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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/98865] Missed transform of (a >> 63) * b
Date: Tue, 20 Jul 2021 22:19:46 +0000	[thread overview]
Message-ID: <bug-98865-4-rcm0rO718v@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-98865-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98865

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu.org

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Actually I think we should do:
(simplify
 (mult:c truth_valuep@0 @1)
 (and (neg @0) @1))

Instead. What do you think?

This will catch things like:
unsigned long foo (long a, unsigned long b)
{
  unsigned long t =  a & 1;
  return t * b;
}

---- CUT ---
We can put a ! after neg if we want it to be optimized out even.

  parent reply	other threads:[~2021-07-20 22:19 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-28 13:38 [Bug middle-end/98865] New: " rguenth at gcc dot gnu.org
2021-01-28 13:40 ` [Bug middle-end/98865] " rguenth at gcc dot gnu.org
2021-01-28 14:26 ` jakub at gcc dot gnu.org
2021-03-07  2:46 ` pinskia at gcc dot gnu.org
2021-07-20 22:19 ` pinskia at gcc dot gnu.org [this message]
2021-09-22 18:19 ` cvs-commit at gcc dot gnu.org
2022-01-11 11:19 ` rguenth at gcc dot gnu.org
2022-05-18 15:24 ` cvs-commit at gcc dot gnu.org
2022-05-19 16:55 ` cvs-commit at gcc dot gnu.org
2022-05-27  8:02 ` cvs-commit at gcc dot gnu.org
2022-05-28  9:18 ` roger at nextmovesoftware dot com

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