# v3.1 setbc instructions

There are additional setb conditional instructions in v3.1 (p129)

    RT = (CR[BI] == 1) ? 1 : 0

which also negate that, and also return -1 / 0.  these are similar to
crweird but not the same purpose.  most notable is that crweird acts on
CR fields rather than the entire 32 bit CR.