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From: "hjl.tools at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/101456] Unnecessary vzeroupper when upper bits of YMM registers already zero
Date: Tue, 15 Feb 2022 13:42:23 +0000	[thread overview]
Message-ID: <bug-101456-4-Fa3OrsGNge@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-101456-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101456

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
         Resolution|FIXED                       |---
             Status|RESOLVED                    |REOPENED
   Last reconfirmed|                            |2022-02-15

--- Comment #8 from H.J. Lu <hjl.tools at gmail dot com> ---
It turns out that reading YMM registers with all zero bits needs VZEROUPPER
on Sandy Bride, Ivy Bridge, Haswell, Broadwell and Alder Lake to avoid
SSE <-> AVX transition penalty.

  parent reply	other threads:[~2022-02-15 13:42 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-14 22:39 [Bug target/101456] New: " hjl.tools at gmail dot com
2021-07-14 22:59 ` [Bug target/101456] " arjan at linux dot intel.com
2021-07-15  0:04 ` hjl.tools at gmail dot com
2021-07-15  0:06 ` hjl.tools at gmail dot com
2021-07-15 14:32 ` hjl.tools at gmail dot com
2021-07-16 12:18 ` hjl.tools at gmail dot com
2021-07-28 14:29 ` cvs-commit at gcc dot gnu.org
2021-07-28 15:02 ` hjl.tools at gmail dot com
2022-02-15 13:42 ` hjl.tools at gmail dot com [this message]
2022-02-16  4:57 ` crazylht at gmail dot com
2022-05-06  8:30 ` jakub at gcc dot gnu.org
2023-05-08 12:22 ` rguenth at gcc dot gnu.org

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