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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/94145] Longcalls mis-optimize loading the function address
Date: Thu, 12 Mar 2020 08:48:26 +0000	[thread overview]
Message-ID: <bug-94145-4-qLnD0mZkrb@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-94145-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94145

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
So what prevents GIMPLE from doing the transform to an indirect call and
hoisting the call address computation out of the loop?  I fear your volatile
marking is
papering over an entirely different issue.  Of course it will likely work
as a workaround since nobody is going to do that above mentioned dance.  Maybe
code like

void foo();

void bar()
{
  void (volatile fn*)() = foo;
  void (fn2 *)() = fn;
  for (int i = 0; i<10000; ++i)
    fn2();
}

will expose the same "issue" whatever it really is?

  parent reply	other threads:[~2020-03-12  8:48 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-11 16:00 [Bug target/94145] New: " meissner at gcc dot gnu.org
2020-03-11 18:27 ` [Bug target/94145] " meissner at gcc dot gnu.org
2020-03-11 21:33 ` segher at gcc dot gnu.org
2020-03-11 21:35 ` segher at gcc dot gnu.org
2020-03-11 22:50 ` amodra at gmail dot com
2020-03-11 22:50 ` amodra at gmail dot com
2020-03-12  8:48 ` rguenth at gcc dot gnu.org [this message]
2020-03-12 13:00 ` amodra at gmail dot com
2020-03-12 13:17 ` rguenth at gcc dot gnu.org
2020-03-12 13:34 ` amodra at gmail dot com
2020-03-12 13:57 ` rguenth at gcc dot gnu.org
2020-03-12 15:38 ` segher at gcc dot gnu.org
2020-03-27 22:16 ` cvs-commit at gcc dot gnu.org
2020-05-01  1:18 ` cvs-commit at gcc dot gnu.org
2020-05-01  1:19 ` amodra at gmail dot com

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