On 01/07/15 01:41, Jason Ekstrand wrote: > On Fri, Jun 26, 2015 at 1:07 AM, Eduardo Lima Mitev <el...@igalia.com> wrote: >> From: Samuel Iglesias Gonsalvez <sigles...@igalia.com> >> >> Avoid copying an overwritten swizzle, use the original values. >> >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89580 >> Signed-off-by: Samuel Iglesias Gonsalvez <sigles...@igalia.com> >> --- >> src/glsl/nir/nir_opt_peephole_ffma.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/src/glsl/nir/nir_opt_peephole_ffma.c >> b/src/glsl/nir/nir_opt_peephole_ffma.c >> index 798506b..7c9ac12 100644 >> --- a/src/glsl/nir/nir_opt_peephole_ffma.c >> +++ b/src/glsl/nir/nir_opt_peephole_ffma.c >> @@ -76,6 +76,7 @@ static nir_alu_instr * >> get_mul_for_src(nir_alu_src *src, int num_components, >> uint8_t swizzle[4], bool *negate, bool *abs) >> { >> + uint8_t swizzle_tmp[4]; >> assert(src->src.is_ssa && !src->abs && !src->negate); >> >> nir_instr *instr = src->src.ssa->parent_instr; >> @@ -116,8 +117,10 @@ get_mul_for_src(nir_alu_src *src, int num_components, >> if (!alu) >> return NULL; >> >> + /* Copy swizzle data before overwriting it */ > > I'd like the comment to be a little more detailed. Specifically, an > example of when this is a problem would be really good. Looking at > it, I *think* that if src->swizzle is xyxx, it would trip the problem. >
I found the issue in a test that does something similar to the following: src->swizzle = zyxx swizzle = xyzw As we are overwritting swizzle, we end up having: final swizzle = zyzz But the expected output swizzle is zyxx. I am going to rewrite the comment adding this example. Thanks for the review, Sam >> + memcpy(swizzle_tmp, swizzle, 4*sizeof(uint8_t)); >> for (unsigned i = 0; i < num_components; i++) >> - swizzle[i] = swizzle[src->swizzle[i]]; >> + swizzle[i] = swizzle_tmp[src->swizzle[i]]; >> >> return alu; >> } >> -- >> 2.1.4 >> >> _______________________________________________ >> mesa-dev mailing list >> mesa-dev@lists.freedesktop.org >> http://lists.freedesktop.org/mailman/listinfo/mesa-dev > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
