lib/ack/libp/unp.c

   1 /* $Header$ */
   2 /*
   3  * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
   4  *
   5  *          This product is part of the Amsterdam Compiler Kit.
   6  *
   7  * Permission to use, sell, duplicate or disclose this software must be
   8  * obtained in writing. Requests for such permissions may be sent to
   9  *
  10  *      Dr. Andrew S. Tanenbaum
  11  *      Wiskundig Seminarium
  12  *      Vrije Universiteit
  13  *      Postbox 7161
  14  *      1007 MC Amsterdam
  15  *      The Netherlands
  16  *
  17  */
  18
  19 /* Author: J.W. Stevenson */
  20
  21 #include        <pc_err.h>
  22
  23 extern          _trp();
  24
  25 #define assert(x)       /* nothing */
  26
  27 #ifndef EM_WSIZE
  28 #define EM_WSIZE _EM_WSIZE
  29 #endif
  30
  31 struct descr {
  32         int     low;
  33         int     diff;
  34         int     size;
  35 };
  36
  37 _unp(ad,zd,i,ap,zp,noext) int i; struct descr *ad,*zd; char *ap,*zp; int noext; {
  38
  39         if (zd->diff > ad->diff ||
  40                         (i -= ad->low) < 0 ||
  41                         (i+zd->diff) > ad->diff)
  42                 _trp(EUNPACK);
  43         ap += (i * ad->size);
  44         i = (zd->diff + 1) * zd->size;
  45         if (zd->size == 1) {
  46                 int *aptmp = (int *) ap;
  47                 assert(ad->size == EM_WSIZE);
  48                 while (--i >= 0)
  49                         if (noext) *aptmp++ = *zp++ & 0377;
  50                         else *aptmp++ = *zp++;
  51 #if EM_WSIZE > 2
  52         } else if (zd->size == 2) {
  53                 int *aptmp = (int *) ap;
  54                 short *zptmp = (short *) zp;
  55                 assert(ad->size == EM_WSIZE);
  56                 while (--i >= 0)
  57                         if (noext) *aptmp++ = *zptmp++ & 0177777;
  58                         else *aptmp++ = *zptmp++;
  59 #endif
  60         } else {
  61                 assert(ad->size == zd->size);
  62                 while (--i >= 0)
  63                         *ap++ = *zp++;
  64         }
  65 }