- Fix the x64 store-barrier.

runtime/vm/assembler_x64.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file

[siva, 2012/06/22 23:02:25]

2012

[Ivan Posva, 2012/06/22 23:42:21]

Done.

 // 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"
 #include "vm/runtime_entry.h"
@@ skipping 1392 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,

[cshapiro, 2012/06/22 23:22:40]

Document as destroying value?  Maybe in the header?

[Ivan Posva, 2012/06/22 23:42:21]

Done.

                                       Register value,
                                       Label* no_update) {
-  andl(value, Immediate(0x5));
+  andl(value, Immediate(0x9));

[cshapiro, 2012/06/22 23:22:40]

Can't these values be synthesized from constants?  That would help insulate us
against errors.  0x9 is just a mask composed from the object/smi bit and the
generation bit.

[Ivan Posva, 2012/06/22 23:42:21]

Using the constants would actually be a very nice way of documenting the bit
twiddling. Thanks! Next CL.

   shrl(value, Immediate(1));
   adcl(value, object);
-  andl(value, Immediate(0x7));
-  cmpl(value, Immediate(0x4));
+  andl(value, Immediate(0xf));

[cshapiro, 2012/06/22 23:22:40]

ditto

+  cmpl(value, Immediate(0x6));

[cshapiro, 2012/06/22 23:22:40]

ditto

   j(NOT_ZERO, no_update, Assembler::kNearJump);
 }
 
 
 void Assembler::StoreIntoObject(Register object,
                                 const FieldAddress& dest,
                                 Register value) {
   movq(dest, value);
 
   Label done;
@@ skipping 299 matching lines @@
     comments.SetCommentAt(i, comments_[i]->comment());
   }
 
   return comments;
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64