[heap] New heuristics for incremental marking step size.

src/x64/code-stubs-x64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 3111 matching lines @@
 
 
 void RecordWriteStub::CheckNeedsToInformIncrementalMarker(
     MacroAssembler* masm,
     OnNoNeedToInformIncrementalMarker on_no_need,
     Mode mode) {
   Label on_black;
   Label need_incremental;
   Label need_incremental_pop_object;
 
-  __ movp(regs_.scratch0(), Immediate(~Page::kPageAlignmentMask));
-  __ andp(regs_.scratch0(), regs_.object());
-  __ movp(regs_.scratch1(),
-         Operand(regs_.scratch0(),
-                 MemoryChunk::kWriteBarrierCounterOffset));
-  __ subp(regs_.scratch1(), Immediate(1));
-  __ movp(Operand(regs_.scratch0(),
-                 MemoryChunk::kWriteBarrierCounterOffset),
-         regs_.scratch1());
-  __ j(negative, &need_incremental);
-
   // Let's look at the color of the object:  If it is not black we don't have
   // to inform the incremental marker.
   __ JumpIfBlack(regs_.object(),
                  regs_.scratch0(),
                  regs_.scratch1(),
                  &on_black,
                  Label::kNear);
 
   regs_.Restore(masm);
   if (on_no_need == kUpdateRememberedSetOnNoNeedToInformIncrementalMarker) {
@@ skipping 2008 matching lines @@
                            kStackUnwindSpace, nullptr, return_value_operand,
                            NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64