IAF_CTRL
cpu, (uintmax_t) rdmsr(IAF_CTRL),
wrmsr(IAF_CTRL, 0);
wrmsr(IAF_CTRL, cc->pc_iafctrl);
cc->pc_iafctrl, (uint32_t) rdmsr(IAF_CTRL),
wrmsr(IAF_CTRL, cc->pc_iafctrl);
cc->pc_iafctrl, (uint32_t) rdmsr(IAF_CTRL),
wrmsr(IAF_CTRL, cc->pc_iafctrl & ~(IAF_MASK << (ri * 4)));
wrmsr(IAF_CTRL, cc->pc_iafctrl);
(uintmax_t) rdmsr(IAF_CTRL),