[turbofan] compress live_in bitvectors

src/compiler/register-allocator.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_REGISTER_ALLOCATOR_H_
 #define V8_REGISTER_ALLOCATOR_H_
 
 #include "src/allocation.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/node.h"
@@ skipping 364 matching lines @@
   void AllocateGeneralRegisters();
   void AllocateDoubleRegisters();
   void ConnectRanges();
   void ResolveControlFlow();
   void PopulatePointerMaps();  // TODO(titzer): rename to PopulateReferenceMaps.
   void AllocateRegisters();
   bool CanEagerlyResolveControlFlow(BasicBlock* block) const;
   inline bool SafePointsAreInOrder() const;
 
   // Liveness analysis support.
-  void InitializeLivenessAnalysis();
-  BitVector* ComputeLiveOut(BasicBlock* block);
-  void AddInitialIntervals(BasicBlock* block, BitVector* live_out);
+  void ComputeLiveOut(BasicBlock* block);
+  void AddInitialIntervals(BasicBlock* block);
   bool IsOutputRegisterOf(Instruction* instr, int index);
   bool IsOutputDoubleRegisterOf(Instruction* instr, int index);
-  void ProcessInstructions(BasicBlock* block, BitVector* live);
+  void ProcessInstructions(BasicBlock* block);
   void MeetRegisterConstraints(BasicBlock* block);
   void MeetConstraintsBetween(Instruction* first, Instruction* second,
                               int gap_index);
   void MeetRegisterConstraintsForLastInstructionInBlock(BasicBlock* block);
   void ResolvePhis(BasicBlock* block);
 
   // Helper methods for building intervals.
   InstructionOperand* AllocateFixed(UnallocatedOperand* operand, int pos,
                                     bool is_tagged);
   LiveRange* LiveRangeFor(InstructionOperand* operand);
@@ skipping 90 matching lines @@
 
   inline Instruction* InstructionAt(int index) {
     return code()->InstructionAt(index);
   }
 
   Zone zone_;
   InstructionSequence* code_;
 
   // During liveness analysis keep a mapping from block id to live_in sets
   // for blocks already analyzed.
-  ZoneList<BitVector*> live_in_sets_;
+  class LiveInSets;
+  LiveInSets* live_in_sets_;
 
   // Liveness analysis results.
   ZoneList<LiveRange*> live_ranges_;
 
   // Lists of live ranges
   EmbeddedVector<LiveRange*, Register::kMaxNumAllocatableRegisters>
       fixed_live_ranges_;
   EmbeddedVector<LiveRange*, DoubleRegister::kMaxNumAllocatableRegisters>
       fixed_double_live_ranges_;
   ZoneList<LiveRange*> unhandled_live_ranges_;
@@ skipping 27 matching lines @@
   RegisterAllocator* allocator_;
   unsigned allocator_zone_start_allocation_size_;
 
   DISALLOW_COPY_AND_ASSIGN(RegisterAllocatorPhase);
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_REGISTER_ALLOCATOR_H_