ack/lang/pc/libpc/unp.c

/* $Id$ */
/*
 * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
 *
 *          This product is part of the Amsterdam Compiler Kit.
 *
 * Permission to use, sell, duplicate or disclose this software must be
 * obtained in writing. Requests for such permissions may be sent to
 *
 *      Dr. Andrew S. Tanenbaum
 *      Wiskundig Seminarium
 *      Vrije Universiteit
 *      Postbox 7161
 *      1007 MC Amsterdam
 *      The Netherlands
 *
 */

/* Author: J.W. Stevenson */

#include "pc.h"

#define assert(x) /* nothing */

#ifndef EM_WSIZE
#define EM_WSIZE _EM_WSIZE
#endif

void _unp(struct descr *ad, struct descr *zd, int i, char *ap, char *zp, int noext)
{

	if (zd->diff > ad->diff || (i -= ad->low) < 0 || (i + zd->diff) > ad->diff)
		_trp(EUNPACK);
	ap += (i * ad->size);
	i = (zd->diff + 1) * zd->size;
	if (zd->size == 1)
	{
		int* aptmp = (int*)ap;
		assert(ad->size == EM_WSIZE);
		while (--i >= 0)
			if (noext)
				*aptmp++ = *zp++ & 0377;
			else
				*aptmp++ = *zp++;
#if EM_WSIZE > 2
	}
	else if (zd->size == 2)
	{
		int* aptmp = (int*)ap;
		short* zptmp = (short*)zp;
		assert(ad->size == EM_WSIZE);
		while (--i >= 0)
			if (noext)
				*aptmp++ = *zptmp++ & 0177777;
			else
				*aptmp++ = *zptmp++;
#endif
	}
	else
	{
		assert(ad->size == zd->size);
		while (--i >= 0)
			*ap++ = *zp++;
	}
}