Merge experimental/a64 to bleeding_edge.

src/a64/lithium-codegen-a64.h

-// Copyright 2012 the V8 project authors. All rights reserved.
+// Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef V8_ARM_LITHIUM_CODEGEN_ARM_H_
-#define V8_ARM_LITHIUM_CODEGEN_ARM_H_
+#ifndef V8_A64_LITHIUM_CODEGEN_A64_H_
+#define V8_A64_LITHIUM_CODEGEN_A64_H_
 
-#include "arm/lithium-arm.h"
+#include "a64/lithium-a64.h"
 
-#include "arm/lithium-gap-resolver-arm.h"
+#include "a64/lithium-gap-resolver-a64.h"
 #include "deoptimizer.h"
 #include "lithium-codegen.h"
 #include "safepoint-table.h"
 #include "scopes.h"
 #include "v8utils.h"
 
 namespace v8 {
 namespace internal {
 
 // Forward declarations.
 class LDeferredCode;
 class SafepointGenerator;
+class BranchGenerator;
 
 class LCodeGen: public LCodeGenBase {
  public:
   LCodeGen(LChunk* chunk, MacroAssembler* assembler, CompilationInfo* info)
       : LCodeGenBase(chunk, assembler, info),
         deoptimizations_(4, info->zone()),
         deopt_jump_table_(4, info->zone()),
         deoptimization_literals_(8, info->zone()),
         inlined_function_count_(0),
         scope_(info->scope()),
         translations_(info->zone()),
         deferred_(8, info->zone()),
         osr_pc_offset_(-1),
         frame_is_built_(false),
         safepoints_(info->zone()),
         resolver_(this),
         expected_safepoint_kind_(Safepoint::kSimple) {
     PopulateDeoptimizationLiteralsWithInlinedFunctions();
   }
 
+  // Simple accessors.
+  Scope* scope() const { return scope_; }
 
   int LookupDestination(int block_id) const {
     return chunk()->LookupDestination(block_id);
   }
 
   bool IsNextEmittedBlock(int block_id) const {
     return LookupDestination(block_id) == GetNextEmittedBlock();
   }
 
   bool NeedsEagerFrame() const {
     return GetStackSlotCount() > 0 ||
         info()->is_non_deferred_calling() ||
         !info()->IsStub() ||
         info()->requires_frame();
   }
   bool NeedsDeferredFrame() const {
     return !NeedsEagerFrame() && info()->is_deferred_calling();
   }
 
   LinkRegisterStatus GetLinkRegisterState() const {
     return frame_is_built_ ? kLRHasBeenSaved : kLRHasNotBeenSaved;
   }
 
-  // Support for converting LOperands to assembler types.
-  // LOperand must be a register.
-  Register ToRegister(LOperand* op) const;
-
-  // LOperand is loaded into scratch, unless already a register.
-  Register EmitLoadRegister(LOperand* op, Register scratch);
-
-  // LOperand must be a double register.
-  DwVfpRegister ToDoubleRegister(LOperand* op) const;
-
-  // LOperand is loaded into dbl_scratch, unless already a double register.
-  DwVfpRegister EmitLoadDoubleRegister(LOperand* op,
-                                       SwVfpRegister flt_scratch,
-                                       DwVfpRegister dbl_scratch);
-  int32_t ToRepresentation(LConstantOperand* op, const Representation& r) const;
-  int32_t ToInteger32(LConstantOperand* op) const;
-  Smi* ToSmi(LConstantOperand* op) const;
-  double ToDouble(LConstantOperand* op) const;
-  Operand ToOperand(LOperand* op);
-  MemOperand ToMemOperand(LOperand* op) const;
-  // Returns a MemOperand pointing to the high word of a DoubleStackSlot.
-  MemOperand ToHighMemOperand(LOperand* op) const;
-
-  bool IsInteger32(LConstantOperand* op) const;
-  bool IsSmi(LConstantOperand* op) const;
-  Handle<Object> ToHandle(LConstantOperand* op) const;
-
   // Try to generate code for the entire chunk, but it may fail if the
   // chunk contains constructs we cannot handle. Returns true if the
   // code generation attempt succeeded.
   bool GenerateCode();
 
   // Finish the code by setting stack height, safepoint, and bailout
   // information on it.
   void FinishCode(Handle<Code> code);
 
