- Implement the filtering store barrier on x64.

runtime/vm/assembler_ia32.cc

Index: runtime/vm/assembler_ia32.cc
===================================================================
--- runtime/vm/assembler_ia32.cc	(revision 8939)
+++ runtime/vm/assembler_ia32.cc	(working copy)
@@ -1384,20 +1384,27 @@
 }
 
 
-void Assembler::StoreIntoObject(Register object,
-                                const FieldAddress& dest,
-                                Register value) {
-  movl(dest, value);
-  Label done;
+void Assembler::StoreIntoObjectFilter(Register object,
+                                      Register value,
+                                      Label* no_update) {
   // Check that 'value' is a new object.  Store buffer updates are not
   // required when storing a smi or an old object.
   testl(value, Immediate(kNewObjectAlignmentOffset | kHeapObjectTag));
-  j(PARITY_ODD, &done, Assembler::kNearJump);
-  j(ZERO, &done, Assembler::kNearJump);
+  j(PARITY_ODD, no_update, Assembler::kNearJump);
+  j(ZERO, no_update, Assembler::kNearJump);
   // Check that 'object' is an old object.  A store buffer update is
   // not required when storing into a new object.
   testl(object, Immediate(kNewObjectAlignmentOffset));
-  j(NOT_ZERO, &done, Assembler::kNearJump);
+  j(NOT_ZERO, no_update, Assembler::kNearJump);
+}
+
+
+void Assembler::StoreIntoObject(Register object,
+                                const FieldAddress& dest,
+                                Register value) {
+  movl(dest, value);
+  Label done;
+  StoreIntoObjectFilter(object, value, &done);
   // A store buffer update is required.
   pushl(EAX);  // Preserve EAX.
   leal(EAX, dest);
@@ -1411,15 +1418,12 @@
                                          const FieldAddress& dest,
                                          Register value) {
   movl(dest, value);
-#if 0  // TODO(cshapiro) Turn this back on after it is fixed defined(DEBUG).
+#if defined(DEBUG)
   Label done;
-  testl(value, Immediate(kNewObjectAlignmentOffset | kHeapObjectTag));
-  j(PARITY_ODD, &done, Assembler::kNearJump);
-  testl(object, Immediate(kNewObjectAlignmentOffset));
-  j(NOT_ZERO, &done, Assembler::kNearJump);
+  StoreIntoObjectFilter(object, value, &done);
   Stop("Store buffer update is required");
   Bind(&done);
-#endif
+#endif  // defined(DEBUG)
   // No store buffer update.
 }