/*
* 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 "bounds_check_elimination.h"
#include "builder.h"
#include "gvn.h"
#include "induction_var_analysis.h"
#include "instruction_simplifier.h"
#include "nodes.h"
#include "optimizing_unit_test.h"
#include "side_effects_analysis.h"
#include "gtest/gtest.h"
namespace art {
/**
* Fixture class for the BoundsCheckElimination tests.
*/
class BoundsCheckEliminationTest : public testing::Test {
public:
BoundsCheckEliminationTest() : pool_(), allocator_(&pool_) {
graph_ = CreateGraph(&allocator_);
graph_->SetHasBoundsChecks(true);
}
~BoundsCheckEliminationTest() { }
void RunBCE() {
graph_->BuildDominatorTree();
InstructionSimplifier(graph_).Run();
SideEffectsAnalysis side_effects(graph_);
side_effects.Run();
GVNOptimization(graph_, side_effects).Run();
HInductionVarAnalysis induction(graph_);
induction.Run();
BoundsCheckElimination(graph_, side_effects, &induction).Run();
}
ArenaPool pool_;
ArenaAllocator allocator_;
HGraph* graph_;
};
// if (i < 0) { array[i] = 1; // Can't eliminate. }
// else if (i >= array.length) { array[i] = 1; // Can't eliminate. }
// else { array[i] = 1; // Can eliminate. }
TEST_F(BoundsCheckEliminationTest, NarrowingRangeArrayBoundsElimination) {
HBasicBlock* entry = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(entry);
graph_->SetEntryBlock(entry);
HInstruction* parameter1 = new (&allocator_)
HParameterValue(graph_->GetDexFile(), 0, 0, Primitive::kPrimNot); // array
HInstruction* parameter2 = new (&allocator_)
HParameterValue(graph_->GetDexFile(), 0, 0, Primitive::kPrimInt); // i
entry->AddInstruction(parameter1);
entry->AddInstruction(parameter2);
HInstruction* constant_1 = graph_->GetIntConstant(1);
HInstruction* constant_0 = graph_->GetIntConstant(0);
HBasicBlock* block1 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block1);
HInstruction* cmp = new (&allocator_) HGreaterThanOrEqual(parameter2, constant_0);
HIf* if_inst = new (&allocator_) HIf(cmp);
block1->AddInstruction(cmp);
block1->AddInstruction(if_inst);
entry->AddSuccessor(block1);
HBasicBlock* block2 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block2);
HNullCheck* null_check = new (&allocator_) HNullCheck(parameter1, 0);
HArrayLength* array_length = new (&allocator_) HArrayLength(null_check, 0);
HBoundsCheck* bounds_check2 = new (&allocator_)
HBoundsCheck(parameter2, array_length, 0);
HArraySet* array_set = new (&allocator_) HArraySet(
null_check, bounds_check2, constant_1, Primitive::kPrimInt, 0);
block2->AddInstruction(null_check);
block2->AddInstruction(array_length);
block2->AddInstruction(bounds_check2);
block2->AddInstruction(array_set);
HBasicBlock* block3 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block3);
null_check = new (&allocator_) HNullCheck(parameter1, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
cmp = new (&allocator_) HLessThan(parameter2, array_length);
if_inst = new (&allocator_) HIf(cmp);
block3->AddInstruction(null_check);
block3->AddInstruction(array_length);
block3->AddInstruction(cmp);
block3->AddInstruction(if_inst);
HBasicBlock* block4 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block4);
null_check = new (&allocator_) HNullCheck(parameter1, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HBoundsCheck* bounds_check4 = new (&allocator_)
HBoundsCheck(parameter2, array_length, 0);
array_set = new (&allocator_) HArraySet(
null_check, bounds_check4, constant_1, Primitive::kPrimInt, 0);
block4->AddInstruction(null_check);
block4->AddInstruction(array_length);
block4->AddInstruction(bounds_check4);
block4->AddInstruction(array_set);
HBasicBlock* block5 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block5);
null_check = new (&allocator_) HNullCheck(parameter1, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HBoundsCheck* bounds_check5 = new (&allocator_)
HBoundsCheck(parameter2, array_length, 0);
array_set = new (&allocator_) HArraySet(
null_check, bounds_check5, constant_1, Primitive::kPrimInt, 0);
block5->AddInstruction(null_check);
block5->AddInstruction(array_length);
block5->AddInstruction(bounds_check5);
block5->AddInstruction(array_set);
HBasicBlock* exit = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(exit);
block2->AddSuccessor(exit);
block4->AddSuccessor(exit);
block5->AddSuccessor(exit);
exit->AddInstruction(new (&allocator_) HExit());
block1->AddSuccessor(block3); // True successor
block1->AddSuccessor(block2); // False successor
block3->AddSuccessor(block5); // True successor
block3->AddSuccessor(block4); // False successor
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check2));
ASSERT_FALSE(IsRemoved(bounds_check4));
ASSERT_TRUE(IsRemoved(bounds_check5));
}
// if (i > 0) {
// // Positive number plus MAX_INT will overflow and be negative.
