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

src/ia32/full-codegen-ia32.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 "v8.h"
 
 #if V8_TARGET_ARCH_IA32
 
 #include "code-stubs.h"
 #include "codegen.h"
@@ skipping 2968 matching lines @@
   __ j(equal, &done);
 
   __ LoadInstanceDescriptors(ebx, ebx);
   // ebx: descriptor array.
   // ecx: valid entries in the descriptor array.
   // Calculate the end of the descriptor array.
   STATIC_ASSERT(kSmiTag == 0);
   STATIC_ASSERT(kSmiTagSize == 1);
   STATIC_ASSERT(kPointerSize == 4);
   __ imul(ecx, ecx, DescriptorArray::kDescriptorSize);
-  __ lea(ecx, Operand(ebx, ecx, times_2, DescriptorArray::kFirstOffset));
+  __ lea(ecx, Operand(ebx, ecx, times_4, DescriptorArray::kFirstOffset));
   // Calculate location of the first key name.
   __ add(ebx, Immediate(DescriptorArray::kFirstOffset));
   // Loop through all the keys in the descriptor array. If one of these is the
   // internalized string "valueOf" the result is false.
   __ jmp(&entry);
   __ bind(&loop);
   __ mov(edx, FieldOperand(ebx, 0));
   __ cmp(edx, isolate()->factory()->value_of_string());
   __ j(equal, if_false);
   __ add(ebx, Immediate(DescriptorArray::kDescriptorSize * kPointerSize));
@@ skipping 1828 matching lines @@
   ASSERT_EQ(isolate->builtins()->OsrAfterStackCheck()->entry(),
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32