Category : Assembly Language Source Code
Archive   : CUG292.ZIP
Filename : M01MCH.C

 
Output of file : M01MCH.C contained in archive : CUG292.ZIP

/* m01mch.c */

/*
* (C) Copyright 1989,1990
* All Rights Reserved
*
* Alan R. Baldwin
* 721 Berkeley St.
* Kent, Ohio 44240
*/

#include
#include
#include "asm.h"
#include "m6801.h"

int hd63;

/*
* Process a machine op.
*/
VOID
machine(mp)
struct mne *mp;
{
register op, t1;
struct expr e1, e2;
struct area *espa;
char id[NCPS];
int c, v1, reg;

reg = 0;
op = mp->m_valu;
switch (mp->m_type) {

case S_SDP:
e1.e_mode = 0;
e1.e_flag = 0;
e1.e_addr = 0;
e1.e_base.e_ap = NULL;
espa = NULL;
if (more()) {
expr(&e1, 0);
if (e1.e_flag == 0 && e1.e_base.e_ap == NULL) {
if (e1.e_addr) {
err('b');
}
}
if ((c = getnb()) == ',') {
getid(id, -1);
espa = alookup(id);
if (espa == NULL) {
err('u');
}
} else {
unget(c);
}
}
if (espa) {
outdp(espa, &e1);
} else {
outdp(dot.s_area, &e1);
}
lmode = SLIST;
break;

case S_HD63:
++hd63;
break;

case S_INH63:
if (!hd63) {
err('o');
break;
}

case S_INH:
outab(op);
break;

case S_TYP63:
if (!hd63) {
err('o');
break;
}
if (getnb() != '#')
aerr();
expr(&e2, 0);
comma();
t1 = addr(&e1);
if (t1 == S_DIR) {
outab(op|0x10);
outrb(&e2, 0);
outrb(&e1, R_PAG0);
break;
}
if (t1 == S_INDX) {
outab(op);
outrb(&e2, 0);
outrb(&e1, R_USGN);
break;
}
aerr();
break;

case S_PUL:
v1 = admode(abdx);
if (v1 == S_A) {
outab(op);
break;
}
if (v1 == S_B) {
outab(op+1);
break;
}
if (v1 == S_X) {
outab(op+6);
break;
}
aerr();
break;

case S_BRA:
expr(&e1, 0);
outab(op);
if (e1.e_base.e_ap == NULL || e1.e_base.e_ap == dot.s_area) {
v1 = e1.e_addr - dot.s_addr - 1;
if ((v1 < -128) || (v1 > 127))
aerr();
outab(v1);
} else {
outrb(&e1, R_PCR);
}
if (e1.e_mode != S_USER)
rerr();
break;

case S_TYP1:
t1 = addr(&e1);
if (t1 == S_A) {
outab(op|A);
break;
}
if (t1 == S_B) {
outab(op|B);
break;
}
if (t1 == S_D) {
if (op == 0x44) {
outab(0x04);
break;
}
if (op == 0x48) {
outab(0x05);
break;
}
aerr();
break;
}
if (t1 == S_INDX) {
outab(op|X);
outrb(&e1, R_USGN);
break;
}
if (t1 == S_DIR) {
outab(op|0x30);
outrw(&e1, 0);
aerr();
break;
}
if (t1 == S_EXT) {
outab(op|0x30);
outrw(&e1, 0);
break;
}
aerr();
break;

case S_TYP2:
if ((reg = admode(abdx)) == 0)
aerr();

case S_TYP3:
if (!reg) {
reg = op & 0x40;
} else if (reg == S_A) {
reg = 0x00;
} else if (reg == S_B) {
reg = 0x40;
} else if (reg == S_D) {
if (op == 0x80) {
op = 0x83;
} else
if (op == 0x8B) {
op = 0xC3;
} else {
aerr();
}
reg = 0x00;
} else {
aerr();
reg = 0x00;
}
t1 = addr(&e1);
if (t1 == S_IMMED) {
if ((op|0x40) == 0xC7)
aerr();
if (op == 0x83 || op == 0xC3) {
outab(op|reg);
outrw(&e1, 0);
} else {
outab(op|reg);
outrb(&e1, 0);
}
break;
}
if (t1 == S_DIR) {
outab(op|reg|0x10);
outrb(&e1, R_PAG0);
break;
}
if (t1 == S_INDX) {
outab(op|reg|0x20);
outrb(&e1, R_USGN);
break;
}
if (t1 == S_EXT) {
outab(op|reg|0x30);
outrw(&e1, 0);
break;
}
aerr();
break;

case S_TYP4:
t1 = addr(&e1);
if (t1 == S_IMMED) {
if (op&0x0D == 0x0D)
aerr();
outab(op);
outrw(&e1, 0);
break;
}
if (t1 == S_DIR) {
outab(op|0x10);
outrb(&e1, R_PAG0);
break;
}
if (t1 == S_INDX) {
outab(op|0x20);
outrb(&e1, R_USGN);
break;
}
if (t1 == S_EXT) {
outab(op|0x30);
outrw(&e1, 0);
break;
}
aerr();
break;

case S_TYP5:
t1 = addr(&e1);
if (t1 == S_INDX) {
outab(op);
outrb(&e1, R_USGN);
break;
}
if (t1 == S_DIR) {
outab(op|0x10);
outrw(&e1, 0);
aerr();
break;
}
if (t1 == S_EXT) {
outab(op|0x10);
outrw(&e1, 0);
break;
}
aerr();
break;

default:
err('o');
}
}


/*
* The next character must be a
* comma.
*/
VOID
comma()
{
if (getnb() != ',')
qerr();
}

/*
* Machine dependent initialization
*/
VOID
minit()
{
hd63 = 0;
}