On Wed, Mar 11, 2015 at 6:51 PM, Matt Turner <[email protected]> wrote: > On Wed, Mar 11, 2015 at 3:13 PM, Ilia Mirkin <[email protected]> wrote: >> On Wed, Mar 11, 2015 at 6:09 PM, Matt Turner <[email protected]> wrote: >>> glibc uses roundsd/roundss in rint/f guarded by a runtime check. The >>> SSE code here just allows those instructions to be inlined. >> >> OK, as long as glibc would end up using the same rounding mode settings, >> >> Reviewed-by: Ilia Mirkin <[email protected]> > > Okay, so slight difference. It doesn't use the same rounding mode > settings, since rint() rounds in the current rounding direction it > uses rounds* with imm8=0x4 (current rounding direction) whereas we're > using rounds* with imm8=0x8 (round to nearest). We're assuming the > current rounding mode is to nearest, since that's the default and if > it weren't other things would go badly. > > I don't know if your R-b stands in that case?
Is it possible to determine the current rounding format in a moderately cheap manner? If so, it may be nice to stick that into an assert. _______________________________________________ mesa-dev mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-dev
