child_tid  unsafe.Pointer // *int64
	parent_tid *int64
	flags      int32
	pad_cgo_0  [4]byte
	rtp        *rtprio
	spare      [3]uintptr
}

type thread int64 // long

type sigset struct {
	__bits [4]uint32
}

type stackt struct {
	ss_sp     uintptr
	ss_size   uintptr
	ss_flags  int32
	pad_cgo_0 [4]byte
}

type siginfo struct {
	si_signo  int32
	si_errno  int32

	child_tid  unsafe.Pointer // *int64
	parent_tid *int64
	flags      int32
	pad_cgo_0  [4]byte
	rtp        *rtprio
	spare      [3]uintptr
}

type thread int64 // long

type sigset struct {
	__bits [4]uint32
}

type stackt struct {
	ss_sp     uintptr
	ss_size   uintptr
	ss_flags  int32
	pad_cgo_0 [4]byte
}

type siginfo struct {
	si_signo  int32
	si_errno  int32

//go:nosplit
func setSignalstackSP(s *stackt, sp uintptr) {
	s.ss_sp = sp
}

//go:nosplit
//go:nowritebarrierrec
func sigaddset(mask *sigset, i int) {
	mask.__bits[(i-1)/32] |= 1 << ((uint32(i) - 1) & 31)
}

func sigdelset(mask *sigset, i int) {
	mask.__bits[(i-1)/32] &^= 1 << ((uint32(i) - 1) & 31)
}

//go:nosplit
func (c *sigctxt) fixsigcode(sig uint32) {
}

func setProcessCPUProfiler(hz int32) {

//go:nosplit
func setSignalstackSP(s *stackt, sp uintptr) {
	s.ss_sp = sp
}

//go:nosplit
//go:nowritebarrierrec
func sigaddset(mask *sigset, i int) {
	mask.__bits[(i-1)/32] |= 1 << ((uint32(i) - 1) & 31)
}

func sigdelset(mask *sigset, i int) {
	mask.__bits[(i-1)/32] &^= 1 << ((uint32(i) - 1) & 31)
}

//go:nosplit
func (c *sigctxt) fixsigcode(sig uint32) {
}

func setProcessCPUProfiler(hz int32) {

	// cur is the bit buffer that has not been fed into n.
	// cbits is the number of low order bits in cur that are valid.
	// sbits is the number of bits of the symbol prefix being decoded.
	cur, cbits, sbits := uint(0), uint8(0), uint8(0)
	for _, b := range v {
		cur = cur<<8 | uint(b)
		cbits += 8
		sbits += 8
		for cbits >= 8 {
			idx := byte(cur >> (cbits - 8))
			n = n.children[idx]
			if n == nil {

func test32(a, b float32) {
	abits := math.Float32bits(a)
	bbits := math.Float32bits(b)
	if abits != bbits {
		panic(fmt.Sprintf("%08x != %08x\n", abits, bbits))
	}
}

func test64(a, b float64) {
	abits := math.Float64bits(a)
	bbits := math.Float64bits(b)
	if abits != bbits {
		panic(fmt.Sprintf("%016x != %016x\n", abits, bbits))
	}

// 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()

		f := &instFormats[i]
		if xNoCond&(f.mask|condMask) != f.value || f.priority <= priority {
			continue
		}
		delta := uint32(0)
		deltaShift := uint(0)
		for opBits := f.opBits; opBits != 0; opBits >>= 16 {
			n := uint(opBits & 0xFF)
			off := uint((opBits >> 8) & 0xFF)
			delta |= (x >> off) & (1<<n - 1) << deltaShift
			deltaShift += n
		}
		op := f.op + Op(delta)

	mgf1XOR(db, hash, h)

	// 11. Set the leftmost 8 * emLen - emBits bits of the leftmost octet in
	//     maskedDB to zero.

	db[0] &= 0xff >> (8*emLen - emBits)

	// 12. Let EM = maskedDB || H || 0xbc.
	em[emLen-1] = 0xbc

	// 13. Output EM.
	return em, nil
}

func emsaPSSVerify(mHash, em []byte, emBits, sLen int, hash hash.Hash) error {
	// See RFC 8017, Section 9.1.2.

}

// emit emits the least significant nBits bits of bits to the bit-stream.
// The precondition is bits < 1<<nBits && nBits <= 16.
func (e *encoder) emit(bits, nBits uint32) {
	nBits += e.nBits
	bits <<= 32 - nBits
	bits |= e.bits
	for nBits >= 8 {
		b := uint8(bits >> 24)
		e.writeByte(b)
		if b == 0xff {
			e.writeByte(0x00)
		}
		bits <<= 8
		nBits -= 8
	}
	e.bits, e.nBits = bits, nBits
}