// int j = i + Integer.MAX_VALUE;
// if (j < array.length) array[j] = 1; // Can't eliminate.
// }
TEST_F(BoundsCheckEliminationTest, OverflowArrayBoundsElimination) {
HBasicBlock* entry = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(entry);
graph_->SetEntryBlock(entry);
HInstruction* parameter1 = new (&allocator_)
HParameterValue(graph_->GetDexFile(), 0, 0, Primitive::kPrimNot); // array
HInstruction* parameter2 = new (&allocator_)
HParameterValue(graph_->GetDexFile(), 0, 0, Primitive::kPrimInt); // i
entry->AddInstruction(parameter1);
entry->AddInstruction(parameter2);
HInstruction* constant_1 = graph_->GetIntConstant(1);
HInstruction* constant_0 = graph_->GetIntConstant(0);
HInstruction* constant_max_int = graph_->GetIntConstant(INT_MAX);
HBasicBlock* block1 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block1);
HInstruction* cmp = new (&allocator_) HLessThanOrEqual(parameter2, constant_0);
HIf* if_inst = new (&allocator_) HIf(cmp);
block1->AddInstruction(cmp);
block1->AddInstruction(if_inst);
entry->AddSuccessor(block1);
HBasicBlock* block2 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block2);
HInstruction* add = new (&allocator_) HAdd(Primitive::kPrimInt, parameter2, constant_max_int);
HNullCheck* null_check = new (&allocator_) HNullCheck(parameter1, 0);
HArrayLength* array_length = new (&allocator_) HArrayLength(null_check, 0);
HInstruction* cmp2 = new (&allocator_) HGreaterThanOrEqual(add, array_length);
if_inst = new (&allocator_) HIf(cmp2);
block2->AddInstruction(add);
block2->AddInstruction(null_check);
block2->AddInstruction(array_length);
block2->AddInstruction(cmp2);
block2->AddInstruction(if_inst);
HBasicBlock* block3 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block3);
HBoundsCheck* bounds_check = new (&allocator_)
HBoundsCheck(add, array_length, 0);
HArraySet* array_set = new (&allocator_) HArraySet(
null_check, bounds_check, constant_1, Primitive::kPrimInt, 0);
block3->AddInstruction(bounds_check);
block3->AddInstruction(array_set);
HBasicBlock* exit = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(exit);
exit->AddInstruction(new (&allocator_) HExit());
block1->AddSuccessor(exit); // true successor
block1->AddSuccessor(block2); // false successor
block2->AddSuccessor(exit); // true successor
block2->AddSuccessor(block3); // false successor
block3->AddSuccessor(exit);
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check));
}
// if (i < array.length) {
// int j = i - Integer.MAX_VALUE;
// j = j - Integer.MAX_VALUE; // j is (i+2) after subtracting MAX_INT twice
// if (j > 0) array[j] = 1; // Can't eliminate.
