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authorTimothy Arceri <t_arceri@yahoo.com.au>2014-12-07 00:09:40 +1100
committerTimothy Arceri <t_arceri@yahoo.com.au>2014-12-10 07:35:38 +1100
commitf1b5f2b157a092e93590bd43544fbf2671edab36 (patch)
treef815b493a34d334f2e0bd303be92c278aaa33839 /configure.ac
parent65ef78e8611556780fce0bee1feba805347ec627 (diff)
mesa: use build flag to ensure stack is realigned on x86
Nowadays GCC assumes stack pointer is 16-byte aligned even on 32-bits, but that is an assumption OpenGL drivers (or any dynamic library for that matter) can't afford to make as there are many closed- and open- source application binaries out there that only assume 4-byte stack alignment. V4: fix comment and indentation V3: move all sse4.1 build flag config to the same location and add comment as to why we need to do the realign V2: use $target_cpu rather than $host_cpu and setup build flags in config rather than makefile https://bugs.freedesktop.org/show_bug.cgi?id=86788 Signed-off-by: Timothy Arceri <t_arceri@yahoo.com.au> Reviewed-by: Matt Turner <mattst88@gmail.com> CC: "10.4" <mesa-stable@lists.freedesktop.org>
Diffstat (limited to 'configure.ac')
-rw-r--r--configure.ac11
1 files changed, 10 insertions, 1 deletions
diff --git a/configure.ac b/configure.ac
index b0df1bba899..4bdf75d60d6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -253,8 +253,16 @@ AC_SUBST([VISIBILITY_CXXFLAGS])
dnl
dnl Optional flags, check for compiler support
dnl
+SSE41_CFLAGS="-msse4.1"
+dnl Code compiled by GCC with -msse* assumes a 16 byte aligned
+dnl stack, but on x86-32 such alignment is not guaranteed.
+case "$target_cpu" in
+i?86)
+ SSE41_CFLAGS="$SSE41_CFLAGS -mstackrealign"
+ ;;
+esac
save_CFLAGS="$CFLAGS"
-CFLAGS="-msse4.1 $CFLAGS"
+CFLAGS="$SSE41_CFLAGS $CFLAGS"
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#include <smmintrin.h>
int main () {
@@ -267,6 +275,7 @@ if test "x$SSE41_SUPPORTED" = x1; then
DEFINES="$DEFINES -DUSE_SSE41"
fi
AM_CONDITIONAL([SSE41_SUPPORTED], [test x$SSE41_SUPPORTED = x1])
+AC_SUBST([SSE41_CFLAGS], $SSE41_CFLAGS)
dnl Can't have static and shared libraries, default to static if user
dnl explicitly requested. If both disabled, set to static since shared