for ; c >= npattern; c -= npattern {
				bits |= pattern << nbits
				nbits += npattern
				for nbits >= 8 {
					*dst = uint8(bits)
					dst = add1(dst)
					bits >>= 8
					nbits -= 8
				}
			}

			// Add final fragment to bit buffer.
			if c > 0 {
				pattern &= 1<<c - 1
				bits |= pattern << nbits
				nbits += c
			}
			continue Run
		}

		me = 32 - bits.TrailingZeros32(uint32(mask))
		mbn = bits.LeadingZeros32(^uint32(mask))
		men = 32 - bits.TrailingZeros32(^uint32(mask))
	} else {
		mb = bits.LeadingZeros64(uint64(mask))
		me = 64 - bits.TrailingZeros64(uint64(mask))
		mbn = bits.LeadingZeros64(^uint64(mask))
		men = 64 - bits.TrailingZeros64(^uint64(mask))
	}
	// Check for a wrapping mask (e.g bits at 0 and 63)

// immIFits checks whether the immediate value x fits in nbits bits
// as a signed integer. If it does not, an error is returned.
func immIFits(x int64, nbits uint) error {
	nbits--
	min := int64(-1) << nbits
	max := int64(1)<<nbits - 1
	if x < min || x > max {
		if nbits <= 16 {
			return fmt.Errorf("signed immediate %d must be in range [%d, %d] (%d bits)", x, min, max, nbits)
		}

// addition/subtraction of arguments represented by Bits values with the
// respective Float addition/subtraction for a variety of precisions
// and rounding modes.
func TestFloatAdd(t *testing.T) {
	for _, xbits := range bitsList {
		for _, ybits := range bitsList {
			// exact values
			x := xbits.Float()
			y := ybits.Float()
			zbits := xbits.add(ybits)
			z := zbits.Float()

	// base and extent.
	b := b0
	n := n0

	for i := uintptr(0); i < n; {
		// Find bits for the next word.
		bits := uint32(*addb(ptrmask, i/(goarch.PtrSize*8)))
		if bits == 0 {
			i += goarch.PtrSize * 8
			continue
		}
		for j := 0; j < 8 && i < n; j++ {
			if bits&1 != 0 {
				// Same work as in scanobject; see comments there.
				p := *(*uintptr)(unsafe.Pointer(b + i))

			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)
				}
			}

		// insert low width bits of arg0 into the result starting at bit lsb, bits to the left of the inserted bit field are set to the high/sign bit of the inserted bit field, bits to the right are zeroed
		{name: "SBFIZ", argLength: 1, reg: gp11, asm: "SBFIZ", aux: "ARM64BitField"},
		// extract width bits of arg0 starting at bit lsb and insert at low end of result, remaining high bits are set to the high/sign bit of the extracted bitfield

	// heapAddrBits is the number of bits in a heap address. On
	// amd64, addresses are sign-extended beyond heapAddrBits. On
	// other arches, they are zero-extended.
	//
	// On most 64-bit platforms, we limit this to 48 bits based on a
	// combination of hardware and OS limitations.
	//
	// amd64 hardware limits addresses to 48 bits, sign-extended
	// to 64 bits. Addresses where the top 16 bits are not either

		Response:           (h.bits & headerBitQR) != 0,
		OpCode:             OpCode(h.bits>>11) & 0xF,
		Authoritative:      (h.bits & headerBitAA) != 0,
		Truncated:          (h.bits & headerBitTC) != 0,
		RecursionDesired:   (h.bits & headerBitRD) != 0,
		RecursionAvailable: (h.bits & headerBitRA) != 0,
		AuthenticData:      (h.bits & headerBitAD) != 0,
		CheckingDisabled:   (h.bits & headerBitCD) != 0,

	// that group was all zero in the original x.

	// From each group of m bits subtract 1.
	// Because we know only the top bits of each
	// m-aligned group are set, we know this will
	// set each group to have all the bits set except
	// the top bit, so just OR with the original
	// result to set all the bits.
	return ^((x - (x >> (m - 1))) | x)
}