public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "zhendong.su at inf dot ethz.ch" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/115092] New: wrong code at -O1 with "-fgcse -ftree-pre -fno-tree-dominator-opts -fno-tree-fre -fno-guess-branch-probability" on x86_64-linux-gnu
Date: Tue, 14 May 2024 19:05:45 +0000	[thread overview]
Message-ID: <bug-115092-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115092

            Bug ID: 115092
           Summary: wrong code at -O1 with "-fgcse -ftree-pre
                    -fno-tree-dominator-opts -fno-tree-fre
                    -fno-guess-branch-probability" on x86_64-linux-gnu
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhendong.su at inf dot ethz.ch
  Target Milestone: ---

It appears to be a recent regression as it only reproduces with 14.1 and trunk,
but not 13.* and earlier. It needs several flags, but hope it's still of
interest. 

Compiler Explorer: https://godbolt.org/z/qTc3e6s7f

[521] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/local/suz-local/software/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/15.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--enable-checking=yes --prefix=/local/suz-local/software/local/gcc-trunk
--enable-sanitizers --enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 15.0.0 20240514 (experimental) (GCC) 
[522] % 
[522] % gcctk -O1 small.c; ./a.out
[523] % 
[523] % gcctk -O1 -fgcse -ftree-pre -fno-tree-dominator-opts -fno-tree-fre
-fno-guess-branch-probability small.c
[524] % ./a.out
Floating point exception
[525] % 
[525] % cat small.c
int a, b, c = 1, d, e;
int main() {
  int f, g = a;
  b = -2;
  f = -(1 >> ((c && b) & ~a));
  if (f <= b)
    d = g / e;
  return 0;
}

             reply	other threads:[~2024-05-14 19:05 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-14 19:05 zhendong.su at inf dot ethz.ch [this message]
2024-05-14 19:13 ` [Bug tree-optimization/115092] [14/15 Regression] wrong code at -O1 with "-fgcse -ftree-pre -fno-tree-dominator-opts -fno-tree-fre -fno-guess-branch-probability" on x86_64-linux-gnu since r14-4810 jakub at gcc dot gnu.org
2024-05-14 19:32 ` [Bug rtl-optimization/115092] " pinskia at gcc dot gnu.org
2024-05-14 22:04 ` pinskia at gcc dot gnu.org
2024-05-15 10:02 ` jakub at gcc dot gnu.org
2024-05-15 11:16 ` jakub at gcc dot gnu.org
2024-05-15 11:22 ` segher at gcc dot gnu.org
2024-05-15 11:32 ` segher at gcc dot gnu.org
2024-05-15 11:44 ` jakub at gcc dot gnu.org
2024-05-15 11:49 ` segher at gcc dot gnu.org
2024-05-15 12:09 ` jakub at gcc dot gnu.org
2024-05-15 13:36 ` segher at gcc dot gnu.org
2024-05-15 16:44 ` cvs-commit at gcc dot gnu.org
2024-06-04 14:26 ` cvs-commit at gcc dot gnu.org
2024-06-04 14:28 ` jakub at gcc dot gnu.org
2024-06-11  6:17 ` cvs-commit at gcc dot gnu.org
2024-06-11 10:38 ` cvs-commit at gcc dot gnu.org
2024-06-20 13:23 ` cvs-commit 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-115092-4@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).