}
	return fmt.Sprintf("v%d", v.ID)
}

func (v *Value) AuxInt8() int8 {
	if opcodeTable[v.Op].auxType != auxInt8 && opcodeTable[v.Op].auxType != auxNameOffsetInt8 {
		v.Fatalf("op %s doesn't have an int8 aux field", v.Op)
	}
	return int8(v.AuxInt)
}

func (v *Value) AuxUInt8() uint8 {
	if opcodeTable[v.Op].auxType != auxUInt8 {
		v.Fatalf("op %s doesn't have a uint8 aux field", v.Op)
	}

	fmt.Fprintln(w, "}")

	fmt.Fprintln(w, "func (o Op) Asm() obj.As {return opcodeTable[o].asm}")
	fmt.Fprintln(w, "func (o Op) Scale() int16 {return int16(opcodeTable[o].scale)}")

	// generate op string method
	fmt.Fprintln(w, "func (o Op) String() string {return opcodeTable[o].name }")

	fmt.Fprintln(w, "func (o Op) SymEffect() SymEffect { return opcodeTable[o].symEffect }")

// remove duplicate expressions.
func zcse(f *Func) {
	vals := make(map[vkey]*Value)

	for _, b := range f.Blocks {
		for i := 0; i < len(b.Values); i++ {
			v := b.Values[i]
			if opcodeTable[v.Op].argLen == 0 {
				key := vkey{v.Op, keyFor(v), v.Aux, v.Type}
				if vals[key] == nil {
					vals[key] = v
					if b != f.Entry {
						// Move v to the entry block so it will dominate every block

			// Find any pointers that this op is guaranteed to fault on if nil.
			var ptrstore [2]*Value
			ptrs := ptrstore[:0]
			if opcodeTable[v.Op].faultOnNilArg0 && (faultOnLoad || v.Type.IsMemory()) {
				// On AIX, only writing will fault.
				ptrs = append(ptrs, v.Args[0])
			}
			if opcodeTable[v.Op].faultOnNilArg1 && (faultOnLoad || (v.Type.IsMemory() && v.Op != OpPPC64LoweredMove)) {
				// On AIX, only writing will fault.

	// lowering and a subsequent dead code elimination (because lowering
	// rules may leave dead generic ops behind).
	for _, b := range f.Blocks {
		for _, v := range b.Values {
			if !opcodeTable[v.Op].generic {
				continue // lowered
			}
			switch v.Op {

				q = append(q, v)
				if v.Pos.IsStmt() != src.PosNotStmt {
					liveOrderStmts = append(liveOrderStmts, v)
				}
			}
		}
		for _, v := range b.Values {
			if (opcodeTable[v.Op].call || opcodeTable[v.Op].hasSideEffects || opcodeTable[v.Op].nilCheck) && !live[v.ID] {
				live[v.ID] = true
				q = append(q, v)
				if v.Pos.IsStmt() != src.PosNotStmt {
					liveOrderStmts = append(liveOrderStmts, v)
				}
			}

	}
	if op.IsCall() {
		if ac, ok := v.Aux.(*AuxCall); ok && ac.reg != nil {
			return *ac.Reg(&opcodeTable[op].reg, s.f.Config)
		}
	}
	if op == OpMakeResult && s.f.OwnAux.reg != nil {
		return *s.f.OwnAux.ResultReg(s.f.Config)
	}
	return opcodeTable[op].reg
}

func (s *regAllocState) isGReg(r register) bool {
	return s.f.Config.hasGReg && s.GReg == r
}

	for _, b := range f.Blocks {
		for _, v := range b.Values {
			for i, a := range v.Args {
				if a.Op == OpSPanchored || opcodeTable[a.Op].nilCheck {
					v.SetArg(i, a.Args[0])
				}
			}
		}
		for i, c := range b.ControlValues() {
			if c.Op == OpSPanchored || opcodeTable[c.Op].nilCheck {
				b.ReplaceControl(i, c.Args[0])
			}
		}
	}
	for _, b := range f.Blocks {
		i := 0

			// has the pointer in arg[1] and the index in arg[2].
			ptrIndex := 0
			if opcodeTable[v.Op].resultInArg0 {
				ptrIndex = 1
			}
			p := v.Args[ptrIndex]
			c, ok := combine[[2]Op{v.Op, p.Op}]
			if !ok {
				continue
			}
			// See if we can combine the Aux/AuxInt values.
			switch [2]auxType{opcodeTable[v.Op].auxType, opcodeTable[p.Op].auxType} {
			case [2]auxType{auxSymOff, auxInt32}:
				// TODO: introduce auxSymOff32

	}

	inner.outer = outer
	outer.isInner = false
}

func checkContainsCall(bb *Block) bool {
	if bb.Kind == BlockDefer {
		return true
	}
	for _, v := range bb.Values {
		if opcodeTable[v.Op].call {
			return true
		}
	}
	return false
}

type loopnest struct {
	f              *Func
	b2l            []*loop
	po             []*Block
	sdom           SparseTree