rri2i4 = rri2i3 + MSIZE;

 /*-----------------------------------------------------------------------*
  * Chose the sign of the impulse.                                        *
  *-----------------------------------------------------------------------*/

   for (i=0; i<L_SUBFR; i++)
   {
     if (dn[i] >= 0)
     {
       sign_dn[i] = MAX_16;
       sign_dn_inv[i] = MIN_16;
     }
     else
     {
       sign_dn[i] = MIN_16;
       sign_dn_inv[i] = MAX_16;
       dn[i] = negate(dn[i]);
     }
   }

 /*-------------------------------------------------------------------*
  * Modification of rrixiy[] to take signs into account.              *
  *-------------------------------------------------------------------*/

  p0 = rri0i1;
  p1 = rri0i2;
  p2 = rri0i3;
  p3 = rri0i4;

  for(i0=0; i0<L_SUBFR; i0+=STEP)
  {
    psign = sign_dn;
    if (psign[i0] < 0) psign = sign_dn_inv;

    for(i1=1; i1<L_SUBFR; i1+=STEP)
    {
      *p0++ = mult(*p0, psign[i1]);
      *p1++ = mult(*p1, psign[i1+1]);
      *p2++ = mult(*p2, psign[i1+2]);
      *p3++ = mult(*p3, psign[i1+3]);
    }
  }

  p0 = rri1i2;
  p1 = rri1i3;
  p2 = rri1i4;

  for(i1=1; i1<L_SUBFR; i1+=STEP)
  {
    psign = sign_dn;
    if (psign[i1] < 0) psign = sign_dn_inv;

    for(i2=2; i2<L_SUBFR; i2+=STEP)
    {
      *p0++ = mult(*p0, psign[i2]);
      *p1++ = mult(*p1, psign[i2+1]);
      *p2++ = mult(*p2, psign[i2+2]);
    }
  }

  p0 = rri2i3;
  p1 = rri2i4;

  for(i2=2; i2<L_SUBFR; i2+=STEP)
  {
    psign = sign_dn;
    if (psign[i2] < 0) psign = sign_dn_inv;

    for(i3=3; i3<L_SUBFR; i3+=STEP)
    {
      *p0++ = mult(*p0, psign[i3]);
      *p1++ = mult(*p1, psign[i3+1]);
    }
  }


 /*-------------------------------------------------------------------*
  * Search the optimum positions of the four pulses which maximize    *
  *     square(correlation) / energy                                  *
  *-------------------------------------------------------------------*/

  psk = -1;
  alpk = 1;

  ptr_rri0i3_i4 = rri0i3;
  ptr_rri1i3_i4 = rri1i3;
  ptr_rri2i3_i4 = rri2i3;
  ptr_rri3i3_i4 = rri3i3;

  /* Initializations only to remove warning from some compilers */

  ip0=0; ip1=1; ip2=2; ip3=3; ix=0; iy=0; ps=0;

  /* search 2 times: track 3 and 4 */
  for (track=3, trk=0; track<5; track++, trk++)
  {
   /*------------------------------------------------------------------*
    * depth first search 3, phase A: track 2 and 3/4.                  *
    *------------------------------------------------------------------*/

    sq = -1;
    alp = 1;

    /* i0 loop: 2 positions in track 2 */

    prev_i0  = -1;

    for (i=0; i<2; i++)
    {
      max = -1;
      /* search "dn[]" maximum position in track 2 */
      for (j=2; j<L_SUBFR; j+=STEP)
      {
        if ((sub(dn[j], max) > 0) && (sub(prev_i0,j) != 0))
        {
          max = dn[j];
          i0 = j;
        }
      }
      prev_i0 = i0;

      j = mult(i0, 6554);        /* j = i0/5 */
      p0 = rri2i2 + j;

      ps1 = dn[i0];
      alp1 = L_mult(*p0, _1_4);

      /* i1 loop: 8 positions in track 2 */

      p0 = ptr_rri2i3_i4 + shl(j, 3);
      p1 = ptr_rri3i3_i4;

      for (i1=track; i1<L_SUBFR; i1+=STEP)
      {
        ps2 = add(ps1, dn[i1]);       /* index increment = STEP */

        /* alp1 = alp0 + rr[i0][i1] + 1/2*rr[i1][i1]; */
        alp2 = L_mac(alp1, *p0++, _1_2);
        alp2 = L_mac(alp2, *p1++, _1_4);

        sq2 = mult(ps2, ps2);
        alp_16 = round(alp2);

        s = L_msu(L_mult(alp,sq2),sq,alp_16);
        if (s > 0)
        {
          sq = sq2;
          ps = ps2;
          alp = alp_16;
          ix = i0;
          iy = i1;
        }
      }
    }

    i0 = ix;
    i1 = iy;
    i1_offset = shl(mult(i1, 6554), 3);       /* j = 8*(i1/5) */

   /*------------------------------------------------------------------*
    * depth first search 3, phase B: track 0 and 1.                    *
    *------------------------------------------------------------------*/

    ps0 = ps;
    alp0 = L_mult(alp, _1_4);

    sq = -1;
    alp = 1;

    /* build vector for next loop to decrease complexity */

    p0 = rri1i2 + mult(i0, 6554);
    p1 = ptr_rri1i3_i4 + mult(i1, 6554);
    p2 = rri1i1;
    p3 = tmp_vect;

    for (i3=1; i3<L_SUBFR; i3+=STEP)
    {
      /* rrv[i3] = rr[i3][i3] + rr[i0][i3] + rr[i1][i3]; */
      s = L_mult(*p0, _1_4);        p0 += NB_POS;
      s = L_mac(s, *p1, _1_4);      p1 += NB_POS;
      s = L_mac(s, *p2++, _1_8);
      *p3++ = round(s);
    }

    /* i2 loop: 8 positions in track 0 */

    p0 = rri0i2 + mult(i0, 6554);
    p1 = ptr_rri0i3_i4 + mult(i1, 6554);
    p2 = rri0i0;
    p3 = rri0i1;

    for (i2=0; i2<L_SUBFR; i2+=STEP)
    {
      ps1 = add(ps0, dn[i2]);         /* index increment = STEP */

      /* alp1 = alp0 + rr[i0][i2] + rr[i1][i2] + 1/2*rr[i2][i2]; */
      alp1 = L_mac(alp0, *p0, _1_8);       p0 += NB_POS;
      alp1 = L_mac(alp1, *p1, _1_8);       p1 += NB_POS;
      alp1 = L_mac(alp1, *p2++, _1_16);

      /* i3 loop: 8 positions in track 1 */

      p4 = tmp_vect;

      for (i3=1; i3<L_SUBFR; i3+=STEP)
      {
        ps2 = add(ps1, dn[i3]);       /* index increment = STEP */

        /* alp1 = alp0 + rr[i0][i3] + rr[i1][i3] + rr[i2][i3] + 1/2*rr[i3][i3]; */
        alp2 = L_mac(alp1, *p3++, _1_8);
        alp2 = L_mac(alp2, *p4++, _1_2);

        sq2 = mult(ps2, ps2);
        alp_16 = round(alp2);

        s = L_msu(L_mult(alp,sq2),sq,alp_16);
        if (s > 0)
        {
          sq = sq2;
          alp = alp_16;
          ix = i2;
          iy = i3;
        }
      }
    }

   /*----------------------------------------------------------------*
    * depth first search 3: compare codevector with the best case.   *
    *----------------------------------------------------------------*/

    s = L_msu(L_mult(alpk,sq),psk,alp);
    if (s > 0)
    {
      psk = sq;
      alpk = alp;
      ip2 = i0;
      ip3 = i1;
      ip0 = ix;
      ip1 = iy;
    }

   /*------------------------------------------------------------------*
    * depth first search 4, phase A: track 3 and 0.                    *
    *------------------------------------------------------------------*/

    sq = -1;
    alp = 1;

    /* i0 loop: 2 positions in track 3/4 */

    prev_i0  = -1;

    for (i=0; i<2; i++)
    {
      max = -1;
      /* search "dn[]" maximum position in track 3/4 */
      for (j=track; j<L_SUBFR; j+=STEP)
      {
        if ((sub(dn[j], max) > 0) && (sub(prev_i0,j) != 0))
        {
          max = dn[j];
          i0 = j;
        }
      }
      prev_i0 = i0;

      j = mult(i0, 6554);        /* j = i0/5 */
      p0 = ptr_rri3i3_i4 + j;

      ps1 = dn[i0];
      alp1 = L_mult(*p0, _1_4);

      /* i1 loop: 8 positions in track 0 */

      p0 = ptr_rri0i3_i4 + j;
      p1 = rri0i0;

      for (i1=0; i1<L_SUBFR; i1+=STEP)
      {
        ps2 = add(ps1, dn[i1]);       /* index increment = STEP */

        /* alp1 = alp0 + rr[i0][i1] + 1/2*rr[i1][i1]; */
        alp2 = L_mac(alp1, *p0, _1_2);       p0 += NB_POS;
        alp2 = L_mac(alp2, *p1++, _1_4);

        sq2 = mult(ps2, ps2);
        alp_16 = round(alp2);

        s = L_msu(L_mult(alp,sq2),sq,alp_16);
        if (s > 0)
        {
          sq = sq2;
          ps = ps2;
          alp = alp_16;
          ix = i0;
          iy = i1;
        }
      }
    }

    i0 = ix;
    i1 = iy;
    i1_offset = shl(mult(i1, 6554), 3);       /* j = 8*(i1/5) */

   /*------------------------------------------------------------------*
    * depth first search 4, phase B: track 1 and 2.                    *
    *------------------------------------------------------------------*/

    ps0 = ps;
    alp0 = L_mult(alp, _1_4);

    sq = -1;
    alp = 1;

    /* build vector for next loop to decrease complexity */

    p0 = ptr_rri2i3_i4 + mult(i0, 6554);
    p1 = rri0i2 + i1_offset;
    p2 = rri2i2;
    p3 = tmp_vect;

    for (i3=2; i3<L_SUBFR; i3+=STEP)
    {
      /* rrv[i3] = rr[i3][i3] + rr[i0][i3] + rr[i1][i3]; */
      s = L_mult(*p0, _1_4);         p0 += NB_POS;
      s = L_mac(s, *p1++, _1_4);
      s = L_mac(s, *p2++, _1_8);
      *p3++ = round(s);
    }

