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435 lines
23 KiB
435 lines
23 KiB
/*
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* Copyright (C) 2014 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "gvn.h"
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#include "base/arena_allocator.h"
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#include "builder.h"
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#include "nodes.h"
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#include "optimizing_unit_test.h"
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#include "side_effects_analysis.h"
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namespace art {
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class GVNTest : public OptimizingUnitTest {};
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TEST_F(GVNTest, LocalFieldElimination) {
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HGraph* graph = CreateGraph();
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HBasicBlock* entry = new (GetAllocator()) HBasicBlock(graph);
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graph->AddBlock(entry);
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graph->SetEntryBlock(entry);
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HInstruction* parameter = new (GetAllocator()) HParameterValue(graph->GetDexFile(),
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dex::TypeIndex(0),
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0,
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DataType::Type::kReference);
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entry->AddInstruction(parameter);
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HBasicBlock* block = new (GetAllocator()) HBasicBlock(graph);
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graph->AddBlock(block);
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entry->AddSuccessor(block);
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block->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kReference,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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block->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kReference,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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HInstruction* to_remove = block->GetLastInstruction();
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block->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kReference,
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MemberOffset(43),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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HInstruction* different_offset = block->GetLastInstruction();
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// Kill the value.
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block->AddInstruction(new (GetAllocator()) HInstanceFieldSet(parameter,
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parameter,
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nullptr,
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DataType::Type::kReference,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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block->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kReference,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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HInstruction* use_after_kill = block->GetLastInstruction();
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block->AddInstruction(new (GetAllocator()) HExit());
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ASSERT_EQ(to_remove->GetBlock(), block);
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ASSERT_EQ(different_offset->GetBlock(), block);
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ASSERT_EQ(use_after_kill->GetBlock(), block);
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graph->BuildDominatorTree();
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SideEffectsAnalysis side_effects(graph);
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side_effects.Run();
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GVNOptimization(graph, side_effects).Run();
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ASSERT_TRUE(to_remove->GetBlock() == nullptr);
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ASSERT_EQ(different_offset->GetBlock(), block);
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ASSERT_EQ(use_after_kill->GetBlock(), block);
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}
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TEST_F(GVNTest, GlobalFieldElimination) {
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HGraph* graph = CreateGraph();
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HBasicBlock* entry = new (GetAllocator()) HBasicBlock(graph);
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graph->AddBlock(entry);
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graph->SetEntryBlock(entry);
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HInstruction* parameter = new (GetAllocator()) HParameterValue(graph->GetDexFile(),
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dex::TypeIndex(0),
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0,
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DataType::Type::kReference);
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entry->AddInstruction(parameter);
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HBasicBlock* block = new (GetAllocator()) HBasicBlock(graph);
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graph->AddBlock(block);
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entry->AddSuccessor(block);
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block->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kBool,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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block->AddInstruction(new (GetAllocator()) HIf(block->GetLastInstruction()));
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HBasicBlock* then = new (GetAllocator()) HBasicBlock(graph);
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HBasicBlock* else_ = new (GetAllocator()) HBasicBlock(graph);
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HBasicBlock* join = new (GetAllocator()) HBasicBlock(graph);
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graph->AddBlock(then);
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graph->AddBlock(else_);
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graph->AddBlock(join);
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block->AddSuccessor(then);
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block->AddSuccessor(else_);
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then->AddSuccessor(join);
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else_->AddSuccessor(join);
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then->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kBool,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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then->AddInstruction(new (GetAllocator()) HGoto());
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else_->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kBool,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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else_->AddInstruction(new (GetAllocator()) HGoto());
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join->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kBool,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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join->AddInstruction(new (GetAllocator()) HExit());
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graph->BuildDominatorTree();
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SideEffectsAnalysis side_effects(graph);
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side_effects.Run();
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GVNOptimization(graph, side_effects).Run();
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// Check that all field get instructions have been GVN'ed.
