Combine the incremental-marking write barrier and the remembered-set...

src/ia32/stub-cache-ia32.cc

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1446 matching lines @@
     // Get the elements array of the object.
     __ mov(ebx, FieldOperand(edx, JSArray::kElementsOffset));
 
     // Check that the elements are in fast mode and writable.
     __ cmp(FieldOperand(ebx, HeapObject::kMapOffset),
            Immediate(Factory::fixed_array_map()));
     __ j(not_equal, &call_builtin);
 
     if (argc == 1) {  // Otherwise fall through to call builtin.
       Label exit, attempt_to_grow_elements;
-      Label with_write_barrier;
+      NearLabel with_write_barrier;
 
       // Get the array's length into eax and calculate new length.
       __ mov(eax, FieldOperand(edx, JSArray::kLengthOffset));
       STATIC_ASSERT(kSmiTagSize == 1);
       STATIC_ASSERT(kSmiTag == 0);
       __ add(Operand(eax), Immediate(Smi::FromInt(argc)));
 
       // Get the element's length into ecx.
       __ mov(ecx, FieldOperand(ebx, FixedArray::kLengthOffset));
 
@@ skipping 13 matching lines @@
 
       // Check if value is a smi.
       __ test(ecx, Immediate(kSmiTagMask));
       __ j(not_zero, &with_write_barrier);
 
       __ bind(&exit);
       __ ret((argc + 1) * kPointerSize);
 
       __ bind(&with_write_barrier);
 
-      __ IncrementalMarkingRecordWrite(ebx,
-                                       ecx,
-                                       edx,
-                                       OMIT_SMI_CHECK,
-                                       PRESERVE_OBJECT,
-                                       DESTROY_VALUE,
-                                       PRESERVE_SCRATCH);
+      __ RecordWrite(ebx, edx, ecx,
+                     EMIT_REMEMBERED_SET, kDontSaveFPRegs, OMIT_SMI_CHECK);

[Vyacheslav Egorov (Chromium), 2011/04/06 11:46:40]

strange formatting

[Erik Corry, 2011/04/06 12:31:28]

Done.

 
-      __ InNewSpace(ebx, ecx, equal, &exit);
-
-      __ RecordWriteHelper(ebx, edx, ecx, kDontSaveFPRegs);
       __ ret((argc + 1) * kPointerSize);
 
       __ bind(&attempt_to_grow_elements);
       if (!FLAG_inline_new) {
         __ jmp(&call_builtin);
       }
 
       ExternalReference new_space_allocation_top =
           ExternalReference::new_space_allocation_top_address();
       ExternalReference new_space_allocation_limit =
@@ skipping 18 matching lines @@
       __ mov(ecx, Operand(esp, argc * kPointerSize));
 
       // Push the argument...
       __ mov(Operand(edx, 0), ecx);
       // ... and fill the rest with holes.
       for (int i = 1; i < kAllocationDelta; i++) {
         __ mov(Operand(edx, i * kPointerSize),
                Immediate(Factory::the_hole_value()));
       }
 
-      __ IncrementalMarkingRecordWrite(ebx,
-                                       ecx,
-                                       edx,
-                                       INLINE_SMI_CHECK,
-                                       PRESERVE_OBJECT,
-                                       DESTROY_VALUE,
-                                       DESTROY_SCRATCH);
+      // We know the hole is in old space, so we don't need to update the
+      // remembered set.  We also know that the hole is marked black by the
+      // incremental marker, so we can omit the incremental marking record
+      // write too.

[Vyacheslav Egorov (Chromium), 2011/04/06 11:46:40]

this was not a record write for hole, it's record write for a value we push on
line 1535 

[Erik Corry, 2011/04/06 12:31:28]

Oops.  Nice catch.  Fixed.  And comment added.  This a tricky bit of code.

 
       // Restore receiver to edx as finish sequence assumes it's here.
       __ mov(edx, Operand(esp, (argc + 1) * kPointerSize));
 
       // Increment element's and array's sizes.
       __ add(FieldOperand(ebx, FixedArray::kLengthOffset),
              Immediate(Smi::FromInt(kAllocationDelta)));
       __ mov(FieldOperand(edx, JSArray::kLengthOffset), eax);
 
       // Elements are in new space, so write barrier is not required.
@@ skipping 1047 matching lines @@
   __ cmp(cell_operand, Factory::the_hole_value());
   __ j(equal, &miss);
 
   // Store the value in the cell.
   __ mov(cell_operand, eax);
   Label done;
   __ test(eax, Immediate(kSmiTagMask));
   __ j(zero, &done);
 
   __ mov(ecx, eax);
-  __ IncrementalMarkingRecordWrite(ebx,
-                                   ecx,
-                                   edx,
-                                   INLINE_SMI_CHECK,
-                                   DESTROY_OBJECT,
-                                   DESTROY_VALUE,
-                                   DESTROY_SCRATCH);
+  // Cells are always in the remembered set.
+  __ RecordWrite(ebx, edx, ecx, OMIT_REMEMBERED_SET, kDontSaveFPRegs);
 
   // Return the value (register eax).
   __ bind(&done);
 
   // Return the value (register eax).
   __ IncrementCounter(&Counters::named_store_global_inline, 1);
   __ ret(0);
 
   // Handle store cache miss.
   __ bind(&miss);
@@ skipping 1040 matching lines @@
 
   return GetCode(flags);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32