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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/93080] insert of an extraction on the same location is not optimized
Date: Mon, 21 Aug 2023 14:32:18 +0000	[thread overview]
Message-ID: <bug-93080-4-CTOyRT8EV6@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-93080-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93080

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
comment#4 could be implemented by an associating pattern in match.pd, currently
we get

  a_3 = BIT_INSERT_EXPR <a_1(D), c_2(D), 32 (32 bits)>;
  a_4 = VEC_PERM_EXPR <a_3, a_1(D), { 0, 1, 6, 3 }>;

associating a VEC_PERM_EXPR <a, b, { ... }> when a or b are defined as
insertion into b or a respectively so we get a permute of either a
or b with itself (and in this case it's a noop permute).

Of course with an arbitrary sequence of inserts / extracts / permutes
more "generic" association would be necessary and a pure implementation
in match.pd looks difficult.

  parent reply	other threads:[~2023-08-21 14:32 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-93080-4@http.gcc.gnu.org/bugzilla/>
2021-04-27 11:38 ` jakub at gcc dot gnu.org
2021-07-28  7:04 ` rguenth at gcc dot gnu.org
2023-07-15 17:29 ` pinskia at gcc dot gnu.org
2023-08-21 14:32 ` rguenth at gcc dot gnu.org [this message]
2023-08-22  9:34 ` cvs-commit at gcc dot gnu.org
2023-08-22  9:36 ` rguenth at gcc dot gnu.org

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