[Bug tree-optimization/126703] New: copysign(x, -abs(t)) -> copysign(x, -1.0)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126703

            Bug ID: 126703
           Summary: copysign(x, -abs(t)) -> copysign(x, -1.0)
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Keywords: easyhack, missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```
double f3(double x, double y)
{
  double t = -__builtin_abs(y);
  return __builtin_copysign (x,t);
}
```

This is just copysign(x, -1.0) or -abs(x).