[Bug tree-optimization/41089] [4.8/4.9/5/6 Regression] stdarg pass produces wrong code

["ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=41089

--- Comment #59 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to vries from comment #58)

> Given the fix of PR64950, we should be able to remove the workaround
> committed for this PR.

I have started bootstrap/regtest with the following revert:

--cut here--
Index: config/alpha/alpha.c
===================================================================
--- config/alpha/alpha.c (revision 222228)
+++ config/alpha/alpha.c (working copy)
@@ -5957,10 +5957,6 @@ alpha_build_builtin_va_list (void)
                    integer_type_node);
   DECL_FIELD_CONTEXT (ofs) = record;
   DECL_CHAIN (ofs) = space;
-  /* ??? This is a hack, __offset is marked volatile to prevent
-     DCE that confuses stdarg optimization and results in
-     gcc.c-torture/execute/stdarg-1.c failure.  See PR 41089.  */
-  TREE_THIS_VOLATILE (ofs) = 1;

   base = build_decl (BUILTINS_LOCATION,
                     FIELD_DECL, get_identifier ("__base"),
--cut here--
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From: "paolo.carlini at oracle dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/65801] [5/6 Regression] Allow -Wno-narrowing to silence stricter C++11 narrowing rules
Date: Mon, 20 Apr 2015 10:21:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?ide801

--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Well, at the time I think we agreed that we wanted to be strict at least about
enums... Otherwise, yes, we can do that plus setting ok = true in that case
too, thus collapsing the last two ifs (+ reverting the docs change and
adjusting the testsuite).