Do we have free bits in the info pointer itself?
Florian Weimer
fw at deneb.enyo.de
Fri Sep 16 23:06:34 UTC 2016
* Ryan Newton:
> Our heap object header is one word -- an info table pointer
> <https://ghc.haskell.org/trac/ghc/wiki/Commentary/Rts/Storage/HeapObjects>.
>
> 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.
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