-  // Deferred code support.
-  void DoDeferredNumberTagD(LNumberTagD* instr);
+  // Support for converting LOperands to assembler types.
+  // LOperand must be a register.
+  Register ToRegister(LOperand* op) const;
+  Register ToRegister32(LOperand* op) const;
+  Operand ToOperand(LOperand* op);
+  Operand ToOperand32I(LOperand* op);
+  Operand ToOperand32U(LOperand* op);
+  MemOperand ToMemOperand(LOperand* op) const;
+  Handle<Object> ToHandle(LConstantOperand* op) const;
 
-  enum IntegerSignedness { SIGNED_INT32, UNSIGNED_INT32 };
-  void DoDeferredNumberTagI(LInstruction* instr,
-                            LOperand* value,
-                            IntegerSignedness signedness);
+  // TODO(jbramley): Examine these helpers and check that they make sense.
+  // IsInteger32Constant returns true for smi constants, for example.
+  bool IsInteger32Constant(LConstantOperand* op) const;
+  bool IsSmi(LConstantOperand* op) const;
 
-  void DoDeferredTaggedToI(LTaggedToI* instr);
-  void DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr);
-  void DoDeferredStackCheck(LStackCheck* instr);
-  void DoDeferredStringCharCodeAt(LStringCharCodeAt* instr);
-  void DoDeferredStringCharFromCode(LStringCharFromCode* instr);
-  void DoDeferredAllocate(LAllocate* instr);
-  void DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
-                                       Label* map_check);
-  void DoDeferredInstanceMigration(LCheckMaps* instr, Register object);
-
-  // Parallel move support.
-  void DoParallelMove(LParallelMove* move);
-  void DoGap(LGap* instr);
-
-  MemOperand PrepareKeyedOperand(Register key,
-                                 Register base,
-                                 bool key_is_constant,
-                                 int constant_key,
-                                 int element_size,
-                                 int shift_size,
-                                 int additional_index,
-                                 int additional_offset);
-
-  // Emit frame translation commands for an environment.
-  void WriteTranslation(LEnvironment* environment, Translation* translation);
+  int32_t ToInteger32(LConstantOperand* op) const;
+  Smi* ToSmi(LConstantOperand* op) const;
+  double ToDouble(LConstantOperand* op) const;
+  DoubleRegister ToDoubleRegister(LOperand* op) const;
 
   // Declare methods that deal with the individual node types.
 #define DECLARE_DO(type) void Do##type(L##type* node);
   LITHIUM_CONCRETE_INSTRUCTION_LIST(DECLARE_DO)
 #undef DECLARE_DO
 
  private:
-  StrictModeFlag strict_mode_flag() const {
-    return info()->is_classic_mode() ? kNonStrictMode : kStrictMode;
-  }
+  // Return a double scratch register which can be used locally
+  // when generating code for a lithium instruction.
+  DoubleRegister double_scratch() { return crankshaft_fp_scratch; }
 
-  Scope* scope() const { return scope_; }
+  // Deferred code support.
+  void DoDeferredNumberTagD(LNumberTagD* instr);
+  void DoDeferredStackCheck(LStackCheck* instr);
+  void DoDeferredStringCharCodeAt(LStringCharCodeAt* instr);
+  void DoDeferredStringCharFromCode(LStringCharFromCode* instr);
+  void DoDeferredMathAbsTagged(LMathAbsTagged* instr,
+                               Label* exit,
+                               Label* allocation_entry);
 
-  Register scratch0() { return r9; }
-  LowDwVfpRegister double_scratch0() { return kScratchDoubleReg; }
+  enum IntegerSignedness { SIGNED_INT32, UNSIGNED_INT32 };
+  void DoDeferredNumberTagU(LInstruction* instr,
+                            LOperand* value,
+                            LOperand* temp1,
+                            LOperand* temp2);
+  void DoDeferredTaggedToI(LTaggedToI* instr,
+                           LOperand* value,
+                           LOperand* temp1,
+                           LOperand* temp2);
+  void DoDeferredAllocate(LAllocate* instr);
+  void DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr);
+  void DoDeferredInstanceMigration(LCheckMaps* instr, Register object);
 
-  LInstruction* GetNextInstruction();
+  Operand ToOperand32(LOperand* op, IntegerSignedness signedness);
 
