// the slot we used via an index into locations[v.Type].
	slots := f.Cache.allocIntSlice(f.NumValues())
	defer f.Cache.freeIntSlice(slots)
	for i := range slots {
		slots[i] = -1
	}

	// Pick a stack slot for each value needing one.
	used := f.Cache.allocBoolSlice(f.NumValues())
	defer f.Cache.freeBoolSlice(used)
	for _, b := range f.Blocks {
		for _, v := range b.Values {

						}
						nonNilValues[v.ID] = v
					}
				}
			}
		}
	}

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

	// perform a depth first walk of the dominee tree
	for len(work) > 0 {
		node := work[len(work)-1]
		work = work[:len(work)-1]

func dse(f *Func) {
	var stores []*Value
	loadUse := f.newSparseSet(f.NumValues())
	defer f.retSparseSet(loadUse)
	storeUse := f.newSparseSet(f.NumValues())
	defer f.retSparseSet(storeUse)
	shadowed := f.newSparseMap(f.NumValues())
	defer f.retSparseMap(shadowed)

func schedule(f *Func) {
	// reusable priority queue
	priq := new(ValHeap)

	// "priority" for a value
	score := f.Cache.allocInt8Slice(f.NumValues())
	defer f.Cache.freeInt8Slice(score)

	// maps mem values to the next live memory value
	nextMem := f.Cache.allocValueSlice(f.NumValues())
	defer f.Cache.freeValueSlice(nextMem)

	// inBlockUses records whether a value is used in the block

		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 {