re PR rtl-optimization/85431 (UBSAN: ../../gcc/dse.c:303:15: runtime error:…

re PR rtl-optimization/85431 (UBSAN: ../../gcc/dse.c:303:15: runtime error: shift exponent 64 is too large for 64-bit type 'long unsigned int')

	PR rtl-optimization/85431
	* dse.c (record_store): Ignore zero width stores.

From-SVN: r259448

gcc/ChangeLog

 2018-04-17  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/85431
+	* dse.c (record_store): Ignore zero width stores.
+
 	PR sanitizer/85230
 	* asan.c (handle_builtin_stack_restore): Adjust comment.  Emit
 	__asan_allocas_unpoison call and last_alloca_addr = new_sp before

gcc/dse.c

@@ -1417,6 +1417,9 @@ record_store (rtx body, bb_info_t bb_info)
       return 0;
     }
 
+  if (known_eq (width, 0))
+    return 0;
+
   if (group_id >= 0)
     {
       /* In the restrictive case where the base is a constant or the