From 1a6ae840413d7fb6d2e83f6a83081d5246c7ac9e Mon Sep 17 00:00:00 2001 From: Emil Velikov Date: Sat, 15 Nov 2014 18:37:22 +0000 Subject: [PATCH] configure.ac: roll up a program for the sse4.1 check So when checking/building sse code we have three possibilities: 1 Old compiler, throws an error when using -msse* 2 New compiler, user disables sse* (-mno-sse*) 3 New compiler, user doesn't disable sse The original code, added code for #1 but not #2. Later on we patched around the lack of handling #2 by wrapping the code in __SSE4_1__. Yet it lead to a missing/undefined symbol in case of #1 or #2, which might cause an issue for #2 when using the i965 driver. A bit later we "fixed" the undefined symbol by using #1, rather than updating it to handle #2. With this commit we set things straight :) To top it all up, conventions state that in case of conflicting (-enable-foo -disable-foo) options, the latter one takes precedence. Thus we need to make sure to prepend -msse4.1 to CFLAGS in our test. v2: Clean the #includes. Suggested by Ilia, Matt & Siavash. Cc: "10.3 10.4" Tested-by: David Heidelberg Tested-by: Siavash Eliasi Reviewed-by: Matt Turner Signed-off-by: Emil Velikov --- configure.ac | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index 91e111b..8aa070d 100644 --- a/configure.ac +++ b/configure.ac @@ -252,7 +252,16 @@ 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 -- 2.7.4