Re-reland: Remove register index/code indirection

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/compiler/instruction.h"
 #include "src/ostreams.h"
+#include "src/register-configuration.h"
 #include "src/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 enum RegisterKind {
   GENERAL_REGISTERS,
   DOUBLE_REGISTERS
 };
@@ skipping 214 matching lines @@
   }
   UsePositionType type() const { return TypeField::decode(flags_); }
   void set_type(UsePositionType type, bool register_beneficial);
 
   LifetimePosition pos() const { return pos_; }
 
   UsePosition* next() const { return next_; }
   void set_next(UsePosition* next) { next_ = next; }
 
   // For hinting only.
-  void set_assigned_register(int register_index) {
-    flags_ = AssignedRegisterField::update(flags_, register_index);
+  void set_assigned_register(int register_code) {
+    flags_ = AssignedRegisterField::update(flags_, register_code);
   }
 
   UsePositionHintType hint_type() const {
     return HintTypeField::decode(flags_);
   }
   bool HasHint() const;
-  bool HintRegister(int* register_index) const;
+  bool HintRegister(int* register_code) const;
   void ResolveHint(UsePosition* use_pos);
   bool IsResolved() const {
     return hint_type() != UsePositionHintType::kUnresolved;
   }
   static UsePositionHintType HintTypeForOperand(const InstructionOperand& op);
 
  private:
   typedef BitField<UsePositionType, 0, 2> TypeField;
   typedef BitField<UsePositionHintType, 2, 3> HintTypeField;
   typedef BitField<bool, 5, 1> RegisterBeneficialField;
@@ skipping 396 matching lines @@
  public:
   class PhiMapValue : public ZoneObject {
    public:
     PhiMapValue(PhiInstruction* phi, const InstructionBlock* block, Zone* zone);
 
     const PhiInstruction* phi() const { return phi_; }
     const InstructionBlock* block() const { return block_; }
 
     // For hinting.
     int assigned_register() const { return assigned_register_; }
-    void set_assigned_register(int register_index) {
+    void set_assigned_register(int register_code) {
       DCHECK_EQ(assigned_register_, kUnassignedRegister);
-      assigned_register_ = register_index;
+      assigned_register_ = register_code;
     }
     void UnsetAssignedRegister() { assigned_register_ = kUnassignedRegister; }
 
     void AddOperand(InstructionOperand* operand);
     void CommitAssignment(const InstructionOperand& operand);
 
    private:
     PhiInstruction* const phi_;
     const InstructionBlock* const block_;
     ZoneVector<InstructionOperand*> incoming_operands_;
@@ skipping 80 matching lines @@
 
  private:
   int GetNextLiveRangeId();
 
   Zone* const allocation_zone_;
   Frame* const frame_;
   InstructionSequence* const code_;
   const char* const debug_name_;
   const RegisterConfiguration* const config_;
   PhiMap phi_map_;
+  ZoneVector<int> allocatable_codes_;
+  ZoneVector<int> allocatable_double_codes_;
   ZoneVector<BitVector*> live_in_sets_;
   ZoneVector<BitVector*> live_out_sets_;
   ZoneVector<TopLevelLiveRange*> live_ranges_;
   ZoneVector<TopLevelLiveRange*> fixed_live_ranges_;
   ZoneVector<TopLevelLiveRange*> fixed_double_live_ranges_;
   ZoneVector<SpillRange*> spill_ranges_;
   DelayedReferences delayed_references_;
   BitVector* assigned_registers_;
   BitVector* assigned_double_registers_;
   int virtual_register_count_;
@@ skipping 97 matching lines @@
 
 class RegisterAllocator : public ZoneObject {
  public:
   explicit RegisterAllocator(RegisterAllocationData* data, RegisterKind kind);
 
  protected:
   RegisterAllocationData* data() const { return data_; }
   InstructionSequence* code() const { return data()->code(); }
   RegisterKind mode() const { return mode_; }
   int num_registers() const { return num_registers_; }
+  int num_allocatable_registers() const { return num_allocatable_registers_; }
+  int allocatable_register_code(int allocatable_index) const {
+    return allocatable_register_codes_[allocatable_index];
+  }
 
   Zone* allocation_zone() const { return data()->allocation_zone(); }
 
   // Split the given range at the given position.
   // If range starts at or after the given position then the
   // original range is returned.
   // Otherwise returns the live range that starts at pos and contains
   // all uses from the original range that follow pos. Uses at pos will
   // still be owned by the original range after splitting.
   LiveRange* SplitRangeAt(LiveRange* range, LifetimePosition pos);
@@ skipping 15 matching lines @@
   LifetimePosition FindOptimalSpillingPos(LiveRange* range,
                                           LifetimePosition pos);
 
   const ZoneVector<TopLevelLiveRange*>& GetFixedRegisters() const;
   const char* RegisterName(int allocation_index) const;
 
  private:
   RegisterAllocationData* const data_;
   const RegisterKind mode_;
   const int num_registers_;
+  int num_allocatable_registers_;
+  const int* allocatable_register_codes_;
 
   DISALLOW_COPY_AND_ASSIGN(RegisterAllocator);
 };
 
 
 class LinearScanAllocator final : public RegisterAllocator {
  public:
   LinearScanAllocator(RegisterAllocationData* data, RegisterKind kind,
                       Zone* local_zone);
 
@@ skipping 141 matching lines @@
   RegisterAllocationData* const data_;
 
   DISALLOW_COPY_AND_ASSIGN(LiveRangeConnector);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGISTER_ALLOCATOR_H_