// freeRegs frees up all registers listed in m.
func (s *regAllocState) freeRegs(m regMask) {
	for m&s.used != 0 {
		s.freeReg(pickReg(m & s.used))
	}
}

// clobberRegs inserts instructions that clobber registers listed in m.
func (s *regAllocState) clobberRegs(m regMask) {
	m &= s.allocatable & s.f.Config.gpRegMask // only integer register can contain pointers, only clobber them
	for m != 0 {
		r := pickReg(m)
		m &^= 1 << r