}
	if tp.typ == nil {
		// Handle small objects.
		// Clear any bits before the target address.
		tp.mask &^= (1 << ((target - tp.addr) / goarch.PtrSize)) - 1
		// Clear any bits past the limit.
		if tp.addr+goarch.PtrSize*ptrBits > limit {
			bits := (tp.addr + goarch.PtrSize*ptrBits - limit) / goarch.PtrSize
			tp.mask &^= ((1 << (bits)) - 1) << (ptrBits - bits)
		}
		return tp
	}

	// Move up elem and addr.

	_ = x[len(z)-1] // bounds check elimination hint
	for i := range z {
		hi, lo := bits.Mul(x[i], y)
		lo, c := bits.Add(lo, z[i], 0)
		// We use bits.Add with zero to get an add-with-carry instruction that
		// absorbs the carry from the previous bits.Add.
		hi, _ = bits.Add(hi, 0, c)
		lo, c = bits.Add(lo, carry, 0)
		hi, _ = bits.Add(hi, 0, c)
		carry = hi
		z[i] = lo
	}
	return carry
}

	}
	fmt.Fprintf(w, "\n")

	fmt.Fprintf(w, "// %-9s  %-4s  %-12s\n", "alignment", "bits", "min obj size")
	for bits, size := range minAligns {
		if size == 0 {
			break
		}
		if bits+1 < len(minAligns) && size == minAligns[bits+1] {
			continue
		}
		fmt.Fprintf(w, "// %9d  %4d  %12d\n", 1<<bits, bits, size)
	}
	fmt.Fprintf(w, "\n")
}

func maxObjsPerSpan(classes []class) int {
	most := 0

// It does not allocate. Unlike [Addr.Prefix], [PrefixFrom] does not mask
// off the host bits of ip.
//
// If bits is less than zero or greater than ip.BitLen, [Prefix.Bits]
// will return an invalid value -1.
func PrefixFrom(ip Addr, bits int) Prefix {
	var bitsPlusOne uint8
	if !ip.isZero() && bits >= 0 && bits <= ip.BitLen() {
		bitsPlusOne = uint8(bits) + 1
	}
	return Prefix{
		ip:          ip.withoutZone(),

	return p
}

// CIDRMask returns an [IPMask] consisting of 'ones' 1 bits
// followed by 0s up to a total length of 'bits' bits.
// For a mask of this form, CIDRMask is the inverse of [IPMask.Size].
func CIDRMask(ones, bits int) IPMask {
	if bits != 8*IPv4len && bits != 8*IPv6len {
		return nil
	}
	if ones < 0 || ones > bits {
		return nil
	}
	l := bits / 8
	m := make(IPMask, l)
	n := uint(ones)
	for i := 0; i < l; i++ {

	//
	// We want to compute
	// 	hi, lo := bits.Mul64(r.Uint64(), n)
	// In terms of 32-bit halves, this is:
	// 	x1:x0 := r.Uint64()
	// 	0:hi, lo1:lo0 := bits.Mul64(x1:x0, 0:n)
	// Writing out the multiplication in terms of bits.Mul32 allows
	// using direct hardware instructions and avoiding
	// the computations involving these zeros.
	x := r.Uint64()
	lo1a, lo0 := bits.Mul32(uint32(x), n)

			if err != nil {
				t.Fatal(err)
			}
			if prefix.Addr() != test.ip {
				t.Errorf("IP=%s, want %s", prefix.Addr(), test.ip)
			}
			if prefix.Bits() != test.bits {
				t.Errorf("bits=%d, want %d", prefix.Bits(), test.bits)
			}
			for _, ip := range test.contains {
				if !prefix.Contains(ip) {
					t.Errorf("does not contain %s", ip)
				}
			}

		return nil, errors.New("edwards25519: invalid field element input size")
	}

	// Bits 0:51 (bytes 0:8, bits 0:64, shift 0, mask 51).
	v.l0 = byteorder.LeUint64(x[0:8])
	v.l0 &= maskLow51Bits
	// Bits 51:102 (bytes 6:14, bits 48:112, shift 3, mask 51).
	v.l1 = byteorder.LeUint64(x[6:14]) >> 3
	v.l1 &= maskLow51Bits
	// Bits 102:153 (bytes 12:20, bits 96:160, shift 6, mask 51).
	v.l2 = byteorder.LeUint64(x[12:20]) >> 6

}

func parseBase128Int(bytes []byte, initOffset int) (ret, offset int, failed bool) {
	offset = initOffset
	var ret64 int64
	for shifted := 0; offset < len(bytes); shifted++ {
		// 5 * 7 bits per byte == 35 bits of data
		// Thus the representation is either non-minimal or too large for an int32
		if shifted == 5 {
			failed = true
			return
		}
		ret64 <<= 7
		b := bytes[offset]

					name = fmt.Sprintf("%dM", size/1e6)
				}
				b.Run("size="+name, func(b *testing.B) {
					for _, bits := range []int{32, 64} {
						if ^uint(0) == 0xffffffff && bits == 64 {
							continue
						}
						b.Run(fmt.Sprintf("bits=%d", bits), func(b *testing.B) {
							cleanup := setBits(bits)
							defer cleanup()

							b.SetBytes(int64(len(data)))
							b.ReportAllocs()