public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "acoplan at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c/99768] New: [11 Regression] Bogus -Wuninitialized diagnostic with type punning Date: Thu, 25 Mar 2021 11:46:27 +0000 [thread overview] Message-ID: <bug-99768-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99768 Bug ID: 99768 Summary: [11 Regression] Bogus -Wuninitialized diagnostic with type punning Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: acoplan at gcc dot gnu.org Target Milestone: --- For the following code (which has a strict aliasing violation): float foo(unsigned v) { unsigned tmp = v; float *f = (float *)(&tmp); return *f; } at -O2 -Wall we warn that tmp is used uninitialized: test.c: In function ‘foo’: test.c:5:12: warning: ‘tmp’ is used uninitialized [-Wuninitialized] 5 | return *f; | ^~ test.c:3:14: note: ‘tmp’ declared here 3 | unsigned tmp = v; | ^~~ but this is clearly bogus. Not sure if this is strictly considered a bug given the strict aliasing problem, but thought it might be worth checking in any case.
next reply other threads:[~2021-03-25 11:46 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-03-25 11:46 acoplan at gcc dot gnu.org [this message] 2021-03-25 12:28 ` [Bug c/99768] " rguenth at gcc dot gnu.org 2021-03-25 16:07 ` [Bug middle-end/99768] " msebor at gcc dot gnu.org 2021-04-08 13:13 ` [Bug middle-end/99768] Unhelpful " rguenth at gcc dot gnu.org 2023-07-03 16:04 ` 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-99768-4@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).