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ASSERT_TRUE(then->GetFirstInstruction()->IsGoto());
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ASSERT_TRUE(else_->GetFirstInstruction()->IsGoto());
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ASSERT_TRUE(join->GetFirstInstruction()->IsExit());
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}
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TEST_F(GVNTest, LoopFieldElimination) {
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HGraph* graph = CreateGraph();
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HBasicBlock* entry = new (GetAllocator()) HBasicBlock(graph);
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graph->AddBlock(entry);
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graph->SetEntryBlock(entry);
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HInstruction* parameter = new (GetAllocator()) HParameterValue(graph->GetDexFile(),
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dex::TypeIndex(0),
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0,
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DataType::Type::kReference);
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entry->AddInstruction(parameter);
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HBasicBlock* block = new (GetAllocator()) HBasicBlock(graph);
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graph->AddBlock(block);
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entry->AddSuccessor(block);
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block->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kBool,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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block->AddInstruction(new (GetAllocator()) HGoto());
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HBasicBlock* loop_header = new (GetAllocator()) HBasicBlock(graph);
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HBasicBlock* loop_body = new (GetAllocator()) HBasicBlock(graph);
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HBasicBlock* exit = new (GetAllocator()) HBasicBlock(graph);
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graph->AddBlock(loop_header);
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graph->AddBlock(loop_body);
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graph->AddBlock(exit);
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block->AddSuccessor(loop_header);
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loop_header->AddSuccessor(loop_body);
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loop_header->AddSuccessor(exit);
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loop_body->AddSuccessor(loop_header);
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loop_header->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kBool,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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HInstruction* field_get_in_loop_header = loop_header->GetLastInstruction();
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loop_header->AddInstruction(new (GetAllocator()) HIf(block->GetLastInstruction()));
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// Kill inside the loop body to prevent field gets inside the loop header
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// and the body to be GVN'ed.
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loop_body->AddInstruction(new (GetAllocator()) HInstanceFieldSet(parameter,
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parameter,
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nullptr,
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DataType::Type::kBool,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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HInstruction* field_set = loop_body->GetLastInstruction();
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loop_body->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kBool,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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HInstruction* field_get_in_loop_body = loop_body->GetLastInstruction();
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loop_body->AddInstruction(new (GetAllocator()) HGoto());
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exit->AddInstruction(new (GetAllocator()) HInstanceFieldGet(parameter,
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nullptr,
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DataType::Type::kBool,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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HInstruction* field_get_in_exit = exit->GetLastInstruction();
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exit->AddInstruction(new (GetAllocator()) HExit());
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ASSERT_EQ(field_get_in_loop_header->GetBlock(), loop_header);
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ASSERT_EQ(field_get_in_loop_body->GetBlock(), loop_body);
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ASSERT_EQ(field_get_in_exit->GetBlock(), exit);
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graph->BuildDominatorTree();
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{
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SideEffectsAnalysis side_effects(graph);
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side_effects.Run();
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GVNOptimization(graph, side_effects).Run();
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}
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// Check that all field get instructions are still there.
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ASSERT_EQ(field_get_in_loop_header->GetBlock(), loop_header);
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ASSERT_EQ(field_get_in_loop_body->GetBlock(), loop_body);
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// The exit block is dominated by the loop header, whose field get
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// does not get killed by the loop flags.
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ASSERT_TRUE(field_get_in_exit->GetBlock() == nullptr);
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// Now remove the field set, and check that all field get instructions have been GVN'ed.
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loop_body->RemoveInstruction(field_set);
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{
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SideEffectsAnalysis side_effects(graph);
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side_effects.Run();
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GVNOptimization(graph, side_effects).Run();
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}
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ASSERT_TRUE(field_get_in_loop_header->GetBlock() == nullptr);
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ASSERT_TRUE(field_get_in_loop_body->GetBlock() == nullptr);
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ASSERT_TRUE(field_get_in_exit->GetBlock() == nullptr);
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}
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// Test that inner loops affect the side effects of the outer loop.
