text: /* ISC license. */
  
  #include <errno.h>
  #include <skalibs/uint32.h>
  #include <skalibs/biguint.h>
  
  /*
     q = a/b, a = a mod b. Assumes b != 0 and qn >= alen - blen + 1.
  */
  
  void bu_div_internal (uint32 *a, unsigned int an, uint32 const *b, unsigned int bn, uint32 *q, unsigned int qn)
  {
    unsigned int alen = bu_len(a, an) ;
    unsigned int blen = bu_len(b, bn) ;
    bu_zero(q, qn) ;
    if (alen < blen) return ;
    {
      uint32 bb[alen + 1] ;
      unsigned int i = 1 + ((alen - blen) << 5) ;
      bu_zero(bb, alen - blen) ;
      bu_copy_internal(bb + alen - blen, b, blen) ;
      bb[alen] = 0 ;
  
      while (bu_cmp(a, alen, bb, alen+1) >= 0)
      {
        bu_slb(bb + alen - blen, blen + 1) ;
        i++ ;
      }
      while (i && (bu_cmp(a, alen, bb, alen+1) < 0))
      {
        bu_srb(bb, alen + 1) ;
        i-- ;
      }
  
      while (i--)
      {
        bu_slb(q, alen - blen + 1) ;
        if (bu_cmp(a, alen, bb, alen) >= 0)
        {
          bu_sub(a, alen, a, alen, bb, alen) ;
          q[0] |= 1 ;
        }
        bu_srb(bb, alen) ;
      }
    }
  }
  