1 /*
2  * Copyright (C) 2017 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 "ssa_liveness_analysis.h"
18 
19 #include "arch/instruction_set.h"
20 #include "arch/instruction_set_features.h"
21 #include "base/arena_allocator.h"
22 #include "base/arena_containers.h"
23 #include "code_generator.h"
24 #include "driver/compiler_options.h"
25 #include "nodes.h"
26 #include "optimizing_unit_test.h"
27 
28 namespace art {
29 
30 class SsaLivenessAnalysisTest : public OptimizingUnitTest {
31  protected:
SetUp()32   void SetUp() override {
33     OptimizingUnitTest::SetUp();
34     graph_ = CreateGraph();
35     compiler_options_ = CommonCompilerTest::CreateCompilerOptions(kRuntimeISA, "default");
36     codegen_ = CodeGenerator::Create(graph_, *compiler_options_);
37     CHECK(codegen_ != nullptr);
38     // Create entry block.
39     entry_ = new (GetAllocator()) HBasicBlock(graph_);
40     graph_->AddBlock(entry_);
41     graph_->SetEntryBlock(entry_);
42   }
43 
44  protected:
CreateSuccessor(HBasicBlock * block)45   HBasicBlock* CreateSuccessor(HBasicBlock* block) {
46     HGraph* graph = block->GetGraph();
47     HBasicBlock* successor = new (GetAllocator()) HBasicBlock(graph);
48     graph->AddBlock(successor);
49     block->AddSuccessor(successor);
50     return successor;
51   }
52 
53   HGraph* graph_;
54   std::unique_ptr<CompilerOptions> compiler_options_;
55   std::unique_ptr<CodeGenerator> codegen_;
56   HBasicBlock* entry_;
57 };
58 
TEST_F(SsaLivenessAnalysisTest,TestReturnArg)59 TEST_F(SsaLivenessAnalysisTest, TestReturnArg) {
60   HInstruction* arg = new (GetAllocator()) HParameterValue(
61       graph_->GetDexFile(), dex::TypeIndex(0), 0, DataType::Type::kInt32);
62   entry_->AddInstruction(arg);
63 
64   HBasicBlock* block = CreateSuccessor(entry_);
65   HInstruction* ret = new (GetAllocator()) HReturn(arg);
66   block->AddInstruction(ret);
67   block->AddInstruction(new (GetAllocator()) HExit());
68 
69   graph_->BuildDominatorTree();
70   SsaLivenessAnalysis ssa_analysis(graph_, codegen_.get(), GetScopedAllocator());
71   ssa_analysis.Analyze();
72 
73   std::ostringstream arg_dump;
74   arg->GetLiveInterval()->Dump(arg_dump);
75   EXPECT_STREQ("ranges: { [2,6) }, uses: { 6 }, { } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
76                arg_dump.str().c_str());
77 }
78 
TEST_F(SsaLivenessAnalysisTest,TestAput)79 TEST_F(SsaLivenessAnalysisTest, TestAput) {
80   HInstruction* array = new (GetAllocator()) HParameterValue(
81       graph_->GetDexFile(), dex::TypeIndex(0), 0, DataType::Type::kReference);
82   HInstruction* index = new (GetAllocator()) HParameterValue(
83       graph_->GetDexFile(), dex::TypeIndex(1), 1, DataType::Type::kInt32);
84   HInstruction* value = new (GetAllocator()) HParameterValue(
85       graph_->GetDexFile(), dex::TypeIndex(2), 2, DataType::Type::kInt32);
86   HInstruction* extra_arg1 = new (GetAllocator()) HParameterValue(
87       graph_->GetDexFile(), dex::TypeIndex(3), 3, DataType::Type::kInt32);
88   HInstruction* extra_arg2 = new (GetAllocator()) HParameterValue(
89       graph_->GetDexFile(), dex::TypeIndex(4), 4, DataType::Type::kReference);
90   HInstruction* const args[] = { array, index, value, extra_arg1, extra_arg2 };
91   for (HInstruction* insn : args) {
92     entry_->AddInstruction(insn);
93   }
94 
95   HBasicBlock* block = CreateSuccessor(entry_);
96   HInstruction* null_check = new (GetAllocator()) HNullCheck(array, 0);
97   block->AddInstruction(null_check);
98   HEnvironment* null_check_env = new (GetAllocator()) HEnvironment(GetAllocator(),
