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From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/97127] FMA3 code transformation leads to slowdown on Skylake
Date: Fri, 25 Sep 2020 05:24:21 +0000 [thread overview]
Message-ID: <bug-97127-4-G08az3JLSL@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
--- Comment #14 from Hongtao.liu <crazylht at gmail dot com> ---
> Still I don't understand why compiler does not compare the cost of full loop
> body after combining to the cost before combining and does not come to
> conclusion that combining increased the cost.
As Richard says, GCC does not model CPU pipelines in such detail.
next prev parent reply other threads:[~2020-09-25 5:24 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 [this message]
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
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