func RoundUp(o int64, r int64) int64 {
	if r < 1 || r > 8 || r&(r-1) != 0 {
		base.Fatalf("Round %d", r)
	}
	return (o + r - 1) &^ (r - 1)
}

// expandiface computes the method set for interface type t by
// expanding embedded interfaces.
func expandiface(t *Type) {
	seen := make(map[*Sym]*Field)
	var methods []*Field

	addMethod := func(m *Field, explicit bool) {
		switch prev := seen[m.Sym]; {
		case prev == nil: