1 // Copyright 2016 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_COMPILER_BYTECODE_ANALYSIS_H_ 6 #define V8_COMPILER_BYTECODE_ANALYSIS_H_ 7 8 #include "src/base/hashmap.h" 9 #include "src/bit-vector.h" 10 #include "src/compiler/bytecode-liveness-map.h" 11 #include "src/handles.h" 12 #include "src/interpreter/bytecode-register.h" 13 #include "src/utils.h" 14 #include "src/zone/zone-containers.h" 15 16 namespace v8 { 17 namespace internal { 18 19 class BytecodeArray; 20 21 namespace compiler { 22 23 class V8_EXPORT_PRIVATE BytecodeLoopAssignments { 24 public: 25 BytecodeLoopAssignments(int parameter_count, int register_count, Zone* zone); 26 27 void Add(interpreter::Register r); 28 void AddList(interpreter::Register r, uint32_t count); 29 void Union(const BytecodeLoopAssignments& other); 30 31 bool ContainsParameter(int index) const; 32 bool ContainsLocal(int index) const; 33 34 int parameter_count() const { return parameter_count_; } 35 int local_count() const { return bit_vector_->length() - parameter_count_; } 36 37 private: 38 int parameter_count_; 39 BitVector* bit_vector_; 40 }; 41 42 // Jump targets for resuming a suspended generator. 43 class V8_EXPORT_PRIVATE ResumeJumpTarget { 44 public: 45 // Create a resume jump target representing an actual resume. 46 static ResumeJumpTarget Leaf(int suspend_id, int target_offset); 47 48 // Create a resume jump target at a loop header, which will have another 49 // resume jump after the loop header is crossed. 50 static ResumeJumpTarget AtLoopHeader(int loop_header_offset, 51 const ResumeJumpTarget& next); 52 53 int suspend_id() const { return suspend_id_; } 54 int target_offset() const { return target_offset_; } 55 bool is_leaf() const { return target_offset_ == final_target_offset_; } 56 57 private: 58 // The suspend id of the resume. 59 int suspend_id_; 60 // The target offset of this resume jump. 61 int target_offset_; 62 // The final offset of this resume, which may be across multiple jumps. 63 int final_target_offset_; 64 65 ResumeJumpTarget(int suspend_id, int target_offset, int final_target_offset); 66 }; 67 68 struct V8_EXPORT_PRIVATE LoopInfo { 69 public: 70 LoopInfo(int parent_offset, int parameter_count, int register_count, 71 Zone* zone) 72 : parent_offset_(parent_offset), 73 assignments_(parameter_count, register_count, zone), 74 resume_jump_targets_(zone) {} 75 76 int parent_offset() const { return parent_offset_; } 77 78 const ZoneVector<ResumeJumpTarget>& resume_jump_targets() const { 79 return resume_jump_targets_; 80 } 81 void AddResumeTarget(const ResumeJumpTarget& target) { 82 resume_jump_targets_.push_back(target); 83 } 84 85 BytecodeLoopAssignments& assignments() { return assignments_; } 86 const BytecodeLoopAssignments& assignments() const { return assignments_; } 87 88 private: 89 // The offset to the parent loop, or -1 if there is no parent. 90 int parent_offset_; 91 BytecodeLoopAssignments assignments_; 92 ZoneVector<ResumeJumpTarget> resume_jump_targets_; 93 }; 94 95 class V8_EXPORT_PRIVATE BytecodeAnalysis BASE_EMBEDDED { 96 public: 97 BytecodeAnalysis(Handle<BytecodeArray> bytecode_array, Zone* zone, 98 bool do_liveness_analysis); 99 100 // Analyze the bytecodes to find the loop ranges, loop nesting, loop 101 // assignments and liveness, under the assumption that there is an OSR bailout 102 // at {osr_bailout_id}. 103 // 104 // No other methods in this class return valid information until this has been 105 // called. 106 void Analyze(BailoutId osr_bailout_id); 107 108 // Return true if the given offset is a loop header 109 bool IsLoopHeader(int offset) const; 110 // Get the loop header offset of the containing loop for arbitrary 111 // {offset}, or -1 if the {offset} is not inside any loop. 112 int GetLoopOffsetFor(int offset) const; 113 // Get the loop info of the loop header at {header_offset}. 114 const LoopInfo& GetLoopInfoFor(int header_offset) const; 115 116 // Get the top-level resume jump targets. 117 const ZoneVector<ResumeJumpTarget>& resume_jump_targets() const { 118 return resume_jump_targets_; 119 } 120 121 // True if the current analysis has an OSR entry point. 122 bool HasOsrEntryPoint() const { return osr_entry_point_ != -1; } 123 124 int osr_entry_point() const { return osr_entry_point_; } 125 126 // Gets the in-liveness for the bytecode at {offset}. 127 const BytecodeLivenessState* GetInLivenessFor(int offset) const; 128 129 // Gets the out-liveness for the bytecode at {offset}. 130 const BytecodeLivenessState* GetOutLivenessFor(int offset) const; 131 132 std::ostream& PrintLivenessTo(std::ostream& os) const; 133 134 private: 135 struct LoopStackEntry { 136 int header_offset; 137 LoopInfo* loop_info; 138 }; 139 140 void PushLoop(int loop_header, int loop_end); 141 142 #if DEBUG 143 bool ResumeJumpTargetsAreValid(); 144 bool ResumeJumpTargetLeavesResolveSuspendIds( 145 int parent_offset, 146 const ZoneVector<ResumeJumpTarget>& resume_jump_targets, 147 std::map<int, int>* unresolved_suspend_ids); 148 149 bool LivenessIsValid(); 150 #endif 151 152 Zone* zone() const { return zone_; } 153 Handle<BytecodeArray> bytecode_array() const { return bytecode_array_; } 154 155 private: 156 Handle<BytecodeArray> bytecode_array_; 157 bool do_liveness_analysis_; 158 Zone* zone_; 159 160 ZoneStack<LoopStackEntry> loop_stack_; 161 ZoneVector<int> loop_end_index_queue_; 162 ZoneVector<ResumeJumpTarget> resume_jump_targets_; 163 164 ZoneMap<int, int> end_to_header_; 165 ZoneMap<int, LoopInfo> header_to_info_; 166 int osr_entry_point_; 167 168 BytecodeLivenessMap liveness_map_; 169 170 DISALLOW_COPY_AND_ASSIGN(BytecodeAnalysis); 171 }; 172 173 } // namespace compiler 174 } // namespace internal 175 } // namespace v8 176 177 #endif // V8_COMPILER_BYTECODE_ANALYSIS_H_ 178