// }
TEST_F(BoundsCheckEliminationTest, UnderflowArrayBoundsElimination) {
HBasicBlock* entry = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(entry);
graph_->SetEntryBlock(entry);
HInstruction* parameter1 = new (&allocator_)
HParameterValue(graph_->GetDexFile(), 0, 0, Primitive::kPrimNot); // array
HInstruction* parameter2 = new (&allocator_)
HParameterValue(graph_->GetDexFile(), 0, 0, Primitive::kPrimInt); // i
entry->AddInstruction(parameter1);
entry->AddInstruction(parameter2);
HInstruction* constant_1 = graph_->GetIntConstant(1);
HInstruction* constant_0 = graph_->GetIntConstant(0);
HInstruction* constant_max_int = graph_->GetIntConstant(INT_MAX);
HBasicBlock* block1 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block1);
HNullCheck* null_check = new (&allocator_) HNullCheck(parameter1, 0);
HArrayLength* array_length = new (&allocator_) HArrayLength(null_check, 0);
HInstruction* cmp = new (&allocator_) HGreaterThanOrEqual(parameter2, array_length);
HIf* if_inst = new (&allocator_) HIf(cmp);
block1->AddInstruction(null_check);
block1->AddInstruction(array_length);
block1->AddInstruction(cmp);
block1->AddInstruction(if_inst);
entry->AddSuccessor(block1);
HBasicBlock* block2 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block2);
HInstruction* sub1 = new (&allocator_) HSub(Primitive::kPrimInt, parameter2, constant_max_int);
HInstruction* sub2 = new (&allocator_) HSub(Primitive::kPrimInt, sub1, constant_max_int);
HInstruction* cmp2 = new (&allocator_) HLessThanOrEqual(sub2, constant_0);
if_inst = new (&allocator_) HIf(cmp2);
block2->AddInstruction(sub1);
block2->AddInstruction(sub2);
block2->AddInstruction(cmp2);
block2->AddInstruction(if_inst);
HBasicBlock* block3 = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block3);
HBoundsCheck* bounds_check = new (&allocator_)
HBoundsCheck(sub2, array_length, 0);
HArraySet* array_set = new (&allocator_) HArraySet(
null_check, bounds_check, constant_1, Primitive::kPrimInt, 0);
block3->AddInstruction(bounds_check);
block3->AddInstruction(array_set);
HBasicBlock* exit = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(exit);
exit->AddInstruction(new (&allocator_) HExit());
block1->AddSuccessor(exit); // true successor
block1->AddSuccessor(block2); // false successor
block2->AddSuccessor(exit); // true successor
block2->AddSuccessor(block3); // false successor
block3->AddSuccessor(exit);
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check));
}
// array[6] = 1; // Can't eliminate.
// array[5] = 1; // Can eliminate.
// array[4] = 1; // Can eliminate.
TEST_F(BoundsCheckEliminationTest, ConstantArrayBoundsElimination) {
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);
HInstruction* constant_5 = graph_->GetIntConstant(5);
HInstruction* constant_4 = graph_->GetIntConstant(4);
HInstruction* constant_6 = graph_->GetIntConstant(6);
HInstruction* constant_1 = graph_->GetIntConstant(1);
HBasicBlock* block = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block);
entry->AddSuccessor(block);
HNullCheck* null_check = new (&allocator_) HNullCheck(parameter, 0);
HArrayLength* array_length = new (&allocator_) HArrayLength(null_check, 0);
HBoundsCheck* bounds_check6 = new (&allocator_)
HBoundsCheck(constant_6, array_length, 0);
HInstruction* array_set = new (&allocator_) HArraySet(
null_check, bounds_check6, constant_1, Primitive::kPrimInt, 0);
block->AddInstruction(null_check);
block->AddInstruction(array_length);
block->AddInstruction(bounds_check6);
block->AddInstruction(array_set);
null_check = new (&allocator_) HNullCheck(parameter, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HBoundsCheck* bounds_check5 = new (&allocator_)
HBoundsCheck(constant_5, array_length, 0);
array_set = new (&allocator_) HArraySet(
null_check, bounds_check5, constant_1, Primitive::kPrimInt, 0);
block->AddInstruction(null_check);
block->AddInstruction(array_length);
block->AddInstruction(bounds_check5);
block->AddInstruction(array_set);
null_check = new (&allocator_) HNullCheck(parameter, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HBoundsCheck* bounds_check4 = new (&allocator_)
HBoundsCheck(constant_4, array_length, 0);
array_set = new (&allocator_) HArraySet(
null_check, bounds_check4, constant_1, Primitive::kPrimInt, 0);
block->AddInstruction(null_check);
block->AddInstruction(array_length);
block->AddInstruction(bounds_check4);
block->AddInstruction(array_set);
block->AddInstruction(new (&allocator_) HGoto());
HBasicBlock* exit = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(exit);
block->AddSuccessor(exit);
