func countRegs(r regMask) int {
	return bits.OnesCount64(uint64(r))
}

// for sorting a pair of integers by key
type intPair struct {
	key, val int
}
type byKey []intPair

func (a byKey) Len() int           { return len(a) }
func (a byKey) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
func (a byKey) Less(i, j int) bool { return a[i].key < a[j].key }

type ArchsByName []arch

}

var ignoreTests = []ignoreTest{
	// Decode normal struct into an empty struct
	{&struct{ A int }{23}, &struct{}{}},
	// Decode normal struct into a nil.
	{&struct{ A int }{23}, nil},
	// Decode singleton string into a nil.
	{"hello, world", nil},
	// Decode singleton slice into a nil.
	{[]int{1, 2, 3, 4}, nil},
	// Decode struct containing an interface into a nil.
	{&Struct0{&NewType0{"value0"}}, nil},

		golden func(int16) int16
	}{
		{"x|x", func(x int16) int16 { return x | x }, id},
		{"x|0", func(x int16) int16 { return x | 0 }, id},
		{"x|-1", func(x int16) int16 { return x | -1 }, func(x int16) int16 { return -1 }},
		{"x&x", func(x int16) int16 { return x & x }, id},
		{"x&0", func(x int16) int16 { return x & 0 }, zero},
		{"x&-1", func(x int16) int16 { return x & -1 }, id},

	tReserved7 = bootstrapType("_reserved1", (*struct{ r7 int })(nil))
	tReserved6 = bootstrapType("_reserved1", (*struct{ r6 int })(nil))
	tReserved5 = bootstrapType("_reserved1", (*struct{ r5 int })(nil))
	tReserved4 = bootstrapType("_reserved1", (*struct{ r4 int })(nil))
	tReserved3 = bootstrapType("_reserved1", (*struct{ r3 int })(nil))
	tReserved2 = bootstrapType("_reserved1", (*struct{ r2 int })(nil))

        IN 1: R{ I3 } spilloffset: 8 typ: *struct { int16; int16; int16 }
        IN 2: R{ } offset: 0 typ: [7]*struct { int16; int16; int16 }
        IN 3: R{ F0 } spilloffset: 16 typ: float64
        IN 4: R{ I4 } spilloffset: 24 typ: int16
        IN 5: R{ I5 } spilloffset: 26 typ: int16
        IN 6: R{ I6 } spilloffset: 28 typ: int16

		}
	}
}

type allScalars struct {
	True1     bool
	True2     bool
	False1    bool
	False2    bool
	Int       int
	Int8      int8
	Int16     int16
	Int32     int32
	Int64     int64
	Uint      int
	Uint8     uint8
	Uint16    uint16
	Uint32    uint32
	Uint64    uint64
	Uintptr   uintptr
	Float32   float32
	Float64   float64
	String    string

}

type XSocket struct {
	Xso_len      uint32
	Xso_so       uint32
	So_type      int16
	So_options   int16
	So_linger    int16
	So_state     int16
	So_pcb       uint32
	Xso_protocol int32
	Xso_family   int32
	So_qlen      int16
	So_incqlen   int16
	So_qlimit    int16
	So_timeo     int16
	So_error     uint16
	So_pgid      int32
	So_oobmark   uint32
	So_rcv       XSockbuf

		{8, true, 64, false, func(n int8, s uint64) int8 { return n >> s }},
		{8, false, 64, false, func(n uint8, s uint64) uint8 { return n >> s }},
		{8, true, 32, true, func(n int8, s uint32) int8 { return n << s }},
		{8, true, 32, false, func(n int8, s uint32) int8 { return n >> s }},
		{8, false, 32, false, func(n uint8, s uint32) uint8 { return n >> s }},

	}
	for i := ppc64.REG_VS0; i <= ppc64.REG_VS63; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := ppc64.REG_A0; i <= ppc64.REG_A7; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := ppc64.REG_CR0; i <= ppc64.REG_CR7; i++ {
		register[obj.Rconv(i)] = int16(i)
	}
	for i := ppc64.REG_MSR; i <= ppc64.REG_CR; i++ {
		register[obj.Rconv(i)] = int16(i)
	}

	type ParamVal struct {
		Int int `xml:"int,attr"`
	}

	type ParamPtr struct {
		Int *int `xml:"int,attr"`
	}

	type ParamStringPtr struct {
		Int *string `xml:"int,attr"`
	}

	x := []byte(`<Param int="1" />`)

	p1 := &ParamPtr{}
	if err := Unmarshal(x, p1); err != nil {
		t.Fatalf("Unmarshal: %s", err)
	}
	if p1.Int == nil {