ref: dfa1176b9c16e83e4bb024e2d260fb92c38cebb0
dir: /sys/src/games/blit/cpu.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include "dat.h"
#include "fns.h"
enum {
FLAGS = 1<<13,
FLAGX = 16,
FLAGN = 8,
FLAGZ = 4,
FLAGV = 2,
FLAGC = 1,
};
u32int r[16], pc, curpc;
u32int asp, irq, stop;
extern u32int irql[8];
u32int irqla[8];
u16int rS;
static u32int op;
int trace, tim;
#define ra (r+8)
static void
undef(void)
{
sysfatal("undefined opcode %#o at pc=%#.6x", op, curpc);
}
static u16int
fetch16(void)
{
u16int v;
v = memread(pc);
pc += 2;
return v;
}
static u32int
fetch32(void)
{
u32int v;
v = fetch16() << 16;
return v | fetch16();
}
static void
push16(u16int u)
{
ra[7] -= 2;
memwrite(ra[7], u, -1);
}
static u16int
pop16(void)
{
u16int v;
v = memread(ra[7]);
ra[7] += 2;
return v;
}
static void
push32(u32int u)
{
ra[7] -= 4;
memwrite(ra[7], u >> 16, -1);
memwrite(ra[7] + 2, u, -1);
}
static u32int
pop32(void)
{
u32int v;
v = memread(ra[7]) << 16;
v |= memread(ra[7] + 2);
ra[7] += 4;
return v;
}
static vlong
amode(int m, int n, int s)
{
u16int w;
u32int v;
m &= 7;
n &= 7;
s &= 3;
if(n == 7 && s == 0)
s++;
switch(m){
case 0:
return ~n;
case 1:
return ~(n+8);
case 2:
tim += s == 2 ? 8 : 4;
return ra[n];
case 3:
v = ra[n];
ra[n] += 1<<s;
tim += s == 2 ? 8 : 4;
return v;
case 4:
tim += s == 2 ? 10 : 6;
return ra[n] -= 1<<s;
case 5:
tim += s == 2 ? 12 : 8;
return (u32int)(ra[n] + (s16int)fetch16());
case 6:
tim += s == 2 ? 14 : 10;
w = fetch16();
v = r[w >> 12];
if((w & 1<<11) == 0)
v = (s16int)v;
return (u32int)(ra[n] + v + (s8int)w);
case 7:
switch(n){
case 0:
tim += s == 2 ? 12 : 8;
return (u32int)(s16int)fetch16();
case 1:
tim += s == 2 ? 16 : 12;
return fetch32();
case 2:
tim += s == 2 ? 12 : 8;
v = fetch16();
return (u32int)(pc + (s16int)v - 2);
case 3:
tim += s == 2 ? 14 : 10;
w = fetch16();
v = r[w >> 12];
if((w & 1<<11) == 0)
v = (s16int)v;
return (u32int)(pc + v + (s8int)w - 2);
case 4:
tim += s == 2 ? 8 : 4;
v = pc;
pc += 1<<s;
if(s == 0)
v = pc++;
return v;
default:
undef();
}
default:
undef();
}
return 0;
}
static u32int
rmode(vlong a, int s)
{
u32int v;
if(a >= 0){
switch(s & 3){
case 0:
v = memread(a);
if((a & 1) == 0)
v >>= 8;
return (s8int) v;
default:
return (s16int) memread(a);
case 2:
v = memread(a) << 16;
return v | memread(a + 2);
}
}
v = r[~a];
switch(s & 3){
case 0: return (s8int) v;
case 1: return (s16int) v;
default: return v;
}
}
static void
wmode(vlong a, int s, u32int v)
{
int n;
if(a >= 0){
switch(s & 3){
case 0:
memwrite(a, (u8int)v | (u8int)v << 8, (a & 1) != 0 ? 0xff : 0xff00);
return;
default:
memwrite(a, v, -1);
return;
case 2:
memwrite(a, v >> 16, -1);
memwrite(a + 2, v, -1);
return;
}
}
n = ~a;
if(n < 8){
switch(s){
case 0: r[n] = r[n] & 0xffffff00 | v & 0xff; break;
case 1: r[n] = r[n] & 0xffff0000 | v & 0xffff; break;
default: r[n] = v;
}
}else{
if(s == 1)
v = (s16int) v;
r[n] = v;
}
}
static void
