[Bug tree-optimization/123061] wrong code at -O3 with -ffinite-loops on x86_64-linux-gnu

[zhendong.su at inf dot ethz.ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123061

--- Comment #1 from Zhendong Su <zhendong.su at inf dot ethz.ch> ---
Another very likely related reproducer that only fails at -O1.

Compiler Explorer: https://godbolt.org/z/YTWhM7Gnn

Note:
- fails: 12.1 and later
- works: 11.4 and earlier

[591] % 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/16.0.0/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 16.0.0 20251209 (experimental) (GCC)
[592] %
[592] % gcctk -O1 small.c; ./a.out
[593] %
[593] % gcctk -O1 -ffinite-loops small.c
[594] % ./a.out
Floating point exception
[595] %
[595] % cat small.c
int a, b, c;
int d() {
  while (a)
    ;
  return 0;
}
static int e(int f, int g) {
  c = f;
  while (1) {
    f = 0;
    do {
      c = -c;
      if (c >= 0)
        goto h;
    } while (-1 / b);
    return d();
  h:
    b = g;
  }
}
int main() {
  while (e(-4, 3))
    ;
  return 0;
}