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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/113779] Very inefficient m68k code generated for simple copy loop
Date: Mon, 05 Feb 2024 21:20:21 +0000 [thread overview]
Message-ID: <bug-113779-4-4hwMepihPi@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-113779-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113779
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
> So what's the catch here? Why gcc hates move.l (ax)+,(ay)+ so much?
At one point of time (before I think GCC 9 or 8 or so), GCC's IV-OPTs
optimization does not take into account post/pre increment, but now it does.
BUT if the target cost model does not take those into account, then IV-OPTs
could decide not to use them.
Now m68k is a target which not many GCC developers look at fixing, so it is up
to someone to look into why the post increment is no longer being used.
next prev parent reply other threads:[~2024-02-05 21:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-05 21:07 [Bug c/113779] New: " miro.kropacek at gmail dot com
2024-02-05 21:20 ` pinskia at gcc dot gnu.org [this message]
2024-02-06 7:58 ` [Bug target/113779] " rguenth at gcc dot gnu.org
2024-02-06 8:16 ` miro.kropacek at gmail dot com
2024-02-06 12:47 ` mikpelinux at gmail dot com
2024-02-06 12:58 ` miro.kropacek at gmail dot com
2024-02-06 13:14 ` rguenth at gcc dot gnu.org
2024-02-17 0:39 ` hp at gcc dot gnu.org
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