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From: "shaohua.li at inf dot ethz.ch" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/110701] New: Wrong code at -O1/2/3/s on x86_64-linux-gnu
Date: Mon, 17 Jul 2023 10:21:54 +0000	[thread overview]
Message-ID: <bug-110701-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110701

            Bug ID: 110701
           Summary: Wrong code at -O1/2/3/s on x86_64-linux-gnu
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: shaohua.li at inf dot ethz.ch
  Target Milestone: ---

This looks like a recent regression. gcc at -O1 and above produce the wrong
code.

Compiler explorer: https://godbolt.org/z/6Wczv9dK6

$ cat a.c
int printf(const char *, ...);
int a;
long b;
int *c = &a;
short(d)(short e, short f) { return e * f; }
int main() {
  *c = d(340, b >= 0) ^ 3;
  printf("%d\n", a);
}
$
$ gcc-tk -O0 a.c && ./a.out
343
$ gcc-tk -O1 a.c && ./a.out
-65193
$ gcc-tk -O2 a.c && ./a.out
-65193
$ gcc-tk -O3 a.c && ./a.out
-65193
$ gcc-tk -Os a.c && ./a.out
-65193
$
$ gcc-tk -v
Using built-in specs.
COLLECT_GCC=gcc-tk
COLLECT_LTO_WRAPPER=/zdata/shaoli/compilers/ccbuilder-compilers/gcc-322d17ae51ea0137167424e0018d7fa355948f9f/libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../configure --disable-multilib --disable-bootstrap
--enable-languages=c,c++
--prefix=/zdata/shaoli/compilers/ccbuilder-compilers/gcc-322d17ae51ea0137167424e0018d7fa355948f9f
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20230711 (experimental) (GCC)
$

             reply	other threads:[~2023-07-17 10:21 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-17 10:21 shaohua.li at inf dot ethz.ch [this message]
2023-07-17 12:43 ` [Bug rtl-optimization/110701] [14 Regression] " xry111 at gcc dot gnu.org
2023-07-17 17:51 ` pinskia at gcc dot gnu.org
2023-07-17 17:55 ` pinskia at gcc dot gnu.org
2023-07-17 17:58 ` pinskia at gcc dot gnu.org
2023-07-18 15:38 ` roger at nextmovesoftware dot com
2023-07-18 17:17 ` roger at nextmovesoftware dot com
2023-07-27 18:23 ` roger at nextmovesoftware dot com
2023-10-04 16:12 ` cvs-commit at gcc dot gnu.org
2023-10-11  7:59 ` roger at nextmovesoftware dot com

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