nz(u32int v, int s)
{
switch(s){
case 0: v = (s8int) v; break;
case 1: v = (s16int) v; break;
}
rS &= ~(FLAGC|FLAGN|FLAGV|FLAGZ);
if(v == 0)
rS |= FLAGZ;
if((s32int)v < 0)
rS |= FLAGN;
}
static u32int
add(u32int u, u32int w, int c, int s)
{
u64int v;
rS &= ~(FLAGN|FLAGV|FLAGC);
switch(s){
case 0:
v = (u8int)w + (u8int)u + c;
if(v >= 0x100)
rS |= FLAGC;
if((v & 0x80) != 0)
rS |= FLAGN;
if((~(w ^ u) & (v ^ u) & 0x80) != 0)
rS |= FLAGV;
if((u8int)v != 0)
rS &= ~FLAGZ;
break;
case 1:
v = (u16int)w + (u16int)u + c;
if(v >= 0x10000)
rS |= FLAGC;
if((v & 0x8000) != 0)
rS |= FLAGN;
if((~(w ^ u) & (v ^ u) & 0x8000) != 0)
rS |= FLAGV;
if((u16int)v != 0)
rS &= ~FLAGZ;
break;
default:
v = (u64int)w + u + c;
if((v >> 32) != 0)
rS |= FLAGC;
if((v & 0x80000000) != 0)
rS |= FLAGN;
if((~(w ^ u) & (v ^ u) & 0x80000000) != 0)
rS |= FLAGV;
if((u32int)v != 0)
rS &= ~FLAGZ;
break;
}
return v;
}
static u32int
sub(u32int u, u32int w, int c, int s)
{
u64int v;
rS &= ~(FLAGN|FLAGV|FLAGC);
switch(s){
case 0:
v = (u8int)u - (u8int)w - c;
if(v >= 0x100)
rS |= FLAGC;
if((v & 0x80) != 0)
rS |= FLAGN;
if(((w ^ u) & (v ^ u) & 0x80) != 0)
rS |= FLAGV;
if((u8int)v != 0)
rS &= ~FLAGZ;
break;
case 1:
v = (u16int)u - (u16int)w - c;
if(v >= 0x10000)
rS |= FLAGC;
if((v & 0x8000) != 0)
rS |= FLAGN;
if(((w ^ u) & (v ^ u) & 0x8000) != 0)
rS |= FLAGV;
if((u16int)v != 0)
rS &= ~FLAGZ;
break;
default:
v = (u64int)u - w - c;
if((v >> 32) != 0)
rS |= FLAGC;
if((v & 0x80000000) != 0)
rS |= FLAGN;
if(((w ^ u) & (v ^ u) & (1<<31)) != 0)
rS |= FLAGV;
if((u32int)v != 0)
rS &= ~FLAGZ;
break;
}
return v;
}
static int
cond(int n)
{
switch(n){
case 0: return 1; break;
default: return 0; break;
case 2: return (rS & (FLAGC|FLAGZ)) == 0; break;
case 3: return (rS & (FLAGC|FLAGZ)) != 0; break;
case 4: return (rS & FLAGC) == 0; break;
case 5: return (rS & FLAGC) != 0; break;
case 6: return (rS & FLAGZ) == 0; break;
case 7: return (rS & FLAGZ) != 0; break;
case 8: return (rS & FLAGV) == 0; break;
case 9: return (rS & FLAGV) != 0; break;
case 10: return (rS & FLAGN) == 0; break;
case 11: return (rS & FLAGN) != 0; break;
case 12: return ((rS ^ (rS << 2)) & FLAGN) == 0; break;
case 13: return ((rS ^ (rS << 2)) & FLAGN) != 0; break;
case 14: return ((rS ^ (rS << 2)) & FLAGN) == 0 && (rS & FLAGZ) == 0; break;
case 15: return ((rS ^ (rS << 2)) & FLAGN) != 0 || (rS & FLAGZ) != 0; break;
}
}
static u32int
rot(u32int v, int m, int n, int s)
{
int l, ll, x, vf;
u32int msb;
/* abandon all hope ye who enter here */
msb = 1 << (8 << s) - 1;
v &= (msb << 1) - 1;
if(m == 0)
x = (v & msb) != 0;
else
x = 0;
if((m & 6) == 4)
ll = l = (rS & FLAGX) != 0;
else
ll = l = 0;
vf = 0;
while(n--){
if((m & 1) == 0){
l = v & 1;
v >>= 1;
}else{
l = (v & msb) != 0;
v <<= 1;
}
if((m & 6) != 6)
rS = rS & ~FLAGX | l << 4;
if(m >= 6)
x = l;
else if(m >= 4){
x = ll;
ll = l;
}
if((m & 1) == 0){
if(x != 0)
v |= msb;
}else
v |= x;
