* Ryan Newton:
> Our heap object header is one word -- an info table pointer
> Well, a 64 bit info table pointer leaves *at least* 16 high bits inside the
> object header for other purposes, right?
x86_64 has signed pointers, so the uppoer 16 bits are either all zero
or all ones. Some systems use both, but it's rare on Linux.
Other 64-bit platforms use more bits.
ghc-devs mailing list