99                                                                    /* number_of_vregs= */ 5,
100                                                                    /* method= */ nullptr,
101                                                                    /* dex_pc= */ 0u,
102                                                                    null_check);
103   null_check_env->CopyFrom(ArrayRef<HInstruction* const>(args));
104   null_check->SetRawEnvironment(null_check_env);
105   HInstruction* length = new (GetAllocator()) HArrayLength(array, 0);
106   block->AddInstruction(length);
107   HInstruction* bounds_check = new (GetAllocator()) HBoundsCheck(index, length, /* dex_pc= */ 0u);
108   block->AddInstruction(bounds_check);
109   HEnvironment* bounds_check_env = new (GetAllocator()) HEnvironment(GetAllocator(),
110                                                                      /* number_of_vregs= */ 5,
111                                                                      /* method= */ nullptr,
112                                                                      /* dex_pc= */ 0u,
113                                                                      bounds_check);
114   bounds_check_env->CopyFrom(ArrayRef<HInstruction* const>(args));
115   bounds_check->SetRawEnvironment(bounds_check_env);
116   HInstruction* array_set =
117       new (GetAllocator()) HArraySet(array, index, value, DataType::Type::kInt32, /* dex_pc= */ 0);
118   block->AddInstruction(array_set);
119 
120   graph_->BuildDominatorTree();
121   SsaLivenessAnalysis ssa_analysis(graph_, codegen_.get(), GetScopedAllocator());
122   ssa_analysis.Analyze();
123 
124   EXPECT_FALSE(graph_->IsDebuggable());
125   EXPECT_EQ(18u, bounds_check->GetLifetimePosition());
126   static const char* const expected[] = {
127       "ranges: { [2,21) }, uses: { 15 17 21 }, { 15 19 } is_fixed: 0, is_split: 0 is_low: 0 "
128           "is_high: 0",
129       "ranges: { [4,21) }, uses: { 19 21 }, { } is_fixed: 0, is_split: 0 is_low: 0 "
130           "is_high: 0",
131       "ranges: { [6,21) }, uses: { 21 }, { } is_fixed: 0, is_split: 0 is_low: 0 "
132           "is_high: 0",
133       // Environment uses do not keep the non-reference argument alive.
134       "ranges: { [8,10) }, uses: { }, { } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
135       // Environment uses keep the reference argument alive.
136       "ranges: { [10,19) }, uses: { }, { 15 19 } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
137   };
138   static_assert(arraysize(expected) == arraysize(args), "Array size check.");
139   size_t arg_index = 0u;
140   for (HInstruction* arg : args) {
141     std::ostringstream arg_dump;
142     arg->GetLiveInterval()->Dump(arg_dump);
143     EXPECT_STREQ(expected[arg_index], arg_dump.str().c_str()) << arg_index;
144     ++arg_index;
145   }
146 }
147 
TEST_F(SsaLivenessAnalysisTest,TestDeoptimize)148 TEST_F(SsaLivenessAnalysisTest, TestDeoptimize) {
149   HInstruction* array = new (GetAllocator()) HParameterValue(
150       graph_->GetDexFile(), dex::TypeIndex(0), 0, DataType::Type::kReference);
151   HInstruction* index = new (GetAllocator()) HParameterValue(
152       graph_->GetDexFile(), dex::TypeIndex(1), 1, DataType::Type::kInt32);
153   HInstruction* value = new (GetAllocator()) HParameterValue(
154       graph_->GetDexFile(), dex::TypeIndex(2), 2, DataType::Type::kInt32);
155   HInstruction* extra_arg1 = new (GetAllocator()) HParameterValue(
156       graph_->GetDexFile(), dex::TypeIndex(3), 3, DataType::Type::kInt32);
157   HInstruction* extra_arg2 = new (GetAllocator()) HParameterValue(
