// variable" ICEs (issue 19632).
	switch v.Op {
	case ssa.OpVarDef, ssa.OpVarLive, ssa.OpKeepAlive:
		if !n.Used() {
			return -1, 0
		}
	}

	if n.Class == ir.PPARAM && !n.Addrtaken() && n.Type().Size() > int64(types.PtrSize) {
		// Only aggregate-typed arguments that are not address-taken can be
		// partially live.
		lv.partLiveArgs[n] = true
	}

	var effect liveEffect

// analysis.
func IsMergeCandidate(n *ir.Name) bool {
	if base.Debug.MergeLocals == 0 ||
		base.Flag.N != 0 ||
		n.Class != ir.PAUTO ||
		n.Type().Size() <= int64(3*types.PtrSize) ||
		n.Addrtaken() ||
		n.NonMergeable() ||
		n.OpenDeferSlot() {
		return false
	}
	return true