public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/107765] New: missing (int)-(unsigned)int_val to just -int_val if int_val is known not to contain INT_MIN Date: Sat, 19 Nov 2022 23:27:53 +0000 [thread overview] Message-ID: <bug-107765-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107765 Bug ID: 107765 Summary: missing (int)-(unsigned)int_val to just -int_val if int_val is known not to contain INT_MIN Product: gcc Version: 13.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: enhancement Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: pinskia at gcc dot gnu.org Target Milestone: --- Take: ``` #include <limits.h> int a(int input) { if (input == INT_MIN) __builtin_unreachable(); unsigned t = input; int tt = -t; return tt == -input; } ``` We should be able to optimize this at the tree level because we know we don't invoke undefined behavior.
next reply other threads:[~2022-11-19 23:27 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-11-19 23:27 pinskia at gcc dot gnu.org [this message] 2022-11-22 8:32 ` [Bug tree-optimization/107765] " rguenth at gcc dot gnu.org 2023-08-31 18:38 ` pinskia at gcc dot gnu.org 2023-09-01 2:27 ` pinskia at gcc dot gnu.org 2023-09-01 16:24 ` pinskia at gcc dot gnu.org 2023-09-02 7:03 ` pinskia at gcc dot gnu.org 2023-09-02 7:29 ` 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-107765-4@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: 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).