12:24:04kami_when the first compilation occurs. Wait, I'll paste the stack
12:25:06hayleyMy understanding is VPTEST sets flags and not a register; DEFINE-BORING-VOP won't work there. I can't remember how to specify which flag the VOP "returns", but you'd need to specify the Carry flag.
12:25:38hayleyAnd so the instruction is (inst vptest a b)
12:30:39hayleyThe DEFINE-VOP form should have (:conditional :c) I think, and similarly the DEFKNOWN should return a BOOLEAN. A guess though, I don't have any conditional VOPs I wrote on me.
12:32:17kami_I'll check the vop sources. Thanks again