//
// BEWARE of doing this *before* you've applied intended
// updates to SSA.
func (v *Value) invalidateRecursively() bool {
	lostStmt := v.Pos.IsStmt() == src.PosIsStmt
	if v.InCache {
		v.Block.Func.unCache(v)
	}
	v.Op = OpInvalid

	for _, a := range v.Args {
		a.Uses--
		if a.Uses == 0 {
			lost := a.invalidateRecursively()
			lostStmt = lost || lostStmt
		}
	}

	v.argstorage[0] = nil

}

func (x *expandState) invalidateRecursively(a *Value) {
	var s string
	if x.debug > 0 {
		plus := " "
		if a.Pos.IsStmt() == src.PosIsStmt {
			plus = " +"
		}
		s = a.String() + plus + a.Pos.LineNumber() + " " + a.LongString()
		if x.debug > 1 {
			x.Printf("...marking %v unused\n", s)
		}
	}
	lost := a.invalidateRecursively()