On Sat, Dec 12, 2015 at 06:41:56PM +0000, Emil Velikov wrote: > On 10 December 2015 at 08:42, Oded Gabbay <oded.gab...@gmail.com> wrote: > > On Wed, Dec 9, 2015 at 8:30 PM, Matt Turner <matts...@gmail.com> wrote: > >> On Tue, Dec 8, 2015 at 9:37 PM, Jonathan Gray <j...@jsg.id.au> wrote: > >>> Change the __m128i variables to be volatile so gcc 4.9 won't optimise > >>> all of them out with -O1 or greater. The _mm_set1_epi32/pinsrd calls > >>> still get optimised out but now there is at least one SSE4.1 instruction > >>> generated via _mm_max_epu32/pmaxud. When all of the sse4.1 instructions > >>> got optimised out the configure test would incorrectly pass when the > >>> compiler supported the intrinsics and the assembler didn't support the > >>> instructions. > >>> > >>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91806 > >>> Signed-off-by: Jonathan Gray <j...@jsg.id.au> > >>> Cc: "11.0 11.1" <mesa-sta...@lists.freedesktop.org> > >>> --- > >>> configure.ac | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/configure.ac b/configure.ac > >>> index 260934d..1d82e47 100644 > >>> --- a/configure.ac > >>> +++ b/configure.ac > >>> @@ -384,7 +384,7 @@ CFLAGS="$SSE41_CFLAGS $CFLAGS" > >>> AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ > >>> #include <smmintrin.h> > >>> int main () { > >>> - __m128i a = _mm_set1_epi32 (0), b = _mm_set1_epi32 (0), c; > >>> + volatile __m128i a = _mm_set1_epi32 (0), b = _mm_set1_epi32 (0), c; > >>> c = _mm_max_epu32(a, b); > >>> return 0; > >> > >> I would have extracted an int from the result of _mm_max_epu32 and > >> returned that instead of 0. > > > > Instead of the volatile I assume ? > > > Precisely. If anyone wants to follow on Matt's suggestion we can pick > that one as well. I'd like to get a patch for the next stable releases > (next Friday for 11.0.x and just after new year for 11.1.1) so I'll > take whatever's around :-) > > -Emil
I avoided that as I wasn't sure if there was a case where autoconf cared about the return code. If someone wants to create a new diff feel free, I have limited connectivity till the middle of next week. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