    /* i2 loop: 8 positions in track 1 */

    p0 = ptr_rri1i3_i4 + mult(i0, 6554);
    p1 = rri0i1 + i1_offset;
    p2 = rri1i1;
    p3 = rri1i2;

    for (i2=1; i2<L_SUBFR; i2+=STEP)
    {
      ps1 = add(ps0, dn[i2]);         /* index increment = STEP */

      /* alp1 = alp0 + rr[i0][i2] + rr[i1][i2] + 1/2*rr[i2][i2]; */
      alp1 = L_mac(alp0, *p0, _1_8);       p0 += NB_POS;
      alp1 = L_mac(alp1, *p1++, _1_8);
      alp1 = L_mac(alp1, *p2++, _1_16);

      /* i3 loop: 8 positions in track 2 */

      p4 = tmp_vect;

      for (i3=2; i3<L_SUBFR; i3+=STEP)
      {
        ps2 = add(ps1, dn[i3]);       /* index increment = STEP */

        /* alp1 = alp0 + rr[i0][i3] + rr[i1][i3] + rr[i2][i3] + 1/2*rr[i3][i3]; */
        alp2 = L_mac(alp1, *p3++, _1_8);
        alp2 = L_mac(alp2, *p4++, _1_2);

        sq2 = mult(ps2, ps2);
        alp_16 = round(alp2);

        s = L_msu(L_mult(alp,sq2),sq,alp_16);
        if (s > 0)
        {
          sq = sq2;
          alp = alp_16;
          ix = i2;
          iy = i3;
        }
      }
    }

   /*----------------------------------------------------------------*
    * depth first search 1: compare codevector with the best case.   *
    *----------------------------------------------------------------*/

    s = L_msu(L_mult(alpk,sq),psk,alp);
    if (s > 0)
    {
      psk = sq;
      alpk = alp;
      ip3 = i0;
      ip0 = i1;
      ip1 = ix;
      ip2 = iy;
    }

  ptr_rri0i3_i4 = rri0i4;
  ptr_rri1i3_i4 = rri1i4;
  ptr_rri2i3_i4 = rri2i4;
  ptr_rri3i3_i4 = rri4i4;

  }


 /* Set the sign of impulses */

 i0 = sign_dn[ip0];
 i1 = sign_dn[ip1];
 i2 = sign_dn[ip2];
 i3 = sign_dn[ip3];

 /* Find the codeword corresponding to the selected positions */


 for(i=0; i<L_SUBFR; i++) {
   cod[i] = 0;
 }

 cod[ip0] = shr(i0, 2);         /* From Q15 to Q13 */
 cod[ip1] = shr(i1, 2);
 cod[ip2] = shr(i2, 2);
 cod[ip3] = shr(i3, 2);

 /* find the filtered codeword */

 for (i = 0; i < ip0; i++) y[i] = 0;

 if(i0 > 0)
   for(i=ip0, j=0; i<L_SUBFR; i++, j++) y[i] = h[j];
 else
   for(i=ip0, j=0; i<L_SUBFR; i++, j++) y[i] = negate(h[j]);

 if(i1 > 0)
   for(i=ip1, j=0; i<L_SUBFR; i++, j++) y[i] = add(y[i], h[j]);
 else
   for(i=ip1, j=0; i<L_SUBFR; i++, j++) y[i] = sub(y[i], h[j]);

 if(i2 > 0)
   for(i=ip2, j=0; i<L_SUBFR; i++, j++) y[i] = add(y[i], h[j]);
 else
   for(i=ip2, j=0; i<L_SUBFR; i++, j++) y[i] = sub(y[i], h[j]);

 if(i3 > 0)
   for(i=ip3, j=0; i<L_SUBFR; i++, j++) y[i] = add(y[i], h[j]);
 else
   for(i=ip3, j=0; i<L_SUBFR; i++, j++) y[i] = sub(y[i], h[j]);

 /* find codebook index;  17-bit address */

 i = 0;
 if(i0 > 0) i = add(i, 1);
 if(i1 > 0) i = add(i, 2);
 if(i2 > 0) i = add(i, 4);
 if(i3 > 0) i = add(i, 8);
 *sign = i;

 ip0 = mult(ip0, 6554);         /* ip0/5 */
 ip1 = mult(ip1, 6554);         /* ip1/5 */
 ip2 = mult(ip2, 6554);         /* ip2/5 */
 i   = mult(ip3, 6554);         /* ip3/5 */
 j   = add(i, shl(i, 2));       /* j = i*5 */
 j   = sub(ip3, add(j, 3));     /* j= ip3%5 -3 */
 ip3 = add(shl(i, 1), j);

 i = add(ip0, shl(ip1, 3));
 i = add(i  , shl(ip2, 6));
 i = add(i  , shl(ip3, 9));

 return i;
}