Make InToSpace/InFromSpace use the page header.

src/ia32/macro-assembler-ia32.cc

 // 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 35 matching lines @@
     : Assembler(arg_isolate, buffer, size),
       generating_stub_(false),
       allow_stub_calls_(true) {
   if (isolate() != NULL) {
     code_object_ = Handle<Object>(isolate()->heap()->undefined_value(),
                                   isolate());
   }
 }
 
 
+void MacroAssembler::InNewSpace(
+    Register object,
+    Register scratch,
+    Condition cc,
+    Label* condition_met,
+    Label::Distance condition_met_distance) {
+  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));
+  }
+  // Check that we can use a test_b.
+  ASSERT(MemoryChunk::IN_FROM_SPACE < 8);
+  ASSERT(MemoryChunk::IN_TO_SPACE < 8);
+  int mask = (1 << MemoryChunk::IN_FROM_SPACE)
+           | (1 << MemoryChunk::IN_TO_SPACE);
+  // If non-zero, the page belongs to new-space.
+  test_b(Operand(scratch, MemoryChunk::kFlagsOffset),
+         static_cast<uint8_t>(mask));
+  j(NegateCondition(cc), condition_met, condition_met_distance);
+}
+
+
 void MacroAssembler::IncrementalMarkingRecordWriteHelper(
     Register object,
     Register value,
     Register address) {
   ASSERT(!object.is(address));
   ASSERT(!value.is(address));
   ASSERT(!value.is(object));
 
   bool preserve[Register::kNumRegisters];
 
@@ skipping 2115 matching lines @@
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32