// a' = (ADDCC x y)
// a  = (Select0 a')
// b  = (CMPconst [0] a)
// c  = (OR a z)
//
// Which makes it trivial to rewrite b using a lowering rule.
func convertPPC64OpToOpCC(op *Value) *Value {
	ccOpMap := map[Op]Op{
		OpPPC64ADD:      OpPPC64ADDCC,
		OpPPC64ADDconst: OpPPC64ADDCCconst,
		OpPPC64AND:      OpPPC64ANDCC,
		OpPPC64ANDconst: OpPPC64ANDCCconst,
		OpPPC64ANDN:     OpPPC64ANDNCC,