158       graph_->GetDexFile(), dex::TypeIndex(4), 4, DataType::Type::kReference);
159   HInstruction* const args[] = { array, index, value, extra_arg1, extra_arg2 };
160   for (HInstruction* insn : args) {
161     entry_->AddInstruction(insn);
162   }
163 
164   HBasicBlock* block = CreateSuccessor(entry_);
165   HInstruction* null_check = new (GetAllocator()) HNullCheck(array, 0);
166   block->AddInstruction(null_check);
167   HEnvironment* null_check_env = new (GetAllocator()) HEnvironment(GetAllocator(),
168                                                                    /* number_of_vregs= */ 5,
169                                                                    /* method= */ nullptr,
170                                                                    /* dex_pc= */ 0u,
171                                                                    null_check);
172   null_check_env->CopyFrom(ArrayRef<HInstruction* const>(args));
173   null_check->SetRawEnvironment(null_check_env);
174   HInstruction* length = new (GetAllocator()) HArrayLength(array, 0);
175   block->AddInstruction(length);
176   // Use HAboveOrEqual+HDeoptimize as the bounds check.
177   HInstruction* ae = new (GetAllocator()) HAboveOrEqual(index, length);
178   block->AddInstruction(ae);
179   HInstruction* deoptimize = new(GetAllocator()) HDeoptimize(
180       GetAllocator(), ae, DeoptimizationKind::kBlockBCE, /* dex_pc= */ 0u);
181   block->AddInstruction(deoptimize);
182   HEnvironment* deoptimize_env = new (GetAllocator()) HEnvironment(GetAllocator(),
183                                                                    /* number_of_vregs= */ 5,
184                                                                    /* method= */ nullptr,
185                                                                    /* dex_pc= */ 0u,
186                                                                    deoptimize);
187   deoptimize_env->CopyFrom(ArrayRef<HInstruction* const>(args));
188   deoptimize->SetRawEnvironment(deoptimize_env);
189   HInstruction* array_set =
190       new (GetAllocator()) HArraySet(array, index, value, DataType::Type::kInt32, /* dex_pc= */ 0);
191   block->AddInstruction(array_set);
192 
193   graph_->BuildDominatorTree();
194   SsaLivenessAnalysis ssa_analysis(graph_, codegen_.get(), GetScopedAllocator());
195   ssa_analysis.Analyze();
196 
197   EXPECT_FALSE(graph_->IsDebuggable());
198   EXPECT_EQ(20u, deoptimize->GetLifetimePosition());
199   static const char* const expected[] = {
200       "ranges: { [2,23) }, uses: { 15 17 23 }, { 15 21 } is_fixed: 0, is_split: 0 is_low: 0 "
201           "is_high: 0",
202       "ranges: { [4,23) }, uses: { 19 23 }, { 21 } is_fixed: 0, is_split: 0 is_low: 0 "
203           "is_high: 0",
204       "ranges: { [6,23) }, uses: { 23 }, { 21 } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
205       // Environment use in HDeoptimize keeps even the non-reference argument alive.
206       "ranges: { [8,21) }, uses: { }, { 21 } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
207       // Environment uses keep the reference argument alive.
208       "ranges: { [10,21) }, uses: { }, { 15 21 } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
209   };
210   static_assert(arraysize(expected) == arraysize(args), "Array size check.");
211   size_t arg_index = 0u;
212   for (HInstruction* arg : args) {
213     std::ostringstream arg_dump;
214     arg->GetLiveInterval()->Dump(arg_dump);
215     EXPECT_STREQ(expected[arg_index], arg_dump.str().c_str()) << arg_index;
216     ++arg_index;
217   }
218 }
219 
220 }  // namespace art
221