- Update the header word atomically on ia32.

runtime/vm/assembler_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/code_generator.h"
 #include "vm/cpu.h"
@@ skipping 2194 matching lines @@
                                 bool can_value_be_smi) {
   ASSERT(object != value);
   movl(dest, value);
   Label done;
   if (can_value_be_smi) {
     StoreIntoObjectFilter(object, value, &done);
   } else {
     StoreIntoObjectFilterNoSmi(object, value, &done);
   }
   // A store buffer update is required.
-  if (value != EAX) pushl(EAX);  // Preserve EAX.
-  if (object != EAX) {
-    movl(EAX, object);
+  if (value != EDX) {
+    pushl(EDX);  // Preserve EDX.
+  }
+  if (object != EDX) {
+    movl(EDX, object);
   }
   StubCode* stub_code = Isolate::Current()->stub_code();
   call(&stub_code->UpdateStoreBufferLabel());
-  if (value != EAX) popl(EAX);  // Restore EAX.
+  if (value != EDX) {
+    popl(EDX);  // Restore EDX.
+  }
   Bind(&done);
 }
 
 
 void Assembler::StoreIntoObjectNoBarrier(Register object,
                                          const Address& dest,
                                          Register value) {
   movl(dest, value);
 #if defined(DEBUG)
   Label done;
@@ skipping 642 matching lines @@
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfXmmRegisters));
   return xmm_reg_names[reg];
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32