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

src/code-stubs.cc

 // 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.
 
 #include "src/code-stubs.h"
 
 #include <sstream>
 
 #include "src/bootstrapper.h"
 #include "src/code-factory.h"
@@ skipping 444 matching lines @@
 }
 
 void AllocateHeapNumberStub::GenerateAssembly(
     CodeStubAssembler* assembler) const {
   typedef compiler::Node Node;
 
   Node* result = assembler->AllocateHeapNumber();
   assembler->Return(result);
 }
 
-void AllocateMutableHeapNumberStub::GenerateAssembly(
-    CodeStubAssembler* assembler) const {
-  typedef compiler::Node Node;
-
-  Node* result = assembler->Allocate(HeapNumber::kSize);
-  assembler->StoreMapNoWriteBarrier(
-      result,
-      assembler->HeapConstant(isolate()->factory()->mutable_heap_number_map()));
-  assembler->Return(result);
-}
-
 #define SIMD128_GEN_ASM(TYPE, Type, type, lane_count, lane_type)            \
   void Allocate##Type##Stub::GenerateAssembly(CodeStubAssembler* assembler) \
       const {                                                               \
     compiler::Node* result =                                                \
         assembler->Allocate(Simd128Value::kSize, CodeStubAssembler::kNone); \
     compiler::Node* map_offset =                                            \
         assembler->IntPtrConstant(HeapObject::kMapOffset - kHeapObjectTag); \
     compiler::Node* map = assembler->IntPtrAdd(result, map_offset);         \
     assembler->StoreNoWriteBarrier(                                         \
         MachineRepresentation::kTagged, map,                                \
@@ skipping 3549 matching lines @@
 }
 
 
 void AllocateHeapNumberStub::InitializeDescriptor(
     CodeStubDescriptor* descriptor) {
   descriptor->Initialize(
       Runtime::FunctionForId(Runtime::kAllocateHeapNumber)->entry);
 }
 
 
-void AllocateMutableHeapNumberStub::InitializeDescriptor(
-    CodeStubDescriptor* descriptor) {
-  descriptor->Initialize();
-}
-
 #define SIMD128_INIT_DESC(TYPE, Type, type, lane_count, lane_type) \
   void Allocate##Type##Stub::InitializeDescriptor(                 \
       CodeStubDescriptor* descriptor) {                            \
     descriptor->Initialize(                                        \
         Runtime::FunctionForId(Runtime::kCreate##Type)->entry);    \
   }
 SIMD128_TYPES(SIMD128_INIT_DESC)
 #undef SIMD128_INIT_DESC
 
 void ToBooleanICStub::InitializeDescriptor(CodeStubDescriptor* descriptor) {
@@ skipping 384 matching lines @@
   if (type->Is(Type::UntaggedPointer())) {
     return Representation::External();
   }
 
   DCHECK(!type->Is(Type::Untagged()));
   return Representation::Tagged();
 }
 
 }  // namespace internal
 }  // namespace v8