[Bug tree-optimization/107052] New: Range of __builtin_popcount can be improved with nonzerobits

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107052

            Bug ID: 107052
           Summary: Range of __builtin_popcount can be improved with
                    nonzerobits
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: 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:
```
void link_failure();
void f(int a)
{
    a &= 0x300;
    int b =  __builtin_popcount(a);
    if (b > 3)
        link_failure();
}

```
The if statement should be optimized away as the only values for popcount here
is 0-3.