Use page header information to test for InNewSpace.

src/ia32/macro-assembler-ia32-inl.h

 // Copyright 2011 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 15 matching lines @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_IA32_MACRO_ASSEMBLER_IA32_INL_H_
 #define V8_IA32_MACRO_ASSEMBLER_IA32_INL_H_
 
 #include "macro-assembler.h"
 
 namespace v8 {
 namespace internal {
 
+template <typename LabelType>
+void MacroAssembler::InNewSpace(Register object,

[Erik Corry, 2011/05/19 07:22:32]

Seems like you can just use CheckPageFlag instead of this having an
implementation.

[Lasse Reichstein, 2011/05/19 08:40:40]

Merged this with CheckPageFlag (accept object and scratch being the same
register, use byte test).

+                                Register scratch,
+                                Condition cc,
+                                LabelType* branch) {
+  ASSERT(cc == equal || cc == not_equal);
+  if (scratch.is(object)) {
+    and_(scratch, Immediate(~Page::kPageAlignmentMask));
+  } else {
+    mov(scratch, Immediate(~Page::kPageAlignmentMask));
+    and_(scratch, Operand(object));
+  }
+  // Ensure that flag is in the first byte of flags field.
+  ASSERT(MemoryChunk::IN_NEW_SPACE < kBitsPerByte);
+  test_b(Operand(scratch, MemoryChunk::kFlagsOffset),
+         1 << MemoryChunk::IN_NEW_SPACE);
+  j(NegateCondition(cc), branch);
+}
+
 
 template<typename LabelType>
 void MacroAssembler::CheckPageFlag(
     Register object,
     Register scratch,
     MemoryChunk::MemoryChunkFlags flag,
     Condition cc,
     LabelType* condition_met) {
   Move(scratch, object);
   and_(scratch, ~Page::kPageAlignmentMask);
@@ skipping 146 matching lines @@
 
   // Value is a data object, and it is white.  Mark it black.  Since we know
   // that the object is white we can make it black by flipping one bit.
   or_(Operand(bitmap_scratch, MemoryChunk::kHeaderSize), mask_scratch);
   bind(&done);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_MACRO_ASSEMBLER_IA32_INL_H_