-  void EmitClassOfTest(Label* if_true,
-                       Label* if_false,
-                       Handle<String> class_name,
-                       Register input,
-                       Register temporary,
-                       Register temporary2);
+  static Condition TokenToCondition(Token::Value op, bool is_unsigned);
+  void EmitGoto(int block);
+  void DoGap(LGap* instr);
+
+  // Generic version of EmitBranch. It contains some code to avoid emitting a
+  // branch on the next emitted basic block where we could just fall-through.
+  // You shouldn't use that directly but rather consider one of the helper like
+  // LCodeGen::EmitBranch, LCodeGen::EmitCompareAndBranch...
+  template<class InstrType>
+  void EmitBranchGeneric(InstrType instr,
+                         const BranchGenerator& branch);
+
+  template<class InstrType>
+  void EmitBranch(InstrType instr, Condition condition);
+
+  template<class InstrType>
+  void EmitCompareAndBranch(InstrType instr,
+                            Condition condition,
+                            const Register& lhs,
+                            const Operand& rhs);
+
+  template<class InstrType>
+  void EmitTestAndBranch(InstrType instr,
+                         Condition condition,
+                         const Register& value,
+                         uint64_t mask);
+
+  template<class InstrType>
+  void EmitBranchIfNonZeroNumber(InstrType instr,
+                                 const FPRegister& value,
+                                 const FPRegister& scratch);
+
+  template<class InstrType>
+  void EmitBranchIfHeapNumber(InstrType instr,
+                              const Register& value);
+
+  template<class InstrType>
+  void EmitBranchIfRoot(InstrType instr,
+                        const Register& value,
+                        Heap::RootListIndex index);
+
+  // Emits optimized code to deep-copy the contents of statically known object
+  // graphs (e.g. object literal boilerplate). Expects a pointer to the
+  // allocated destination object in the result register, and a pointer to the
+  // source object in the source register.
+  void EmitDeepCopy(Handle<JSObject> object,
+                    Register result,
+                    Register source,
+                    Register scratch,
+                    int* offset,
+                    AllocationSiteMode mode);
+
+  // Emits optimized code for %_IsString(x).  Preserves input register.
+  // Returns the condition on which a final split to
+  // true and false label should be made, to optimize fallthrough.
+  Condition EmitIsString(Register input, Register temp1, Label* is_not_string,
+                         SmiCheck check_needed);
+
+  int DefineDeoptimizationLiteral(Handle<Object> literal);
+  void PopulateDeoptimizationData(Handle<Code> code);
+  void PopulateDeoptimizationLiteralsWithInlinedFunctions();
+
+  MemOperand BuildSeqStringOperand(Register string,
+                                   Register temp,
+                                   LOperand* index,
+                                   String::Encoding encoding);
+  Deoptimizer::BailoutType DeoptimizeHeader(
+      LEnvironment* environment,
+      Deoptimizer::BailoutType* override_bailout_type);
+  void Deoptimize(LEnvironment* environment);
+  void Deoptimize(LEnvironment* environment,
+                  Deoptimizer::BailoutType bailout_type);
+  void DeoptimizeIf(Condition cc, LEnvironment* environment);
+  void DeoptimizeIfZero(Register rt, LEnvironment* environment);
+  void DeoptimizeIfNegative(Register rt, LEnvironment* environment);
+  void DeoptimizeIfSmi(Register rt, LEnvironment* environment);
+  void DeoptimizeIfNotSmi(Register rt, LEnvironment* environment);
+  void DeoptimizeIfRoot(Register rt,
+                        Heap::RootListIndex index,
+                        LEnvironment* environment);
+  void DeoptimizeIfNotRoot(Register rt,
+                           Heap::RootListIndex index,
+                           LEnvironment* environment);
+  void ApplyCheckIf(Condition cc, LBoundsCheck* check);
+
+  MemOperand PrepareKeyedExternalArrayOperand(Register key,
+                                              Register base,
+                                              Register scratch,
+                                              bool key_is_smi,
+                                              bool key_is_constant,
+                                              int constant_key,
+                                              ElementsKind elements_kind,
+                                              int additional_index);
+  void CalcKeyedArrayBaseRegister(Register base,
+                                  Register elements,
+                                  Register key,
+                                  bool key_is_tagged,
+                                  ElementsKind elements_kind);
+
+  void RegisterEnvironmentForDeoptimization(LEnvironment* environment,
+                                            Safepoint::DeoptMode mode);
 
   int GetStackSlotCount() const { return chunk()->spill_slot_count(); }
 
   void Abort(BailoutReason reason);
 
   void AddDeferredCode(LDeferredCode* code) { deferred_.Add(code, zone()); }
 
+  // Emit frame translation commands for an environment.
+  void WriteTranslation(LEnvironment* environment, Translation* translation);
+
+  void AddToTranslation(LEnvironment* environment,
+                        Translation* translation,
+                        LOperand* op,
+                        bool is_tagged,
+                        bool is_uint32,
+                        int* object_index_pointer,
+                        int* dematerialized_index_pointer);
+
   void SaveCallerDoubles();
   void RestoreCallerDoubles();
 
