Index: perftest-3.0/configure.ac
===================================================================
--- perftest-3.0.orig/configure.ac
+++ perftest-3.0/configure.ac
@@ -189,7 +189,7 @@ if [test $HAVE_GID_ATTR = yes] && [test
         AC_DEFINE([HAVE_GID_ATTR], [1], [Enable GID Attribute query feature])
 fi
 
-CFLAGS="-g -Wall -D_GNU_SOURCE -O3"
+CFLAGS+=" -g -Wall -D_GNU_SOURCE -O3"
 AC_SUBST([LIBUMAD])
 AC_SUBST([LIBMATH])
 AC_CONFIG_FILES([Makefile])