tree-ssa-structalias.c (get_constraint_for_ptr_offset): Multiply in UWHI to…

tree-ssa-structalias.c (get_constraint_for_ptr_offset): Multiply in UWHI to avoid undefined overflow.

	* tree-ssa-structalias.c (get_constraint_for_ptr_offset): Multiply
	in UWHI to avoid undefined overflow.

From-SVN: r249381

gcc/ChangeLog

 2017-06-19  Jakub Jelinek  <jakub@redhat.com>
 
+	* tree-ssa-structalias.c (get_constraint_for_ptr_offset): Multiply
+	in UWHI to avoid undefined overflow.
+
 	PR sanitizer/81125
 	* ubsan.h (enum ubsan_encode_value_phase): New.
 	(ubsan_encode_value): Change second argument to

gcc/tree-ssa-structalias.c

@@ -3087,7 +3087,7 @@ get_constraint_for_ptr_offset (tree ptr, tree offset,
 	{
 	  /* Make sure the bit-offset also fits.  */
 	  HOST_WIDE_INT rhsunitoffset = soffset.to_shwi ();
-	  rhsoffset = rhsunitoffset * BITS_PER_UNIT;
+	  rhsoffset = rhsunitoffset * (unsigned HOST_WIDE_INT) BITS_PER_UNIT;
 	  if (rhsunitoffset != rhsoffset / BITS_PER_UNIT)
 	    rhsoffset = UNKNOWN_OFFSET;
 	}