Update comment in gimple-ssa-store-merging.c

	* gimple-ssa-store-merging.c (clear_bit_region): Replace reference to
	loop in comment with memset.

From-SVN: r250201

gcc/ChangeLog

+2017-07-14  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* gimple-ssa-store-merging.c (clear_bit_region): Replace reference to
+	loop in comment with memset.
+
 2017-07-14  Martin Liska  <mliska@suse.cz>
 
 	* cfgexpand.c (expand_gimple_basic_block): Remove dead comment.

gcc/gimple-ssa-store-merging.c

@@ -331,8 +331,8 @@ clear_bit_region (unsigned char *ptr, unsigned int start,
   else if (start == 0 && len > BITS_PER_UNIT)
     {
       unsigned int nbytes = len / BITS_PER_UNIT;
-      /* We could recurse on each byte but do the loop here to avoid
-	 recursing too deep.  */
+      /* We could recurse on each byte but we clear whole bytes, so a simple
+	 memset will do.  */
       memset (ptr, '\0', nbytes);
       /* Clear the remaining sub-byte region if there is one.  */
       if (len % BITS_PER_UNIT != 0)