Add complete ElementKind information directly to Map for objects with elements.

src/arm/ic-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 926 matching lines @@
 
   // Check that the key is a smi.
   __ JumpIfNotSmi(key, &check_string);
   __ bind(&index_smi);
   // Now the key is known to be a smi. This place is also jumped to from below
   // where a numeric string is converted to a smi.
 
   GenerateKeyedLoadReceiverCheck(
       masm, receiver, r2, r3, Map::kHasIndexedInterceptor, &slow);
 
-  // Check the "has fast elements" bit in the receiver's map which is
-  // now in r2.
-  __ ldrb(r3, FieldMemOperand(r2, Map::kBitField2Offset));
-  __ tst(r3, Operand(1 << Map::kHasFastElements));
-  __ b(eq, &check_number_dictionary);
+  // Check the receiver's map to see if it has fast elements.
+  __ CheckFastElements(r2, r3, &check_number_dictionary);
 
   GenerateFastArrayLoad(
       masm, receiver, key, r4, r3, r2, r0, NULL, &slow);
   __ IncrementCounter(isolate->counters()->keyed_load_generic_smi(), 1, r2, r3);
   __ Ret();
 
   __ bind(&check_number_dictionary);
   __ ldr(r4, FieldMemOperand(receiver, JSObject::kElementsOffset));
   __ ldr(r3, FieldMemOperand(r4, JSObject::kMapOffset));
 
@@ skipping 596 matching lines @@
     Register reg = Assembler::GetRn(instr_at_patch);
     patcher.masm()->tst(reg, Operand(kSmiTagMask));
     patcher.EmitCondition(eq);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM