public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "gabravier at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/95424] New: Failure to optimize division with numerator of 1
Date: Fri, 29 May 2020 20:21:50 +0000	[thread overview]
Message-ID: <bug-95424-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95424

            Bug ID: 95424
           Summary: Failure to optimize division with numerator of 1
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gabravier at gmail dot com
  Target Milestone: ---

unsigned f(unsigned x)
{
    return 1 / x;
}

This can be optimized to `return (x == 1);`, and for `int` to `return
(unsigned)(x + 1) < 3 ? x : 0;`. This transformation is done by LLVM, but not
by GCC.

             reply	other threads:[~2020-05-29 20:21 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-29 20:21 gabravier at gmail dot com [this message]
2020-06-02  6:46 ` [Bug tree-optimization/95424] " rguenth at gcc dot gnu.org
2021-08-14 23:59 ` pinskia at gcc dot gnu.org
2021-12-30  7:12 ` zhaoweiliew at gmail dot com
2021-12-31  1:16 ` zhaoweiliew at gmail dot com
2021-12-31  1:17 ` zhaoweiliew at gmail dot com
2021-12-31  1:18 ` zhaoweiliew at gmail dot com
2021-12-31  1:19 ` zhaoweiliew at gmail dot com
2022-01-05  3:33 ` zhaoweiliew at gmail dot com
2022-01-28 18:37 ` cvs-commit at gcc dot gnu.org
2022-01-28 18:41 ` law at gcc dot gnu.org
2022-01-29 16:56 ` cvs-commit at gcc dot gnu.org
2024-01-20 17:16 ` pinskia at gcc dot gnu.org

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bug-95424-4@http.gcc.gnu.org/bugzilla/ \
    --to=gcc-bugzilla@gcc.gnu.org \
    --cc=gcc-bugs@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).