On Sun, Feb 7, 2016 at 6:13 PM, Axel Davy <axel.d...@ens.fr> wrote: > SQRT is not supported everywhere, so replace > it by RSQ + RCP > > Signed-off-by: Axel Davy <axel.d...@ens.fr> > --- > src/gallium/state_trackers/nine/nine_ff.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/src/gallium/state_trackers/nine/nine_ff.c > b/src/gallium/state_trackers/nine/nine_ff.c > index a5466a7..894fc63 100644 > --- a/src/gallium/state_trackers/nine/nine_ff.c > +++ b/src/gallium/state_trackers/nine/nine_ff.c > @@ -563,7 +563,8 @@ nine_ff_build_vs(struct NineDevice9 *device, struct > vs_build_ctx *vs) > struct ureg_src cPsz2 = ureg_DECL_constant(ureg, 27); > > ureg_DP3(ureg, tmp_x, ureg_src(r[1]), ureg_src(r[1])); > - ureg_SQRT(ureg, tmp_y, _X(tmp)); > + ureg_RSQ(ureg, tmp_y, _X(tmp)); > + ureg_RCP(ureg, tmp_y, _Y(tmp));
I'd recommend doing ureg_MUL(ureg, tmp_y, _Y(tmp), _X(tmp)) instead. That should be (a) more numerically stable (rcp doesn't have great precision), and (b) not blow up for 0. > ureg_MAD(ureg, tmp_x, _Y(tmp), _YYYY(cPsz2), _XXXX(cPsz2)); > ureg_MAD(ureg, tmp_x, _Y(tmp), _X(tmp), _WWWW(cPsz1)); > ureg_RCP(ureg, tmp_x, ureg_src(tmp)); > -- > 2.7.0 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
