[Mesa-dev] [RFC PATCH] mesa: Replace _mesa_round_to_even() with roundeven().

[Matt Turner]

On Wed, Mar 11, 2015 at 3:04 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> While I'm not opposed to this style of implementation, do note that
> 99.9999738% of users will end up with distro-compiled packages
> targeting generic x86_64 and thus won't use the SSE variant. If it's
> really better, might make sense to do it "for real" (i.e. runtime
> selection), otherwise just let it go and use rint/rintf everywhere so
> that developers (who build their own libraries, probably with the
> "right" -march) will get the same behaviour as users.

glibc uses roundsd/roundss in rint/f guarded by a runtime check. The
SSE code here just allows those instructions to be inlined.