Add bit_field3 to Map objects

src/ia32/macro-assembler-ia32.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 1956 matching lines @@
 
   push(eax);
   push(Immediate(p0));
   push(Immediate(reinterpret_cast<intptr_t>(Smi::FromInt(p1 - p0))));
   CallRuntime(Runtime::kAbort, 2);
   // will not return here
   int3();
 }
 
 
+void MacroAssembler::LoadInstanceDescriptors(Register map,
+                                             Register descriptors) {
+  mov(descriptors,
+      FieldOperand(map, Map::kInstanceDescriptorsOrBitField3Offset));
+  Label not_smi;
+  JumpIfNotSmi(descriptors, &not_smi);
+  mov(descriptors, isolate()->factory()->empty_descriptor_array());
+  bind(&not_smi);
+}
+
+
 void MacroAssembler::LoadPowerOf2(XMMRegister dst,
                                   Register scratch,
                                   int power) {
   ASSERT(is_uintn(power + HeapNumber::kExponentBias,
                   HeapNumber::kExponentBits));
   mov(scratch, Immediate(power + HeapNumber::kExponentBias));
   movd(dst, Operand(scratch));
   psllq(dst, HeapNumber::kMantissaBits);
 }
 
@@ skipping 101 matching lines @@
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32