public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/94782] Simple multiplication-related arithmetic not optimized to direct multiplication Date: Mon, 27 Apr 2020 07:07:52 +0000 [thread overview] Message-ID: <bug-94782-4-Sb5JL4UGow@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-94782-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94782 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Ever confirmed|0 |1 Status|UNCONFIRMED |NEW Last reconfirmed| |2020-04-27 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- Since the inner (a - 1U) * b is unsigned but a * b would be signed due to undefined signed overflow we cannot optimize to that. But we could indeed. optimize to (unsigned)a * (unsigned)b. fold-const.c contains related transforms that could be amended. reassoc could as well but would need enhancement for signed arithmetic.
next prev parent reply other threads:[~2020-04-27 7:07 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-04-27 2:08 [Bug tree-optimization/94782] New: " gabravier at gmail dot com 2020-04-27 7:07 ` rguenth at gcc dot gnu.org [this message] 2023-02-17 18:16 ` [Bug tree-optimization/94782] " gabravier at gmail dot com 2023-02-17 18:24 ` pinskia at gcc dot gnu.org 2023-02-17 18:28 ` 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-94782-4-Sb5JL4UGow@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: linkBe 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).