exit->AddInstruction(new (&allocator_) HExit());
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check6));
ASSERT_TRUE(IsRemoved(bounds_check5));
ASSERT_TRUE(IsRemoved(bounds_check4));
}
// for (int i=initial; i<array.length; i+=increment) { array[i] = 10; }
static HInstruction* BuildSSAGraph1(HGraph* graph,
ArenaAllocator* allocator,
int initial,
int increment,
IfCondition cond = kCondGE) {
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);
HInstruction* constant_initial = graph->GetIntConstant(initial);
HInstruction* constant_increment = graph->GetIntConstant(increment);
HInstruction* constant_10 = graph->GetIntConstant(10);
HBasicBlock* block = new (allocator) HBasicBlock(graph);
graph->AddBlock(block);
entry->AddSuccessor(block);
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(exit); // true successor
loop_header->AddSuccessor(loop_body); // false successor
loop_body->AddSuccessor(loop_header);
HPhi* phi = new (allocator) HPhi(allocator, 0, 0, Primitive::kPrimInt);
HInstruction* null_check = new (allocator) HNullCheck(parameter, 0);
HInstruction* array_length = new (allocator) HArrayLength(null_check, 0);
HInstruction* cmp = nullptr;
if (cond == kCondGE) {
cmp = new (allocator) HGreaterThanOrEqual(phi, array_length);
} else {
DCHECK(cond == kCondGT);
cmp = new (allocator) HGreaterThan(phi, array_length);
}
HInstruction* if_inst = new (allocator) HIf(cmp);
loop_header->AddPhi(phi);
loop_header->AddInstruction(null_check);
loop_header->AddInstruction(array_length);
loop_header->AddInstruction(cmp);
loop_header->AddInstruction(if_inst);
phi->AddInput(constant_initial);
null_check = new (allocator) HNullCheck(parameter, 0);
array_length = new (allocator) HArrayLength(null_check, 0);
HInstruction* bounds_check = new (allocator) HBoundsCheck(phi, array_length, 0);
HInstruction* array_set = new (allocator) HArraySet(
null_check, bounds_check, constant_10, Primitive::kPrimInt, 0);
HInstruction* add = new (allocator) HAdd(Primitive::kPrimInt, phi, constant_increment);
loop_body->AddInstruction(null_check);
loop_body->AddInstruction(array_length);
loop_body->AddInstruction(bounds_check);
loop_body->AddInstruction(array_set);
loop_body->AddInstruction(add);
loop_body->AddInstruction(new (allocator) HGoto());
phi->AddInput(add);
exit->AddInstruction(new (allocator) HExit());
return bounds_check;
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination1a) {
// for (int i=0; i<array.length; i++) { array[i] = 10; // Can eliminate with gvn. }
HInstruction* bounds_check = BuildSSAGraph1(graph_, &allocator_, 0, 1);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination1b) {
// for (int i=1; i<array.length; i++) { array[i] = 10; // Can eliminate. }
HInstruction* bounds_check = BuildSSAGraph1(graph_, &allocator_, 1, 1);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination1c) {
// for (int i=-1; i<array.length; i++) { array[i] = 10; // Can't eliminate. }
HInstruction* bounds_check = BuildSSAGraph1(graph_, &allocator_, -1, 1);
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination1d) {
// for (int i=0; i<=array.length; i++) { array[i] = 10; // Can't eliminate. }
HInstruction* bounds_check = BuildSSAGraph1(graph_, &allocator_, 0, 1, kCondGT);
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination1e) {
// for (int i=0; i<array.length; i += 2) {
// array[i] = 10; // Can't eliminate due to overflow concern. }
HInstruction* bounds_check = BuildSSAGraph1(graph_, &allocator_, 0, 2);
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination1f) {
// for (int i=1; i<array.length; i += 2) { array[i] = 10; // Can eliminate. }
HInstruction* bounds_check = BuildSSAGraph1(graph_, &allocator_, 1, 2);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
// for (int i=array.length; i>0; i+=increment) { array[i-1] = 10; }
static HInstruction* BuildSSAGraph2(HGraph *graph,
ArenaAllocator* allocator,
int initial,
int increment = -1,
IfCondition cond = kCondLE) {
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);
HInstruction* constant_initial = graph->GetIntConstant(initial);
HInstruction* constant_increment = graph->GetIntConstant(increment);
HInstruction* constant_minus_1 = graph->GetIntConstant(-1);
HInstruction* constant_10 = graph->GetIntConstant(10);
HBasicBlock* block = new (allocator) HBasicBlock(graph);
graph->AddBlock(block);
entry->AddSuccessor(block);
HInstruction* null_check = new (allocator) HNullCheck(parameter, 0);
HInstruction* array_length = new (allocator) HArrayLength(null_check, 0);
block->AddInstruction(null_check);
block->AddInstruction(array_length);
