Line data    Source code

       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_