{"schedule", "late nilcheck"},
	// flagalloc needs instructions to be scheduled.
	{"schedule", "flagalloc"},
	// regalloc needs flags to be allocated first.
	{"flagalloc", "regalloc"},
	// loopRotate will confuse regalloc.
	{"regalloc", "loop rotate"},
	// trim needs regalloc to be done first.
	{"regalloc", "trim"},
	// memcombine works better if fuse happens first, to help merge stores.
	{"late fuse", "memcombine"},

		}
	}
}

func (f *Func) getHome(vid ID) Location {
	if int(vid) >= len(f.RegAlloc) {
		return nil
	}
	return f.RegAlloc[vid]
}

func (f *Func) setHome(v *Value, loc Location) {
	for v.ID >= ID(len(f.RegAlloc)) {
		f.RegAlloc = append(f.RegAlloc, nil)
	}
	f.RegAlloc[v.ID] = loc
}

func (s *stackAllocState) buildInterferenceGraph() {
	f := s.f

func (v *Value) Reg() int16 {
	reg := v.Block.Func.RegAlloc[v.ID]
	if reg == nil {
		v.Fatalf("nil register for value: %s\n%s\n", v.LongString(), v.Block.Func)
	}
	return reg.(*Register).objNum
}

// Reg0 returns the register assigned to the first output of v, in cmd/internal/obj/$ARCH numbering.
func (v *Value) Reg0() int16 {
	reg := v.Block.Func.RegAlloc[v.ID].(LocPair)[0]
	if reg == nil {

		if valueMark[v.ID] {
			f.Fatalf("used value v%d in free list", v.ID)
		}
	}

	// Check to make sure all args dominate uses.
	if f.RegAlloc == nil {
		// Note: regalloc introduces non-dominating args.
		// See TODO in regalloc.go.
		sdom := f.Sdom()
		for _, b := range f.Blocks {
			for _, v := range b.Values {
				for i, arg := range v.Args {
					x := arg.Block
					y := b

				// are not stomped (similar to the closure pointer above).
				// In particular, they need to come before regular OpArg operations because
				// of how regalloc places spill code (see regalloc.go:placeSpills:mustBeFirst).
				if b != f.Entry {
					f.Fatalf("%s appeared outside of entry block, b=%s", v.Op, b.String())
				}
				score[v.ID] = ScorePhi

	children []*loop  // loops nested directly within this loop. Initialized by assembleChildren().
	exits    []*Block // exits records blocks reached by exits from this loop. Initialized by findExits().

	// Next three fields used by regalloc and/or
	// aid in computation of inner-ness and list of blocks.
	nBlocks int32 // Number of blocks in this loop but not within inner loops

	"R11",
	"R12",
	"R13",
	"R14",
	"R15",
	"R16",
	"R17",
	"R18",
	"R19",
	"R20",
	"R21",
	"R22",
	// R23 = REGTMP not used in regalloc
	"R24",
	"R25",
	// R26 reserved by kernel
	// R27 reserved by kernel
	// R28 = REGSB not used in regalloc
	"SP",  // aka R29
	"g",   // aka R30
	"R31", // aka REGLINK

	"F0",
	"F1",
	"F2",
	"F3",
	"F4",
	"F5",
	"F6",
	"F7",
	"F8",

// H (half word) = 16 bit
// HU            = 16 bit unsigned
// B (byte)      = 8 bit
// BU            = 8 bit unsigned
// F (float)     = 32 bit float
// D (double)    = 64 bit float

// Note: registers not used in regalloc are not included in this list,
// so that regmask stays within int64
// Be careful when hand coding regmasks.
var regNamesLOONG64 = []string{
	"R0", // constant 0
	"R1",
	"SP", // aka R3
	"R4",
	"R5",
	"R6",

		//	BC 16,0,loop         branch ctr
		// For this purpose, VS32 and VS33 are treated as
		// scratch registers. Since regalloc does not
		// track vector registers, even if it could be marked
		// as clobbered it would have no effect.
		// TODO: If vector registers are managed by regalloc
		// mark these as clobbered.
		//
		// Bytes not moved by this loop are moved
		// with a combination of the following instructions,

			// keep their relative offsets correct, treat them all as used.
			continue
		}

		if needAlloc(ln) {
			ln.SetUsed(false)
		}
	}

	for _, l := range f.RegAlloc {
		if ls, ok := l.(ssa.LocalSlot); ok {
			ls.N.SetUsed(true)
		}
	}

	for _, b := range f.Blocks {
		for _, v := range b.Values {
			if n, ok := v.Aux.(*ir.Name); ok {
				switch n.Class {