1 /*
2  * Copyright (C) 2014 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 "builder.h"
18 
19 #include "art_field-inl.h"
20 #include "base/arena_bit_vector.h"
21 #include "base/bit_vector-inl.h"
22 #include "base/logging.h"
23 #include "block_builder.h"
24 #include "code_generator.h"
25 #include "data_type-inl.h"
26 #include "dex/verified_method.h"
27 #include "driver/compiler_options.h"
28 #include "driver/dex_compilation_unit.h"
29 #include "instruction_builder.h"
30 #include "mirror/class_loader.h"
31 #include "mirror/dex_cache.h"
32 #include "nodes.h"
33 #include "optimizing_compiler_stats.h"
34 #include "ssa_builder.h"
35 #include "thread.h"
36 #include "utils/dex_cache_arrays_layout-inl.h"
37 
38 namespace art {
39 
HGraphBuilder(HGraph * graph,const CodeItemDebugInfoAccessor & accessor,const DexCompilationUnit * dex_compilation_unit,const DexCompilationUnit * outer_compilation_unit,CodeGenerator * code_generator,OptimizingCompilerStats * compiler_stats,ArrayRef<const uint8_t> interpreter_metadata,VariableSizedHandleScope * handles)40 HGraphBuilder::HGraphBuilder(HGraph* graph,
41                              const CodeItemDebugInfoAccessor& accessor,
42                              const DexCompilationUnit* dex_compilation_unit,
43                              const DexCompilationUnit* outer_compilation_unit,
44                              CodeGenerator* code_generator,
45                              OptimizingCompilerStats* compiler_stats,
46                              ArrayRef<const uint8_t> interpreter_metadata,
47                              VariableSizedHandleScope* handles)
48     : graph_(graph),
49       dex_file_(&graph->GetDexFile()),
50       code_item_accessor_(accessor),
51       dex_compilation_unit_(dex_compilation_unit),
52       outer_compilation_unit_(outer_compilation_unit),
53       code_generator_(code_generator),
54       compilation_stats_(compiler_stats),
55       interpreter_metadata_(interpreter_metadata),
56       handles_(handles),
57       return_type_(DataType::FromShorty(dex_compilation_unit_->GetShorty()[0])) {}
58 
HGraphBuilder(HGraph * graph,const DexCompilationUnit * dex_compilation_unit,const CodeItemDebugInfoAccessor & accessor,VariableSizedHandleScope * handles,DataType::Type return_type)59 HGraphBuilder::HGraphBuilder(HGraph* graph,
60                              const DexCompilationUnit* dex_compilation_unit,
61                              const CodeItemDebugInfoAccessor& accessor,
62                              VariableSizedHandleScope* handles,
63                              DataType::Type return_type)
64     : graph_(graph),
65       dex_file_(&graph->GetDexFile()),
66       code_item_accessor_(accessor),
67       dex_compilation_unit_(dex_compilation_unit),
68       outer_compilation_unit_(nullptr),
69       code_generator_(nullptr),
70       compilation_stats_(nullptr),
71       handles_(handles),
72       return_type_(return_type) {}
73 
SkipCompilation(size_t number_of_branches)74 bool HGraphBuilder::SkipCompilation(size_t number_of_branches) {
75   if (code_generator_ == nullptr) {
76     // Note that the codegen is null when unit testing.
77     return false;
78   }
79 
80   const CompilerOptions& compiler_options = code_generator_->GetCompilerOptions();
81   CompilerFilter::Filter compiler_filter = compiler_options.GetCompilerFilter();
82   if (compiler_filter == CompilerFilter::kEverything) {
83     return false;
84   }
85 
86   const uint32_t code_units = code_item_accessor_.InsnsSizeInCodeUnits();
87   if (compiler_options.IsHugeMethod(code_units)) {
88     VLOG(compiler) << "Skip compilation of huge method "
89                    << dex_file_->PrettyMethod(dex_compilation_unit_->GetDexMethodIndex())
90                    << ": " << code_units << " code units";
91     MaybeRecordStat(compilation_stats_, MethodCompilationStat::kNotCompiledHugeMethod);
92     return true;
93   }
94 
95   // If it's large and contains no branches, it's likely to be machine generated initialization.
96   if (compiler_options.IsLargeMethod(code_units) && (number_of_branches == 0)) {
97     VLOG(compiler) << "Skip compilation of large method with no branch "
98                    << dex_file_->PrettyMethod(dex_compilation_unit_->GetDexMethodIndex())
99                    << ": " << code_units << " code units";
100     MaybeRecordStat(compilation_stats_, MethodCompilationStat::kNotCompiledLargeMethodNoBranches);
101     return true;
102   }
103 
104   return false;
105 }
106 
BuildGraph()107 GraphAnalysisResult HGraphBuilder::BuildGraph() {
108   DCHECK(code_item_accessor_.HasCodeItem());
109   DCHECK(graph_->GetBlocks().empty());
110 
111   graph_->SetNumberOfVRegs(code_item_accessor_.RegistersSize());
112   graph_->SetNumberOfInVRegs(code_item_accessor_.InsSize());
113   graph_->SetMaximumNumberOfOutVRegs(code_item_accessor_.OutsSize());
114   graph_->SetHasTryCatch(code_item_accessor_.TriesSize() != 0);
115 
116   // Use ScopedArenaAllocator for all local allocations.
