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From: "zhendong.su at inf dot ethz.ch" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/110391] wrong code at -O2 and -O3 with "-fsel-sched-pipelining -fselective-scheduling2" on x86_64-linux-gnu
Date: Sat, 24 Jun 2023 13:20:52 +0000	[thread overview]
Message-ID: <bug-110391-4-jtWzIfPVMK@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-110391-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110391

Zhendong Su <zhendong.su at inf dot ethz.ch> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|wrong code at -O2 and -O3   |wrong code at -O2 and -O3
                   |with "on x86_64-linux-gnu   |with
                   |                            |"-fsel-sched-pipelining
                   |                            |-fselective-scheduling2" on
                   |                            |x86_64-linux-gnu

--- Comment #1 from Zhendong Su <zhendong.su at inf dot ethz.ch> ---
It appears to be a regression from 11.*, and affects 12.* and later.

Compiler Explorer: https://godbolt.org/z/WEhzh66Pz

[571] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/local/home/suz/suz-local/software/local/gcc-trunk/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.0/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
--disable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20230623 (experimental) [master r14-924-gd709841ae0f] (GCC) 
[572] % 
[572] % gcctk -O3 -fsel-sched-pipelining -fselective-scheduling2 -fPIC small.c
[573] % ./a.out
Floating point exception
[574] % 
[574] % gcctk -O3 small.c; ./a.out
[575] % 
[575] % cat small.c
int printf(const char *, ...);
int a, d, b, i = 2, e;
static unsigned c = 1;
char f, g = 1;
void j() {
k:
  if (b)
    for (;;)
      __builtin_abort();
  unsigned l = i && 2 / c * d % g;
  if (a) {
    l = c;
    g = i;
    if (d > 1) {
      printf("%d", c);
      goto k;
    }
  }
  a = c = l;
}
int main() {
  a = -2;
  j();
  i = 0;
  f = ~c;
  if (f > 0) {
    printf("%d", f);
    a = 2 % i;
  }
  return 0;
}

  reply	other threads:[~2023-06-24 13:20 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-24 13:17 [Bug rtl-optimization/110391] New: wrong code at -O2 and -O3 with "on x86_64-linux-gnu zhendong.su at inf dot ethz.ch
2023-06-24 13:20 ` zhendong.su at inf dot ethz.ch [this message]
2023-06-24 15:23 ` [Bug rtl-optimization/110391] [12/13/14 Regression] wrong code at -O2 and -O3 with "-fsel-sched-pipelining -fselective-scheduling2" on x86_64-linux-gnu pinskia at gcc dot gnu.org
2023-06-26  9:12 ` zhendong.su at inf dot ethz.ch
2023-06-29  9:18 ` zhendong.su at inf dot ethz.ch
2023-06-29 17:33 ` zhendong.su at inf dot ethz.ch
2024-03-04  1:49 ` law at gcc dot gnu.org

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