Index: gcc/config/rs6000/driver-rs6000.c
--- gcc/config/rs6000/driver-rs6000.c.orig
+++ gcc/config/rs6000/driver-rs6000.c
@@ -82,6 +82,8 @@ const char *host_detect_local_cpu (int argc, const cha
 
 #if GCC_VERSION >= 0
 
+#if defined(_AIX) || defined(__APPLE__) || defined(__FreeBSD__) || \
+	defined(__linux__)
 /* Returns parameters that describe L1_ASSOC associative cache of size
    L1_SIZEKB with lines of size L1_LINE, and L2_SIZEKB.  */
 
@@ -100,6 +102,7 @@ describe_cache (unsigned l1_sizekb, unsigned l1_line,
 
   return concat (l1size, " ", line, " ", l2size, " ", NULL);
 }
+#endif
 
 #ifdef __APPLE__