Make BitField3 a raw uint32 field, and move to the start of the map.

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 "v8.h"
 
 #if V8_TARGET_ARCH_ARM
 
@@ skipping 3578 matching lines @@
   b(cc, condition_met);
 }
 
 
 void MacroAssembler::CheckMapDeprecated(Handle<Map> map,
                                         Register scratch,
                                         Label* if_deprecated) {
   if (map->CanBeDeprecated()) {
     mov(scratch, Operand(map));
     ldr(scratch, FieldMemOperand(scratch, Map::kBitField3Offset));
-    tst(scratch, Operand(Smi::FromInt(Map::Deprecated::kMask)));
+    tst(scratch, Operand(Map::Deprecated::kMask));
     b(ne, if_deprecated);
   }
 }
 
 
 void MacroAssembler::JumpIfBlack(Register object,
                                  Register scratch0,
                                  Register scratch1,
                                  Label* on_black) {
   HasColor(object, scratch0, scratch1, on_black, 1, 0);  // kBlackBitPattern.
@@ skipping 237 matching lines @@
 
 void MacroAssembler::NumberOfOwnDescriptors(Register dst, Register map) {
   ldr(dst, FieldMemOperand(map, Map::kBitField3Offset));
   DecodeField<Map::NumberOfOwnDescriptorsBits>(dst);
 }
 
 
 void MacroAssembler::EnumLength(Register dst, Register map) {
   STATIC_ASSERT(Map::EnumLengthBits::kShift == 0);
   ldr(dst, FieldMemOperand(map, Map::kBitField3Offset));
-  and_(dst, dst, Operand(Smi::FromInt(Map::EnumLengthBits::kMask)));
+  and_(dst, dst, Operand(Map::EnumLengthBits::kMask));
+  SmiTag(dst);
 }
 
 
 void MacroAssembler::CheckEnumCache(Register null_value, Label* call_runtime) {
   Register  empty_fixed_array_value = r6;
   LoadRoot(empty_fixed_array_value, Heap::kEmptyFixedArrayRootIndex);
   Label next, start;
   mov(r2, r0);
 
   // Check if the enum length field is properly initialized, indicating that
@@ skipping 189 matching lines @@
     sub(result, result, Operand(dividend));
   }
   if (ms.shift() > 0) mov(result, Operand(result, ASR, ms.shift()));
   add(result, result, Operand(dividend, LSR, 31));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM