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From: "ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/95632] Redundant zero extension
Date: Tue, 16 Jun 2020 07:15:11 +0000	[thread overview]
Message-ID: <bug-95632-4-1qhZAhpiHo@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-95632-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95632

--- Comment #5 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Mel Chen from comment #2)
> Is it possible to pretend that we have a pattern that can match xor (reg:SI
> 80), (reg: SI 72), 0xa001 in combine pass?
> And then, if the constant part is too large to put in to the immediate part,
> it can be split to 2 xor in split pass.

Please note that the combine pass has its own (rather limited) splitter, it is
documented in the second part of "Defining How to Split Instructions"
paragraph. The example is dealing with the instruction that has too large
immediate part, and looks similar to your problem.

  parent reply	other threads:[~2020-06-16  7:15 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-11  4:06 [Bug target/95632] New: " bina2374 at gmail dot com
2020-06-12  4:25 ` [Bug target/95632] " wilson at gcc dot gnu.org
2020-06-15  9:49 ` bina2374 at gmail dot com
2020-06-16  0:01 ` wilson at gcc dot gnu.org
2020-06-16  0:02 ` wilson at gcc dot gnu.org
2020-06-16  7:15 ` ubizjak at gmail dot com [this message]
2020-06-16  7:21 ` ubizjak at gmail dot com
2021-05-30 22:26 ` pinskia at gcc dot gnu.org
2022-12-27 23:31 ` cvs-commit at gcc dot gnu.org
2022-12-27 23:32 ` law at gcc dot gnu.org

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