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 "base/macros.h"
24 #include "code_generator.h"
25 #include "driver/compiler_options.h"
26 #include "nodes.h"
27 #include "optimizing_unit_test.h"
28 
29 namespace art HIDDEN {
30 
31 class SsaLivenessAnalysisTest : public OptimizingUnitTest {
32  protected:
SetUp()33   void SetUp() override {
34     OptimizingUnitTest::SetUp();
35     graph_ = CreateGraph();
36     compiler_options_ = CommonCompilerTest::CreateCompilerOptions(kRuntimeISA, "default");
37     codegen_ = CodeGenerator::Create(graph_, *compiler_options_);
38     CHECK(codegen_ != nullptr);
39     // Create entry block.
40     entry_ = new (GetAllocator()) HBasicBlock(graph_);
41     graph_->AddBlock(entry_);
42     graph_->SetEntryBlock(entry_);
43   }
44 
45  protected:
CreateSuccessor(HBasicBlock * block)46   HBasicBlock* CreateSuccessor(HBasicBlock* block) {
47     HGraph* graph = block->GetGraph();
48     HBasicBlock* successor = new (GetAllocator()) HBasicBlock(graph);
49     graph->AddBlock(successor);
50     block->AddSuccessor(successor);
51     return successor;
52   }
53 
54   HGraph* graph_;
55   std::unique_ptr<CompilerOptions> compiler_options_;
56   std::unique_ptr<CodeGenerator> codegen_;
57   HBasicBlock* entry_;
58 };
59 
TEST_F(SsaLivenessAnalysisTest,TestReturnArg)60 TEST_F(SsaLivenessAnalysisTest, TestReturnArg) {
61   HInstruction* arg = new (GetAllocator()) HParameterValue(
62       graph_->GetDexFile(), dex::TypeIndex(0), 0, DataType::Type::kInt32);
63   entry_->AddInstruction(arg);
64 
65   HBasicBlock* block = CreateSuccessor(entry_);
66   HInstruction* ret = new (GetAllocator()) HReturn(arg);
67   block->AddInstruction(ret);
68   block->AddInstruction(new (GetAllocator()) HExit());
69 
70   graph_->BuildDominatorTree();
71   SsaLivenessAnalysis ssa_analysis(graph_, codegen_.get(), GetScopedAllocator());
72   ssa_analysis.Analyze();
73 
74   std::ostringstream arg_dump;
75   arg->GetLiveInterval()->Dump(arg_dump);
76   EXPECT_STREQ("ranges: { [2,6) }, uses: { 6 }, { } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
77                arg_dump.str().c_str());
78 }
79 
TEST_F(SsaLivenessAnalysisTest,TestAput)80 TEST_F(SsaLivenessAnalysisTest, TestAput) {
81   HInstruction* array = new (GetAllocator()) HParameterValue(
82       graph_->GetDexFile(), dex::TypeIndex(0), 0, DataType::Type::kReference);
83   HInstruction* index = new (GetAllocator()) HParameterValue(
84       graph_->GetDexFile(), dex::TypeIndex(1), 1, DataType::Type::kInt32);
85   HInstruction* value = new (GetAllocator()) HParameterValue(
86       graph_->GetDexFile(), dex::TypeIndex(2), 2, DataType::Type::kInt32);
87   HInstruction* extra_arg1 = new (GetAllocator()) HParameterValue(
88       graph_->GetDexFile(), dex::TypeIndex(3), 3, DataType::Type::kInt32);
89   HInstruction* extra_arg2 = new (GetAllocator()) HParameterValue(
90       graph_->GetDexFile(), dex::TypeIndex(4), 4, DataType::Type::kReference);
91   HInstruction* const args[] = { array, index, value, extra_arg1, extra_arg2 };
92   for (HInstruction* insn : args) {
93     entry_->AddInstruction(insn);
94   }
95 
96   HBasicBlock* block = CreateSuccessor(entry_);
97   HInstruction* null_check = new (GetAllocator()) HNullCheck(array, 0);
98   block->AddInstruction(null_check);
99   HEnvironment* null_check_env = new (GetAllocator()) HEnvironment(GetAllocator(),
100                                                                    /* number_of_vregs= */ 5,
101                                                                    /* method= */ nullptr,
