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