- Add AtomicOperations::CompareAndSwapWord

runtime/vm/stub_code_ia32.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 1003 matching lines @@
   // store buffer if the object is in the store buffer already.
   // Spilled: EDX, ECX
   // EAX: Address being stored
   __ movl(ECX, FieldAddress(EAX, Object::tags_offset()));
   __ testl(ECX, Immediate(1 << RawObject::kRememberedBit));
   __ j(EQUAL, &add_to_buffer, Assembler::kNearJump);
   __ popl(ECX);
   __ popl(EDX);
   __ ret();
 
+  // Update the tags that this object has been remembered.
+  // EAX: Address being stored
+  // ECX: Current tag value
   __ Bind(&add_to_buffer);
   __ orl(ECX, Immediate(1 << RawObject::kRememberedBit));
   __ movl(FieldAddress(EAX, Object::tags_offset()), ECX);
 
   // Load the isolate out of the context.
   // Spilled: EDX, ECX
   // EAX: Address being stored
   __ movl(EDX, FieldAddress(CTX, Context::isolate_offset()));
 
   // Load the StoreBuffer block out of the isolate. Then load top_ out of the
@@ skipping 1004 matching lines @@
   const Register temp = ECX;
   __ movl(left, Address(ESP, 2 * kWordSize));
   __ movl(right, Address(ESP, 1 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32