102                                                                    /* dex_pc= */ 0u,
103                                                                    null_check);
104   null_check_env->CopyFrom(ArrayRef<HInstruction* const>(args));
105   null_check->SetRawEnvironment(null_check_env);
106   HInstruction* length = new (GetAllocator()) HArrayLength(array, 0);
107   block->AddInstruction(length);
108   HInstruction* bounds_check = new (GetAllocator()) HBoundsCheck(index, length, /* dex_pc= */ 0u);
109   block->AddInstruction(bounds_check);
110   HEnvironment* bounds_check_env = new (GetAllocator()) HEnvironment(GetAllocator(),
111                                                                      /* number_of_vregs= */ 5,
112                                                                      /* method= */ nullptr,
113                                                                      /* dex_pc= */ 0u,
114                                                                      bounds_check);
115   bounds_check_env->CopyFrom(ArrayRef<HInstruction* const>(args));
116   bounds_check->SetRawEnvironment(bounds_check_env);
117   HInstruction* array_set =
118       new (GetAllocator()) HArraySet(array, index, value, DataType::Type::kInt32, /* dex_pc= */ 0);
119   block->AddInstruction(array_set);
120 
121   graph_->BuildDominatorTree();
122   SsaLivenessAnalysis ssa_analysis(graph_, codegen_.get(), GetScopedAllocator());
123   ssa_analysis.Analyze();
124 
125   EXPECT_FALSE(graph_->IsDebuggable());
126   EXPECT_EQ(18u, bounds_check->GetLifetimePosition());
127   static const char* const expected[] = {
128       "ranges: { [2,21) }, uses: { 15 17 21 }, { 15 19 } is_fixed: 0, is_split: 0 is_low: 0 "
129           "is_high: 0",
130       "ranges: { [4,21) }, uses: { 19 21 }, { } is_fixed: 0, is_split: 0 is_low: 0 "
131           "is_high: 0",
132       "ranges: { [6,21) }, uses: { 21 }, { } is_fixed: 0, is_split: 0 is_low: 0 "
133           "is_high: 0",
134       // Environment uses do not keep the non-reference argument alive.
135       "ranges: { [8,10) }, uses: { }, { } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
136       // Environment uses keep the reference argument alive.
137       "ranges: { [10,19) }, uses: { }, { 15 19 } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
138   };
139   static_assert(arraysize(expected) == arraysize(args), "Array size check.");
140   size_t arg_index = 0u;
141   for (HInstruction* arg : args) {
142     std::ostringstream arg_dump;
143     arg->GetLiveInterval()->Dump(arg_dump);
144     EXPECT_STREQ(expected[arg_index], arg_dump.str().c_str()) << arg_index;
145     ++arg_index;
146   }
147 }
148 
TEST_F(SsaLivenessAnalysisTest,TestDeoptimize)149 TEST_F(SsaLivenessAnalysisTest, TestDeoptimize) {
150   HInstruction* array = new (GetAllocator()) HParameterValue(
151       graph_->GetDexFile(), dex::TypeIndex(0), 0, DataType::Type::kReference);
152   HInstruction* index = new (GetAllocator()) HParameterValue(
153       graph_->GetDexFile(), dex::TypeIndex(1), 1, DataType::Type::kInt32);
154   HInstruction* value = new (GetAllocator()) HParameterValue(
155       graph_->GetDexFile(), dex::TypeIndex(2), 2, DataType::Type::kInt32);
156   HInstruction* extra_arg1 = new (GetAllocator()) HParameterValue(
157       graph_->GetDexFile(), dex::TypeIndex(3), 3, DataType::Type::kInt32);
158   HInstruction* extra_arg2 = new (GetAllocator()) HParameterValue(
159       graph_->GetDexFile(), dex::TypeIndex(4), 4, DataType::Type::kReference);
