[Bug tree-optimization/112859] New: wrong code at -O3 on x86_64-linux-gnu

[zhendong.su at inf dot ethz.ch via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112859

            Bug ID: 112859
           Summary: wrong code at -O3 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: ---

This appears to be a regression from 11.*, and affects 12.* and later.

Compiler Explorer: https://godbolt.org/z/aa8vrex9c

[555] % 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 --enable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20231205 (experimental) (GCC) 
[556] % 
[556] % gcctk -O2 small.c; ./a.out
[557] % 
[557] % gcctk -O3 small.c
[558] % ./a.out
Aborted
[559] % 
[559] % cat small.c
struct a {
  char b;
  int c;
} f, *i = &f;
static struct a e[4];
int *d, **g = &d;
static int h, j;
int main() {
  for (; h < 1; h++) {
    struct a k = {1, 1};
    for (j = 0; j < 2; j++) {
      *i = e[h];
      e[h] = k;
    }
    *g = 0;
  }
  if (f.c != 1)
    __builtin_abort();
  return 0;
}