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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/109758] std::abs(__float128) doesn't support NaN
Date: Mon, 08 May 2023 08:31:59 +0000	[thread overview]
Message-ID: <bug-109758-4-2qDFqjNKIw@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-109758-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109758

--- Comment #10 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #8)
> If the builtin isn't supported, perhaps we could use bit_cast if supported
> to toggle the sign bit if we know where it is, but if that isn't supported
> either, there is nothing we can do, as the function needs to be constexpr.

The implementation of fabsq in libquadmath just assumes the sign bit is the MSB
so it seems reasonable to do that here too. I already have a patch doing that
which I'll finish testing when back at work.

  parent reply	other threads:[~2023-05-08  8:32 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-06 17:44 [Bug libquadmath/109758] New: quadmath abs g.peterhoff@t-online.de
2023-05-06 20:33 ` [Bug libstdc++/109758] " jakub at gcc dot gnu.org
2023-05-06 22:15 ` [Bug libstdc++/109758] std::abs(__float128) doesn't support NaN redi at gcc dot gnu.org
2023-05-06 22:48 ` g.peterhoff@t-online.de
2023-05-06 22:57 ` redi at gcc dot gnu.org
2023-05-06 23:06 ` g.peterhoff@t-online.de
2023-05-06 23:09 ` redi at gcc dot gnu.org
2023-05-07  0:09 ` g.peterhoff@t-online.de
2023-05-07 10:04 ` jakub at gcc dot gnu.org
2023-05-08  8:29 ` redi at gcc dot gnu.org
2023-05-08  8:31 ` redi at gcc dot gnu.org [this message]
2023-05-08  8:47 ` jakub at gcc dot gnu.org
2023-05-08 16:40 ` redi at gcc dot gnu.org
2023-05-11 11:55 ` cvs-commit at gcc dot gnu.org
2023-05-11 11:57 ` redi at gcc dot gnu.org
2023-05-11 12:12 ` redi at gcc dot gnu.org
2023-06-01 22:44 ` cvs-commit at gcc dot gnu.org
2023-06-01 22:45 ` redi at gcc dot gnu.org
2024-03-18 14:05 ` cvs-commit at gcc dot gnu.org
2024-03-18 14:12 ` redi at gcc dot gnu.org

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