Fix for big-endian gcc.c-torture/execute/pr55750.c

	* gimple-ssa-store-merging.c (encode_tree_to_bitpos): Don't forget to
	clear padding bits even when they're less than a byte.

From-SVN: r241798

gcc/ChangeLog

+2016-11-02  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* gimple-ssa-store-merging.c (encode_tree_to_bitpos): Don't forget to
+	clear padding bits even when they're less than a byte.
+
 2016-11-02  Richard Biener  <rguenther@suse.de>
 
 	* gimple-ssa-store-merging.c: Include gimplify-me.h.

gcc/gimple-ssa-store-merging.c

@@ -431,7 +431,8 @@ encode_tree_to_bitpos (tree expr, unsigned char *ptr, int bitlen, int bitpos,
      contain a sign bit due to sign-extension).  */
   unsigned int padding
     = byte_size - ROUND_UP (bitlen, BITS_PER_UNIT) / BITS_PER_UNIT - 1;
-  if (padding != 0)
+  if (padding != 0
+      || bitlen % BITS_PER_UNIT != 0)
     {
       /* On big-endian the padding is at the 'front' so just skip the initial
 	 bytes.  */