https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114009
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- That said, I fail to see why the a/2*2 in there matters. a*!a is simply always 0 for integral types, both signed and unsigned, including signed 1-bit precision. If a is 0, the result is 0*1 (or for the last one 0*-1), if a is non-zero, then the result is a*0.
