); if (elements_kind == EXTERNAL_PIXEL_ELEMENTS) { val = Add
(val); } return Add
(elements, checked_key, val, elements_kind); } ASSERT(!is_store); ASSERT(val == NULL); HLoadKeyed* load = Add
( elements, checked_key, dependency, elements_kind, load_mode); if (FLAG_opt_safe_uint32_operations && elements_kind == EXTERNAL_UNSIGNED_INT_ELEMENTS) { graph()->RecordUint32Instruction(load); } return load; } HLoadNamedField* HGraphBuilder::AddLoadElements(HValue* object) { return Add
(object, HObjectAccess::ForElementsPointer()); } HLoadNamedField* HGraphBuilder::AddLoadFixedArrayLength(HValue* object) { return Add
(object, HObjectAccess::ForFixedArrayLength()); } HValue* HGraphBuilder::BuildNewElementsCapacity(HValue* old_capacity) { HValue* half_old_capacity = AddUncasted
(old_capacity, graph_->GetConstant1()); HValue* new_capacity = AddUncasted
(half_old_capacity, old_capacity); new_capacity->ClearFlag(HValue::kCanOverflow); HValue* min_growth = Add
(16); new_capacity = AddUncasted
(new_capacity, min_growth); new_capacity->ClearFlag(HValue::kCanOverflow); return new_capacity; } void HGraphBuilder::BuildNewSpaceArrayCheck(HValue* length, ElementsKind kind) { Heap* heap = isolate()->heap(); int element_size = IsFastDoubleElementsKind(kind) ? kDoubleSize : kPointerSize; int max_size = heap->MaxRegularSpaceAllocationSize() / element_size; max_size -= JSArray::kSize / element_size; HConstant* max_size_constant = Add
(max_size); Add
(length, max_size_constant); } HValue* HGraphBuilder::BuildGrowElementsCapacity(HValue* object, HValue* elements, ElementsKind kind, ElementsKind new_kind, HValue* length, HValue* new_capacity) { BuildNewSpaceArrayCheck(new_capacity, new_kind); HValue* new_elements = BuildAllocateElementsAndInitializeElementsHeader( new_kind, new_capacity); BuildCopyElements(elements, kind, new_elements, new_kind, length, new_capacity); Add
(object, HObjectAccess::ForElementsPointer(), new_elements); return new_elements; } void HGraphBuilder::BuildFillElementsWithHole(HValue* elements, ElementsKind elements_kind, HValue* from, HValue* to) { // Fast elements kinds need to be initialized in case statements below cause // a garbage collection. Factory* factory = isolate()->factory(); double nan_double = FixedDoubleArray::hole_nan_as_double(); HValue* hole = IsFastSmiOrObjectElementsKind(elements_kind) ? Add
(factory->the_hole_value()) : Add
(nan_double); // Special loop unfolding case static const int kLoopUnfoldLimit = 8; STATIC_ASSERT(JSArray::kPreallocatedArrayElements <= kLoopUnfoldLimit); int initial_capacity = -1; if (from->IsInteger32Constant() && to->IsInteger32Constant()) { int constant_from = from->GetInteger32Constant(); int constant_to = to->GetInteger32Constant(); if (constant_from == 0 && constant_to <= kLoopUnfoldLimit) { initial_capacity = constant_to; } } // Since we're about to store a hole value, the store instruction below must // assume an elements kind that supports heap object values. if (IsFastSmiOrObjectElementsKind(elements_kind)) { elements_kind = FAST_HOLEY_ELEMENTS; } if (initial_capacity >= 0) { for (int i = 0; i < initial_capacity; i++) { HInstruction* key = Add
(i); Add
(elements, key, hole, elements_kind); } } else { LoopBuilder builder(this, context(), LoopBuilder::kPostIncrement); HValue* key = builder.BeginBody(from, to, Token::LT); Add
(elements, key, hole, elements_kind); builder.EndBody(); } } void HGraphBuilder::BuildCopyElements(HValue* from_elements, ElementsKind from_elements_kind, HValue* to_elements, ElementsKind to_elements_kind, HValue* length, HValue* capacity) { bool pre_fill_with_holes = IsFastDoubleElementsKind(from_elements_kind) && IsFastObjectElementsKind(to_elements_kind); if (pre_fill_with_holes) { // If the copy might trigger a GC, make sure that the FixedArray is // pre-initialized with holes to make sure that it's always in a consistent // state. BuildFillElementsWithHole(to_elements, to_elements_kind, graph()->GetConstant0(), capacity); } LoopBuilder builder(this, context(), LoopBuilder::kPostIncrement); HValue* key = builder.BeginBody(graph()->GetConstant0(), length, Token::LT); HValue* element = Add
(from_elements, key, static_cast
(NULL), from_elements_kind, ALLOW_RETURN_HOLE); ElementsKind kind = (IsHoleyElementsKind(from_elements_kind) && IsFastSmiElementsKind(to_elements_kind)) ? FAST_HOLEY_ELEMENTS : to_elements_kind; if (IsHoleyElementsKind(from_elements_kind) && from_elements_kind != to_elements_kind) { IfBuilder if_hole(this); if_hole.If
