[Bug tree-optimization/109638] unsigned > 1 ? 0 : n is not optimized to n == 1

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109638

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Hmm, but more generally

 if (n != x)
   n = 0;
 return n != 0;

could be handled as well.  Or

 if (n != x)
   n = 0;
 return n;

->

 return (n == x) * x;


-1 might be another special case that CPUs can efficiently handle.