vf |= l ^ (v & msb) != 0;
tim += 2;
}
nz(v, s);
rS |= l;
if(m == 1 && vf)
rS |= FLAGV;
tim += s == 2 ? 8 : 6;
return v;
}
static u8int
addbcd(u8int a, u8int b)
{
int r;
u8int bc, dc, s;
r = a + b + (rS >> 4 & 1);
bc = ((a ^ b ^ r) & 0x110) >> 1;
dc = ((r + 0x66 ^ r) & 0x110) >> 1;
s = r + (bc | dc) - ((bc | dc) >> 2);
rS &= ~(FLAGC|FLAGX|FLAGN|FLAGV);
if(((bc | r & ~s) & 0x80) != 0)
rS |= FLAGC|FLAGX;
if(s != 0)
rS &= ~FLAGZ;
if((s & 0x80) != 0)
rS |= FLAGN;
if((~r & s & 0x80) != 0)
rS |= FLAGV;
return s;
}
static u8int
subbcd(u8int a, u8int b)
{
int r;
u8int bc, s;
r = a - b - (rS >> 4 & 1);
bc = ((a ^ b ^ r) & 0x110) >> 1;
s = r - (bc - (bc >> 2));
rS &= ~(FLAGC|FLAGX|FLAGN|FLAGV);
if(((bc | (~r & s)) & 0x80) != 0)
rS |= FLAGC|FLAGX;
if(s != 0)
rS &= ~FLAGZ;
if((s & 0x80) != 0)
rS |= FLAGN;
if((r & ~s & 0x80) != 0)
rS |= FLAGV;
return s;
}
static void
dtime(u16int op, u8int s)
{
if((op & 0x100) == 0){
if(s == 2)
if((op & 0x30) == 0 || (op & 0x3f) == 0x3c)
tim += 8;
else
tim += 6;
else
tim += 4;
}else
tim += s == 2 ? 12 : 8;
}
static void
stime(int a, u8int s)
{
if(a)
tim += s == 2 ? 6 : 4;
else
tim += s == 2 ? 12 : 8;
}
static void
trap(int n, u32int pcv)
{
int l, v;
u32int sr, t;
sr = rS;
if(n < 0){
for(l = 7; l > ((rS >> 8) & 7); l--)
if((irql[l] & irq) != 0)
break;
v = intack(l);
rS = rS & ~0x700 | l << 8;
tim += 44;
}else{
switch(n){
case 2: case 3: tim += 50; break;
case 5: tim += 38; break;
case 6: tim += 40; break;
default: tim += 34; break;
}
v = n;
}
if((rS & FLAGS) == 0){
t = asp;
asp = ra[7];
ra[7] = t;
}
rS |= FLAGS;
push32(pcv);
push16(sr);
pc = memread(v * 4) << 16;
pc |= memread(v * 4 + 2);
stop = 0;
}
void
cpureset(void)
{
u32int v;
int i;
ra[7] = memread(0) << 16 | memread(2);
pc = memread(4) << 16 | memread(6);
rS = 0x2700;
for(i = 7, v = 0; i >= 0; i--){
irqla[i] = v;
v |= irql[i];
}
}
static void
cputrace(void)
{
int i;
static char buf[1024];
static u32int oldr[16];
char *p, *e;
p = buf;
e = buf + sizeof(buf);
p = seprint(p, e, "%.6ux %.6uo %.4x %.8ux %.8ux |", curpc, op, rS, ra[7], asp);
for(i = 0; i < 16; i++)
if(oldr[i] != r[i])
p = seprint(p, e, " %c%d=%.8ux", i >= 8 ? 'A' : 'D', i & 7, r[i]);
print("%s\n", buf);
memcpy(oldr, r, sizeof(r));
}
static void
ccr_sr_op(u16int op)
{
int s;
u32int v, w;
s = op >> 6 & 3;
if(s == 1 && (rS & FLAGS) == 0){
trap(8, curpc);
return;
}
v = rS;
w = fetch16();
switch(op >> 9 & 7){
case 0: v |= w; break;
case 1: v &= w; break;
case 5: v ^= w; break;
default: undef();
}
if(s != 1)
v = v & 0x1f | rS & 0xff00;
rS = v;
if(s == 1 && (rS & FLAGS) == 0){
v = ra[7];
ra[7] = asp;
asp = v;
}
tim += 20;
}
static void
op_movep(u16int op)
{
int s, n;
vlong a;
u32int v;
a = (u32int)(ra[op & 7] + (s16int)fetch16());
s = op >> 6 & 3;
n = op >> 9 & 7;
switch(s){
case 0:
v = (u8int)rmode(a, 0) << 8;
v |= (u8int)rmode(a + 2, 0);
r[n] = r[n] & 0xffff0000 | v;
tim += 16;
break;
case 1:
