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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/54571] Missed optimization converting between bit sets
Date: Mon, 15 Nov 2021 00:52:27 +0000	[thread overview]
Message-ID: <bug-54571-4-1SIxLwbMwQ@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-54571-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54571

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |pinskia at gcc dot gnu.org
             Status|NEW                         |ASSIGNED
         Depends on|                            |103216

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is fixed mostly by the patch which fixes PR 103216.
We still have stuff like:
  _1 = x_3(D) & 1;
  _7 = _1 != 0;
  _8 = (int) _7;
  _9 = y_4(D) | _8;

and:
  _1 = x_3(D) & 2;
  _7 = _1 != 0;
  _8 = (int) _7;
  _9 = y_4(D) | _8;

and
   _1 = x_3(D) & 2;
  _7 = _1 != 0;
  _8 = (int) _7;
  _9 = _8 << 1;
  _10 = y_4(D) | _9;

Which we produce things like:
        xorl    %eax, %eax
        andl    $2, %edi
        sete    %al
        orl     %esi, %eax

Where the sete/xor could be reproduced with shift for an example.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103216
[Bug 103216] missed optimization, phiopt/vrp?

  parent reply	other threads:[~2021-11-15  0:52 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-13 21:25 [Bug middle-end/54571] New: " rth at gcc dot gnu.org
2012-09-13 21:25 ` [Bug middle-end/54571] " rth at gcc dot gnu.org
2012-09-14  8:40 ` rguenth at gcc dot gnu.org
2021-07-06  8:39 ` pinskia at gcc dot gnu.org
2021-07-20  3:16 ` pinskia at gcc dot gnu.org
2021-11-15  0:52 ` pinskia at gcc dot gnu.org [this message]
2023-06-07 15:20 ` pinskia at gcc dot gnu.org

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