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(exit); // true successor
loop_header->AddSuccessor(loop_body); // false successor
loop_body->AddSuccessor(loop_header);
HPhi* phi = new (allocator) HPhi(allocator, 0, 0, Primitive::kPrimInt);
HInstruction* cmp = nullptr;
if (cond == kCondLE) {
cmp = new (allocator) HLessThanOrEqual(phi, constant_initial);
} else {
DCHECK(cond == kCondLT);
cmp = new (allocator) HLessThan(phi, constant_initial);
}
HInstruction* if_inst = new (allocator) HIf(cmp);
loop_header->AddPhi(phi);
loop_header->AddInstruction(cmp);
loop_header->AddInstruction(if_inst);
phi->AddInput(array_length);
HInstruction* add = new (allocator) HAdd(Primitive::kPrimInt, phi, constant_minus_1);
null_check = new (allocator) HNullCheck(parameter, 0);
array_length = new (allocator) HArrayLength(null_check, 0);
HInstruction* bounds_check = new (allocator) HBoundsCheck(add, array_length, 0);
HInstruction* array_set = new (allocator) HArraySet(
null_check, bounds_check, constant_10, Primitive::kPrimInt, 0);
HInstruction* add_phi = new (allocator) HAdd(Primitive::kPrimInt, phi, constant_increment);
loop_body->AddInstruction(add);
loop_body->AddInstruction(null_check);
loop_body->AddInstruction(array_length);
loop_body->AddInstruction(bounds_check);
loop_body->AddInstruction(array_set);
loop_body->AddInstruction(add_phi);
loop_body->AddInstruction(new (allocator) HGoto());
phi->AddInput(add);
exit->AddInstruction(new (allocator) HExit());
return bounds_check;
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination2a) {
// for (int i=array.length; i>0; i--) { array[i-1] = 10; // Can eliminate with gvn. }
HInstruction* bounds_check = BuildSSAGraph2(graph_, &allocator_, 0);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination2b) {
// for (int i=array.length; i>1; i--) { array[i-1] = 10; // Can eliminate. }
HInstruction* bounds_check = BuildSSAGraph2(graph_, &allocator_, 1);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination2c) {
// for (int i=array.length; i>-1; i--) { array[i-1] = 10; // Can't eliminate. }
HInstruction* bounds_check = BuildSSAGraph2(graph_, &allocator_, -1);
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination2d) {
// for (int i=array.length; i>=0; i--) { array[i-1] = 10; // Can't eliminate. }
HInstruction* bounds_check = BuildSSAGraph2(graph_, &allocator_, 0, -1, kCondLT);
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination2e) {
// for (int i=array.length; i>0; i-=2) { array[i-1] = 10; // Can eliminate. }
HInstruction* bounds_check = BuildSSAGraph2(graph_, &allocator_, 0, -2);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
// int[] array = new int[10];
// for (int i=0; i<10; i+=increment) { array[i] = 10; }
static HInstruction* BuildSSAGraph3(HGraph* graph,
ArenaAllocator* allocator,
int initial,
int increment,
IfCondition cond) {
HBasicBlock* entry = new (allocator) HBasicBlock(graph);
graph->AddBlock(entry);
graph->SetEntryBlock(entry);
HInstruction* constant_10 = graph->GetIntConstant(10);
HInstruction* constant_initial = graph->GetIntConstant(initial);
HInstruction* constant_increment = graph->GetIntConstant(increment);
HBasicBlock* block = new (allocator) HBasicBlock(graph);
graph->AddBlock(block);
entry->AddSuccessor(block);
HInstruction* new_array = new (allocator) HNewArray(
constant_10,
graph->GetCurrentMethod(),
0,
Primitive::kPrimInt,
graph->GetDexFile(),
kQuickAllocArray);
block->AddInstruction(new_array);
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(exit); // true successor
loop_header->AddSuccessor(loop_body); // false successor
loop_body->AddSuccessor(loop_header);
HPhi* phi = new (allocator) HPhi(allocator, 0, 0, Primitive::kPrimInt);
HInstruction* cmp = nullptr;
if (cond == kCondGE) {
cmp = new (allocator) HGreaterThanOrEqual(phi, constant_10);
} else {
DCHECK(cond == kCondGT);
cmp = new (allocator) HGreaterThan(phi, constant_10);
}
HInstruction* if_inst = new (allocator) HIf(cmp);
loop_header->AddPhi(phi);
loop_header->AddInstruction(cmp);
loop_header->AddInstruction(if_inst);
phi->AddInput(constant_initial);
HNullCheck* null_check = new (allocator) HNullCheck(new_array, 0);
HArrayLength* array_length = new (allocator) HArrayLength(null_check, 0);
HInstruction* bounds_check = new (allocator) HBoundsCheck(phi, array_length, 0);
HInstruction* array_set = new (allocator) HArraySet(
null_check, bounds_check, constant_10, Primitive::kPrimInt, 0);
HInstruction* add = new (allocator) HAdd(Primitive::kPrimInt, phi, constant_increment);
loop_body->AddInstruction(null_check);
loop_body->AddInstruction(array_length);