v = (u8int)rmode(a, 0) << 24;
v |= (u8int)rmode(a + 2, 0) << 16;
v |= (u8int)rmode(a + 4, 0) << 8;
v |= (u8int)rmode(a + 6, 0);
tim += 24;
r[n] = v;
break;
case 2:
wmode(a, 0, r[n] >> 8);
wmode(a + 2, 0, r[n]);
tim += 16;
break;
case 3:
wmode(a, 0, r[n] >> 24);
wmode(a + 2, 0, r[n] >> 16);
wmode(a + 4, 0, r[n] >> 8);
wmode(a + 6, 0, r[n]);
tim += 24;
break;
}
}
static void
bitop(u16int op)
{
int s, n;
u32int v, w;
vlong a;
s = op >> 6 & 3;
n = op >> 9 & 7;
if((op & 0x100) != 0)
w = r[n];
else
w = fetch16();
if((op & 0x38) != 0){
n = 0;
w = 1<<(w & 7);
}else{
n = 2;
w = 1<<(w & 31);
}
a = amode(op >> 3, op, n);
v = rmode(a, n);
rS &= ~FLAGZ;
if((v & w) == 0)
rS |= FLAGZ;
switch(s){
case 1: v ^= w; break;
case 2: v &= ~w; if(n == 2) tim += 2; break;
case 3: v |= w; break;
}
if(s != 0){
wmode(a, n, v);
tim += (op & 0x100) != 0 ? 8 : 12;
}else{
tim += (op & 0x100) != 0 ? 4 : 8;
if(n == 2)
tim += 2;
}
}
static void
immop(u16int op)
{
int s, n;
u32int v, w;
vlong a;
s = op >> 6 & 3;
n = op >> 9 & 7;
switch(s){
case 0: w = (s8int)fetch16(); break;
default: w = fetch16(); break;
case 2: w = fetch32(); break;
}
a = amode(op >> 3, op, s);
v = rmode(a, s);
switch(n){
case 0: nz(v |= w, s); break;
case 1: nz(v &= w, s); break;
case 2: rS |= FLAGZ; v = sub(v, w, 0, s); rS = rS & ~FLAGX | rS << 4 & FLAGX; break;
case 3: rS |= FLAGZ; v = add(v, w, 0, s); rS = rS & ~FLAGX | rS << 4 & FLAGX; break;
case 5: nz(v ^= w, s); break;
case 6: rS |= FLAGZ; sub(v, w, 0, s); break;
default: undef();
}
if(n == 6){
if(a < 0)
tim += s == 2 ? 14 : 8;
else
tim += s == 2 ? 12 : 8;
}else{
if(a < 0)
tim += s == 2 ? 16 : 8;
else
tim += s == 2 ? 20 : 12;
}
if(n != 6)
wmode(a, s, v);
}
void
op_move(u16int op, int s)
{
u32int v;
v = rmode(amode(op >> 3, op, s), s);
wmode(amode(op >> 6, op >> 9, s), s, v);
if((op & 0x1c0) != 0x40)
nz(v, s);
tim += 4;
if((op & 0700) == 0400)
tim -= 2;
}
static void
op_lea(u16int op)
{
int n;
n = op >> 9 & 7;
ra[n] = amode(op >> 3, op, 1);
if((op & 070) == 060 || (op & 077) == 073) tim += 2;
}
static void
op_chk(u16int op)
{
int s, n;
u32int v;
vlong a;
s = op >> 6 & 3;
n = op >> 9 & 7;
a = amode(op >> 3, op, s);
v = rmode(a, s);
if((s32int)r[n] < 0 || (s32int)r[n] > (s32int)v)
trap(6, curpc);
else
tim += 10;
}
static void
op_movem(u16int op)
{
int s, n, m;
u32int w;
vlong a;
s = (op >> 6 & 1) + 1;
w = fetch16();
if((op & 0x38) == 0x18){
n = op & 7;
a = ra[n];
for(m = 0; m < 16; m++){
if((w & 1) != 0){
r[m] = rmode(a, s);
a += 1<<s;
tim += 2<<s;
}
w >>= 1;
}
ra[n] = a;
tim += 12;
}else if((op & 0x38) == 0x20){
n = op & 7;
a = ra[n];
for(m = 0; m < 16; m++){
if((w & 1) != 0){
a -= 1<<s;
wmode(a, s, r[15 - m]);
tim += 2<<s;
}
w >>= 1;
}
ra[n] = a;
tim += 8;
}else{
a = amode(op >> 3, op, s);
for(m = 0; m < 16; m++){
if((w & 1) != 0){
if((op & 0x400) != 0)
r[m] = rmode(a, s);
else
wmode(a, s, r[m]);
a += 1<<s;
tim += 2<<s;
}
w >>= 1;
}
