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/* pdkadr.c */
/*
* Copyright (C) 1998-2009 Alan R. Baldwin
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*
* Alan R. Baldwin
* 721 Berkeley St.
* Kent, Ohio 44240
*
* This Assember Ported by
* John L. Hartman (JLH)
* jhartman at compuserve dot com
* noice at noicedebugger dot com
*
*/
#include "asxxxx.h"
#include "pdk.h"
/* Classify argument as to address mode */
int
addr(struct expr *esp)
{
int c = getnb(), c1;
switch (c) {
case '#':
/* Immediate mode */
expr(esp, 0);
esp->e_mode = S_K;
break;
case 'a':
/* Accumulator */
esp->e_mode = S_A;
break;
case 's':
if ((c1 = getnb()) == 'p') {
/* Stack (SP) */
esp->e_mode = S_IO;
esp->e_addr = 2;
break;
}
unget(c1);
goto fallback;
case 'f':
/* ACC flag */
esp->e_mode = S_IO;
esp->e_addr = 0;
break;
default:
fallback:
unget(c);
/* Memory address */
expr(esp, 0);
esp->e_mode = S_M;
/* If there is no area information, assume that we have in
fact parsed an IO register variable - since any other constant
would have been prefixed by a '#'. */
if (!esp->e_flag && !esp->e_base.e_ap)
esp->e_mode = S_IO;
}
return (esp->e_mode);
}
int
pdkbit(struct expr *esp)
{
int c = getnb(), c1;
switch (c) {
case '#':
/* Bit number */
expr(esp, 0);
esp->e_mode = S_K;
break;
case 'a':
if ((c1 = getnb()) == 'c') {
/* AC bit of ACC flag */
esp->e_mode = S_K;
esp->e_addr = 2;
break;
}
unget(c1);
goto fallback;
case 'o':
if ((c1 = getnb()) == 'v') {
/* OV bit of ACC flag */
esp->e_mode = S_K;
esp->e_addr = 3;
break;
}
unget(c1);
goto fallback;
case 'c':
/* C bit of ACC flag */
esp->e_mode = S_K;
esp->e_addr = 1;
break;
case 'z':
/* Z bit of ACC flag */
esp->e_mode = S_K;
esp->e_addr = 0;
break;
case 'f':
/* ACC status flag */
esp->e_mode = S_IO;
esp->e_addr = -2;
break;
default:
fallback:
unget(c);
/* Error */
esp->e_mode = 0;
esp->e_addr = 0;
}
return (esp->e_mode);
}
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