-  // Code generation passes.  Returns true if code generation should
-  // continue.
+  // Code generation steps.  Returns true if code generation should continue.
   bool GeneratePrologue();
   bool GenerateDeferredCode();
   bool GenerateDeoptJumpTable();
   bool GenerateSafepointTable();
 
   // Generates the custom OSR entrypoint and sets the osr_pc_offset.
   void GenerateOsrPrologue();
 
   enum SafepointMode {
     RECORD_SIMPLE_SAFEPOINT,
     RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS
   };
 
-  void CallCode(
-      Handle<Code> code,
-      RelocInfo::Mode mode,
-      LInstruction* instr,
-      TargetAddressStorageMode storage_mode = CAN_INLINE_TARGET_ADDRESS);
+  void CallCode(Handle<Code> code,
+                RelocInfo::Mode mode,
+                LInstruction* instr);
 
-  void CallCodeGeneric(
-      Handle<Code> code,
-      RelocInfo::Mode mode,
-      LInstruction* instr,
-      SafepointMode safepoint_mode,
-      TargetAddressStorageMode storage_mode = CAN_INLINE_TARGET_ADDRESS);
+  void CallCodeGeneric(Handle<Code> code,
+                       RelocInfo::Mode mode,
+                       LInstruction* instr,
+                       SafepointMode safepoint_mode);
 
   void CallRuntime(const Runtime::Function* function,
                    int num_arguments,
                    LInstruction* instr,
                    SaveFPRegsMode save_doubles = kDontSaveFPRegs);
 
   void CallRuntime(Runtime::FunctionId id,
                    int num_arguments,
                    LInstruction* instr) {
     const Runtime::Function* function = Runtime::FunctionForId(id);
     CallRuntime(function, num_arguments, instr);
   }
 
   void LoadContextFromDeferred(LOperand* context);
   void CallRuntimeFromDeferred(Runtime::FunctionId id,
                                int argc,
                                LInstruction* instr,
                                LOperand* context);
 
-  enum R1State {
-    R1_UNINITIALIZED,
-    R1_CONTAINS_TARGET
-  };
-
-  // Generate a direct call to a known function.  Expects the function
-  // to be in r1.
+  // Generate a direct call to a known function.
+  // If the function is already loaded into x1 by the caller, function_reg may
+  // be set to x1. Otherwise, it must be NoReg, and CallKnownFunction will
+  // automatically load it.
   void CallKnownFunction(Handle<JSFunction> function,
                          int formal_parameter_count,
                          int arity,
                          LInstruction* instr,
-                         R1State r1_state);
-
-  void RecordSafepointWithLazyDeopt(LInstruction* instr,
-                                    SafepointMode safepoint_mode);
-
-  void RegisterEnvironmentForDeoptimization(LEnvironment* environment,
-                                            Safepoint::DeoptMode mode);
-  void DeoptimizeIf(Condition condition,
-                    LEnvironment* environment,
-                    Deoptimizer::BailoutType bailout_type);
-  void DeoptimizeIf(Condition condition, LEnvironment* environment);
-  void ApplyCheckIf(Condition condition, LBoundsCheck* check);
-
-  void AddToTranslation(LEnvironment* environment,
-                        Translation* translation,
-                        LOperand* op,
-                        bool is_tagged,
-                        bool is_uint32,
-                        int* object_index_pointer,
-                        int* dematerialized_index_pointer);
-  void PopulateDeoptimizationData(Handle<Code> code);
-  int DefineDeoptimizationLiteral(Handle<Object> literal);
-
-  void PopulateDeoptimizationLiteralsWithInlinedFunctions();
-
-  Register ToRegister(int index) const;
-  DwVfpRegister ToDoubleRegister(int index) const;
-
-  MemOperand BuildSeqStringOperand(Register string,
-                                   LOperand* index,
-                                   String::Encoding encoding);
-
-  void EmitIntegerMathAbs(LMathAbs* instr);
+                         Register function_reg = NoReg);
 
