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authorOded Gabbay <[email protected]>2015-12-15 12:05:22 +0200
committerEmil Velikov <[email protected]>2015-12-17 09:37:24 +0000
commit6e44bbe0f5496b1aea2b4a29adae7990b62fda33 (patch)
treed20d0882bdad5de848f758d1fc842a2bc8af99b6
parent4ef44bb484cbc0336d4fdcb8edce889ed1283732 (diff)
configura.ac: fix test for SSE4.1 assembler support
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 11.1" <[email protected]> Signed-off-by: Oded Gabbay <[email protected]> Reviewed-by: Emil Velikov <[email protected]>
-rw-r--r--configure.ac5
1 files changed, 3 insertions, 2 deletions
diff --git a/configure.ac b/configure.ac
index adc582b9581..7eb3d207415 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