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From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/51954] __int128_t (and long long on x86) negation can be optimized
Date: Mon, 21 Feb 2022 06:49:16 +0000	[thread overview]
Message-ID: <bug-51954-4-X2JJMkGwzc@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-51954-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51954

--- Comment #5 from Hongtao.liu <crazylht at gmail dot com> ---
> 
> Yes, neg rdx = (0 - rdx) = (0 - (rdx + CF)(last def)) = (sbb 0, rdx)

And we need an extra register for it.

  parent reply	other threads:[~2022-02-21  6:49 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-23  1:43 [Bug rtl-optimization/51954] New: __int128_t " svfuerst at gmail dot com
2012-01-23  4:00 ` [Bug rtl-optimization/51954] __int128_t (and long long on x86) " pinskia at gcc dot gnu.org
2021-12-26 22:34 ` [Bug target/51954] " pinskia at gcc dot gnu.org
2022-02-21  5:57 ` pinskia at gcc dot gnu.org
2022-02-21  6:29 ` crazylht at gmail dot com
2022-02-21  6:49 ` crazylht at gmail dot com [this message]
2022-02-21  7:45 ` ubizjak at gmail dot com
2022-02-21  7:52 ` ubizjak at gmail dot com
2022-02-21  7:57 ` ubizjak at gmail dot com
2022-04-29 11:31 ` cvs-commit at gcc dot gnu.org
2022-04-29 11:33 ` ubizjak at gmail dot com

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