licm_test.cc revision 8030c4100d2586fac39ed4007c61ee91d4ea4f25 
1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "base/arena_allocator.h"
18#include "builder.h"
19#include "gtest/gtest.h"
20#include "licm.h"
21#include "nodes.h"
22#include "optimizing_unit_test.h"
23#include "side_effects_analysis.h"
24
25namespace art {
26
27/**
28 * Fixture class for the LICM tests.
29 */
30class LICMTest : public testing::Test {
31 public:
32  LICMTest() : pool_(), allocator_(&pool_) {
33    graph_ = CreateGraph(&allocator_);
34  }
35
36  ~LICMTest() { }
37
38  // Builds a singly-nested loop structure in CFG. Tests can further populate
39  // the basic blocks with instructions to set up interesting scenarios.
40  void BuildLoop() {
41    entry_ = new (&allocator_) HBasicBlock(graph_);
42    loop_preheader_ = new (&allocator_) HBasicBlock(graph_);
43    loop_header_ = new (&allocator_) HBasicBlock(graph_);
44    loop_body_ = new (&allocator_) HBasicBlock(graph_);
45    exit_ = new (&allocator_) HBasicBlock(graph_);
46
47    graph_->AddBlock(entry_);
48    graph_->AddBlock(loop_preheader_);
49    graph_->AddBlock(loop_header_);
50    graph_->AddBlock(loop_body_);
51    graph_->AddBlock(exit_);
52
53    graph_->SetEntryBlock(entry_);
54    graph_->SetExitBlock(exit_);
55
56    // Set up loop flow in CFG.
57    entry_->AddSuccessor(loop_preheader_);
58    loop_preheader_->AddSuccessor(loop_header_);
59    loop_header_->AddSuccessor(loop_body_);
60    loop_header_->AddSuccessor(exit_);
61    loop_body_->AddSuccessor(loop_header_);
62
63    // Provide boiler-plate instructions.
64    parameter_ = new (&allocator_) HParameterValue(0, Primitive::kPrimNot);
65    entry_->AddInstruction(parameter_);
66    constant_ = graph_->GetIntConstant(42);
67    loop_preheader_->AddInstruction(new (&allocator_) HGoto());
68    loop_header_->AddInstruction(new (&allocator_) HIf(parameter_));
69    loop_body_->AddInstruction(new (&allocator_) HGoto());
70    exit_->AddInstruction(new (&allocator_) HExit());
71  }
72
73  // Performs LICM optimizations (after proper set up).
74  void PerformLICM() {
75    ASSERT_TRUE(graph_->TryBuildingSsa());
76    SideEffectsAnalysis side_effects(graph_);
77    side_effects.Run();
78    LICM licm(graph_, side_effects);
79    licm.Run();
80  }
81
82  // General building fields.
83  ArenaPool pool_;
84  ArenaAllocator allocator_;
85  HGraph* graph_;
86
87  // Specific basic blocks.
88  HBasicBlock* entry_;
89  HBasicBlock* loop_preheader_;
90  HBasicBlock* loop_header_;
91  HBasicBlock* loop_body_;
92  HBasicBlock* exit_;
93
94  HInstruction* parameter_;  // "this"
95  HInstruction* constant_;
96};
97
98//
99// The actual LICM tests.
100//
101
102TEST_F(LICMTest, FieldHoisting) {
103  BuildLoop();
104
105  // Populate the loop with instructions: set/get field with different types.
