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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/107591] range-op{,-float}.cc for x * x
Date: Wed, 09 Nov 2022 16:40:07 +0000	[thread overview]
Message-ID: <bug-107591-4-s5Jz2pHCxL@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-107591-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107591

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Aldy Hernandez from comment #6)
> FYI, the range operators have a relation field, so it should be able to tell
> you that both operands are equal with VREL_EQ (?).  You could use that to
> optimize things.

You're right, at least for irange trio.op1_op2 () in the mult fold_range is
VREL_EQ and we could just go from that.
For frange perhaps it isn't as perfect because of signed zeros, so in
float
foo (float x, float y)
{
  if (x == y)
    return x * y;
  return 42.0f;
}
trio.op1_op2 () could be VREL_EQ even if one is signed and the other unsigned
zero, and in that case -0.0 would need to be in the range too.  But maybe that
is good enough for now.

  parent reply	other threads:[~2022-11-09 16:40 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-09 15:37 [Bug tree-optimization/107591] New: " jakub at gcc dot gnu.org
2022-11-09 15:49 ` [Bug tree-optimization/107591] " aldyh at gcc dot gnu.org
2022-11-09 15:55 ` aldyh at gcc dot gnu.org
2022-11-09 15:57 ` jakub at gcc dot gnu.org
2022-11-09 15:59 ` pinskia at gcc dot gnu.org
2022-11-09 16:01 ` pinskia at gcc dot gnu.org
2022-11-09 16:02 ` aldyh at gcc dot gnu.org
2022-11-09 16:04 ` aldyh at gcc dot gnu.org
2022-11-09 16:31 ` jakub at gcc dot gnu.org
2022-11-09 16:40 ` jakub at gcc dot gnu.org [this message]
2022-11-09 17:45 ` amacleod at redhat dot com
2022-11-09 17:49 ` jakub at gcc dot gnu.org
2022-11-09 18:22 ` amacleod at redhat dot com
2022-11-09 18:35 ` jakub at gcc dot gnu.org
2022-11-09 19:20 ` amacleod at redhat dot com
2022-11-09 20:24 ` jakub at gcc dot gnu.org
2022-11-09 20:45 ` jakub at gcc dot gnu.org
2022-11-09 22:25 ` amacleod at redhat dot com
2022-11-09 23:27 ` jakub at gcc dot gnu.org
2022-11-12  8:42 ` cvs-commit at gcc dot gnu.org
2023-04-05  7:14 ` pilarlatiesa at gmail dot com

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