if x.mode != variable {
			check.errorf(x, NonSliceableOperand, invalidOp+"%s (slice of unaddressable value)", x)
			x.mode = invalid
			return
		}
		x.typ = &Slice{elem: u.elem}

	case *Pointer:
		if u, _ := under(u.base).(*Array); u != nil {
			valid = true
			length = u.len
			x.typ = &Slice{elem: u.elem}
		}

	case *Slice:
		valid = true
		// x.typ doesn't change
	}

	if !valid {

}

func walkAppendArgs(n *ir.CallExpr, init *ir.Nodes) {
	walkExprListSafe(n.Args, init)

	// walkExprListSafe will leave OINDEX (s[n]) alone if both s
	// and n are name or literal, but those may index the slice we're
	// modifying here. Fix explicitly.
	ls := n.Args
	for i1, n1 := range ls {
		ls[i1] = cheapExpr(n1, init)
	}
}

// appendWalkStmt typechecks and walks stmt and then appends it to init.

		if !n.X.Type().IsSlice() && !n.Y.Type().IsSlice() {
			base.Errorf("arguments to copy must be slices; have %L, %L", n.X.Type(), n.Y.Type())
		} else if !n.X.Type().IsSlice() {
			base.Errorf("first argument to copy should be slice; have %L", n.X.Type())
		} else {
			base.Errorf("second argument to copy should be slice or string; have %L", n.Y.Type())
		}
		n.SetType(nil)
		return n
	}

		}

	case _SliceData:
		// unsafe.SliceData(slice []T) *T
		check.verifyVersionf(call.Fun, go1_20, "unsafe.SliceData")

		slice, _ := coreType(x.typ).(*Slice)
		if slice == nil {
			check.errorf(x, InvalidUnsafeSliceData, invalidArg+"%s is not a slice", x)
			return
		}

		x.mode = value
		x.typ = NewPointer(slice.elem)
		if check.recordTypes() {

		}

	case *Array:
		elem := subst.typOrNil(t.elem)
		if elem != t.elem {
			return &Array{len: t.len, elem: elem}
		}

	case *Slice:
		elem := subst.typOrNil(t.elem)
		if elem != t.elem {
			return &Slice{elem: elem}
		}

	case *Struct:
		if fields, copied := subst.varList(t.fields); copied {
			s := &Struct{fields: fields, tags: t.tags}
			s.markComplete()
			return s

	nif.Likely = true

	// then { s = s[:n] }
	slice := ir.NewSliceExpr(base.Pos, ir.OSLICE, s, nil, newLen, nil)
	slice.SetBounded(true)
	nif.Body = []ir.Node{
		ir.NewAssignStmt(base.Pos, s, slice),
	}

	// else { s = growslice(s.ptr, n, s.cap, a, T) }
	nif.Else = []ir.Node{

			// We also assume unsafe pointer arithmetic generates non-nil pointers. See #27180.
			// We assume that SlicePtr is non-nil because we do a bounds check
			// before the slice access (and all cap>0 slices have a non-nil ptr). See #30366.
			if v.Op == OpAddr || v.Op == OpLocalAddr || v.Op == OpAddPtr || v.Op == OpOffPtr || v.Op == OpAdd32 || v.Op == OpAdd64 || v.Op == OpSub32 || v.Op == OpSub64 || v.Op == OpSlicePtr {

type graphNode struct {
	obj        dependency // object represented by this node
	pred, succ nodeSet    // consumers and dependencies of this node (lazily initialized)
	index      int        // node index in graph slice/priority queue
	ndeps      int        // number of outstanding dependencies before this object can be initialized
}

// cost returns the cost of removing this node, which involves copying each

		[]ir.Node{ir.NewAssignOpStmt(base.Pos, ir.OADD, counter, ir.NewInt(base.Pos, 1))}))
}

// orderBlock orders the block of statements in n into a new slice,
// and then replaces the old slice in n with the new slice.
// free is a map that can be used to obtain temporary variables by type.
func orderBlock(n *ir.Nodes, free map[string][]*ir.Name) {
	if len(*n) != 0 {

		b.w = 0
		n, b.err = b.rd.Read(b.buf)
		if n < 0 {
			panic(errNegativeRead)
		}
		if n == 0 {
			return 0, b.readErr()
		}
		b.w += n
	}

	// copy as much as we can
	// Note: if the slice panics here, it is probably because
	// the underlying reader returned a bad count. See issue 49795.
	n = copy(p, b.buf[b.r:b.w])
	b.r += n
	b.lastByte = int(b.buf[b.r-1])
	b.lastRuneSize = -1
	return n, nil
}