106  NullHandle<mirror::DexCache> dex_cache;
107  HInstruction* get_field = new (&allocator_) HInstanceFieldGet(
108      parameter_, Primitive::kPrimLong, MemberOffset(10),
109      false, kUnknownFieldIndex, graph_->GetDexFile(), dex_cache, 0);
110  loop_body_->InsertInstructionBefore(get_field, loop_body_->GetLastInstruction());
111  HInstruction* set_field = new (&allocator_) HInstanceFieldSet(
112      parameter_, constant_, Primitive::kPrimInt, MemberOffset(20),
113      false, kUnknownFieldIndex, graph_->GetDexFile(), dex_cache, 0);
114  loop_body_->InsertInstructionBefore(set_field, loop_body_->GetLastInstruction());
115
116  EXPECT_EQ(get_field->GetBlock(), loop_body_);
117  EXPECT_EQ(set_field->GetBlock(), loop_body_);
118  PerformLICM();
119  EXPECT_EQ(get_field->GetBlock(), loop_preheader_);
120  EXPECT_EQ(set_field->GetBlock(), loop_body_);
121}
122
123TEST_F(LICMTest, NoFieldHoisting) {
124  BuildLoop();
125
126  // Populate the loop with instructions: set/get field with same types.
127  NullHandle<mirror::DexCache> dex_cache;
128  HInstruction* get_field = new (&allocator_) HInstanceFieldGet(
129      parameter_, Primitive::kPrimLong, MemberOffset(10),
130      false, kUnknownFieldIndex, graph_->GetDexFile(), dex_cache, 0);
131  loop_body_->InsertInstructionBefore(get_field, loop_body_->GetLastInstruction());
132  HInstruction* set_field = new (&allocator_) HInstanceFieldSet(
133      parameter_, get_field, Primitive::kPrimLong, MemberOffset(10),
134      false, kUnknownFieldIndex, graph_->GetDexFile(), dex_cache, 0);
135  loop_body_->InsertInstructionBefore(set_field, loop_body_->GetLastInstruction());
136
137  EXPECT_EQ(get_field->GetBlock(), loop_body_);
138  EXPECT_EQ(set_field->GetBlock(), loop_body_);
139  PerformLICM();
140  EXPECT_EQ(get_field->GetBlock(), loop_body_);
141  EXPECT_EQ(set_field->GetBlock(), loop_body_);
142}
143
144TEST_F(LICMTest, ArrayHoisting) {
145  BuildLoop();
146
147  // Populate the loop with instructions: set/get array with different types.
148  HInstruction* get_array = new (&allocator_) HArrayGet(
149      parameter_, constant_, Primitive::kPrimLong, 0);
150  loop_body_->InsertInstructionBefore(get_array, loop_body_->GetLastInstruction());
151  HInstruction* set_array = new (&allocator_) HArraySet(
152      parameter_, constant_, constant_, Primitive::kPrimInt, 0);
153  loop_body_->InsertInstructionBefore(set_array, loop_body_->GetLastInstruction());
154
155  EXPECT_EQ(get_array->GetBlock(), loop_body_);
156  EXPECT_EQ(set_array->GetBlock(), loop_body_);
157  PerformLICM();
158  EXPECT_EQ(get_array->GetBlock(), loop_preheader_);
159  EXPECT_EQ(set_array->GetBlock(), loop_body_);
160}
161
162TEST_F(LICMTest, NoArrayHoisting) {
163  BuildLoop();
164
165  // Populate the loop with instructions: set/get array with same types.
166  HInstruction* get_array = new (&allocator_) HArrayGet(
167      parameter_, constant_, Primitive::kPrimLong, 0);
168  loop_body_->InsertInstructionBefore(get_array, loop_body_->GetLastInstruction());
169  HInstruction* set_array = new (&allocator_) HArraySet(
170      parameter_, get_array, constant_, Primitive::kPrimLong, 0);
171  loop_body_->InsertInstructionBefore(set_array, loop_body_->GetLastInstruction());
172
173  EXPECT_EQ(get_array->GetBlock(), loop_body_);
174  EXPECT_EQ(set_array->GetBlock(), loop_body_);
175  PerformLICM();
176  EXPECT_EQ(get_array->GetBlock(), loop_body_);
177  EXPECT_EQ(set_array->GetBlock(), loop_body_);
178}
179
180}  // namespace art
181