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From: "rsandifo at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/97127] FMA3 code transformation leads to slowdown on Skylake
Date: Wed, 30 Sep 2020 12:09:20 +0000	[thread overview]
Message-ID: <bug-97127-4-0g8KUZc3k3@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-97127-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97127

rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rsandifo at gcc dot gnu.org

--- Comment #18 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
Not sure this is a good idea or not, but: combine could
look at the constraints of the instruction it matches,
compare that with the information it has about whether
the inputs remain live after the instruction, and cost
in an extra move if all alternatives require a reload.

      parent reply	other threads:[~2020-09-30 12:09 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-20 20:36 [Bug target/97127] New: " already5chosen at yahoo dot com
2020-09-21  6:54 ` [Bug target/97127] " rguenth at gcc dot gnu.org
2020-09-21 10:35 ` amonakov at gcc dot gnu.org
2020-09-21 13:40 ` already5chosen at yahoo dot com
2020-09-21 15:17 ` amonakov at gcc dot gnu.org
2020-09-22  8:10 ` crazylht at gmail dot com
2020-09-22 10:01 ` already5chosen at yahoo dot com
2020-09-23  1:38 ` crazylht at gmail dot com
2020-09-23 17:49 ` already5chosen at yahoo dot com
2020-09-24  3:23 ` crazylht at gmail dot com
2020-09-24  8:28 ` already5chosen at yahoo dot com
2020-09-24 10:06 ` crazylht at gmail dot com
2020-09-24 10:46 ` crazylht at gmail dot com
2020-09-24 12:38 ` already5chosen at yahoo dot com
2020-09-25  5:24 ` crazylht at gmail dot com
2020-09-25 13:21 ` already5chosen at yahoo dot com
2020-09-25 14:02 ` amonakov at gcc dot gnu.org
2020-09-25 15:55 ` amonakov at gcc dot gnu.org
2020-09-30 12:09 ` rsandifo at gcc dot gnu.org [this message]

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