[Bug tree-optimization/123514] New: bit manip to ABS detection

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123514

            Bug ID: 123514
           Summary: bit manip to ABS detection
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```
int bit_trick(int dec_exp) {
  int mask = -(dec_exp < 0);
  dec_exp = ((dec_exp + mask) ^ mask);  // absolute value
  return  dec_exp;
}
```

This should be optimized to ABS<dec_exp>.