re PR tree-optimization/70948 (r235622 caused…

re PR tree-optimization/70948 (r235622 caused gcc.c-torture/execute/va-arg-pack-1.c execution failure AArch64)

2016-05-06  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/70948
	* tree-ssa-structalias.c (find_func_aliases_for_builtin_call):
	Properly clobber all fields of va_list for __builtin_va_start.

From-SVN: r235963

gcc/ChangeLog

+2016-05-06  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/70948
+	* tree-ssa-structalias.c (find_func_aliases_for_builtin_call):
+	Properly clobber all fields of va_list for __builtin_va_start.
+
 2016-05-06  Yuri Rumyantsev  <ysrumyan@gmail.com>
 
 	PR debug/70935

gcc/tree-ssa-structalias.c

@@ -4492,7 +4492,7 @@ find_func_aliases_for_builtin_call (struct function *fn, gcall *t)
 	  tree valist = gimple_call_arg (t, 0);
 	  struct constraint_expr rhs, *lhsp;
 	  unsigned i;
-	  get_constraint_for (valist, &lhsc);
+	  get_constraint_for_ptr_offset (valist, NULL_TREE, &lhsc);
 	  do_deref (&lhsc);
 	  /* The va_list gets access to pointers in variadic
 	     arguments.  Which we know in the case of IPA analysis