160   HInstruction* const args[] = { array, index, value, extra_arg1, extra_arg2 };
161   for (HInstruction* insn : args) {
162     entry_->AddInstruction(insn);
163   }
164 
165   HBasicBlock* block = CreateSuccessor(entry_);
166   HInstruction* null_check = new (GetAllocator()) HNullCheck(array, 0);
167   block->AddInstruction(null_check);
168   HEnvironment* null_check_env = new (GetAllocator()) HEnvironment(GetAllocator(),
169                                                                    /* number_of_vregs= */ 5,
170                                                                    /* method= */ nullptr,
171                                                                    /* dex_pc= */ 0u,
172                                                                    null_check);
173   null_check_env->CopyFrom(ArrayRef<HInstruction* const>(args));
174   null_check->SetRawEnvironment(null_check_env);
175   HInstruction* length = new (GetAllocator()) HArrayLength(array, 0);
176   block->AddInstruction(length);
177   // Use HAboveOrEqual+HDeoptimize as the bounds check.
178   HInstruction* ae = new (GetAllocator()) HAboveOrEqual(index, length);
179   block->AddInstruction(ae);
180   HInstruction* deoptimize = new(GetAllocator()) HDeoptimize(
181       GetAllocator(), ae, DeoptimizationKind::kBlockBCE, /* dex_pc= */ 0u);
182   block->AddInstruction(deoptimize);
183   HEnvironment* deoptimize_env = new (GetAllocator()) HEnvironment(GetAllocator(),
184                                                                    /* number_of_vregs= */ 5,
185                                                                    /* method= */ nullptr,
186                                                                    /* dex_pc= */ 0u,
187                                                                    deoptimize);
188   deoptimize_env->CopyFrom(ArrayRef<HInstruction* const>(args));
189   deoptimize->SetRawEnvironment(deoptimize_env);
190   HInstruction* array_set =
191       new (GetAllocator()) HArraySet(array, index, value, DataType::Type::kInt32, /* dex_pc= */ 0);
192   block->AddInstruction(array_set);
193 
194   graph_->BuildDominatorTree();
195   SsaLivenessAnalysis ssa_analysis(graph_, codegen_.get(), GetScopedAllocator());
196   ssa_analysis.Analyze();
197 
198   EXPECT_FALSE(graph_->IsDebuggable());
199   EXPECT_EQ(20u, deoptimize->GetLifetimePosition());
200   static const char* const expected[] = {
201       "ranges: { [2,23) }, uses: { 15 17 23 }, { 15 21 } is_fixed: 0, is_split: 0 is_low: 0 "
202           "is_high: 0",
203       "ranges: { [4,23) }, uses: { 19 23 }, { 21 } is_fixed: 0, is_split: 0 is_low: 0 "
204           "is_high: 0",
205       "ranges: { [6,23) }, uses: { 23 }, { 21 } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
206       // Environment use in HDeoptimize keeps even the non-reference argument alive.
207       "ranges: { [8,21) }, uses: { }, { 21 } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
208       // Environment uses keep the reference argument alive.
209       "ranges: { [10,21) }, uses: { }, { 15 21 } is_fixed: 0, is_split: 0 is_low: 0 is_high: 0",
210   };
211   static_assert(arraysize(expected) == arraysize(args), "Array size check.");
212   size_t arg_index = 0u;
213   for (HInstruction* arg : args) {
214     std::ostringstream arg_dump;
215     arg->GetLiveInterval()->Dump(arg_dump);
216     EXPECT_STREQ(expected[arg_index], arg_dump.str().c_str()) << arg_index;
217     ++arg_index;
218   }
219 }
220 
221 }  // namespace art
222