loop_body->AddInstruction(bounds_check);
loop_body->AddInstruction(array_set);
loop_body->AddInstruction(add);
loop_body->AddInstruction(new (allocator) HGoto());
phi->AddInput(add);
exit->AddInstruction(new (allocator) HExit());
return bounds_check;
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination3a) {
// int[] array = new int[10];
// for (int i=0; i<10; i++) { array[i] = 10; // Can eliminate. }
HInstruction* bounds_check = BuildSSAGraph3(graph_, &allocator_, 0, 1, kCondGE);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination3b) {
// int[] array = new int[10];
// for (int i=1; i<10; i++) { array[i] = 10; // Can eliminate. }
HInstruction* bounds_check = BuildSSAGraph3(graph_, &allocator_, 1, 1, kCondGE);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination3c) {
// int[] array = new int[10];
// for (int i=0; i<=10; i++) { array[i] = 10; // Can't eliminate. }
HInstruction* bounds_check = BuildSSAGraph3(graph_, &allocator_, 0, 1, kCondGT);
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination3d) {
// int[] array = new int[10];
// for (int i=1; i<10; i+=8) { array[i] = 10; // Can eliminate. }
HInstruction* bounds_check = BuildSSAGraph3(graph_, &allocator_, 1, 8, kCondGE);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
// for (int i=initial; i<array.length; i++) { array[array.length-i-1] = 10; }
static HInstruction* BuildSSAGraph4(HGraph* graph,
ArenaAllocator* allocator,
int initial,
IfCondition cond = kCondGE) {
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);
HInstruction* constant_initial = graph->GetIntConstant(initial);
HInstruction* constant_1 = graph->GetIntConstant(1);
HInstruction* constant_10 = graph->GetIntConstant(10);
HInstruction* constant_minus_1 = graph->GetIntConstant(-1);
HBasicBlock* block = new (allocator) HBasicBlock(graph);
graph->AddBlock(block);
entry->AddSuccessor(block);
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(exit); // true successor
loop_header->AddSuccessor(loop_body); // false successor
loop_body->AddSuccessor(loop_header);
HPhi* phi = new (allocator) HPhi(allocator, 0, 0, Primitive::kPrimInt);
HInstruction* null_check = new (allocator) HNullCheck(parameter, 0);
HInstruction* array_length = new (allocator) HArrayLength(null_check, 0);
HInstruction* cmp = nullptr;
if (cond == kCondGE) {
cmp = new (allocator) HGreaterThanOrEqual(phi, array_length);
} else if (cond == kCondGT) {
cmp = new (allocator) HGreaterThan(phi, array_length);
}
HInstruction* if_inst = new (allocator) HIf(cmp);
loop_header->AddPhi(phi);
loop_header->AddInstruction(null_check);
loop_header->AddInstruction(array_length);
loop_header->AddInstruction(cmp);
loop_header->AddInstruction(if_inst);
phi->AddInput(constant_initial);
null_check = new (allocator) HNullCheck(parameter, 0);
array_length = new (allocator) HArrayLength(null_check, 0);
HInstruction* sub = new (allocator) HSub(Primitive::kPrimInt, array_length, phi);
HInstruction* add_minus_1 = new (allocator)
HAdd(Primitive::kPrimInt, sub, constant_minus_1);
HInstruction* bounds_check = new (allocator) HBoundsCheck(add_minus_1, array_length, 0);
HInstruction* array_set = new (allocator) HArraySet(
null_check, bounds_check, constant_10, Primitive::kPrimInt, 0);
HInstruction* add = new (allocator) HAdd(Primitive::kPrimInt, phi, constant_1);
loop_body->AddInstruction(null_check);
loop_body->AddInstruction(array_length);
loop_body->AddInstruction(sub);
loop_body->AddInstruction(add_minus_1);
loop_body->AddInstruction(bounds_check);
loop_body->AddInstruction(array_set);
loop_body->AddInstruction(add);
loop_body->AddInstruction(new (allocator) HGoto());
phi->AddInput(add);
exit->AddInstruction(new (allocator) HExit());
return bounds_check;
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination4a) {
// for (int i=0; i<array.length; i++) { array[array.length-i-1] = 10; // Can eliminate with gvn. }
HInstruction* bounds_check = BuildSSAGraph4(graph_, &allocator_, 0);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination4b) {
// for (int i=1; i<array.length; i++) { array[array.length-i-1] = 10; // Can eliminate. }
HInstruction* bounds_check = BuildSSAGraph4(graph_, &allocator_, 1);
RunBCE();
ASSERT_TRUE(IsRemoved(bounds_check));
}
TEST_F(BoundsCheckEliminationTest, LoopArrayBoundsElimination4c) {
// for (int i=0; i<=array.length; i++) { array[array.length-i] = 10; // Can't eliminate. }
HInstruction* bounds_check = BuildSSAGraph4(graph_, &allocator_, 0, kCondGT);
RunBCE();
ASSERT_FALSE(IsRemoved(bounds_check));
}
// Bubble sort:
// (Every array access bounds-check can be eliminated.)