(element); if_hole.Then(); HConstant* hole_constant = IsFastDoubleElementsKind(to_elements_kind) ? Add
(FixedDoubleArray::hole_nan_as_double()) : graph()->GetConstantHole(); Add
(to_elements, key, hole_constant, kind); if_hole.Else(); HStoreKeyed* store = Add
(to_elements, key, element, kind); store->SetFlag(HValue::kAllowUndefinedAsNaN); if_hole.End(); } else { HStoreKeyed* store = Add
(to_elements, key, element, kind); store->SetFlag(HValue::kAllowUndefinedAsNaN); } builder.EndBody(); if (!pre_fill_with_holes && length != capacity) { // Fill unused capacity with the hole. BuildFillElementsWithHole(to_elements, to_elements_kind, key, capacity); } } HValue* HGraphBuilder::BuildCloneShallowArray(HValue* boilerplate, HValue* allocation_site, AllocationSiteMode mode, ElementsKind kind, int length) { NoObservableSideEffectsScope no_effects(this); // All sizes here are multiples of kPointerSize. int size = JSArray::kSize; if (mode == TRACK_ALLOCATION_SITE) { size += AllocationMemento::kSize; } HValue* size_in_bytes = Add
(size); HInstruction* object = Add
(size_in_bytes, HType::JSObject(), NOT_TENURED, JS_OBJECT_TYPE); // Copy the JS array part. for (int i = 0; i < JSArray::kSize; i += kPointerSize) { if ((i != JSArray::kElementsOffset) || (length == 0)) { HObjectAccess access = HObjectAccess::ForJSArrayOffset(i); Add
(object, access, Add
(boilerplate, access)); } } // Create an allocation site info if requested. if (mode == TRACK_ALLOCATION_SITE) { BuildCreateAllocationMemento( object, Add
(JSArray::kSize), allocation_site); } if (length > 0) { HValue* boilerplate_elements = AddLoadElements(boilerplate); HValue* object_elements; if (IsFastDoubleElementsKind(kind)) { HValue* elems_size = Add
(FixedDoubleArray::SizeFor(length)); object_elements = Add
(elems_size, HType::JSArray(), NOT_TENURED, FIXED_DOUBLE_ARRAY_TYPE); } else { HValue* elems_size = Add
(FixedArray::SizeFor(length)); object_elements = Add
(elems_size, HType::JSArray(), NOT_TENURED, FIXED_ARRAY_TYPE); } Add
(object, HObjectAccess::ForElementsPointer(), object_elements); // Copy the elements array header. for (int i = 0; i < FixedArrayBase::kHeaderSize; i += kPointerSize) { HObjectAccess access = HObjectAccess::ForFixedArrayHeader(i); Add
(object_elements, access, Add
(boilerplate_elements, access)); } // Copy the elements array contents. // TODO(mstarzinger): Teach HGraphBuilder::BuildCopyElements to unfold // copying loops with constant length up to a given boundary and use this // helper here instead. for (int i = 0; i < length; i++) { HValue* key_constant = Add
(i); HInstruction* value = Add
(boilerplate_elements, key_constant, static_cast
(NULL), kind); Add
(object_elements, key_constant, value, kind); } } return object; } void HGraphBuilder::BuildCompareNil( HValue* value, Handle
type, HIfContinuation* continuation) { IfBuilder if_nil(this); bool some_case_handled = false; bool some_case_missing = false; if (type->Maybe(Type::Null())) { if (some_case_handled) if_nil.Or(); if_nil.If
(value, graph()->GetConstantNull()); some_case_handled = true; } else { some_case_missing = true; } if (type->Maybe(Type::Undefined())) { if (some_case_handled) if_nil.Or(); if_nil.If
(value, graph()->GetConstantUndefined()); some_case_handled = true; } else { some_case_missing = true; } if (type->Maybe(Type::Undetectable())) { if (some_case_handled) if_nil.Or(); if_nil.If
(value); some_case_handled = true; } else { some_case_missing = true; } if (some_case_missing) { if_nil.Then(); if_nil.Else(); if (type->NumClasses() == 1) { BuildCheckHeapObject(value); // For ICs, the map checked below is a sentinel map that gets replaced by // the monomorphic map when the code is used as a template to generate a // new IC. For optimized functions, there is no sentinel map, the map // emitted below is the actual monomorphic map. BuildCheckMap(value, type->Classes().Current()); } else { if_nil.Deopt("Too many undetectable types"); } } if_nil.CaptureContinuation(continuation); } void HGraphBuilder::BuildCreateAllocationMemento( HValue* previous_object, HValue* previous_object_size, HValue* allocation_site) { ASSERT(allocation_site != NULL); HInnerAllocatedObject* allocation_memento = Add
( previous_object, previous_object_size); AddStoreMapConstant( allocation_memento, isolate()->factory()->allocation_memento_map()); Add