public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "zsojka at seznam dot cz" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/103181] New: [9/10/11/12 Regression] wrong code at -O1 due to conditional division by 0 being executed
Date: Thu, 11 Nov 2021 04:47:15 +0000	[thread overview]
Message-ID: <bug-103181-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103181

            Bug ID: 103181
           Summary: [9/10/11/12 Regression] wrong code at -O1 due to
                    conditional division by 0 being executed
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu

Created attachment 51762
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51762&action=edit
reduced testcase

Output:
$ x86_64-pc-linux-gnu-gcc testcase.c -O0 && ./a.out
$ x86_64-pc-linux-gnu-gcc testcase.c -O1 && ./a.out 
Floating point exception
$ x86_64-pc-linux-gnu-gcc testcase.c -O2 && ./a.out
$ x86_64-pc-linux-gnu-gcc testcase.c -O3 && ./a.out

The right hand operand of || in
  v += __builtin_bswap16 (s) || (S) (a / ((U){3, 0}));
is executed, even though s != 0 and it may trap.

$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64//bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r12-5136-20211110203027-gabc2f01914d-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-cloog --with-ppl --with-isl --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu
--with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r12-5136-20211110203027-gabc2f01914d-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.0 20211110 (experimental) (GCC)

             reply	other threads:[~2021-11-11  4:47 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-11  4:47 zsojka at seznam dot cz [this message]
2021-11-11  5:01 ` [Bug tree-optimization/103181] " pinskia at gcc dot gnu.org
2021-11-11  5:12 ` pinskia at gcc dot gnu.org
2021-11-11  5:18 ` pinskia at gcc dot gnu.org
2021-11-11  8:03 ` rguenth at gcc dot gnu.org
2021-11-11  8:33 ` rguenth at gcc dot gnu.org
2021-11-11  9:18 ` rguenth at gcc dot gnu.org
2021-11-11  9:33 ` cvs-commit at gcc dot gnu.org
2021-11-19  8:36 ` [Bug tree-optimization/103181] [9/10/11 " rguenth at gcc dot gnu.org
2021-11-22  8:00 ` cvs-commit at gcc dot gnu.org
2022-02-17 10:48 ` [Bug tree-optimization/103181] [9/10 " cvs-commit at gcc dot gnu.org
2022-02-17 11:57 ` [Bug tree-optimization/103181] [9 " cvs-commit at gcc dot gnu.org
2022-02-17 11:57 ` rguenth 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-103181-4@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: link
Be 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).