r.Sync(pkgbits.SyncSignature)

	params := r.params()
	results := r.params()
	variadic := r.Bool()

	return types.NewSignatureType(recv, rtparams, tparams, params, results, variadic)
}

func (r *reader) params() *types.Tuple {
	r.Sync(pkgbits.SyncParams)

	params := make([]*types.Var, r.Len())
	for i := range params {

					if check.recordTypes() {
						sig := makeSig(S, S, y.typ)
						sig.variadic = true
						check.recordBuiltinType(call.Fun, sig)
					}
					x.mode = value
					x.typ = S
					break
				}
			}
		}

		// check general case by creating custom signature
		sig := makeSig(S, S, NewSlice(T)) // []T required for variadic signature
		sig.variadic = true

				tparams: t.tparams,
				// instantiated signatures have a nil scope
				recv:     recv,
				params:   params,
				results:  results,
				variadic: t.variadic,
			}
		}

	case *Union:
		terms, copied := subst.termlist(t.terms)
		if copied {
			// term list substitution may introduce duplicate terms (unlikely but possible).

// typesSummary returns a string of the form "(t1, t2, ...)" where the
// ti's are user-friendly string representations for the given types.
// If variadic is set and the last type is a slice, its string is of
// the form "...E" where E is the slice's element type.
func (check *Checker) typesSummary(list []Type, variadic bool) string {
	var res []string
	for i, t := range list {
		var s string
		switch {
		case t == nil:

				tparams: t.tparams,
				// instantiated signatures have a nil scope
				recv:     recv,
				params:   params,
				results:  results,
				variadic: t.variadic,
			}
		}

	case *Union:
		terms, copied := subst.termlist(t.terms)
		if copied {
			// term list substitution may introduce duplicate terms (unlikely but possible).

					return false
				}
			}

			yparams = check.subst(nopos, y.params, smap, nil, ctxt).(*Tuple)
			yresults = check.subst(nopos, y.results, smap, nil, ctxt).(*Tuple)
		}

		return x.variadic == y.variadic &&
			c.identical(x.params, yparams, p) &&
			c.identical(x.results, yresults, p)

	case *Union:
		if y, _ := y.(*Union); y != nil {
			// TODO(rfindley): can this be reached during type checking? If so,

   %4 = "quantfork.dcast"(%3) : (tensor<1x2x!quant.uniform<i8:f32, 6.000000e-03:-128>>) -> tensor<1x2xf32>
// expected-error @+2 {{Failed to find a valid entry function}}
// expected-error @+1 {{'tf.XlaCallModule' op operand #0 must be variadic of tensor of tf.dtype values}}

//             tilde bool
//             Type  typeOff
//         }
//     }
//
//
//
//     type Signature struct {
//         Params   []Param
//         Results  []Param
//         Variadic bool  // omitted if Results is empty
//     }
//
//     type Param struct {
//         Pos  Pos
//         Name stringOff
//         Type typOff
//     }
//
//

					return false
				}
			}

			yparams = check.subst(nopos, y.params, smap, nil, ctxt).(*Tuple)
			yresults = check.subst(nopos, y.results, smap, nil, ctxt).(*Tuple)
		}

		return x.variadic == y.variadic &&
			c.identical(x.params, yparams, p) &&
			c.identical(x.results, yresults, p)

	case *Union:
		if y, _ := y.(*Union); y != nil {
			// TODO(rfindley): can this be reached during type checking? If so,

}

func f0() (a []int)         { return }
func f1() (a []int, b int)  { return }
func f2() (a, b []int)      { return }

func append_([]int, ...int) {}

func issue9473(a []int, b ...int) {
	// variadic builtin function
	_ = append(f0())
	_ = append(f0(), f0()...)
	_ = append(f1())
	_ = append(f2 /* ERRORx `cannot use .* in argument` */ ())
	_ = append(f2()... /* ERROR "cannot use ..." */ )