PCB_FP_USERMASK
KASSERT((curpcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
KASSERT((pcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
(td->td_pcb->pcb_fpflags & ~(PCB_FP_USERMASK|PCB_FP_SVEVALID)) == 0,
KASSERT((curpcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
curpcb->pcb_fpflags = mcp->mc_fpregs.fp_flags & PCB_FP_USERMASK;