$*$ addOK $-$ Determine if can compute x$+$y without overflow

$*$ Example: addOK$(0$x$80000000,0$x$80000000)=0,$

$*$ addOK$(0$x$80000000,0$x$70000000)=1,$

$*$ Legal ops: $!$ ~ & $^|+<<>>$

$*$ Max ops: $14$

$*$ Rating: $3$