InNewSpace(object, value, equal, &done);
- if ((offset > 0) && (offset < Page::kMaxHeapObjectSize)) {
+ // The offset is relative to a tagged or untagged HeapObject pointer,
+ // so either offset or offset + kHeapObjectTag must be a
+ // multiple of kPointerSize.
+ ASSERT(IsAligned(offset, kPointerSize) ||
+ IsAligned(offset + kHeapObjectTag, kPointerSize));
+
+ // We use optimized write barrier code if the word being written to is not in
+ // a large object chunk or is in the first page of a large object chunk.
+ // We make sure that an offset is inside the right limits whether it is
+ // tagged or untagged.
+ if ((offset > 0) && (offset < Page::kMaxHeapObjectSize - kHeapObjectTag)) {
// Compute the bit offset in the remembered set, leave it in 'value'.
lea(value, Operand(object, offset));
and_(value, Page::kPageAlignmentMask);
cmpq(scratch, kScratchRegister);
j(equal, &done);
- if ((offset > 0) && (offset < Page::kMaxHeapObjectSize)) {
+ // The offset is relative to a tagged or untagged HeapObject pointer,
+ // so either offset or offset + kHeapObjectTag must be a
+ // multiple of kPointerSize.
+ ASSERT(IsAligned(offset, kPointerSize) ||
+ IsAligned(offset + kHeapObjectTag, kPointerSize));
+
+ // We use optimized write barrier code if the word being written to is not in
+ // a large object page, or is in the first "page" of a large object page.
+ // We make sure that an offset is inside the right limits whether it is
+ // tagged or untagged.
+ if ((offset > 0) && (offset < Page::kMaxHeapObjectSize - kHeapObjectTag)) {
// Compute the bit offset in the remembered set, leave it in 'value'.
lea(scratch, Operand(object, offset));
ASSERT(is_int32(Page::kPageAlignmentMask));