tree 711351a4febbeb7699ff7a3c7b36d7cb91015bdc
parent 3ad2d85995eccc5b79732f93a2ced4800275b19b
author Jason Ekstrand <jason@jlekstrand.net> 1604640187 -0600
committer Marge Bot <eric+marge@anholt.net> 1604948331 +0000

intel/nir: Lower 8-bit scan/reduce ops to 16-bit

We can't really support these directly on any platform.  May as well let
NIR lower them.  The NIR lowering is potentially one more instruction
for scan/reduce ops thanks to not being able to do the B->W conversion
as part of SEL_EXEC.  For imax/imin exclusive scan, it's yet another
instruction thanks to the extra imax/imin NIR has to insert to deal with
the fact that the first live channel will contain the identity value
which, when signed, will cast wrong.  However, it does let us drop some
complexity from our back-end so it's probably worth it.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7482>