[turbofan] Avoid unnecessary write barriers and improve code generation.

src/compiler/instruction-codes.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_COMPILER_INSTRUCTION_CODES_H_
 #define V8_COMPILER_INSTRUCTION_CODES_H_
 
 #include <iosfwd>
 
 #if V8_TARGET_ARCH_ARM
@@ skipping 15 matching lines @@
 #else
 #define TARGET_ARCH_OPCODE_LIST(V)
 #define TARGET_ADDRESSING_MODE_LIST(V)
 #endif
 #include "src/utils.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
+// Modes for ArchRecordWrite below.
+enum class RecordWriteMode { kValueIsMap, kValueIsPointer, kValueIsAny };
+
+std::ostream& operator<<(std::ostream&, RecordWriteMode);
+
+
 // Target-specific opcodes that specify which assembly sequence to emit.
 // Most opcodes specify a single instruction.
 #define ARCH_OPCODE_LIST(V)   \
   V(ArchCallCodeObject)       \
   V(ArchTailCallCodeObject)   \
   V(ArchCallJSFunction)       \
   V(ArchTailCallJSFunction)   \
   V(ArchPrepareCallCFunction) \
   V(ArchCallCFunction)        \
   V(ArchLazyBailout)          \
   V(ArchJmp)                  \
   V(ArchLookupSwitch)         \
   V(ArchTableSwitch)          \
   V(ArchNop)                  \
   V(ArchDeoptimize)           \
   V(ArchRet)                  \
   V(ArchStackPointer)         \
   V(ArchFramePointer)         \
   V(ArchTruncateDoubleToI)    \
+  V(ArchRecordWrite)          \
   V(CheckedLoadInt8)          \
   V(CheckedLoadUint8)         \
   V(CheckedLoadInt16)         \
   V(CheckedLoadUint16)        \
   V(CheckedLoadWord32)        \
   V(CheckedLoadWord64)        \
   V(CheckedLoadFloat32)       \
   V(CheckedLoadFloat64)       \
   V(CheckedStoreWord8)        \
   V(CheckedStoreWord16)       \
@@ skipping 86 matching lines @@
 typedef BitField<AddressingMode, 8, 5> AddressingModeField;
 typedef BitField<FlagsMode, 13, 2> FlagsModeField;
 typedef BitField<FlagsCondition, 15, 5> FlagsConditionField;
 typedef BitField<int, 20, 12> MiscField;
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_CODES_H_