// for (int i=0; i<array.length-1; i++) {
// for (int j=0; j<array.length-i-1; j++) {
// if (array[j] > array[j+1]) {
// int temp = array[j+1];
// array[j+1] = array[j];
// array[j] = temp;
// }
// }
// }
TEST_F(BoundsCheckEliminationTest, BubbleSortArrayBoundsElimination) {
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);
HInstruction* constant_0 = graph_->GetIntConstant(0);
HInstruction* constant_minus_1 = graph_->GetIntConstant(-1);
HInstruction* constant_1 = graph_->GetIntConstant(1);
HBasicBlock* block = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block);
entry->AddSuccessor(block);
block->AddInstruction(new (&allocator_) HGoto());
HBasicBlock* exit = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(exit);
exit->AddInstruction(new (&allocator_) HExit());
HBasicBlock* outer_header = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(outer_header);
HPhi* phi_i = new (&allocator_) HPhi(&allocator_, 0, 0, Primitive::kPrimInt);
HNullCheck* null_check = new (&allocator_) HNullCheck(parameter, 0);
HArrayLength* array_length = new (&allocator_) HArrayLength(null_check, 0);
HAdd* add = new (&allocator_) HAdd(Primitive::kPrimInt, array_length, constant_minus_1);
HInstruction* cmp = new (&allocator_) HGreaterThanOrEqual(phi_i, add);
HIf* if_inst = new (&allocator_) HIf(cmp);
outer_header->AddPhi(phi_i);
outer_header->AddInstruction(null_check);
outer_header->AddInstruction(array_length);
outer_header->AddInstruction(add);
outer_header->AddInstruction(cmp);
outer_header->AddInstruction(if_inst);
phi_i->AddInput(constant_0);
HBasicBlock* inner_header = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(inner_header);
HPhi* phi_j = new (&allocator_) HPhi(&allocator_, 0, 0, Primitive::kPrimInt);
null_check = new (&allocator_) HNullCheck(parameter, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HSub* sub = new (&allocator_) HSub(Primitive::kPrimInt, array_length, phi_i);
add = new (&allocator_) HAdd(Primitive::kPrimInt, sub, constant_minus_1);
cmp = new (&allocator_) HGreaterThanOrEqual(phi_j, add);
if_inst = new (&allocator_) HIf(cmp);
inner_header->AddPhi(phi_j);
inner_header->AddInstruction(null_check);
inner_header->AddInstruction(array_length);
inner_header->AddInstruction(sub);
inner_header->AddInstruction(add);
inner_header->AddInstruction(cmp);
inner_header->AddInstruction(if_inst);
phi_j->AddInput(constant_0);
HBasicBlock* inner_body_compare = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(inner_body_compare);
null_check = new (&allocator_) HNullCheck(parameter, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HBoundsCheck* bounds_check1 = new (&allocator_) HBoundsCheck(phi_j, array_length, 0);
HArrayGet* array_get_j = new (&allocator_)
HArrayGet(null_check, bounds_check1, Primitive::kPrimInt, 0);
inner_body_compare->AddInstruction(null_check);
inner_body_compare->AddInstruction(array_length);
inner_body_compare->AddInstruction(bounds_check1);
inner_body_compare->AddInstruction(array_get_j);
HInstruction* j_plus_1 = new (&allocator_) HAdd(Primitive::kPrimInt, phi_j, constant_1);
null_check = new (&allocator_) HNullCheck(parameter, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HBoundsCheck* bounds_check2 = new (&allocator_) HBoundsCheck(j_plus_1, array_length, 0);
HArrayGet* array_get_j_plus_1 = new (&allocator_)
HArrayGet(null_check, bounds_check2, Primitive::kPrimInt, 0);
cmp = new (&allocator_) HGreaterThanOrEqual(array_get_j, array_get_j_plus_1);
if_inst = new (&allocator_) HIf(cmp);
inner_body_compare->AddInstruction(j_plus_1);
inner_body_compare->AddInstruction(null_check);
inner_body_compare->AddInstruction(array_length);
inner_body_compare->AddInstruction(bounds_check2);
inner_body_compare->AddInstruction(array_get_j_plus_1);
