[Bug tree-optimization/123657] [16 Regression] wrong code at -O3

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123657

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|wrong code at -O3           |[16 Regression] wrong code
                   |                            |at -O3
     Ever confirmed|0                           |1
   Target Milestone|---                         |16.0
                 CC|                            |pinskia at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2026-01-18
          Component|middle-end                  |tree-optimization

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed self contained testcase:
```
int a;
int main() {

  for (int b = 0; b < 21; b++) {
    int c = b;
    while (c)
      a = c >>= 1;
  }
  if (a != 0) __builtin_abort();
}
```