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; }]])], SSE41_SUPPORTED=1) -- 2.6.3 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
