This patch modifies the SSE4.1 test in configure.ac to use a global variable to initialize vector variables. In addition, we now return the value of the computation instead of 0.
This is done so gcc 4.9 (and lower) won't optimize the SSE4.1 assembly instructions (when using -O1 and higher), because then the configure test might incorrectly pass even though the assembler doesn't support the SSE4.1 instructions (the test will pass because the compiler does support the intrinsics). Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91806 Cc: "11.0" <mesa-sta...@lists.freedesktop.org> Signed-off-by: Oded Gabbay <oded.gab...@gmail.com> --- configure.ac | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/configure.ac b/configure.ac index b6680d0..172ffae 100644 --- a/configure.ac +++ b/configure.ac @@ -383,10 +383,11 @@ save_CFLAGS="$CFLAGS" CFLAGS="$SSE41_CFLAGS $CFLAGS" AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ #include <smmintrin.h> +int param; int main () { - __m128i a = _mm_set1_epi32 (0), b = _mm_set1_epi32 (0), c; + __m128i a = _mm_set1_epi32 (param), b = _mm_set1_epi32 (param + 1), c; c = _mm_max_epu32(a, b); - return 0; + return _mm_cvtsi128_si32(c); }]])], SSE41_SUPPORTED=1) CFLAGS="$save_CFLAGS" if test "x$SSE41_SUPPORTED" = x1; then -- 2.5.0 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
