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From: "guihaoc at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/105414] constant folding for fmin/max(snan, snan) is wrong
Date: Fri, 29 Apr 2022 10:02:37 +0000	[thread overview]
Message-ID: <bug-105414-4-j81sTPWEjb@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-105414-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105414

--- Comment #8 from HaoChen Gui <guihaoc at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #7)
> Sure, but you don't want to do that at least if flag_trapping_math.
> Otherwise, the predicate would be tree_expr_signaling_nan_p and real_nan
> function with "", 1 as the middle 2 arguments can create it.  But note that
> nothing in match.pd does that right now, so I don't think we should do it in
> this case either.

If either of arguments is sNaN, fmin/max should return a qNaN. So I really want
to create a pattern in match.pd to do this. It needs to create a qNaN and
return it.  I can't find an existing example in match.pd. Seems the return
value should be relevant to the arguments?

  parent reply	other threads:[~2022-04-29 10:02 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-28  1:25 [Bug tree-optimization/105414] New: " guihaoc at gcc dot gnu.org
2022-04-28  1:28 ` [Bug tree-optimization/105414] " pinskia at gcc dot gnu.org
2022-04-28  1:31 ` guihaoc at gcc dot gnu.org
2022-04-28  3:07 ` guihaoc at gcc dot gnu.org
2022-04-28  7:07 ` rguenth at gcc dot gnu.org
2022-04-28  7:51 ` jakub at gcc dot gnu.org
2022-04-28  8:10 ` guihaoc at gcc dot gnu.org
2022-04-28  8:18 ` jakub at gcc dot gnu.org
2022-04-29 10:02 ` guihaoc at gcc dot gnu.org [this message]
2022-04-29 10:06 ` jakub at gcc dot gnu.org
2022-04-29 12:21 ` rguenth at gcc dot gnu.org
2022-05-11  1:32 ` cvs-commit at gcc dot gnu.org
2022-05-12  2:54 ` guihaoc at gcc dot gnu.org
2022-09-28 10:05 ` cvs-commit at gcc dot gnu.org
2022-11-07  4:48 ` pinskia at gcc dot gnu.org

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