// Regalloc wants a critical-edge-free CFG so it can implement phi values.
func critical(f *Func) {
	// maps from phi arg ID to the new block created for that argument
	blocks := f.Cache.allocBlockSlice(f.NumValues())
	defer f.Cache.freeBlockSlice(blocks)
	// need to iterate over f.Blocks without range, as we might
	// need to split critical edges on newly constructed blocks
	for j := 0; j < len(f.Blocks); j++ {
		b := f.Blocks[j]

		for k, vs := range s.NumLabel {
			if k == "bytes" {
				unit := o.NumLabelUnits[k]
				numValues := make([]int64, len(vs))
				numUnit := make([]string, len(vs))
				for i, v := range vs {
					numValues[i] = v
					numUnit[i] = unit
				}
				numLabels[k] = append(numLabels[k], numValues...)
				numUnits[k] = append(numUnits[k], numUnit...)
			}
		}
		s.NumLabel = numLabels

			// allocate auxiliary data structures for computing store order
			sset = f.newSparseSet(f.NumValues())
			defer f.retSparseSet(sset)
			sset2 = f.newSparseSet(f.NumValues())
			defer f.retSparseSet(sset2)
			storeNumber = f.Cache.allocInt32Slice(f.NumValues())
			defer f.Cache.freeInt32Slice(storeNumber)
		}

		// order values in store order

	"cmd/internal/obj/s390x"
	"math"
	"math/bits"
)

// checkFunc checks invariants of f.
func checkFunc(f *Func) {
	blockMark := make([]bool, f.NumBlocks())
	valueMark := make([]bool, f.NumValues())

	for _, b := range f.Blocks {
		if blockMark[b.ID] {
			f.Fatalf("block %s appears twice in %s!", b, f.Name)
		}
		blockMark[b.ID] = true
		if b.Func != f {

					labels[key] = append(labels[key], value)
				} else if l.numX != 0 || l.unitX != 0 {
					numValues := numLabels[key]
					units := numUnits[key]
					if l.unitX != 0 {
						var unit string
						unit, err = getString(p.stringTable, &l.unitX, err)
						units = padStringArray(units, len(numValues))
						numUnits[key] = append(units, unit)
					}
					numLabels[key] = append(numLabels[key], l.numX)
				}

	if !f.Config.unalignedOK {
		return
	}

	memcombineLoads(f)
	memcombineStores(f)
}

func memcombineLoads(f *Func) {
	// Find "OR trees" to start with.
	mark := f.newSparseSet(f.NumValues())
	defer f.retSparseSet(mark)
	var order []*Value

	// Mark all values that are the argument of an OR.
	for _, b := range f.Blocks {
		for _, v := range b.Values {

		// implemented
	default:
		return
	}

	// Find all the values used in computing the address of any load.
	// Typically these values have operations like AddPtr, Lsh64x64, etc.
	loadAddr := f.newSparseSet(f.NumValues())
	defer f.retSparseSet(loadAddr)
	for _, b := range f.Blocks {
		for _, v := range b.Values {
			switch v.Op {

	}
}

// 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()
}

// NameABI returns the function name followed by comma and the ABI number.

func findLastMems(f *Func) []*Value {

	var stores []*Value
	lastMems := f.Cache.allocValueSlice(f.NumBlocks())
	defer f.Cache.freeValueSlice(lastMems)
	storeUse := f.newSparseSet(f.NumValues())
	defer f.retSparseSet(storeUse)
	for _, b := range f.Blocks {
		// Find all the stores in this block. Categorize their uses:
		//  storeUse contains stores which are used by a subsequent store.
		storeUse.clear()

	f := s.f
	s.live = make([][]liveInfo, f.NumBlocks())
	s.desired = make([]desiredState, f.NumBlocks())
	var phis []*Value

	live := f.newSparseMapPos(f.NumValues())
	defer f.retSparseMapPos(live)
	t := f.newSparseMapPos(f.NumValues())
	defer f.retSparseMapPos(t)

	// Keep track of which value we want in each register.
	var desired desiredState