Improve write barriers in optimized code.

src/arm64/macro-assembler-arm64.h

 // Copyright 2013 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_ARM64_MACRO_ASSEMBLER_ARM64_H_
 #define V8_ARM64_MACRO_ASSEMBLER_ARM64_H_
 
 #include <vector>
 
 #include "src/globals.h"
@@ skipping 71 matching lines @@
   if (kBranchTypeFirstCondition <= type && type <= kBranchTypeLastCondition) {
     return static_cast<BranchType>(
         InvertCondition(static_cast<Condition>(type)));
   } else {
     return static_cast<BranchType>(type ^ 1);
   }
 }
 
 enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
 enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
+enum PointersToHereCheck {
+  kPointersToHereMaybeInteresting,
+  kPointersToHereAreAlwaysInteresting
+};
 enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
 enum TargetAddressStorageMode {
   CAN_INLINE_TARGET_ADDRESS,
   NEVER_INLINE_TARGET_ADDRESS
 };
 enum UntagMode { kNotSpeculativeUntag, kSpeculativeUntag };
 enum ArrayHasHoles { kArrayCantHaveHoles, kArrayCanHaveHoles };
 enum CopyHint { kCopyUnknown, kCopyShort, kCopyLong };
 enum DiscardMoveMode { kDontDiscardForSameWReg, kDiscardForSameWReg };
 enum SeqStringSetCharCheckIndexType { kIndexIsSmi, kIndexIsInteger32 };
@@ skipping 1678 matching lines @@
   // The offset is the offset from the start of the object, not the offset from
   // the tagged HeapObject pointer.  For use with FieldOperand(reg, off).
   void RecordWriteField(
       Register object,
       int offset,
       Register value,
       Register scratch,
       LinkRegisterStatus lr_status,
       SaveFPRegsMode save_fp,
       RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      SmiCheck smi_check = INLINE_SMI_CHECK,
+      PointersToHereCheck pointers_to_here_check_for_value =
+          kPointersToHereMaybeInteresting);
 
   // As above, but the offset has the tag presubtracted. For use with
   // MemOperand(reg, off).
   inline void RecordWriteContextSlot(
       Register context,
       int offset,
       Register value,
       Register scratch,
       LinkRegisterStatus lr_status,
       SaveFPRegsMode save_fp,
       RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK) {
+      SmiCheck smi_check = INLINE_SMI_CHECK,
+      PointersToHereCheck pointers_to_here_check_for_value =
+          kPointersToHereMaybeInteresting) {
     RecordWriteField(context,
                      offset + kHeapObjectTag,
                      value,
                      scratch,
                      lr_status,
                      save_fp,
                      remembered_set_action,
-                     smi_check);
+                     smi_check,
+                     pointers_to_here_check_for_value);
   }
 
+  void RecordWriteForMap(
+      Register object,
+      Register map,
+      Register dst,
+      LinkRegisterStatus lr_status,
+      SaveFPRegsMode save_fp);
+
   // For a given |object| notify the garbage collector that the slot |address|
   // has been written.  |value| is the object being stored. The value and
   // address registers are clobbered by the operation.
   void RecordWrite(
       Register object,
       Register address,
       Register value,
       LinkRegisterStatus lr_status,
       SaveFPRegsMode save_fp,
       RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      SmiCheck smi_check = INLINE_SMI_CHECK,
+      PointersToHereCheck pointers_to_here_check_for_value =
+          kPointersToHereMaybeInteresting);
 
   // Checks the color of an object. If the object is already grey or black
   // then we just fall through, since it is already live. If it is white and
   // we can determine that it doesn't need to be scanned, then we just mark it
   // black and fall through. For the rest we jump to the label so the
   // incremental marker can fix its assumptions.
   void EnsureNotWhite(Register object,
                       Register scratch1,
                       Register scratch2,
                       Register scratch3,
@@ skipping 465 matching lines @@
 #error "Unsupported option"
 #define CODE_COVERAGE_STRINGIFY(x) #x
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 #endif  // V8_ARM64_MACRO_ASSEMBLER_ARM64_H_