/* i51adr.c */

/*
 * (C) Copyright 1989,1990
 * All Rights Reserved
 *
 * Alan R. Baldwin
 * 721 Berkeley St.
 * Kent, Ohio  44240
 *
 * Ported from 8085 to 8051 by John Hartman 30-Apr-1995
 * Continued, 29-May-95
 */

#include <stdio.h>
#include <setjmp.h>
#include "asm.h"
#include "i8051.h"

extern int admode (struct adsym *);

struct adsym reg51[] = {	/* R0 thru R7 registers */
{	"R0",   R0},
{	"R1",   R1},
{	"R2",   R2},
{	"R3",   R3},
{	"R4",   R4},
{	"R5",   R5},
{	"R6",   R6},
{	"R7",   R7},
{	"A",	A},
{	"DPTR", DPTR},
{	"PC",   PC},
{	"C",    C},
{	"AB",   AB},
{	"r0",   R0},
{	"r1",   R1},
{	"r2",   R2},
{	"r3",   R3},
{	"r4",   R4},
{	"r5",   R5},
{	"r6",   R6},
{	"r7",   R7},
{	"a",	A},
{	"dptr", DPTR},
{	"pc",   PC},
{	"c",    C},
{	"ab",   AB},
{	"",	0x00}
};

/*  Classify argument as to address mode */
int
addr(esp)
register struct expr *esp;
{
	register int c;
        register unsigned rd;

	if ((c = getnb()) == '#') {
        	/*  Immediate mode */
		expr(esp, 0);
		esp->e_mode = S_IMMED;
	} 
        else if (c == '@') {
        	/* choices are @R0, @R1, @DPTR, @A+PC, @A+DPTR */
		switch (reg()) {
                case R0:
			esp->e_mode = S_AT_R;
			esp->e_addr = R0;
                        break;
                case R1:
			esp->e_mode = S_AT_R;
			esp->e_addr = R1;
                        break;
                case DPTR:
			esp->e_mode = S_AT_DP;
			esp->e_addr = DPTR;
                        break;
                case A:
			if (getnb() == '+') {
                        	rd = reg();
                                if (rd == PC) {
					esp->e_mode = S_AT_APC;
					esp->e_addr = 0;
				} else if (rd == DPTR) {
					esp->e_mode = S_AT_ADP;
					esp->e_addr = 0;
				} else {
                                	aerr();
                                }
                        } else
				aerr();
                        break;
                }

		esp->e_flag = 0;
		esp->e_base.e_ap = NULL;
	} 
        else if (c == '*') {
        	/* Force direct page */
		expr(esp, 0);
		esp->e_mode = S_DIR;
		if (esp->e_addr & ~0xFF)
			err('d');
	} 
        else if (c == '/') {
        	/* Force inverted bit  */
		expr(esp, 0);
		esp->e_mode = S_NOT_BIT;
		if (esp->e_addr & ~0xFF)
			err('d');
	} 
        else {
		unget(c);

		/* try for register: A, AB, R0-R7, DPTR, PC, Cy */
		if ((esp->e_addr = admode(reg51)) != -1) {
                	switch (esp->e_addr) {
                        case A:
	                        esp->e_mode = S_A;
                                break;
                        case AB:
	                        esp->e_mode = S_RAB;
                                break;
                        case DPTR:
	                        esp->e_mode = S_DPTR;
                                break;
                        case PC:
	                        esp->e_mode = S_PC;
                                break;
                        case C:
	                        esp->e_mode = S_C;
                                break;
                	default:
                        	/* R0-R7 */
	                        esp->e_mode = S_REG;
                        }
		} else {
                	/* Must be an expression */
			expr(esp, 0);
                        if ((!esp->e_flag)
                                && (esp->e_base.e_ap==NULL)
                                && !(esp->e_addr & ~0xFF)) {
                                esp->e_mode = S_DIR;
                        } else {
                                esp->e_mode = S_EXT;
                        }
		}
	}
	return (esp->e_mode);
}


/*
 *      any --- does str contain c?
 */
int
any(c,str)
char    c, *str;
{
	while (*str)
		if(*str++ == c)
			return(1);
	return(0);
}

int
srch(str)
register char *str;
{
	register char *ptr;
	ptr = ip;

#if	CASE_SENSITIVE
	while (*ptr && *str) {
		if(*ptr != *str)
			break;
		ptr++;
		str++;
	}
	if (*ptr == *str) {
		ip = ptr;
		return(1);
	}
#else
	while (*ptr && *str) {
		if(ccase[*ptr] != ccase[*str])
			break;
		ptr++;
		str++;
	}
	if (ccase[*ptr] == ccase[*str]) {
		ip = ptr;
		return(1);
	}
#endif

	if (!*str)
		if (any(*ptr," \t\n,];")) {
			ip = ptr;
			return(1);
		}
	return(0);
}
	
/*
 * Enter admode() to search a specific addressing mode table
 * for a match. Return the addressing value on a match or
 * -1 for no match.
 */
int
admode(sp)
register struct adsym *sp;
{
	register char *ptr;
	register int i;
	unget(getnb());
	i = 0;
	while ( *(ptr = (char *) &sp[i]) ) {
		if (srch(ptr)) {
			return(sp[i].a_val);
		}
		i++;
	}
	return(-1);
}

/*
 *      srch --- does string match ?
 */

/*
 * Read a register name.  Return register value, -1 if no register found
 */
int
reg()
{
	register struct mne *mp;
	char id[NCPS];

	getid(id, -1);
	if ((mp = mlookup(id))==NULL) {
		aerr();
		return (-1);
	}
        switch (mp->m_type) {
        case S_A:
        case S_AB:
        case S_DPTR:
        case S_PC:
        case S_REG:
		return (mp->m_valu);

	default:
        	return (-1);
        }
}