tim += (op & 0x400) != 0 ? 8 : 4;
if(s == 2) tim -= 4;
}
}
static void
op_move_from_sr(u16int op)
{
vlong a;
a = amode(op >> 3, op, 1);
wmode(a, 1, rS);
tim += a < 0 ? 6 : 8;
}
static void
op_negx(u16int op)
{
int s;
u32int v;
vlong a;
s = op >> 6 & 3;
a = amode(op >> 3, op, s);
v = rmode(a, s);
wmode(a, s, sub(0, v, rS>>4 & 1, s));
rS = rS & ~FLAGX | rS << 4 & FLAGX;
stime(a < 0, s);
}
static void
op_clr(u16int op)
{
int s;
vlong a;
s = op >> 6 & 3;
a = amode(op >> 3, op, s);
wmode(a, s, 0);
nz(0, 0);
stime(a < 0, s);
}
static void
op_move_to_ccr(u16int op)
{
rS = rS & 0xff00 | rmode(amode(op >> 3, op, 1), 1) & 0x1f;
tim += 12;
}
static void
op_neg(u16int op)
{
int s;
u32int v;
vlong a;
s = op >> 6 & 3;
a = amode(op >> 3, op, s);
v = rmode(a, s);
rS |= FLAGZ;
wmode(a, s, sub(0, v, 0, s));
rS = rS & ~FLAGX | rS << 4 & FLAGX;
stime(a < 0, s);
}
static void
op_move_to_sr(u16int op)
{
u32int v;
if((rS & FLAGS) != 0){
rS = rmode(amode(op >> 3, op, 1), 1);
if((rS & FLAGS) == 0){
v = asp;
asp = ra[7];
ra[7] = v;
}
tim += 12;
}else
trap(8, curpc);
}
static void
op_not(u16int op)
{
int s;
u32int v;
vlong a;
s = op >> 6 & 3;
a = amode(op >> 3, op, s);
v = ~rmode(a, s);
nz(v, s);
wmode(a, s, v);
stime(a < 0, s);
}
static void
op_nbcd(u16int op)
{
u32int v;
vlong a;
a = amode(op >> 3, op, 0);
v = rmode(a, 0);
wmode(a, 0, subbcd(0, v));
if(a < 0)
tim += 6;
else
tim += 8;
}
static void
op_pea(u16int op)
{
ra[7] -= 4;
wmode(ra[7], 2, amode(op >> 3, op, 1));
tim += 8;
if((op & 070) == 060 || (op & 077) == 073) tim += 2;
}
static void
op_swap(u16int op)
{
int n;
n = op & 7;
nz(r[n] = r[n] >> 16 | r[n] << 16, 2);
tim += 4;
}
static void
op_ext_b(u16int op)
{
int n;
n = op & 7;
nz(r[n] = r[n] & 0xffff0000 | (u16int)(s8int)r[n], 1);
tim += 4;
}
static void
op_ext_w(u16int op)
{
int n;
n = op & 7;
nz(r[n] = (s16int)r[n], 2);
tim += 4;
}
static void
op_tas(u16int op)
{
u32int v;
vlong a;
a = amode(op >> 3, op, 0);
v = rmode(a, 0);
nz(v, 0);
wmode(a, 0, v | 0x80);
tim += a < 0 ? 4 : 14;
}
static void
op_tst(u16int op)
{
int s;
vlong a;
s = op >> 6 & 3;
a = amode(op >> 3, op, s);
nz(rmode(a, s), s);
tim += 4;
}
static void
op_trap(u16int op)
{
trap(0x20 | op & 0xf, pc);
}
static void
op_link(u16int op)
{
int n;
n = op & 7;
push32(ra[n]);
ra[n] = ra[7];
ra[7] += (s16int)fetch16();
tim += 16;
}
static void
op_unlk(u16int op)
{
int n;
n = op & 7;
ra[7] = ra[n];
ra[n] = pop32();
tim += 12;
}
static void
op_move_usp(u16int op)
{
int n;
n = op & 7;
if((rS & FLAGS) != 0){
if((op & 8) != 0)
ra[n] = asp;
else
asp = ra[n];
tim += 4;
}else
trap(8, curpc);
}
static void
jtime(int op)
{
int a;
a = op >> 3 & 7;
if(a == 2 || a == 6 || (op & 077) == 073)
tim += 2;
else if((op & 077) == 071)
tim -= 2;
}
static void
op_jmp(u16int op)
{
pc = amode(op >> 3, op, 1);
jtime(op);
tim += 2;
}
static void
op_jsr(u16int op)
{
vlong a;
a = amode(op >> 3, op, 1);
push32(pc);
pc = a;
jtime(op);
