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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/zone/zone-containers.h"
14 :
15 : namespace v8 {
16 : namespace internal {
17 :
18 : class BytecodeArray;
19 :
20 : namespace compiler {
21 :
22 : class V8_EXPORT_PRIVATE BytecodeLoopAssignments {
23 : public:
24 : BytecodeLoopAssignments(int parameter_count, int register_count, Zone* zone);
25 :
26 : void Add(interpreter::Register r);
27 : void AddPair(interpreter::Register r);
28 : void AddTriple(interpreter::Register r);
29 : void AddAll();
30 : void Union(const BytecodeLoopAssignments& other);
31 :
32 : bool ContainsParameter(int index) const;
33 : bool ContainsLocal(int index) const;
34 : bool ContainsAccumulator() const;
35 :
36 : int parameter_count() const { return parameter_count_; }
37 : int local_count() const { return bit_vector_->length() - parameter_count_; }
38 :
39 : private:
40 : int parameter_count_;
41 : BitVector* bit_vector_;
42 : };
43 :
44 : struct V8_EXPORT_PRIVATE LoopInfo {
45 : public:
46 : LoopInfo(int parent_offset, int parameter_count, int register_count,
47 : Zone* zone)
48 : : parent_offset_(parent_offset),
49 56573 : assignments_(parameter_count, register_count, zone) {}
50 :
51 : int parent_offset() const { return parent_offset_; }
52 :
53 : BytecodeLoopAssignments& assignments() { return assignments_; }
54 : const BytecodeLoopAssignments& assignments() const { return assignments_; }
55 :
56 : private:
57 : // The offset to the parent loop, or -1 if there is no parent.
58 : int parent_offset_;
59 : BytecodeLoopAssignments assignments_;
60 : };
61 :
62 861732 : class V8_EXPORT_PRIVATE BytecodeAnalysis BASE_EMBEDDED {
63 : public:
64 : BytecodeAnalysis(Handle<BytecodeArray> bytecode_array, Zone* zone,
65 : bool do_liveness_analysis);
66 :
67 : // Analyze the bytecodes to find the loop ranges, loop nesting, loop
68 : // assignments and liveness, under the assumption that there is an OSR bailout
69 : // at {osr_bailout_id}.
70 : //
71 : // No other methods in this class return valid information until this has been
72 : // called.
73 : void Analyze(BailoutId osr_bailout_id);
74 :
75 : // Return true if the given offset is a loop header
76 : bool IsLoopHeader(int offset) const;
77 : // Get the loop header offset of the containing loop for arbitrary
78 : // {offset}, or -1 if the {offset} is not inside any loop.
79 : int GetLoopOffsetFor(int offset) const;
80 : // Get the loop info of the loop header at {header_offset}.
81 : const LoopInfo& GetLoopInfoFor(int header_offset) const;
82 :
83 : // True if the current analysis has an OSR entry point.
84 : bool HasOSREntryPoint() const { return osr_entry_point_ != -1; }
85 : // True if {offset} is the OSR entry loop header.
86 : bool IsOSREntryPoint(int offset) const { return osr_entry_point_ == offset; }
87 :
88 : // Gets the in-liveness for the bytecode at {offset}.
89 : const BytecodeLivenessState* GetInLivenessFor(int offset) const;
90 :
91 : // Gets the out-liveness for the bytecode at {offset}.
92 : const BytecodeLivenessState* GetOutLivenessFor(int offset) const;
93 :
94 : std::ostream& PrintLivenessTo(std::ostream& os) const;
95 :
96 : private:
97 : struct LoopStackEntry {
98 : int header_offset;
99 : LoopInfo* loop_info;
100 : };
101 :
102 : void PushLoop(int loop_header, int loop_end);
103 :
104 : #if DEBUG
105 : bool LivenessIsValid();
106 : #endif
107 :
108 : Zone* zone() const { return zone_; }
109 : Handle<BytecodeArray> bytecode_array() const { return bytecode_array_; }
110 :
111 : private:
112 : Handle<BytecodeArray> bytecode_array_;
113 : bool do_liveness_analysis_;
114 : Zone* zone_;
115 :
116 : ZoneStack<LoopStackEntry> loop_stack_;
117 : ZoneVector<int> loop_end_index_queue_;
118 :
119 : ZoneMap<int, int> end_to_header_;
120 : ZoneMap<int, LoopInfo> header_to_info_;
121 : int osr_entry_point_;
122 :
123 : BytecodeLivenessMap liveness_map_;
124 :
125 : DISALLOW_COPY_AND_ASSIGN(BytecodeAnalysis);
126 : };
127 :
128 : } // namespace compiler
129 : } // namespace internal
130 : } // namespace v8
131 :
132 : #endif // V8_COMPILER_BYTECODE_ANALYSIS_H_
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