   // Support for recording safepoint and position information.
+  void RecordAndWritePosition(int position) V8_OVERRIDE;
   void RecordSafepoint(LPointerMap* pointers,
                        Safepoint::Kind kind,
                        int arguments,
                        Safepoint::DeoptMode mode);
   void RecordSafepoint(LPointerMap* pointers, Safepoint::DeoptMode mode);
   void RecordSafepoint(Safepoint::DeoptMode mode);
   void RecordSafepointWithRegisters(LPointerMap* pointers,
                                     int arguments,
                                     Safepoint::DeoptMode mode);
   void RecordSafepointWithRegistersAndDoubles(LPointerMap* pointers,
                                               int arguments,
                                               Safepoint::DeoptMode mode);
-
-  void RecordAndWritePosition(int position) V8_OVERRIDE;
-
-  static Condition TokenToCondition(Token::Value op, bool is_unsigned);
-  void EmitGoto(int block);
-
-  // EmitBranch expects to be the last instruction of a block.
-  template<class InstrType>
-  void EmitBranch(InstrType instr, Condition condition);
-  template<class InstrType>
-  void EmitFalseBranch(InstrType instr, Condition condition);
-  void EmitNumberUntagD(Register input,
-                        DwVfpRegister result,
-                        bool allow_undefined_as_nan,
-                        bool deoptimize_on_minus_zero,
-                        LEnvironment* env,
-                        NumberUntagDMode mode);
-
-  // Emits optimized code for typeof x == "y".  Modifies input register.
-  // Returns the condition on which a final split to
-  // true and false label should be made, to optimize fallthrough.
-  Condition EmitTypeofIs(Label* true_label,
-                         Label* false_label,
-                         Register input,
-                         Handle<String> type_name);
-
-  // Emits optimized code for %_IsObject(x).  Preserves input register.
-  // Returns the condition on which a final split to
-  // true and false label should be made, to optimize fallthrough.
-  Condition EmitIsObject(Register input,
-                         Register temp1,
-                         Label* is_not_object,
-                         Label* is_object);
-
-  // Emits optimized code for %_IsString(x).  Preserves input register.
-  // Returns the condition on which a final split to
-  // true and false label should be made, to optimize fallthrough.
-  Condition EmitIsString(Register input,
-                         Register temp1,
-                         Label* is_not_string,
-                         SmiCheck check_needed);
-
-  // Emits optimized code for %_IsConstructCall().
-  // Caller should branch on equal condition.
-  void EmitIsConstructCall(Register temp1, Register temp2);
-
-  // Emits optimized code to deep-copy the contents of statically known
-  // object graphs (e.g. object literal boilerplate).
-  void EmitDeepCopy(Handle<JSObject> object,
-                    Register result,
-                    Register source,
-                    int* offset,
-                    AllocationSiteMode mode);
-
-  // Emit optimized code for integer division.
-  // Inputs are signed.
-  // All registers are clobbered.
-  // If 'remainder' is no_reg, it is not computed.
-  void EmitSignedIntegerDivisionByConstant(Register result,
-                                           Register dividend,
-                                           int32_t divisor,
-                                           Register remainder,
-                                           Register scratch,
-                                           LEnvironment* environment);
+  void RecordSafepointWithLazyDeopt(LInstruction* instr,
+                                    SafepointMode safepoint_mode);
 
   void EnsureSpaceForLazyDeopt(int space_needed) V8_OVERRIDE;
-  void DoLoadKeyedExternalArray(LLoadKeyed* instr);
-  void DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr);
-  void DoLoadKeyedFixedArray(LLoadKeyed* instr);
-  void DoStoreKeyedExternalArray(LStoreKeyed* instr);
-  void DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr);
-  void DoStoreKeyedFixedArray(LStoreKeyed* instr);
 
   ZoneList<LEnvironment*> deoptimizations_;
   ZoneList<Deoptimizer::JumpTableEntry> deopt_jump_table_;
   ZoneList<Handle<Object> > deoptimization_literals_;
   int inlined_function_count_;
   Scope* const scope_;
   TranslationBuffer translations_;
   ZoneList<LDeferredCode*> deferred_;
   int osr_pc_offset_;
   bool frame_is_built_;
 
-  // Builder that keeps track of safepoints in the code. The table
-  // itself is emitted at the end of the generated code.
+  // Builder that keeps track of safepoints in the code. The table itself is
+  // emitted at the end of the generated code.
   SafepointTableBuilder safepoints_;
 
