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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/94092] Code size and performance degradations after -ftree-loop-distribute-patterns was enabled at -O[2s]+
Date: Mon, 09 Mar 2020 09:48:33 +0000	[thread overview]
Message-ID: <bug-94092-4-ShNgea1wB8@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-94092-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94092

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
With profile feedback we (target or middle-end) can produce specialized
RTL expansion doing small copies inline and larget ones offline.  The
idea of GIMPLE level pattern detection is that even for small sizes
the target usually knows how to expand the copy optimally while the
user may have written a byte copying loop.

Of course that requires targets to pay attention.

Note most compiler optimization involves some heuristics and clearly heuristics
can be off.  I wonder if you can obtain better coremark results by using
link-time optimization.  Iff you're only after benchmark numbers...

  parent reply	other threads:[~2020-03-09  9:48 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-09  6:06 [Bug tree-optimization/94092] New: " bina2374 at gmail dot com
2020-03-09  6:17 ` [Bug tree-optimization/94092] " pinskia at gcc dot gnu.org
2020-03-09  6:29 ` pinskia at gcc dot gnu.org
2020-03-09  6:30 ` pinskia at gcc dot gnu.org
2020-03-09  7:37 ` glisse at gcc dot gnu.org
2020-03-09  9:48 ` rguenth at gcc dot gnu.org [this message]
2021-02-19  8:05 ` aoliva at gcc dot gnu.org
2021-02-23 23:57 ` wilson at gcc dot gnu.org
2021-02-24  7:43 ` rguenth at gcc dot gnu.org
2021-02-24  9:05 ` bina2374 at gmail dot com
2021-02-24  9:20 ` rguenth at gcc dot gnu.org
2021-02-26  6:35 ` bina2374 at gmail dot com
2021-03-03  6:30 ` bina2374 at gmail dot com
2021-03-03  8:03 ` rguenther at suse dot de
2021-04-29  4:24 ` aoliva at gcc dot gnu.org
2021-04-30 14:38 ` law at gcc dot gnu.org
2021-05-03  6:28 ` rguenther at suse dot de
2021-05-04 12:26 ` rguenth at gcc dot gnu.org

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