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From: "kevin.waugh at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/46073] __builtin_choose_expr outputs warnings for unused expression
Date: Mon, 18 Oct 2010 19:17:00 -0000	[thread overview]
Message-ID: <20101018191700.Xe3iX-imy43QqZMCRmBY5n5wP_Ffwj46M_OkhNbiU30@z> (raw)
In-Reply-To: <bug-46073-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46073

--- Comment #2 from kevin.waugh at gmail dot com 2010-10-18 19:17:17 UTC ---
(In reply to comment #1)
> I think this is correct as  __builtin_choose_expr still does semantically
> checking on the two arguments.  Not to mention  __builtin_choose_expr was added
> only to support Altivec intrinsics and that has since been moved away from
> that.

>From the documentation:
Note: This construct is only available for C. Furthermore, the unused
expression (exp1 or exp2 depending on the value of const_exp) may still
generate syntax errors. This may change in future revisions.

What are the chances of getting this changed, or having an option to suppress
warnings on the unevaluated argument?  The implementation of tgmath.h is
essentially using __builtin_choose_expr for the same purpose, but it appers to
avoid any warnings/errors because of implicit casts.


  parent reply	other threads:[~2010-10-18 19:17 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-18 18:57 [Bug c/46073] New: " kevin.waugh at gmail dot com
2010-10-18 19:01 ` [Bug c/46073] " pinskia at gcc dot gnu.org
2010-10-18 19:17 ` kevin.waugh at gmail dot com [this message]
2010-10-18 19:55 ` joseph at codesourcery dot com

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