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TEST_F(GVNTest, LoopSideEffects) {
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static const SideEffects kCanTriggerGC = SideEffects::CanTriggerGC();
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HGraph* graph = CreateGraph();
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HBasicBlock* entry = new (GetAllocator()) HBasicBlock(graph);
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graph->AddBlock(entry);
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graph->SetEntryBlock(entry);
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HBasicBlock* outer_loop_header = new (GetAllocator()) HBasicBlock(graph);
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HBasicBlock* outer_loop_body = new (GetAllocator()) HBasicBlock(graph);
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HBasicBlock* outer_loop_exit = new (GetAllocator()) HBasicBlock(graph);
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HBasicBlock* inner_loop_header = new (GetAllocator()) HBasicBlock(graph);
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HBasicBlock* inner_loop_body = new (GetAllocator()) HBasicBlock(graph);
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HBasicBlock* inner_loop_exit = new (GetAllocator()) HBasicBlock(graph);
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graph->AddBlock(outer_loop_header);
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graph->AddBlock(outer_loop_body);
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graph->AddBlock(outer_loop_exit);
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graph->AddBlock(inner_loop_header);
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graph->AddBlock(inner_loop_body);
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graph->AddBlock(inner_loop_exit);
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entry->AddSuccessor(outer_loop_header);
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outer_loop_header->AddSuccessor(outer_loop_body);
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outer_loop_header->AddSuccessor(outer_loop_exit);
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outer_loop_body->AddSuccessor(inner_loop_header);
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inner_loop_header->AddSuccessor(inner_loop_body);
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inner_loop_header->AddSuccessor(inner_loop_exit);
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inner_loop_body->AddSuccessor(inner_loop_header);
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inner_loop_exit->AddSuccessor(outer_loop_header);
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HInstruction* parameter = new (GetAllocator()) HParameterValue(graph->GetDexFile(),
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dex::TypeIndex(0),
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0,
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DataType::Type::kBool);
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entry->AddInstruction(parameter);
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entry->AddInstruction(new (GetAllocator()) HGoto());
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outer_loop_header->AddInstruction(new (GetAllocator()) HSuspendCheck());
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outer_loop_header->AddInstruction(new (GetAllocator()) HIf(parameter));
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outer_loop_body->AddInstruction(new (GetAllocator()) HGoto());
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inner_loop_header->AddInstruction(new (GetAllocator()) HSuspendCheck());
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inner_loop_header->AddInstruction(new (GetAllocator()) HIf(parameter));
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inner_loop_body->AddInstruction(new (GetAllocator()) HGoto());
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inner_loop_exit->AddInstruction(new (GetAllocator()) HGoto());
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outer_loop_exit->AddInstruction(new (GetAllocator()) HExit());
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graph->BuildDominatorTree();
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ASSERT_TRUE(inner_loop_header->GetLoopInformation()->IsIn(
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*outer_loop_header->GetLoopInformation()));
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// Check that the only side effect of loops is to potentially trigger GC.
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{
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// Make one block with a side effect.
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entry->AddInstruction(new (GetAllocator()) HInstanceFieldSet(parameter,
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parameter,
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nullptr,
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DataType::Type::kReference,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0));
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SideEffectsAnalysis side_effects(graph);
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side_effects.Run();
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ASSERT_TRUE(side_effects.GetBlockEffects(entry).DoesAnyWrite());
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ASSERT_FALSE(side_effects.GetBlockEffects(outer_loop_body).DoesAnyWrite());
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ASSERT_FALSE(side_effects.GetLoopEffects(outer_loop_header).DoesAnyWrite());
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ASSERT_FALSE(side_effects.GetLoopEffects(inner_loop_header).DoesAnyWrite());
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ASSERT_TRUE(side_effects.GetLoopEffects(outer_loop_header).Equals(kCanTriggerGC));
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ASSERT_TRUE(side_effects.GetLoopEffects(inner_loop_header).Equals(kCanTriggerGC));
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}
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// Check that the side effects of the outer loop does not affect the inner loop.
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{
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outer_loop_body->InsertInstructionBefore(
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new (GetAllocator()) HInstanceFieldSet(parameter,
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parameter,
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nullptr,
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DataType::Type::kReference,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0),
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outer_loop_body->GetLastInstruction());
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SideEffectsAnalysis side_effects(graph);
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side_effects.Run();
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ASSERT_TRUE(side_effects.GetBlockEffects(entry).DoesAnyWrite());
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ASSERT_TRUE(side_effects.GetBlockEffects(outer_loop_body).DoesAnyWrite());
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ASSERT_TRUE(side_effects.GetLoopEffects(outer_loop_header).DoesAnyWrite());
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ASSERT_FALSE(side_effects.GetLoopEffects(inner_loop_header).DoesAnyWrite());
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ASSERT_TRUE(side_effects.GetLoopEffects(inner_loop_header).Equals(kCanTriggerGC));
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}
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// Check that the side effects of the inner loop affects the outer loop.
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{
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outer_loop_body->RemoveInstruction(outer_loop_body->GetFirstInstruction());
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inner_loop_body->InsertInstructionBefore(
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new (GetAllocator()) HInstanceFieldSet(parameter,
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parameter,
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nullptr,
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DataType::Type::kReference,
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MemberOffset(42),
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false,
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kUnknownFieldIndex,
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kUnknownClassDefIndex,
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graph->GetDexFile(),
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0),
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inner_loop_body->GetLastInstruction());
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SideEffectsAnalysis side_effects(graph);
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side_effects.Run();
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ASSERT_TRUE(side_effects.GetBlockEffects(entry).DoesAnyWrite());
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ASSERT_FALSE(side_effects.GetBlockEffects(outer_loop_body).DoesAnyWrite());
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ASSERT_TRUE(side_effects.GetLoopEffects(outer_loop_header).DoesAnyWrite());
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ASSERT_TRUE(side_effects.GetLoopEffects(inner_loop_header).DoesAnyWrite());
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}
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}
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} // namespace art
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