tim += 10;
}
static void
op_reset(u16int op)
{
USED(op);
tim += 132;
}
static void
op_nop(u16int op)
{
USED(op);
tim += 4;
}
static void
op_stop(u16int op)
{
USED(op);
if((rS & FLAGS) != 0){
rS = fetch16();
stop = 1;
}else
trap(8, curpc);
tim += 4;
}
static void
op_rte(u16int op)
{
u32int v;
USED(op);
if((rS & FLAGS) != 0){
v = rS;
rS = pop16();
pc = pop32();
if(((v ^ rS) & FLAGS) != 0){
v = asp;
asp = ra[7];
ra[7] = v;
}
tim += 20;
}else
trap(8, curpc);
}
static void
op_rts(u16int op)
{
USED(op);
pc = pop32();
tim += 16;
}
void
op_trapv(u16int op)
{
USED(op);
if((rS & FLAGV) != 0)
trap(7, curpc);
tim += 4;
}
void
op_rtr(u16int op)
{
USED(op);
rS = rS & 0xff00 | pop16() & 0x1f;
pc = pop32();
tim += 20;
}
static void
op_dbcc(u16int op)
{
int n;
u32int v;
n = op & 7;
v = (s16int)fetch16();
if(!cond((op >> 8) & 0xf)){
if((u16int)r[n] != 0){
r[n]--;
pc = pc + v - 2;
tim += 10;
}else{
r[n] |= 0xffff;
tim += 14;
}
}else
tim += 12;
}
static void
op_scc(u16int op)
{
u32int v;
vlong a;
a = amode(op >> 3, op, 0);
v = cond(op >> 8 & 0xf);
wmode(a, 0, -v);
if(a < 0)
tim += 4 + 2 * v;
else
tim += 8;
}
static void
op_addq_subq(u16int op)
{
int s, n;
u32int v;
vlong a;
s = op >> 6 & 3;
n = op >> 9 & 7;
rS |= FLAGZ;
if((op & 0x38) == 0x08)
s = 2;
a = amode(op >> 3, op, s);
v = rmode(a, s);
if(n == 0)
n = 8;
if((op & 0x100) == 0)
v = add(v, n, 0, s);
else
v = sub(v, n, 0, s);
rS = rS & ~FLAGX | rS << 4 & FLAGX;
if(a < 0)
tim += s == 2 ? 8 : 4;
else
tim += s == 2 ? 12 : 8;
wmode(a, s, v);
}
static void
op_addq_subq_a(u16int op)
{
int s, n;
s = op >> 6 & 3;
n = op >> 9 & 7;
if(n == 0)
n = 8;
tim += s == 2 || (op & 0x100) != 0 ? 8 : 4;
if((op & 0x100) == 0)
ra[op & 7] += n;
else
ra[op & 7] -= n;
}
static void
op_bra(u16int op)
{
u32int v;
v = (s8int)op;
if(v == 0)
v = (s16int)fetch16();
else if(v == (u32int)-1)
v = fetch32();
if((op & 0xf00) == 0x100){ /* BSR */
push32(pc);
pc = curpc + 2 + v;
tim += 18;
return;
}
if(cond((op >> 8) & 0xf)){
pc = curpc + 2 + v;
tim += 10;
}else
tim += (u8int)(op + 1) <= 1 ? 12 : 8;
}
static void
op_moveq(u16int op)
{
int n;
n = op >> 9 & 7;
r[n] = (s8int)op;
nz(r[n], 0);
tim += 4;
}
static void
op_divu_divs(u16int op)
{
int n;
u32int v, w;
vlong a;
n = op >> 9 & 7;
a = amode(op >> 3, op, 1);
v = rmode(a, 1);
if(v == 0){
trap(5, curpc);
return;
}
if((op & 0x100) != 0){
w = (s32int)r[n] % (s16int)v;
v = (s32int)r[n] / (s16int)v;
if((s32int)(w ^ r[n]) < 0)
w = -w;
tim += 158;
if(v != (u32int)(s16int)v){
rS = rS & ~FLAGC | FLAGV;
return;
}
}else{
w = r[n] % (u16int)v;
v = r[n] / (u16int)v;
tim += 140;
if(v >= 0x10000){
rS = rS & ~FLAGC | FLAGV;
return;
}
}
r[n] = (u16int)v | w << 16;
nz(v, 1);
}
static void
op_sbcd(u16int op)
{
int n, m;
u32int v, w;
vlong src, dst;
n = op >> 9 & 7;
m = op & 7;
if((op & 8) != 0){
src = amode(4, m, 0);
dst = amode(4, n, 0);
w = rmode(src, 0);
v = rmode(dst, 0);
v = subbcd(v, w);
wmode(dst, 0, v);