   // Compiler from a set of parallel moves to a sequential list of moves.
   LGapResolver resolver_;
 
   Safepoint::Kind expected_safepoint_kind_;
 
-  class PushSafepointRegistersScope V8_FINAL BASE_EMBEDDED {
+  int old_position_;
+
+  class PushSafepointRegistersScope BASE_EMBEDDED {
    public:
     PushSafepointRegistersScope(LCodeGen* codegen,
                                 Safepoint::Kind kind)
         : codegen_(codegen) {
       ASSERT(codegen_->info()->is_calling());
       ASSERT(codegen_->expected_safepoint_kind_ == Safepoint::kSimple);
       codegen_->expected_safepoint_kind_ = kind;
 
       switch (codegen_->expected_safepoint_kind_) {
         case Safepoint::kWithRegisters:
           codegen_->masm_->PushSafepointRegisters();
           break;
         case Safepoint::kWithRegistersAndDoubles:
-          codegen_->masm_->PushSafepointRegistersAndDoubles();
+          codegen_->masm_->PushSafepointRegisters();
+          codegen_->masm_->PushSafepointFPRegisters();
           break;
         default:
           UNREACHABLE();
       }
     }
 
     ~PushSafepointRegistersScope() {
       Safepoint::Kind kind = codegen_->expected_safepoint_kind_;
       ASSERT((kind & Safepoint::kWithRegisters) != 0);
       switch (kind) {
         case Safepoint::kWithRegisters:
           codegen_->masm_->PopSafepointRegisters();
           break;
         case Safepoint::kWithRegistersAndDoubles:
-          codegen_->masm_->PopSafepointRegistersAndDoubles();
+          codegen_->masm_->PopSafepointFPRegisters();
+          codegen_->masm_->PopSafepointRegisters();
           break;
         default:
           UNREACHABLE();
       }
       codegen_->expected_safepoint_kind_ = Safepoint::kSimple;
     }
 
    private:
     LCodeGen* codegen_;
   };
 
   friend class LDeferredCode;
-  friend class LEnvironment;
   friend class SafepointGenerator;
   DISALLOW_COPY_AND_ASSIGN(LCodeGen);
 };
 
 
-class LDeferredCode : public ZoneObject {
+class LDeferredCode: public ZoneObject {
  public:
   explicit LDeferredCode(LCodeGen* codegen)
       : codegen_(codegen),
         external_exit_(NULL),
         instruction_index_(codegen->current_instruction_) {
     codegen->AddDeferredCode(this);
   }
 
-  virtual ~LDeferredCode() {}
+  virtual ~LDeferredCode() { }
   virtual void Generate() = 0;
   virtual LInstruction* instr() = 0;
 
   void SetExit(Label* exit) { external_exit_ = exit; }
   Label* entry() { return &entry_; }
-  Label* exit() { return external_exit_ != NULL ? external_exit_ : &exit_; }
+  Label* exit() { return (external_exit_ != NULL) ? external_exit_ : &exit_; }
   int instruction_index() const { return instruction_index_; }
 
  protected:
   LCodeGen* codegen() const { return codegen_; }
   MacroAssembler* masm() const { return codegen_->masm(); }
 
  private:
   LCodeGen* codegen_;
   Label entry_;
   Label exit_;
   Label* external_exit_;
   int instruction_index_;
 };
 
+
+// This is the abstract class used by EmitBranchGeneric.
+// It is used to emit code for conditional branching. The Emit() function
+// emits code to branch when the condition holds and EmitInverted() emits
+// the branch when the inverted condition is verified.
+//
+// For actual examples of condition see the concrete implementation in
+// lithium-codegen-a64.cc (e.g. BranchOnCondition, CompareAndBranch).
+class BranchGenerator BASE_EMBEDDED {
+ public:
+  explicit BranchGenerator(LCodeGen* codegen)
+    : codegen_(codegen) { }
+
+  virtual ~BranchGenerator() { }
+
+  virtual void Emit(Label* label) const = 0;
+  virtual void EmitInverted(Label* label) const = 0;
+
+ protected:
+  MacroAssembler* masm() const { return codegen_->masm(); }
+
+  LCodeGen* codegen_;
+};
+
 } }  // namespace v8::internal
 
-#endif  // V8_ARM_LITHIUM_CODEGEN_ARM_H_
+#endif  // V8_A64_LITHIUM_CODEGEN_A64_H_