ftt_base
if (tp->ftt_base != FASTTRAP_NOREG)
addr += fasttrap_getreg(rp, tp->ftt_base);
tp->ftt_base = (mod == 0 && base == 5) ?
tp->ftt_base = REG_RIP;
tp->ftt_base = FASTTRAP_NOREG;
tp->ftt_base = regmap[base];