}else
r[n] = r[n] & 0xffffff00 | subbcd(r[n], r[m]);
tim += 6;
}
static void
logic(u16int op)
{
int s, n;
u32int v;
vlong a;
s = op >> 6 & 3;
a = amode(op >> 3, op, s);
n = op >> 9 & 7;
v = rmode(a, s);
switch(op >> 12){
case 8: v |= r[n]; break;
case 11: v ^= r[n]; break;
case 12: v &= r[n]; break;
}
if((op & 0x100) == 0)
a = ~n;
wmode(a, s, v);
nz(v, s);
dtime(op, s);
}
static void
op_cmpa(u16int op)
{
int s, n;
vlong a;
n = op >> 9 & 7;
s = (op >> 8 & 1) + 1;
a = amode(op >> 3, op, s);
rS |= FLAGZ;
sub(ra[n], rmode(a, s), 0, 2);
tim += 6;
}
static void
op_cmpm(u16int op)
{
int s, n, m;
vlong src, dst;
u32int v, w;
s = op >> 6 & 3;
n = op >> 9 & 7;
m = op & 7;
rS |= FLAGZ;
src = amode(3, m, s);
dst = amode(3, n, s);
v = rmode(src, s);
w = rmode(dst, s);
sub(w, v, 0, s);
tim += 4;
}
static void
op_cmp(u16int op)
{
int s, n;
vlong a;
s = op >> 6 & 3;
n = op >> 9 & 7;
a = amode(op >> 3, op, s);
rS |= FLAGZ;
sub(r[n], rmode(a, s), 0, s);
tim += s == 2 ? 6 : 4;
}
static void
op_mulu_muls(u16int op)
{
int n;
u32int v;
vlong a;
n = op >> 9 & 7;
a = amode(op >> 3, op, 1);
v = rmode(a, 1);
if((op & 0x100) != 0)
v *= (s16int)r[n];
else
v = (u16int)v * (u16int)r[n];
r[n] = v;
nz(v, 2);
tim += 70;
}
static void
op_abcd(u16int op)
{
int n, m;
u32int v, w;
vlong src, dst;
n = op >> 9 & 7;
m = op & 7;
if((op & 8) != 0){
src = amode(4, m, 0);
dst = amode(4, n, 0);
v = rmode(src, 0);
w = rmode(dst, 0);
v = addbcd(v, w);
wmode(dst, 0, v);
}else
r[n] = r[n] & 0xffffff00 | addbcd(r[n], r[m]);
tim += 6;
}
static void
op_exg(u16int op)
{
int n, m;
u32int v;
n = op >> 9 & 7;
m = op & 0xf;
if((op & 0xc8) == 0x48)
n |= 8;
v = r[n];
r[n] = r[m];
r[m] = v;
tim += 6;
}
static void
op_adda_suba(u16int op)
{
int s, n;
vlong a;
n = op >> 9 & 7;
if((op & 0x100) != 0){
s = 2;
if((op & 0x30) == 0 || (op & 0x3f) == 0x3c)
tim += 8;
else
tim += 6;
}else{
s = 1;
tim += 8;
}
a = amode(op >> 3, op, s);
if((op >> 12) == 13)
ra[n] += rmode(a, s);
else
ra[n] -= rmode(a, s);
}
static void
op_addx_subx(u16int op)
{
int s, n, m;
u32int v, w;
vlong src, dst;
s = op >> 6 & 3;
n = op >> 9 & 7;
m = op & 7;
if((op & 8) != 0){
src = amode(4, m, s);
dst = amode(4, n, s);
w = rmode(src, s);
v = rmode(dst, s);
tim += s == 2 ? 10 : 6;
}else{
w = r[m];
v = r[n];
dst = ~n;
tim += s == 2 ? 8 : 4;
}
if((op >> 12) == 13)
v = add(v, w, (rS & FLAGX) != 0, s);
else
v = sub(v, w, (rS & FLAGX) != 0, s);
wmode(dst, s, v);
rS = rS & ~FLAGX | rS << 4 & FLAGX;
}
static void
op_add_sub(u16int op)
{
int s, n, d;
u32int v;
vlong a;
s = op >> 6 & 3;
n = op >> 9 & 7;
a = amode(op >> 3, op, s);
rS |= FLAGZ;
d = (op & 0x100) == 0;
v = rmode(a, s);
if((op >> 12) == 13)
v = add(v, r[n], 0, s);
else
v = sub(d ? r[n] : v, d ? v : r[n], 0, s);
rS = rS & ~FLAGX | rS << 4 & FLAGX;
if(d)
a = ~n;
wmode(a, s, v);
dtime(op, s);
}
static void
shifts(u16int op)
{
int s, n, m;
vlong a;
s = op >> 6 & 3;
if(s == 3){
