Merge "Use word copying for CopyObject"
diff --git a/runtime/mirror/object.cc b/runtime/mirror/object.cc
index fbb7c96..8e49743 100644
--- a/runtime/mirror/object.cc
+++ b/runtime/mirror/object.cc
@@ -72,18 +72,45 @@
Object* const dest_obj_;
};
-Object* Object::CopyObject(Thread* self, mirror::Object* dest, mirror::Object* src,
+Object* Object::CopyObject(Thread* self,
+ mirror::Object* dest,
+ mirror::Object* src,
size_t num_bytes) {
- // Copy instance data. We assume memcpy copies by words.
- // TODO: expose and use move32.
- uint8_t* src_bytes = reinterpret_cast<uint8_t*>(src);
- uint8_t* dst_bytes = reinterpret_cast<uint8_t*>(dest);
- size_t offset = sizeof(Object);
- memcpy(dst_bytes + offset, src_bytes + offset, num_bytes - offset);
+ // Copy instance data. Don't assume memcpy copies by words (b/32012820).
+ {
+ const size_t offset = sizeof(Object);
+ uint8_t* src_bytes = reinterpret_cast<uint8_t*>(src) + offset;
+ uint8_t* dst_bytes = reinterpret_cast<uint8_t*>(dest) + offset;
+ num_bytes -= offset;
+ DCHECK_ALIGNED(src_bytes, sizeof(uintptr_t));
+ DCHECK_ALIGNED(dst_bytes, sizeof(uintptr_t));
+ // Use word sized copies to begin.
+ while (num_bytes >= sizeof(uintptr_t)) {
+ *reinterpret_cast<uintptr_t*>(dst_bytes) = *reinterpret_cast<uintptr_t*>(src_bytes);
+ src_bytes += sizeof(uintptr_t);
+ dst_bytes += sizeof(uintptr_t);
+ num_bytes -= sizeof(uintptr_t);
+ }
+ // Copy possible 32 bit word.
+ if (sizeof(uintptr_t) != sizeof(uint32_t) && num_bytes >= sizeof(uint32_t)) {
+ *reinterpret_cast<uint32_t*>(dst_bytes) = *reinterpret_cast<uint32_t*>(src_bytes);
+ src_bytes += sizeof(uint32_t);
+ dst_bytes += sizeof(uint32_t);
+ num_bytes -= sizeof(uint32_t);
+ }
+ // Copy remaining bytes, avoid going past the end of num_bytes since there may be a redzone
+ // there.
+ while (num_bytes > 0) {
+ *reinterpret_cast<uint8_t*>(dst_bytes) = *reinterpret_cast<uint8_t*>(src_bytes);
+ src_bytes += sizeof(uint8_t);
+ dst_bytes += sizeof(uint8_t);
+ num_bytes -= sizeof(uint8_t);
+ }
+ }
+
if (kUseReadBarrier) {
- // We need a RB here. After the memcpy that covers the whole
- // object above, copy references fields one by one again with a
- // RB. TODO: Optimize this later?
+ // We need a RB here. After copying the whole object above, copy references fields one by one
+ // again with a RB to make sure there are no from space refs. TODO: Optimize this later?
CopyReferenceFieldsWithReadBarrierVisitor visitor(dest);
src->VisitReferences(visitor, visitor);
}