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 middle-end/58270] Wrong code while accessing trailing array elements in a global common structure Date: Tue, 03 Sep 2013 09:23:00 -0000 [thread overview] Message-ID: <bug-58270-4-dscpwri7vW@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-58270-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58270 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target|i386-pc-linux | Status|WAITING |NEW CC| |rguenth at gcc dot gnu.org Component|fortran |middle-end Host|i386-pc-linux | Summary|Wrong code while accessing |Wrong code while accessing |array elements in a global |trailing array elements in |structure |a global common structure Known to fail| |4.9.0 --- Comment #19 from Richard Biener <rguenth at gcc dot gnu.org> --- DECL_COMMONs could be special-cased in places that look at DECL_SIZE (I'll declare this a QOI issue). Or all decls that do not bind locally. The place that would "fix" tree-fre, tree-pre and tree-dse is in get_ref_base_and_extent where it does if (DECL_P (exp)) { /* If maxsize is unknown adjust it according to the size of the base decl. */ if (maxsize == -1 && host_integerp (DECL_SIZE (exp), 1)) maxsize = TREE_INT_CST_LOW (DECL_SIZE (exp)) - hbit_offset; } else if (CONSTANT_CLASS_P (exp)) { /* If maxsize is unknown adjust it according to the size of the base type constant. */ if (maxsize == -1 && host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1)) maxsize = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp))) - hbit_offset; } In its general processing the function treats all trailing arrays as possibly of undefined size. Note that because -fcommon is still the default for all C dialects the impact of changing the above for example in the simple && !DECL_COMMON (exp) way is unknown. -fcommon is a source of interesting bugs.
next prev parent reply other threads:[~2013-09-03 9:23 UTC|newest] Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-08-29 10:48 [Bug c/58270] New: Wrong code accessing array elements strasbur at chkw386 dot ch.pwr.wroc.pl 2013-08-29 10:58 ` [Bug c/58270] Wrong code while accessing array elements in a global structure fweimer at redhat dot com 2013-08-29 11:15 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-08-29 11:29 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-08-29 12:19 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-08-29 12:21 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-08-29 12:23 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-08-29 12:39 ` mikpe at it dot uu.se 2013-08-29 13:32 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-08-29 14:48 ` jakub at gcc dot gnu.org 2013-08-29 16:23 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-09-02 8:20 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-09-02 8:24 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-09-02 12:21 ` [Bug fortran/58270] " dominiq at lps dot ens.fr 2013-09-02 13:14 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-09-02 14:39 ` dominiq at lps dot ens.fr 2013-09-02 16:32 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-09-02 17:53 ` dominiq at lps dot ens.fr 2013-09-03 7:56 ` strasbur at chkw386 dot ch.pwr.wroc.pl 2013-09-03 9:23 ` rguenth at gcc dot gnu.org [this message] 2013-09-03 9:41 ` [Bug middle-end/58270] Wrong code while accessing trailing array elements in a global common structure dominiq at lps dot ens.fr 2013-09-03 9:48 ` dominiq at lps dot ens.fr 2021-11-29 2:32 ` 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-58270-4-dscpwri7vW@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).