func newShake128Asm() ShakeHash {
	if cpu.S390X.HasSHA3 {
		return newAsmState(shake_128)
	}
	return nil
}
newShake128Asm returns an assembly implementation of SHAKE-128 if available,
otherwise it returns nil.
package sha3
import (
	"hash"
	"golang.org/x/sys/cpu"
)
type code uint64
const (
	sha3_224  code = 32
	sha3_256       = 33
	sha3_384       = 34
	sha3_512       = 35
	shake_128      = 36
	shake_256      = 37
	nopad          = 0x100
)
func kimd(function code, chain *[200]byte, src []byte)
func klmd(function code, chain *[200]byte, dst, src []byte)
type asmState struct {
	a         [200]byte        
	buf       []byte           
	rate      int              
	storage   [3072]byte       
	outputLen int              
	function  code             
	state     spongeDirection  
}
func newAsmState(function code) *asmState {
	var s asmState
	s.function = function
	switch function {
	case sha3_224:
		s.rate = 144
		s.outputLen = 28
	case sha3_256:
		s.rate = 136
		s.outputLen = 32
	case sha3_384:
		s.rate = 104
		s.outputLen = 48
	case sha3_512:
		s.rate = 72
		s.outputLen = 64
	case shake_128:
		s.rate = 168
	case shake_256:
		s.rate = 136
	default:
		panic("sha3: unrecognized function code")
	}
	s.resetBuf()
	return &s
}
func (s *asmState) clone() *asmState {
	c := *s
	c.buf = c.storage[:len(s.buf):cap(s.buf)]
	return &c
}
func (s *asmState) copyIntoBuf(b []byte) {
	bufLen := len(s.buf)
	s.buf = s.buf[:len(s.buf)+len(b)]
	copy(s.buf[bufLen:], b)
}
func (s *asmState) resetBuf() {
	max := (cap(s.storage) / s.rate) * s.rate
	s.buf = s.storage[:0:max]
}
func (s *asmState) Write(b []byte) (int, error) {
	if s.state != spongeAbsorbing {
		panic("sha3: write to sponge after read")
	}
	length := len(b)
	for len(b) > 0 {
		if len(s.buf) == 0 && len(b) >= cap(s.buf) {
			remainder := len(s.buf) % s.rate
			kimd(s.function, &s.a, b[:len(b)-remainder])
			if remainder != 0 {
				s.copyIntoBuf(b[len(b)-remainder:])
			}
			return length, nil
		}
		if len(s.buf) == cap(s.buf) {
			kimd(s.function, &s.a, s.buf)
			s.buf = s.buf[:0]
		}
		n := len(b)
		if len(b) > cap(s.buf)-len(s.buf) {
			n = cap(s.buf) - len(s.buf)
		}
		s.copyIntoBuf(b[:n])
		b = b[n:]
	}
	return length, nil
}
func (s *asmState) Read(out []byte) (n int, err error) {
	n = len(out)
	if s.state == spongeAbsorbing {
		s.state = spongeSqueezing
		if len(out)%s.rate == 0 {
			klmd(s.function, &s.a, out, s.buf)  
			s.buf = s.buf[:0]
			return
		}
		max := cap(s.buf)
		if max > len(out) {
			max = (len(out)/s.rate)*s.rate + s.rate
		}
		klmd(s.function, &s.a, s.buf[:max], s.buf)
		s.buf = s.buf[:max]
	}
	for len(out) > 0 {
		if len(s.buf) != 0 {
			c := copy(out, s.buf)
			out = out[c:]
			s.buf = s.buf[c:]
			continue
		}
		if len(out)%s.rate == 0 {
			klmd(s.function|nopad, &s.a, out, nil)
			return
		}
		s.resetBuf()
		if cap(s.buf) > len(out) {
			s.buf = s.buf[:(len(out)/s.rate)*s.rate+s.rate]
		}
		klmd(s.function|nopad, &s.a, s.buf, nil)
	}
	return
}
func (s *asmState) Sum(b []byte) []byte {
	if s.outputLen == 0 {
		panic("sha3: cannot call Sum on SHAKE functions")
	}
	a := s.a
	klmd(s.function, &a, nil, s.buf)
	return append(b, a[:s.outputLen]...)
}
func (s *asmState) Reset() {
	for i := range s.a {
		s.a[i] = 0
	}
	s.resetBuf()
	s.state = spongeAbsorbing
}
func (s *asmState) Size() int {
	return s.outputLen
}
func (s *asmState) BlockSize() int {
	return s.rate
}
func (s *asmState) Clone() ShakeHash {
	return s.clone()
}
func new224Asm() hash.Hash {
	if cpu.S390X.HasSHA3 {
		return newAsmState(sha3_224)
	}
	return nil
}
func new256Asm() hash.Hash {
	if cpu.S390X.HasSHA3 {
		return newAsmState(sha3_256)
	}
	return nil
}
func new384Asm() hash.Hash {
	if cpu.S390X.HasSHA3 {
		return newAsmState(sha3_384)
	}
	return nil
}
func new512Asm() hash.Hash {
	if cpu.S390X.HasSHA3 {
		return newAsmState(sha3_512)
	}
	return nil
}