Use weak cell to embed known map in CompareIC

src/arm64/code-stubs-arm64.cc

 // 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.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 3556 matching lines @@
 
   __ Bind(&miss);
   GenerateMiss(masm);
 }
 
 
 void CompareICStub::GenerateKnownObjects(MacroAssembler* masm) {
   ASM_LOCATION("CompareICStub[KnownObjects]");
 
   Label miss;
+  Handle<WeakCell> cell = Map::WeakCellForMap(known_map_);
 
   Register result = x0;
   Register rhs = x0;
   Register lhs = x1;
 
   __ JumpIfEitherSmi(rhs, lhs, &miss);
 
   Register rhs_map = x10;
   Register lhs_map = x11;
+  Register map = x12;
+  __ GetWeakValue(map, cell);
   __ Ldr(rhs_map, FieldMemOperand(rhs, HeapObject::kMapOffset));
   __ Ldr(lhs_map, FieldMemOperand(lhs, HeapObject::kMapOffset));
-  __ Cmp(rhs_map, Operand(known_map_));
+  __ Cmp(rhs_map, map);
   __ B(ne, &miss);
-  __ Cmp(lhs_map, Operand(known_map_));
+  __ Cmp(lhs_map, map);
   __ B(ne, &miss);
 
   __ Sub(result, rhs, lhs);
   __ Ret();
 
   __ Bind(&miss);
   GenerateMiss(masm);
 }
 
 
@@ skipping 1802 matching lines @@
                            kStackUnwindSpace, NULL, spill_offset,
                            MemOperand(fp, 6 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64