[Bug middle-end/122213] [15/16 Regression] {CEIL,ROUND}_DIV_EXPR produces wrong results when constant operand is 2 or power of 2 with O2 flag

[avinashd at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122213

--- Comment #5 from Avinash Jayakar <avinashd at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
> I am not even sure this have ever been used or tested.

Yeah, even I am not sure which frontend can generate these operations. 
Fortran uses __FLOOR_DIV_EXPR and __FLOOR_MOD_EXPR, but I encountered this 
when I was implementing functionality for PR104116.