m = op >> 8 & 7;
n = 1;
s = 1;
a = amode(op >> 3, op, s);
}else{
a = ~(uvlong)(op & 7);
m = op >> 2 & 6 | op >> 8 & 1;
n = (op >> 9) & 7;
if((op & 0x20) != 0)
n = r[n] & 63;
else if(n == 0)
n = 8;
}
wmode(a, s, rot(rmode(a, s), m, n, s));
}
int
step(void)
{
int s;
int n;
static int cnt;
if(0 && pc == 0x4118c){
trace++;
print("%x\n", curpc);
}
// if(pc == 0x410de) trace++;
tim = 0;
curpc = pc;
if(irq && (irqla[(rS >> 8) & 7] & irq) != 0){
trap(-1, curpc);
return tim;
}
if(stop)
return 1;
op = fetch16();
if(trace)
cputrace();
s = op >> 6 & 3;
n = op >> 9 & 7;
switch(op >> 12){
case 0:
if((op & 0x3f) == 0x3c)
ccr_sr_op(op);
else if((op & 0x138) == 0x108)
op_movep(op);
else if((op & 0x100) != 0 || n == 4)
bitop(op);
else
immop(op);
break;
case 1: op_move(op, 0); break;
case 2: op_move(op, 2); break;
case 3: op_move(op, 1); break;
case 4:
if((op & 0x1c0) == 0x1c0)
op_lea(op);
else if((op & 0x1c0) == 0x180)
op_chk(op);
else if((op & 0xb80) == 0x880 && (op & 0x38) >= 0x10)
op_movem(op);
else
switch(op >> 8 & 0xf){
case 0:
if(s == 3)
op_move_from_sr(op);
else
op_negx(op);
break;
case 2: op_clr(op); break;
case 4:
if(s == 3)
op_move_to_ccr(op);
else
op_neg(op);
break;
case 6:
if(s == 3)
op_move_to_sr(op);
else
op_not(op);
break;
case 8:
switch(s){
case 0: op_nbcd(op); break;
case 1:
if((op >> 3 & 7) != 0)
op_pea(op);
else
op_swap(op);
break;
case 2: op_ext_b(op); break;
case 3: op_ext_w(op); break;
}
break;
case 10:
if(s == 3)
op_tas(op);
else
op_tst(op);
break;
case 14:
switch(op >> 4 & 0xf){
case 4: op_trap(op); break;
case 5:
if((op & 8) == 0)
op_link(op);
else
op_unlk(op);
break;
case 6: op_move_usp(op); break;
default:
if((op & 0xc0) == 0xc0)
op_jmp(op);
else if((op & 0x80) == 0x80)
op_jsr(op);
else
switch(op){
case 0x4e70: op_reset(op); break;
case 0x4e71: op_nop(op); break;
case 0x4e72: op_stop(op); break;
case 0x4e73: op_rte(op); break;
case 0x4e75: op_rts(op); break;
case 0x4e76: op_trapv(op); break;
case 0x4e77: op_rtr(op); break;
default: undef();
}
}
break;
default:
undef();
break;
}
break;
case 5:
if((op & 0xf8) == 0xc8)
op_dbcc(op);
else if(s == 3)
op_scc(op);
else if((op & 070) == 010)
op_addq_subq_a(op);
else
op_addq_subq(op);
break;
case 6:
op_bra(op);
break;
case 7:
op_moveq(op);
break;
case 8:
if(s == 3)
op_divu_divs(op);
else if((op & 0x1f0) == 0x100)
op_sbcd(op);
else
logic(op);
break;
case 11:
if(s == 3)
op_cmpa(op);
else if((op & 0x138) == 0x108)
op_cmpm(op);
else if((op & 0x100) == 0)
op_cmp(op);
else
logic(op);
break;
case 12:
if(s == 3)
op_mulu_muls(op);
else if((op & 0x1f0) == 0x100)
op_abcd(op);
else if((op & 0x130) == 0x100)
op_exg(op);
else
logic(op);
break;
case 9:
case 13:
if(s == 3)
op_adda_suba(op);
else if((op & 0x130) == 0x100)
op_addx_subx(op);
else
op_add_sub(op);
break;
case 14:
shifts(op);
break;
case 10:
trap(10, curpc);
break;
case 15:
trap(11, curpc);
break;
default:
undef();
}
return tim;
}