func bitSetTest(x int) bool {
	// amd64:"ANDL\t[$]9, AX"
	// amd64:"CMPQ\tAX, [$]9"
	return x&9 == 9
}

// mask contiguous one bits
func cont1Mask64U(x uint64) uint64 {
	// s390x:"RISBGZ\t[$]16, [$]47, [$]0,"
	return x & 0x0000ffffffff0000
}

// mask contiguous zero bits
func cont0Mask64U(x uint64) uint64 {
	// s390x:"RISBGZ\t[$]48, [$]15, [$]0,"
	return x & 0xffff00000000ffff
}

}

// writeLSB writes the code c for "Least Significant Bits first" data.
func (w *Writer) writeLSB(c uint32) error {
	w.bits |= c << w.nBits
	w.nBits += w.width
	for w.nBits >= 8 {
		if err := w.w.WriteByte(uint8(w.bits)); err != nil {
			return err
		}
		w.bits >>= 8
		w.nBits -= 8
	}
	return nil
}

// writeMSB writes the code c for "Most Significant Bits first" data.
func (w *Writer) writeMSB(c uint32) error {

		{11, 2048 - 1024},
		{12, 4096 - 2048},
	}
	nCodes, nBits := 0, 0
	for _, e := range iterations {
		nCodes += e.n
		nBits += e.n * e.width
	}
	if nCodes != 3839 {
		t.Fatalf("nCodes: got %v, want %v", nCodes, 3839)
	}
	if nBits != 43255 {
		t.Fatalf("nBits: got %v, want %v", nBits, 43255)
	}

	// Construct our input of 43255 zero bits (which gets d.hi and d.width up

// bytes, and throws if it finds an unpinned Go pointer. The gcbits mark each
// pointer value. The src pointer is off bytes into the gcbits.
//
//go:nosplit
//go:nowritebarrier
func cgoCheckBits(src unsafe.Pointer, gcbits *byte, off, size uintptr) {
	skipMask := off / goarch.PtrSize / 8
	skipBytes := skipMask * goarch.PtrSize * 8
	ptrmask := addb(gcbits, skipMask)
	src = add(src, skipBytes)
	off -= skipBytes

}

// setCheckmark throws if marking object is a checkmarks violation,
// and otherwise sets obj's checkmark. It returns true if obj was
// already checkmarked.
func setCheckmark(obj, base, off uintptr, mbits markBits) bool {
	if !mbits.isMarked() {
		printlock()
		print("runtime: checkmarks found unexpected unmarked object obj=", hex(obj), "\n")
		print("runtime: found obj at *(", hex(base), "+", hex(off), ")\n")

	}
}

func genCrc32ConstTable(w *bytes.Buffer, poly uint32, polyid string) {

	ref_poly := reflect_bits(uint64(poly), 32)
	fmt.Fprintf(w, "\n\t/* Reduce %d kbits to 1024 bits */\n", blocking*8)
	j := 0
	for i := (blocking * 8) - 1024; i > 0; i -= 1024 {
		a := reflect_bits(get_remainder(ref_poly, 32, uint(i)), 32) << 1
		b := reflect_bits(get_remainder(ref_poly, 32, uint(i+64)), 32) << 1

		obj, span, objIndex := findObject(ptr, 0, 0)
		if obj == 0 {
			continue
		}
		// TODO: Consider making two passes where the first
		// just prefetches the mark bits.
		mbits := span.markBitsForIndex(objIndex)
		if mbits.isMarked() {
			continue
		}
		mbits.setMarked()

		// Mark span.
		arena, pageIdx, pageMask := pageIndexOf(span.base())
		if arena.pageMarks[pageIdx]&pageMask == 0 {

			}
			return err
		}
		d.bits.a = d.bits.a<<8 | uint32(c)
		d.bits.n += 8
		if d.bits.m == 0 {
			d.bits.m = 1 << 7
		} else {
			d.bits.m <<= 8
		}
		if d.bits.n >= n {
			break
		}
	}
	return nil
}

// receiveExtend is the composition of RECEIVE and EXTEND, specified in section
// F.2.2.1.
func (d *decoder) receiveExtend(t uint8) (int32, error) {
	if d.bits.n < int32(t) {

	var p Bits
	for _, x := range x {
		for _, y := range y {
			p = append(p, x+y)
		}
	}
	return p
}

func TestMulBits(t *testing.T) {
	for _, test := range []struct {
		x, y, want Bits
	}{
		{nil, nil, nil},
		{Bits{}, Bits{}, nil},
		{Bits{0}, Bits{0}, Bits{0}},
		{Bits{0}, Bits{1}, Bits{1}},
		{Bits{1}, Bits{1, 2, 3}, Bits{2, 3, 4}},
		{Bits{-1}, Bits{1}, Bits{0}},

		d = a + bits.RotateLeft32((a^b^c)+d+x4+0x4bdecfa9, 11)
		c = d + bits.RotateLeft32((d^a^b)+c+x7+0xf6bb4b60, 16)
		b = c + bits.RotateLeft32((c^d^a)+b+xa+0xbebfbc70, 23)
		a = b + bits.RotateLeft32((b^c^d)+a+xd+0x289b7ec6, 4)
		d = a + bits.RotateLeft32((a^b^c)+d+x0+0xeaa127fa, 11)
		c = d + bits.RotateLeft32((d^a^b)+c+x3+0xd4ef3085, 16)
		b = c + bits.RotateLeft32((c^d^a)+b+x6+0x04881d05, 23)