Am 17.01.2016 um 14:31 schrieb Oded Gabbay: > This patch fixes a classic "confuse the enemy" bug. > > _mm_andnot_si128 (SSE) and vec_andc (VMX) do the same operation, but the > arguments are opposite. > > _mm_andnot_si128 performs "r = (~a) & b" while > vec_andc performs "r = a & (~b)" > > To make sure this error won't return in another place, I added a wrapper > function, vec_andnot_si128, in u_pwr8.h, which makes the swap inside. > > Signed-off-by: Oded Gabbay <[email protected]> > --- > src/gallium/auxiliary/util/u_pwr8.h | 6 ++++++ > src/gallium/drivers/llvmpipe/lp_setup_tri.c | 2 +- > 2 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/src/gallium/auxiliary/util/u_pwr8.h > b/src/gallium/auxiliary/util/u_pwr8.h > index 1eca6d6..ffd9f92 100644 > --- a/src/gallium/auxiliary/util/u_pwr8.h > +++ b/src/gallium/auxiliary/util/u_pwr8.h > @@ -153,6 +153,12 @@ vec_mullo_epi32 (__m128i a, __m128i b) > return v; > } > > +static inline __m128i > +vec_andnot_si128 (__m128i a, __m128i b) > +{ > + return vec_andc (b, a); > +} > + > static inline void > transpose4_epi32(const __m128i * restrict a, > const __m128i * restrict b, > diff --git a/src/gallium/drivers/llvmpipe/lp_setup_tri.c > b/src/gallium/drivers/llvmpipe/lp_setup_tri.c > index aa24176..907129d 100644 > --- a/src/gallium/drivers/llvmpipe/lp_setup_tri.c > +++ b/src/gallium/drivers/llvmpipe/lp_setup_tri.c > @@ -556,7 +556,7 @@ do_triangle_ccw(struct lp_setup_context *setup, > > /* Calculate trivial reject values: > */ > - eo = vec_sub_epi32(vec_andc(dcdy_neg_mask, dcdy), > + eo = vec_sub_epi32(vec_andnot_si128(dcdy_neg_mask, dcdy), > vec_and(dcdx_neg_mask, dcdx)); > > /* ei = _mm_sub_epi32(_mm_sub_epi32(dcdy, dcdx), eo); */ >
Reviewed-by: Roland Scheidegger <[email protected]> FWIW the order on the SSE intrinsic intuitively feels wrong to me, which is why I end up doing it wrong (http://lists.freedesktop.org/archives/mesa-dev/2016-January/105058.html) but ah well... Roland _______________________________________________ mesa-dev mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-dev
