v_0 := v.Args[0]
	b := v.Block
	config := b.Func.Config
	typ := &b.Func.Config.Types
	// match: (SliceLen (SliceMake _ len _))
	// result: len
	for {
		if v_0.Op != OpSliceMake {
			break
		}
		len := v_0.Args[1]
		v.copyOf(len)
		return true
	}
	// match: (SliceLen x:(Load <t> ptr mem))
	// cond: t.IsSlice()
	// result: @x.Block (Load <typ.Int> (OffPtr <typ.IntPtr> [config.PtrSize] ptr) mem)

			// TODO(mdempsky): Limit to static callees with
			// //go:uintptr{escapes,keepalive}?
			if arg.Type().IsUintptr() && arg.X.Type().IsUnsafePtr() {
				visit(&arg.X)
				return
			}

		case ir.OARRAYLIT, ir.OSLICELIT, ir.OSTRUCTLIT:
			// TODO(mdempsky): For very large slices, it may be preferable
			// to construct them at the go/defer statement instead.
			list := arg.(*ir.CompLitExpr).List
			for i, el := range list {

	case types.TARRAY:
		typecheckarraylit(t.Elem(), t.NumElem(), n.List, "array literal")
		n.SetOp(ir.OARRAYLIT)

	case types.TSLICE:
		length := typecheckarraylit(t.Elem(), -1, n.List, "slice literal")
		n.SetOp(ir.OSLICELIT)
		n.Len = length

	case types.TMAP:
		for i3, l := range n.List {
			ir.SetPos(l)
			if l.Op() != ir.OKEY {
				n.List[i3] = Expr(l)
				base.Errorf("missing key in map literal")
				continue

pair (-type id, encoded-type) where encoded-type is the gob encoding of a wireType
description, constructed from these types:

	type wireType struct {
		ArrayT           *ArrayType
		SliceT           *SliceType
		StructT          *StructType
		MapT             *MapType
		GobEncoderT      *gobEncoderType
		BinaryMarshalerT *gobEncoderType
		TextMarshalerT   *gobEncoderType

	}

		n := n.(*ir.SelectorExpr)
		n.X = o.expr(n.X, nil)
		if n.Transient() {
			t := typecheck.MethodValueType(n)
			n.Prealloc = o.newTemp(t, false)
		}
		return n

	case ir.OSLICELIT:
		n := n.(*ir.CompLitExpr)
		o.exprList(n.List)
		if n.Transient() {
			t := types.NewArray(n.Type().Elem(), n.Len)
			n.Prealloc = o.newTemp(t, false)
		}
		return n

	// Slices
	{name: "SliceMake", argLength: 3},                // arg0=ptr, arg1=len, arg2=cap
	{name: "SlicePtr", argLength: 1, typ: "BytePtr"}, // ptr(arg0)
	{name: "SliceLen", argLength: 1},                 // len(arg0)
	{name: "SliceCap", argLength: 1},                 // cap(arg0)
	// SlicePtrUnchecked, like SlicePtr, extracts the pointer from a slice.