AC_CACHE_CHECK([whether it is safe to use -floop-parallelize-all],
[ac_cv_safe_to_use_floop_parallelize_all_],
[save_CFLAGS="$CFLAGS"
- CFLAGS="-floop-parallelize-all ${AM_CFLAGS} ${CFLAGS}"
+ CFLAGS="-Werror -floop-parallelize-all ${AM_CFLAGS} ${CFLAGS}"
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM([],[])],
[ac_cv_safe_to_use_floop_parallelize_all_=yes],