[turbofan] Initial version of allocation folding and write barrier elimination.

src/code-stubs.h

 // Copyright 2012 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_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/code-stub-assembler.h"
@@ skipping 76 matching lines @@
   V(StoreFastElement)                       \
   V(StoreGlobalViaContext)                  \
   V(StoreScriptContextField)                \
   V(StringAdd)                              \
   V(ToBooleanIC)                            \
   V(TransitionElementsKind)                 \
   V(KeyedLoadIC)                            \
   V(LoadIC)                                 \
   /* TurboFanCodeStubs */                   \
   V(AllocateHeapNumber)                     \
-  V(AllocateMutableHeapNumber)              \
   V(AllocateFloat32x4)                      \
   V(AllocateInt32x4)                        \
   V(AllocateUint32x4)                       \
   V(AllocateBool32x4)                       \
   V(AllocateInt16x8)                        \
   V(AllocateUint16x8)                       \
   V(AllocateBool16x8)                       \
   V(AllocateInt8x16)                        \
   V(AllocateUint8x16)                       \
   V(AllocateBool8x16)                       \
@@ skipping 2628 matching lines @@
   explicit AllocateHeapNumberStub(Isolate* isolate)
       : TurboFanCodeStub(isolate) {}
 
   void InitializeDescriptor(CodeStubDescriptor* descriptor) override;
   void GenerateAssembly(CodeStubAssembler* assembler) const override;
 
   DEFINE_CALL_INTERFACE_DESCRIPTOR(AllocateHeapNumber);
   DEFINE_CODE_STUB(AllocateHeapNumber, TurboFanCodeStub);
 };
 
-class AllocateMutableHeapNumberStub : public TurboFanCodeStub {
- public:
-  explicit AllocateMutableHeapNumberStub(Isolate* isolate)
-      : TurboFanCodeStub(isolate) {}
-
-  void InitializeDescriptor(CodeStubDescriptor* descriptor) override;
-  void GenerateAssembly(CodeStubAssembler* assembler) const override;
-
-  DEFINE_CALL_INTERFACE_DESCRIPTOR(AllocateMutableHeapNumber);
-  DEFINE_CODE_STUB(AllocateMutableHeapNumber, TurboFanCodeStub);
-};
-
 #define SIMD128_ALLOC_STUB(TYPE, Type, type, lane_count, lane_type)     \
   class Allocate##Type##Stub : public TurboFanCodeStub {                \
    public:                                                              \
     explicit Allocate##Type##Stub(Isolate* isolate)                     \
         : TurboFanCodeStub(isolate) {}                                  \
                                                                         \
     void InitializeDescriptor(CodeStubDescriptor* descriptor) override; \
     void GenerateAssembly(CodeStubAssembler* assembler) const override; \
                                                                         \
     DEFINE_CALL_INTERFACE_DESCRIPTOR(Allocate##Type);                   \
@@ skipping 467 matching lines @@
 #undef DEFINE_HYDROGEN_CODE_STUB
 #undef DEFINE_CODE_STUB
 #undef DEFINE_CODE_STUB_BASE
 
 extern Representation RepresentationFromType(Type* type);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CODE_STUBS_H_