volk_8u_conv_k7_r2puppet_8u.h

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#ifndef INCLUDED_volk_8u_conv_k7_r2puppet_8u_H
#define INCLUDED_volk_8u_conv_k7_r2puppet_8u_H

#include <volk/volk.h>
#include <volk/volk_8u_x4_conv_k7_r2_8u.h>

typedef union {
  //decision_t is a BIT vector
  unsigned char* t;
  unsigned int* w;
} p_decision_t;

static inline int parity(int x, unsigned char* Partab)
{
  x ^= (x >> 16);
  x ^= (x >> 8);
  return Partab[x];
}

static inline int chainback_viterbi(unsigned char* data,
                                    unsigned int nbits,
                                    unsigned int endstate,
                                    unsigned int tailsize,
                                    unsigned char* decisions)
{
  unsigned char* d;
  int d_ADDSHIFT = 0;
  int d_numstates = (1 << 6);
  int d_decision_t_size = d_numstates/8;
  unsigned int d_k = 7;
  int d_framebits = nbits;
  /* ADDSHIFT and SUBSHIFT make sure that the thing returned is a byte. */
  d = decisions;
  /* Make room beyond the end of the encoder register so we can
   * accumulate a full byte of decoded data
   */

  endstate = (endstate%d_numstates) << d_ADDSHIFT;

  /* The store into data[] only needs to be done every 8 bits.
   * But this avoids a conditional branch, and the writes will
   * combine in the cache anyway
   */

  d += tailsize * d_decision_t_size ; /* Look past tail */
  int retval;
  int dif = tailsize - (d_k - 1);
  //printf("break, %d, %d\n", dif, (nbits+dif)%d_framebits);
  p_decision_t dec;
  while(nbits-- > d_framebits - (d_k - 1)) {
    int k;
    dec.t =  &d[nbits * d_decision_t_size];
    k = (dec.w[(endstate>>d_ADDSHIFT)/32] >> ((endstate>>d_ADDSHIFT)%32)) & 1;

    endstate = (endstate >> 1) | (k << (d_k-2+d_ADDSHIFT));
    //data[((nbits+dif)%nbits)>>3] = endstate>>d_SUBSHIFT;
    //printf("%d, %d\n", k, (nbits+dif)%d_framebits);
    data[((nbits+dif)%d_framebits)] = k;

    retval = endstate;
  }
  nbits += 1;

  while(nbits-- != 0) {
    int k;

    dec.t = &d[nbits * d_decision_t_size];

    k = (dec.w[(endstate>>d_ADDSHIFT)/32] >> ((endstate>>d_ADDSHIFT)%32)) & 1;

    endstate = (endstate >> 1) | (k << (d_k-2+d_ADDSHIFT));
    data[((nbits+dif)%d_framebits)] = k;
  }
  //printf("%d, %d, %d, %d, %d, %d, %d, %d\n", data[4095],data[4094],data[4093],data[4092],data[4091],data[4090],data[4089],data[4088]);


  return retval >> d_ADDSHIFT;
}


#if LV_HAVE_SSE3

#include <pmmintrin.h>
#include <emmintrin.h>
#include <xmmintrin.h>
#include <mmintrin.h>
#include <stdio.h>





static inline void volk_8u_conv_k7_r2puppet_8u_spiral(unsigned char* syms, unsigned char* dec, unsigned int framebits) {


  static int once = 1;
  int d_numstates = (1 << 6);
  int rate = 2;
  static unsigned char* D;
  static unsigned char* Y;
  static unsigned char* X;
  static unsigned int excess = 6;
  static unsigned char* Branchtab;
  static unsigned char Partab[256];

  int d_polys[2] = {79, 109};


  if(once) {

    X = (unsigned char*)volk_malloc(2*d_numstates, volk_get_alignment());
    Y = X + d_numstates;
    Branchtab = (unsigned char*)volk_malloc(d_numstates/2*rate, volk_get_alignment());
    D = (unsigned char*)volk_malloc((d_numstates/8) * (framebits + 6), volk_get_alignment());
    int state, i;
    int cnt,ti;

    /* Initialize parity lookup table */
    for(i=0;i<256;i++){
      cnt = 0;
      ti = i;
      while(ti){
        if(ti & 1)
          cnt++;
        ti >>= 1;
      }
      Partab[i] = cnt & 1;
    }
    /*  Initialize the branch table */
    for(state=0;state < d_numstates/2;state++){
      for(i=0; i<rate; i++){
        Branchtab[i*d_numstates/2+state] = (d_polys[i] < 0) ^ parity((2*state) & abs(d_polys[i]), Partab) ? 255 : 0;
      }
    }

    once = 0;
  }

    //unbias the old_metrics
  memset(X, 31, d_numstates);

  volk_8u_x4_conv_k7_r2_8u_spiral(Y, X, syms, D, framebits/2 - excess, excess, Branchtab);

  unsigned int min = X[0];
  int i = 0, state = 0;
  for(i = 0; i < (d_numstates); ++i) {
    if(X[i] < min) {
      min = X[i];
      state = i;
    }
  }

  chainback_viterbi(dec, framebits/2 -excess, state, excess, D);

  return;
}

#endif /*LV_HAVE_SSE3*/





#if LV_HAVE_GENERIC


static inline void volk_8u_conv_k7_r2puppet_8u_generic(unsigned char* syms, unsigned char* dec, unsigned int framebits) {



  static int once = 1;
  int d_numstates = (1 << 6);
  int rate = 2;
  static unsigned char* Y;
  static unsigned char* X;
  static unsigned char* D;
  static unsigned int excess = 6;
  static unsigned char* Branchtab;
  static unsigned char Partab[256];

  int d_polys[2] = {79, 109};


  if(once) {

    X = (unsigned char*)volk_malloc(2*d_numstates, volk_get_alignment());
    Y = X + d_numstates;
    Branchtab = (unsigned char*)volk_malloc(d_numstates/2*rate, volk_get_alignment());
    D = (unsigned char*)volk_malloc((d_numstates/8) * (framebits + 6), volk_get_alignment());

    int state, i;
    int cnt,ti;

    /* Initialize parity lookup table */
    for(i=0;i<256;i++){
      cnt = 0;
      ti = i;
      while(ti){
        if(ti & 1)
          cnt++;
        ti >>= 1;
      }
      Partab[i] = cnt & 1;
    }
    /*  Initialize the branch table */
    for(state=0;state < d_numstates/2;state++){
      for(i=0; i<rate; i++){
        Branchtab[i*d_numstates/2+state] = (d_polys[i] < 0) ^ parity((2*state) & abs(d_polys[i]), Partab) ? 255 : 0;
      }
    }

    once = 0;
  }




    //unbias the old_metrics
  memset(X, 31, d_numstates);

  volk_8u_x4_conv_k7_r2_8u_generic(Y, X, syms, D, framebits/2 - excess, excess, Branchtab);

  unsigned int min = X[0];
  int i = 0, state = 0;
  for(i = 0; i < (d_numstates); ++i) {
    if(X[i] < min) {
      min = X[i];
      state = i;
    }
  }

  chainback_viterbi(dec, framebits/2 -excess, state, excess, D);

  return;


}

#endif /* LV_HAVE_GENERIC */

#endif /*INCLUDED_volk_8u_conv_k7_r2puppet_8u_H*/