ack/lang/m2/libm2/load.c

/*
  (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
  See the copyright notice in the ACK home directory, in the file "Copyright".
*/

/*
  Module:	get value on stack, byte by byte
  Author:	Ceriel J.H. Jacobs
  Version:	$Id$
*/

#include "libm2.h"
#include <m2_traps.h>

#ifndef EM_WSIZE
#define EM_WSIZE _EM_WSIZE
#define EM_PSIZE _EM_PSIZE
#endif

void load(size_t siz, char* addr, int p)
{
	/*	Make sure, that a value with a size that could have been
	    handled by the LOI instruction ends up at the same place,
	    where it would, were the LOI instruction used.
	*/
	register char* q = (char*)&p;
	char t[4];

	if (siz < EM_WSIZE && EM_WSIZE % siz == 0)
	{
		/* as long as EM_WSIZE <= 4 ... */
		if (siz != 2)
			TRP(M2_INTERNAL); /* internal error */
		q = &t[0];
	}
	while (siz--)
		*q++ = *addr++;
	if (q - t == 2)
	{
		*((unsigned*)(&p)) = *((unsigned short*)(&t[0]));
	}
}