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From: "ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/94877] Failure to simplify ~(x + 1) to -2 - x
Date: Wed, 06 May 2020 15:56:39 +0000 [thread overview]
Message-ID: <bug-94877-4-GWFPqIA6wR@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-94877-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94877
--- Comment #4 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Jakub Jelinek from comment #3)
> I'm not sure why this is considered a simplification, two insns vs. two, and
> on the subtraction it isn't specific to just one target, but I think for
> most the constant will need to be forced into register, the immediates the
> instructions have is mostly for the second operand.
Two ALU operations are merged into one, assuming that move is "free".
next prev parent reply other threads:[~2020-05-06 15:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-30 12:02 [Bug tree-optimization/94877] New: " gabravier at gmail dot com
2020-04-30 12:50 ` [Bug tree-optimization/94877] " rguenth at gcc dot gnu.org
2020-04-30 19:08 ` pinskia at gcc dot gnu.org
2020-05-06 14:55 ` jakub at gcc dot gnu.org
2020-05-06 15:56 ` ubizjak at gmail dot com [this message]
2021-08-14 23:47 ` pinskia at gcc dot gnu.org
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