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From: "rearnsha at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/111096] Frame pointer is not used even when -fomit-frame-pointer is specified
Date: Wed, 23 Aug 2023 10:51:47 +0000	[thread overview]
Message-ID: <bug-111096-4-pHNv79F7on@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-111096-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111096

Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |WONTFIX
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #5 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
This was a deliberate design choice.  Although the frame chain is not set up by
code that omits the frame pointer, the chain of frames that are set up by other
functions is still valid this way.  This ensures that any code that does try to
walk the frame chain will not crash.  If we reused the frame pointer for other
purposes, then any code trying to walk the frame chain (eg backtrace()) would
encounter an invalid record and likely crash.

With 31 main registers, the benefit from one additional one is not especially
large.

  parent reply	other threads:[~2023-08-23 10:51 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-22  5:25 [Bug rtl-optimization/111096] New: " tkoenig at gcc dot gnu.org
2023-08-22  5:48 ` [Bug target/111096] " pinskia at gcc dot gnu.org
2023-08-22  5:52 ` pinskia at gcc dot gnu.org
2023-08-22  9:18 ` tkoenig at gcc dot gnu.org
2023-08-22 16:49 ` gccbug at provalid dot com
2023-08-23 10:51 ` rearnsha at gcc dot gnu.org [this message]
2023-08-23 15:31 ` rearnsha at gcc dot gnu.org
2023-08-23 20:57 ` tkoenig at gcc dot gnu.org
2023-08-24 14:29 ` rearnsha at gcc dot gnu.org
2023-08-25 18:15 ` tkoenig at gcc dot gnu.org

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