Don't hoist volatile mems out of loops.

From-SVN: r30834

gcc/ChangeLog

+1999-12-08  Bernd Schmidt  <bernds@cygnus.co.uk>
+
+	* loop.c (insert_loop_mem): Don't hoist volatile mems out of loops.
+
 1999-12-08  Jakub Jelinek  <jakub@redhat.com>
 
 	* config/sparc/sparc.c (ultra_cmove_results_ready_p,

gcc/loop.c

@@ -9667,7 +9667,8 @@ insert_loop_mem (mem, data)
      because we can't put it in a register.  We still store it in the
      table, though, so that if we see the same address later, but in a
      non-BLK mode, we'll not think we can optimize it at that point.  */
-  loop_mems[loop_mems_idx].optimize = (GET_MODE (m) != BLKmode);
+  loop_mems[loop_mems_idx].optimize = (GET_MODE (m) != BLKmode
+				       && ! MEM_VOLATILE_P (m));
   loop_mems[loop_mems_idx].reg = NULL_RTX;
   ++loop_mems_idx;