lib/ack/libm2/load.c

   1 /*
   2   (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3   See the copyright notice in the ACK home directory, in the file "Copyright".
   4 */
   5
   6 /*
   7   Module:       get value on stack, byte by byte
   8   Author:       Ceriel J.H. Jacobs
   9   Version:      $Header$
  10 */
  11
  12 #include <m2_traps.h>
  13
  14 #ifndef EM_WSIZE
  15 #define EM_WSIZE _EM_WSIZE
  16 #define EM_PSIZE _EM_PSIZE
  17 #endif
  18
  19 #if EM_WSIZE==EM_PSIZE
  20 typedef unsigned pcnt;
  21 #else
  22 typedef long pcnt;
  23 #endif
  24
  25 load(siz, addr, p)
  26         register char *addr;
  27         register pcnt siz;
  28 {
  29         /*      Make sure, that a value with a size that could have been
  30                 handled by the LOI instruction ends up at the same place,
  31                 where it would, were the LOI instruction used.
  32         */
  33         register char *q = (char *) &p;
  34         char t[4];
  35
  36         if (siz < EM_WSIZE && EM_WSIZE % siz == 0) {
  37                 /* as long as EM_WSIZE <= 4 ... */
  38                 if (siz != 2) TRP(M2_INTERNAL); /* internal error */
  39                 q = &t[0];
  40         }
  41         while (siz--) *q++ = *addr++;
  42         if (q - t == 2) {
  43                 *((unsigned *)(&p)) = *((unsigned short *) (&t[0]));
  44         }
  45 }