public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "kristerw at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/106884] ifcombine may move shift so it shifts more than bitwidth Date: Sun, 06 Aug 2023 00:07:37 +0000 [thread overview] Message-ID: <bug-106884-4-JYi4NFReQ1@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-106884-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106884 --- Comment #6 from Krister Walfridsson <kristerw at gcc dot gnu.org> --- One more similar case (that may be the same as comment #3): int g; void foo(int a, int b, int c, int d, int e) { if ((10 + a) * b) { g = (c || (g >> d)) << 1; } } In this case, reassoc1 optimizes the IR for c || (g >> d) to do (c | (g >> d)) != 0 and we are now always doing the shift, even when c is true.
next prev parent reply other threads:[~2023-08-06 0:07 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-09-08 0:20 [Bug tree-optimization/106884] New: " kristerw at gcc dot gnu.org 2022-09-08 9:52 ` [Bug tree-optimization/106884] " rguenth at gcc dot gnu.org 2022-09-08 10:53 ` kristerw at gcc dot gnu.org 2022-09-30 11:34 ` kristerw at gcc dot gnu.org 2023-07-11 9:45 ` rguenth at gcc dot gnu.org 2023-07-11 15:36 ` pinskia at gcc dot gnu.org 2023-08-06 0:07 ` kristerw at gcc dot gnu.org [this message] 2023-11-01 15:57 ` 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-106884-4-JYi4NFReQ1@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).