PPC/s390: [heap] New heuristics for incremental marking step size.

src/s390/code-stubs-s390.cc

 // Copyright 2014 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_S390
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 3307 matching lines @@
   regs_.RestoreCallerSaveRegisters(masm, save_fp_regs_mode());
 }
 
 void RecordWriteStub::CheckNeedsToInformIncrementalMarker(
     MacroAssembler* masm, OnNoNeedToInformIncrementalMarker on_no_need,
     Mode mode) {
   Label on_black;
   Label need_incremental;
   Label need_incremental_pop_scratch;
 
-  DCHECK((~Page::kPageAlignmentMask & 0xffff) == 0);
-  __ AndP(regs_.scratch0(), regs_.object(), Operand(~Page::kPageAlignmentMask));
-  __ LoadP(
-      regs_.scratch1(),
-      MemOperand(regs_.scratch0(), MemoryChunk::kWriteBarrierCounterOffset));
-  __ SubP(regs_.scratch1(), regs_.scratch1(), Operand(1));
-  __ StoreP(
-      regs_.scratch1(),
-      MemOperand(regs_.scratch0(), MemoryChunk::kWriteBarrierCounterOffset));
-  __ CmpP(regs_.scratch1(), Operand::Zero());  // S390, we could do better here
-  __ blt(&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);
 
   regs_.Restore(masm);
   if (on_no_need == kUpdateRememberedSetOnNoNeedToInformIncrementalMarker) {
     __ RememberedSetHelper(object(), address(), value(), save_fp_regs_mode(),
                            MacroAssembler::kReturnAtEnd);
   } else {
     __ Ret();
@@ skipping 2005 matching lines @@
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                            kStackUnwindSpace, NULL, return_value_operand, NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_S390