in      string
		want    uint64
		wantErr string
	}
	tests := []testCase{
		{"x", 0, "invalid byte in chunk length"},
		{"0000000000000000", 0, ""},
		{"0000000000000001", 1, ""},
		{"ffffffffffffffff", 1<<64 - 1, ""},
		{"000000000000bogus", 0, "invalid byte in chunk length"},
		{"00000000000000000", 0, "http chunk length too large"}, // could accept if we wanted
		{"10000000000000000", 0, "http chunk length too large"},

	a.d[0] = '1'
	a.nd = 1
	a.dp++
}

// Extract integer part, rounded appropriately.
// No guarantees about overflow.
func (a *decimal) RoundedInteger() uint64 {
	if a.dp > 20 {
		return 0xFFFFFFFFFFFFFFFF
	}
	var i int
	n := uint64(0)
	for i = 0; i < a.dp && i < a.nd; i++ {
		n = n*10 + uint64(a.d[i]-'0')
	}
	for ; i < a.dp; i++ {
		n *= 10
	}
	if shouldRoundUp(a, a.dp) {
		n++
	}

DATA shuff_00BA<>+0x08(SB)/8, $0xFFFFFFFFFFFFFFFF
DATA shuff_00BA<>+0x10(SB)/8, $0x0b0a090803020100
DATA shuff_00BA<>+0x18(SB)/8, $0xFFFFFFFFFFFFFFFF
GLOBL shuff_00BA<>(SB), 8, $32

// shuffle xDxC -> DC00
DATA shuff_DC00<>+0x00(SB)/8, $0xFFFFFFFFFFFFFFFF
DATA shuff_DC00<>+0x08(SB)/8, $0x0b0a090803020100
DATA shuff_DC00<>+0x10(SB)/8, $0xFFFFFFFFFFFFFFFF
DATA shuff_DC00<>+0x18(SB)/8, $0x0b0a090803020100

	a[0] = x ^ (y ^ 0xffffffff)

	// arm64:`EON\t`,-`EOR`,-`MVN`
	a[1] = ^(y ^ z)

	// arm64:`EON\t`,-`XOR`
	a[2] = x ^ ^z

	// arm64:`EON\t`,-`EOR`,-`MVN`
	return n ^ (m ^ 0xffffffffffffffff)
}

func op_orn(x, y uint32) uint32 {
	// arm64:`ORN\t`,-`ORR`
	return x | ^y
}

// check bitsets
func bitSetPowerOf2Test(x int) bool {
	// amd64:"BTL\t[$]3"
	return x&8 == 8
}

DATA ·andMask<>+0x68(SB)/8, $0x0000000000000000
DATA ·andMask<>+0x70(SB)/8, $0xffffffffffffffff
DATA ·andMask<>+0x78(SB)/8, $0x0000000000000000
DATA ·andMask<>+0x80(SB)/8, $0xffffffffffffffff
DATA ·andMask<>+0x88(SB)/8, $0x00000000000000ff
DATA ·andMask<>+0x90(SB)/8, $0xffffffffffffffff
DATA ·andMask<>+0x98(SB)/8, $0x000000000000ffff
DATA ·andMask<>+0xa0(SB)/8, $0xffffffffffffffff
DATA ·andMask<>+0xa8(SB)/8, $0x0000000000ffffff

type op struct {
	name, symbol string
}
type szD struct {
	name string
	sn   string
	u    []uint64
	i    []int64
}

var szs []szD = []szD{
	szD{name: "uint64", sn: "64", u: []uint64{0, 1, 4294967296, 0xffffFFFFffffFFFF}},
	szD{name: "int64", sn: "64", i: []int64{-0x8000000000000000, -0x7FFFFFFFFFFFFFFF,
		-4294967296, -1, 0, 1, 4294967296, 0x7FFFFFFFFFFFFFFE, 0x7FFFFFFFFFFFFFFF}},

func select64(v, x, y uint64) uint64 { return ^(v-1)&x | (v-1)&y }

// [p0, p1, p2] is 2¹³⁰ - 5 in little endian order.
const (
	p0 = 0xFFFFFFFFFFFFFFFB
	p1 = 0xFFFFFFFFFFFFFFFF
	p2 = 0x0000000000000003
)

// finalize completes the modular reduction of h and computes
//
//	out = h + s  mod  2¹²⁸
func finalize(out *[TagSize]byte, h *[3]uint64, s *[2]uint64) {

	{"%#v", new(byte), "(*uint8)(0xPTR)"},
	{"%#v", TestFmtInterface, "(func(*testing.T))(0xPTR)"},
	{"%#v", make(chan int), "(chan int)(0xPTR)"},
	{"%#v", uint64(1<<64 - 1), "0xffffffffffffffff"},
	{"%#v", 1000000000, "1000000000"},
	{"%#v", map[string]int{"a": 1}, `map[string]int{"a":1}`},
	{"%#v", map[string]B{"a": {1, 2}}, `map[string]fmt_test.B{"a":fmt_test.B{I:1, j:2}}`},

DATA p256ord<>+0x00(SB)/8, $0xffffffff00000000
DATA p256ord<>+0x08(SB)/8, $0xffffffffffffffff
DATA p256ord<>+0x10(SB)/8, $0xbce6faada7179e84
DATA p256ord<>+0x18(SB)/8, $0xf3b9cac2fc632551
DATA p256<>+0x00(SB)/8, $0xffffffff00000001 // P256
DATA p256<>+0x08(SB)/8, $0x0000000000000000 // P256
DATA p256<>+0x10(SB)/8, $0x00000000ffffffff // P256
DATA p256<>+0x18(SB)/8, $0xffffffffffffffff // P256
DATA p256<>+0x20(SB)/8, $0x0c0d0e0f1c1d1e1f // SEL d1 d0 d1 d0

// systems. We will see.

var faultAddrs = []uint64{
	// low addresses
	0,
	1,
	0xfff,
	// high (kernel) addresses
	// or else malformed.
	0xffffffffffffffff,
	0xfffffffffffff001,
	0xffffffffffff0001,
	0xfffffffffff00001,
	0xffffffffff000001,
	0xfffffffff0000001,
	0xffffffff00000001,
	0xfffffff000000001,
	0xffffff0000000001,
	0xfffff00000000001,