if lc, _ := f.Cache.Liveness.(*livenessFuncCache); lc == nil {
		// Prep the cache so liveness can fill it later.
		f.Cache.Liveness = new(livenessFuncCache)
	} else {
		if cap(lc.be) >= f.NumBlocks() {
			lv.be = lc.be[:f.NumBlocks()]
		}
		lv.livenessMap = Map{
			Vals:         lc.livenessMap.Vals,
			UnsafeVals:   lc.livenessMap.UnsafeVals,
			UnsafeBlocks: lc.livenessMap.UnsafeBlocks,

		CanonicalLocalSlots:  make(map[LocalSlot]*LocalSlot),
		CanonicalLocalSplits: make(map[LocalSlotSplitKey]*LocalSlot),
	}
}

// NumBlocks returns an integer larger than the id of any Block in the Func.
func (f *Func) NumBlocks() int {
	return f.bid.num()
}

// NumValues returns an integer larger than the id of any Value in the Func.
func (f *Func) NumValues() int {
	return f.vid.num()
}