inner_body_compare->AddInstruction(cmp);
inner_body_compare->AddInstruction(if_inst);
HBasicBlock* inner_body_swap = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(inner_body_swap);
j_plus_1 = new (&allocator_) HAdd(Primitive::kPrimInt, phi_j, constant_1);
// temp = array[j+1]
null_check = new (&allocator_) HNullCheck(parameter, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HInstruction* bounds_check3 = new (&allocator_) HBoundsCheck(j_plus_1, array_length, 0);
array_get_j_plus_1 = new (&allocator_)
HArrayGet(null_check, bounds_check3, Primitive::kPrimInt, 0);
inner_body_swap->AddInstruction(j_plus_1);
inner_body_swap->AddInstruction(null_check);
inner_body_swap->AddInstruction(array_length);
inner_body_swap->AddInstruction(bounds_check3);
inner_body_swap->AddInstruction(array_get_j_plus_1);
// array[j+1] = array[j]
null_check = new (&allocator_) HNullCheck(parameter, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HInstruction* bounds_check4 = new (&allocator_) HBoundsCheck(phi_j, array_length, 0);
array_get_j = new (&allocator_)
HArrayGet(null_check, bounds_check4, Primitive::kPrimInt, 0);
inner_body_swap->AddInstruction(null_check);
inner_body_swap->AddInstruction(array_length);
inner_body_swap->AddInstruction(bounds_check4);
inner_body_swap->AddInstruction(array_get_j);
null_check = new (&allocator_) HNullCheck(parameter, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HInstruction* bounds_check5 = new (&allocator_) HBoundsCheck(j_plus_1, array_length, 0);
HArraySet* array_set_j_plus_1 = new (&allocator_)
HArraySet(null_check, bounds_check5, array_get_j, Primitive::kPrimInt, 0);
inner_body_swap->AddInstruction(null_check);
inner_body_swap->AddInstruction(array_length);
inner_body_swap->AddInstruction(bounds_check5);
inner_body_swap->AddInstruction(array_set_j_plus_1);
// array[j] = temp
null_check = new (&allocator_) HNullCheck(parameter, 0);
array_length = new (&allocator_) HArrayLength(null_check, 0);
HInstruction* bounds_check6 = new (&allocator_) HBoundsCheck(phi_j, array_length, 0);
HArraySet* array_set_j = new (&allocator_)
HArraySet(null_check, bounds_check6, array_get_j_plus_1, Primitive::kPrimInt, 0);
inner_body_swap->AddInstruction(null_check);
inner_body_swap->AddInstruction(array_length);
inner_body_swap->AddInstruction(bounds_check6);
inner_body_swap->AddInstruction(array_set_j);
inner_body_swap->AddInstruction(new (&allocator_) HGoto());
HBasicBlock* inner_body_add = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(inner_body_add);
add = new (&allocator_) HAdd(Primitive::kPrimInt, phi_j, constant_1);
inner_body_add->AddInstruction(add);
inner_body_add->AddInstruction(new (&allocator_) HGoto());
phi_j->AddInput(add);
HBasicBlock* outer_body_add = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(outer_body_add);
add = new (&allocator_) HAdd(Primitive::kPrimInt, phi_i, constant_1);
outer_body_add->AddInstruction(add);
outer_body_add->AddInstruction(new (&allocator_) HGoto());
phi_i->AddInput(add);
block->AddSuccessor(outer_header);
outer_header->AddSuccessor(exit);
outer_header->AddSuccessor(inner_header);
inner_header->AddSuccessor(outer_body_add);
inner_header->AddSuccessor(inner_body_compare);
inner_body_compare->AddSuccessor(inner_body_add);
inner_body_compare->AddSuccessor(inner_body_swap);
inner_body_swap->AddSuccessor(inner_body_add);
inner_body_add->AddSuccessor(inner_header);
outer_body_add->AddSuccessor(outer_header);
RunBCE(); // gvn removes same bounds check already
ASSERT_TRUE(IsRemoved(bounds_check1));
ASSERT_TRUE(IsRemoved(bounds_check2));
ASSERT_TRUE(IsRemoved(bounds_check3));
ASSERT_TRUE(IsRemoved(bounds_check4));
ASSERT_TRUE(IsRemoved(bounds_check5));
ASSERT_TRUE(IsRemoved(bounds_check6));
}
} // namespace art