- Implement the filtering store barrier on x64.

runtime/vm/assembler_x64.cc

 // Copyright (c) 2011, 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_X64)
 
 #include "vm/assembler.h"
 #include "vm/heap.h"
 #include "vm/memory_region.h"
@@ skipping 1384 matching lines @@
   if (object.IsSmi()) {
     cmpq(reg, Immediate(reinterpret_cast<int64_t>(object.raw())));
   } else {
     ASSERT(reg != TMP);
     LoadObject(TMP, object);
     cmpq(reg, TMP);
   }
 }
 
 
+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, 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, no_update, Assembler::kNearJump);
+}
+
+
 void Assembler::StoreIntoObject(Register object,
                                 const FieldAddress& dest,
                                 Register value) {
-  // TODO(iposva): Add write barrier.
   movq(dest, value);
+
+  Label done;
+  StoreIntoObjectFilter(object, value, &done);
+  // A store buffer update is required.
+  pushq(RAX);
+  leaq(RAX, dest);
+  call(&StubCode::UpdateStoreBufferLabel());
+  popq(RAX);
+  Bind(&done);
+}
+
+
+void Assembler::StoreIntoObjectNoBarrier(Register object,
+                                         const FieldAddress& dest,
+                                         Register value) {
+  movq(dest, value);
+#if defined(DEBUG)
+  Label done;
+  StoreIntoObjectFilter(object, value, &done);
+  Stop("Store buffer update is required");
+  Bind(&done);
+#endif  // defined(DEBUG)
+  // No store buffer update.
 }
 
 
 void Assembler::DoubleNegate(XmmRegister d) {
   static const struct ALIGN16 {
     uint64_t a;
     uint64_t b;
   } double_negate_constant =
       {0x8000000000000000LL, 0x8000000000000000LL};
   movq(TMP, Immediate(reinterpret_cast<intptr_t>(&double_negate_constant)));
@@ skipping 264 matching lines @@
     comments.SetCommentAt(i, comments_[i]->comment());
   }
 
   return comments;
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64