/branches/initialv3/asxxxx/as6804/m04adr.c
# · C · 113 lines · 81 code · 12 blank · 20 comment · 22 complexity · 4f31e7bb804ec6555e2cf84ed94b234a MD5 · raw file
- /* m04adr.c */
- /*
- * (C) Copyright 1989-2000
- * All Rights Reserved
- *
- * Alan R. Baldwin
- * 721 Berkeley St.
- * Kent, Ohio 44240
- */
- #include <stdio.h>
- #include <setjmp.h>
- #include "asxxxx.h"
- #include "m6804.h"
- int
- addr(esp)
- register struct expr *esp;
- {
- register int c;
- if ((c = getnb()) == '#') {
- expr(esp, 0);
- esp->e_mode = S_IMMED;
- } else if (c == ',') {
- if ((esp->e_mode = admode(xy)) == 0)
- aerr();
- } else {
- unget(c);
- expr(esp, 0);
- esp->e_mode = S_DIR;
- }
- if (esp->e_addr & ~0xFF)
- aerr();
- return (esp->e_mode);
- }
-
- /*
- * Enter admode() to search a specific addressing mode table
- * for a match. Return the addressing value on a match or
- * zero for no match.
- */
- int
- admode(sp)
- register struct adsym *sp;
- {
- register char *ptr;
- register int i;
- register char *ips;
- ips = ip;
- unget(getnb());
- i = 0;
- while ( *(ptr = &sp[i].a_str[0]) ) {
- if (srch(ptr)) {
- return(sp[i].a_val);
- }
- i++;
- }
- ip = ips;
- return(0);
- }
- /*
- * srch --- does string match ?
- */
- int
- srch(str)
- register char *str;
- {
- register char *ptr;
- ptr = ip;
- while (*ptr && *str) {
- if(ccase[*ptr & 0x007F] != ccase[*str & 0x007F])
- break;
- ptr++;
- str++;
- }
- if (ccase[*ptr & 0x007F] == ccase[*str & 0x007F]) {
- ip = ptr;
- return(1);
- }
- if (!*str)
- if (any(*ptr," \t\n,];")) {
- ip = ptr;
- return(1);
- }
- return(0);
- }
- /*
- * any --- does str contain c?
- */
- int
- any(c,str)
- int c;
- char *str;
- {
- while (*str)
- if(*str++ == c)
- return(1);
- return(0);
- }
- struct adsym xy[] = { /* x or y registers */
- { "x", S_IX },
- { "y", S_IY },
- { "", 0x00 }
- };