https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113484
Segher Boessenkool <segher at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Yup, it needs to be added to the ABI first. And that is unlikely to get any
priority soon, since bf16 is pretty useless anyway, and we have no instructions
that efficiently round to it.
There are instructions to convert from it (by simply adding a bunch of zero
bits
to the right) (xvcvbf16spn), and more proper conversion to it (from SP)
(xvcvspbf16).
Those are ISA 3.1 insns btw, so POWER10, not POWER9! What instructions did you
mean?
This isn't good enough to use it as an actual computational type. It is fine
for
what it is meant for: do all of your computations as SP float, and only load
and
store as bfloat16. We do have builtin functions to do that already.
