Reland parts of 'Use weak cells in map checks in polymorphic ICs'

src/arm/macro-assembler-arm.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 <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM
 
@@ skipping 2251 matching lines @@
     JumpIfSmi(obj, &fail);
   }
   ldr(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
   mov(ip, Operand(map));
   cmp(scratch, ip);
   Jump(success, RelocInfo::CODE_TARGET, eq);
   bind(&fail);
 }
 
 
+void MacroAssembler::CmpWeakValue(Register value, Handle<WeakCell> cell,
+                                  Register scratch) {
+  mov(scratch, Operand(cell));
+  ldr(scratch, FieldMemOperand(scratch, WeakCell::kValueOffset));
+  cmp(value, scratch);
+}
+
+
+void MacroAssembler::LoadWeakValue(Register value, Handle<WeakCell> cell,
+                                   Label* miss) {
+  mov(value, Operand(cell));
+  ldr(value, FieldMemOperand(value, WeakCell::kValueOffset));
+  JumpIfSmi(value, miss);
+}
+
+
 void MacroAssembler::TryGetFunctionPrototype(Register function,
                                              Register result,
                                              Register scratch,
                                              Label* miss,
                                              bool miss_on_bound_function) {
   Label non_instance;
   if (miss_on_bound_function) {
     // Check that the receiver isn't a smi.
     JumpIfSmi(function, miss);
 
@@ skipping 1802 matching lines @@
     }
   }
   if (mag.shift > 0) mov(result, Operand(result, ASR, mag.shift));
   add(result, result, Operand(dividend, LSR, 31));
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM