diff --git a/configure.ac b/configure.ac index e97dccda1da..1a1c0a993d4 100644 --- a/configure.ac +++ b/configure.ac @@ -237,7 +237,16 @@ AC_SUBST([VISIBILITY_CXXFLAGS]) dnl dnl Optional flags, check for compiler support dnl -AX_CHECK_COMPILE_FLAG([-msse4.1], [SSE41_SUPPORTED=1], [SSE41_SUPPORTED=0]) +save_CFLAGS="$CFLAGS" +CFLAGS="-msse4.1 $CFLAGS" +AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ +#include +int main () { + __m128i a = _mm_set1_epi32 (0), b = _mm_set1_epi32 (0), c; + c = _mm_max_epu32(a, b); + return 0; +}]])], SSE41_SUPPORTED=1) +CFLAGS="$save_CFLAGS" if test "x$SSE41_SUPPORTED" = x1; then DEFINES="$DEFINES -DUSE_SSE41" fi