Use weak cell in monomorphic KeyedStore IC.

src/x64/macro-assembler-x64.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/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ skipping 3612 matching lines @@
 
 
 void MacroAssembler::EnumLength(Register dst, Register map) {
   STATIC_ASSERT(Map::EnumLengthBits::kShift == 0);
   movl(dst, FieldOperand(map, Map::kBitField3Offset));
   andl(dst, Immediate(Map::EnumLengthBits::kMask));
   Integer32ToSmi(dst, dst);
 }
 
 
-void MacroAssembler::DispatchMap(Register obj,
-                                 Register unused,
-                                 Handle<Map> map,
-                                 Handle<Code> success,
-                                 SmiCheckType smi_check_type) {
+void MacroAssembler::DispatchWeakMap(Register obj, Register scratch1,
+                                     Register scratch2, Handle<WeakCell> cell,
+                                     Handle<Code> success,
+                                     SmiCheckType smi_check_type) {
   Label fail;
   if (smi_check_type == DO_SMI_CHECK) {
     JumpIfSmi(obj, &fail);
   }
-  Cmp(FieldOperand(obj, HeapObject::kMapOffset), map);
+  movq(scratch1, FieldOperand(obj, HeapObject::kMapOffset));
+  CmpWeakValue(scratch1, cell, scratch2);
   j(equal, success, RelocInfo::CODE_TARGET);
-
   bind(&fail);
 }
 
 
 void MacroAssembler::AssertNumber(Register object) {
   if (emit_debug_code()) {
     Label ok;
     Condition is_smi = CheckSmi(object);
     j(is_smi, &ok, Label::kNear);
     Cmp(FieldOperand(object, HeapObject::kMapOffset),
@@ skipping 1742 matching lines @@
   if (mag.shift > 0) sarl(rdx, Immediate(mag.shift));
   movl(rax, dividend);
   shrl(rax, Immediate(31));
   addl(rdx, rax);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64