117   ScopedArenaAllocator local_allocator(graph_->GetArenaStack());
118   HBasicBlockBuilder block_builder(graph_, dex_file_, code_item_accessor_, &local_allocator);
119   SsaBuilder ssa_builder(graph_,
120                          dex_compilation_unit_->GetClassLoader(),
121                          dex_compilation_unit_->GetDexCache(),
122                          handles_,
123                          &local_allocator);
124   HInstructionBuilder instruction_builder(graph_,
125                                           &block_builder,
126                                           &ssa_builder,
127                                           dex_file_,
128                                           code_item_accessor_,
129                                           return_type_,
130                                           dex_compilation_unit_,
131                                           outer_compilation_unit_,
132                                           code_generator_,
133                                           interpreter_metadata_,
134                                           compilation_stats_,
135                                           handles_,
136                                           &local_allocator);
137 
138   // 1) Create basic blocks and link them together. Basic blocks are left
139   //    unpopulated with the exception of synthetic blocks, e.g. HTryBoundaries.
140   if (!block_builder.Build()) {
141     return kAnalysisInvalidBytecode;
142   }
143 
144   // 2) Decide whether to skip this method based on its code size and number
145   //    of branches.
146   if (SkipCompilation(block_builder.GetNumberOfBranches())) {
147     return kAnalysisSkipped;
148   }
149 
150   // 3) Build the dominator tree and fill in loop and try/catch metadata.
151   GraphAnalysisResult result = graph_->BuildDominatorTree();
152   if (result != kAnalysisSuccess) {
153     return result;
154   }
155 
156   // 4) Populate basic blocks with instructions.
157   if (!instruction_builder.Build()) {
158     return kAnalysisInvalidBytecode;
159   }
160 
161   // 5) Type the graph and eliminate dead/redundant phis.
162   return ssa_builder.BuildSsa();
163 }
164 
BuildIntrinsicGraph(ArtMethod * method)165 void HGraphBuilder::BuildIntrinsicGraph(ArtMethod* method) {
166   DCHECK(!code_item_accessor_.HasCodeItem());
167   DCHECK(graph_->GetBlocks().empty());
168 
169   // Determine the number of arguments and associated vregs.
170   uint32_t method_idx = dex_compilation_unit_->GetDexMethodIndex();
171   const char* shorty = dex_file_->GetMethodShorty(dex_file_->GetMethodId(method_idx));
172   size_t num_args = strlen(shorty + 1);
173   size_t num_wide_args = std::count(shorty + 1, shorty + 1 + num_args, 'J') +
174                          std::count(shorty + 1, shorty + 1 + num_args, 'D');
175   size_t num_arg_vregs = num_args + num_wide_args + (dex_compilation_unit_->IsStatic() ? 0u : 1u);
176 
177   // For simplicity, reserve 2 vregs (the maximum) for return value regardless of the return type.
178   size_t return_vregs = 2u;
179   graph_->SetNumberOfVRegs(return_vregs + num_arg_vregs);
180   graph_->SetNumberOfInVRegs(num_arg_vregs);
181   graph_->SetMaximumNumberOfOutVRegs(num_arg_vregs);
182   graph_->SetHasTryCatch(false);
183 
184   // Use ScopedArenaAllocator for all local allocations.
185   ScopedArenaAllocator local_allocator(graph_->GetArenaStack());
186   HBasicBlockBuilder block_builder(graph_,
187                                    dex_file_,
188                                    CodeItemDebugInfoAccessor(),
189                                    &local_allocator);
190   SsaBuilder ssa_builder(graph_,
191                          dex_compilation_unit_->GetClassLoader(),
192                          dex_compilation_unit_->GetDexCache(),
193                          handles_,
194                          &local_allocator);
195   HInstructionBuilder instruction_builder(graph_,
196                                           &block_builder,
197                                           &ssa_builder,
198                                           dex_file_,
199                                           CodeItemDebugInfoAccessor(),
200                                           return_type_,
201                                           dex_compilation_unit_,
202                                           outer_compilation_unit_,
203                                           code_generator_,
204                                           interpreter_metadata_,
205                                           compilation_stats_,
206                                           handles_,
207                                           &local_allocator);
208 
209   // 1) Create basic blocks for the intrinsic and link them together.
210   block_builder.BuildIntrinsic();
211 
212   // 2) Build the trivial dominator tree.
213   GraphAnalysisResult bdt_result = graph_->BuildDominatorTree();
214   DCHECK_EQ(bdt_result, kAnalysisSuccess);
215 
216   // 3) Populate basic blocks with instructions for the intrinsic.
217   instruction_builder.BuildIntrinsic(method);
218 
219   // 4) Type the graph (no dead/redundant phis to eliminate).
220   GraphAnalysisResult build_ssa_result = ssa_builder.BuildSsa();
221   DCHECK_EQ(build_ssa_result, kAnalysisSuccess);
222 }
223 
224 }  // namespace art
225