JSProperty descriptor is currently laid out like so: JSObject *obj; unsigned attrs; JSPropertyOp getter; JSStrictPropertyOp setter; jsval value; unsigned shortid; which on 64-bit platforms introduces eight bytes of padding: four after each unsigned member. The fields should be reordered to eliminate said padding. Patch coming up.
Comment on attachment 615782 [details] [diff] [review] patch Could you fix the alignment of attrs and shortid? These are some style casualties from the recent removal of uintN.