ack/util/ncgg/emlookup.c

/*
 * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
 * See the copyright notice in the ACK home directory, in the file "Copyright".
 */
#ifndef NORCSID
static char rcsid[] = "$Id$";
#endif

#include <stdlib.h>
#include <string.h>
#include "param.h"
#include "expr.h"
#include "extern.h"
#include <em_spec.h>
#include <em_flag.h>

extern char em_mnem[][4];

#define HASHSIZE        (2*(sp_lmnem-sp_fmnem))

struct emhashmnem
{
	char h_name[3];
	char h_value;
} emhashmnem[HASHSIZE];

/* Forward declarations */
static void enter(char *, int);
static unsigned emhash(register char *);


void initemhash(void)
{
	register int i;

	for (i = 0; i <= sp_lmnem - sp_fmnem; i++)
		enter(em_mnem[i], i + sp_fmnem);
	enter("lab", op_lab);
}

static unsigned emhash(register char *name)
{
	register unsigned int sum;
	register int i;

	for (sum = i = 0; *name; i += 3)
		sum ^= (*name++) << (i & 07);
	return (sum);
}

static void enter(char *name, int value)
{
	register unsigned h;

	h = emhash(name) % HASHSIZE;
	while (emhashmnem[h].h_name[0] != 0)
		h = (h + 1) % HASHSIZE;
	strncpy(emhashmnem[h].h_name, name, 3);
	emhashmnem[h].h_value = value;
}

int mlookup(char *name)
{
	register unsigned h;

	h = emhash(name) % HASHSIZE;
	while (strncmp(emhashmnem[h].h_name, name, 3) != 0
			&& emhashmnem[h].h_name[0] != 0)
		h = (h + 1) % HASHSIZE;
	return (emhashmnem[h].h_value & 0xFF); /* 0 if not found */
}

extern char em_flag[];

int argtyp(int mn)
{

	switch (em_flag[mn - sp_fmnem] & EM_PAR)
	{
		case PAR_W:
		case PAR_S:
		case PAR_Z:
		case PAR_O:
		case PAR_N:
		case PAR_L:
		case PAR_F:
		case PAR_R:
		case PAR_C:
			return (TYPINT);
		default:
			return (TYPADDR);
	}
}