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dnl Adapted from Akim Demaille <akim@epita.fr> ad_GCC_WARNINGS.
AC_DEFUN([ad_GCC_OPTIM],
[AC_ARG_ENABLE([optimizations],
[AC_HELP_STRING([--disable-optimizations],
[turn off aggressive optimizations])])
if test -n "$GCC" -a "${enable_optimizations-yes}" = "yes"; then
AC_CACHE_CHECK([for gcc optimization options], ac_cv_prog_gcc_opt_flags,
[changequote(,)dnl
cat > conftest.$ac_ext <<EOF
#line __oline__ "configure"
int main(int argc, char *argv[]) { return argv[argc-1] == 0; }
EOF
changequote([,])dnl
cf_save_CFLAGS="$CFLAGS"
ac_cv_prog_gcc_opt_flags="-O3"
for cf_opt in \
ffast-math \
fstrict-aliasing \
fomit-frame-pointer
do
CFLAGS="$cf_save_CFLAGS $ac_cv_prog_gcc_opt_flags -$cf_opt"
if AC_TRY_EVAL([ac_compile]); then
ac_cv_prog_gcc_opt_flags="$ac_cv_prog_gcc_opt_flags -$cf_opt"
fi
done
rm -f conftest*
CFLAGS="$cf_save_CFLAGS $ac_cv_prog_gcc_opt_flags"])
else
case $enable_optimizations in
no) ;;
*) CFLAGS="$CFLAGS $enable_optimizations" ;;
esac
fi])
|
