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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/110304] __builtin_adcs missing and jakub you miss the point of builtin_adcb
Date: Tue, 20 Jun 2023 19:41:07 +0000	[thread overview]
Message-ID: <bug-110304-4-QTqmonu3Ra@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-110304-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110304

--- Comment #15 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to cqwrteur from comment #13)
> See this:
> https://godbolt.org/z/eozPahn9G
> 
> 
> addcarry pattern it recognizes but not subcarry.

And see this:
https://gcc.gnu.org/pipermail/gcc-patches/2023-June/620821.html
I've said that due to reassoc subcarry can't be matched because the different
limbs get intermingled too much.  And that one should be using the overflow
builtins (or now the clang compatible builtins) instead, at least for now.

> Also see the pissmeoff2, the instructions GCC generates are very messy.

Please carefully read the Code of Conduct that has been announced today.
https://gcc.gnu.org/conduct.html

  parent reply	other threads:[~2023-06-20 19:41 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-19  6:01 [Bug c++/110304] New: __builtin_adcs missing and " unlvsur at live dot com
2023-06-19  6:06 ` [Bug c++/110304] __builtin_adcs missing and jakub " unlvsur at live dot com
2023-06-19  6:12 ` unlvsur at live dot com
2023-06-19  6:16 ` unlvsur at live dot com
2023-06-19  6:19 ` jakub at gcc dot gnu.org
2023-06-19  6:22 ` jakub at gcc dot gnu.org
2023-06-19  6:27 ` unlvsur at live dot com
2023-06-19  6:32 ` unlvsur at live dot com
2023-06-19  6:34 ` jakub at gcc dot gnu.org
2023-06-19  6:37 ` unlvsur at live dot com
2023-06-19  6:54 ` unlvsur at live dot com
2023-06-20  3:08 ` unlvsur at live dot com
2023-06-20  6:45 ` jakub at gcc dot gnu.org
2023-06-20 19:17 ` unlvsur at live dot com
2023-06-20 19:40 ` unlvsur at live dot com
2023-06-20 19:41 ` jakub at gcc dot gnu.org [this message]
2023-06-20 19:48 ` unlvsur at live dot com
2023-06-20 19:50 ` jakub at gcc dot gnu.org
2023-06-20 20:57 ` unlvsur at live dot com
2023-06-20 21:03 ` unlvsur at live dot com

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