619b1824 |
1 | \r |
2 | // This file is part of the Cyclone 68000 Emulator\r |
3 | \r |
c41b9b97 |
4 | // Copyright (c) 2011 FinalDave (emudave (at) gmail.com)\r |
5 | \r |
619b1824 |
6 | // This code is licensed under the GNU General Public License version 2.0 and the MAME License.\r |
7 | // You can choose the license that has the most advantages for you.\r |
8 | \r |
9 | // SVN repository can be found at http://code.google.com/p/cyclone68000/\r |
10 | \r |
6003a768 |
11 | #include "app.h"\r |
12 | \r |
13 | // --------------------- Opcodes 0x0100+ ---------------------\r |
14 | // Emit a Btst (Register) opcode 0000nnn1 00aaaaaa\r |
15 | int OpBtstReg(int op)\r |
16 | {\r |
17 | int use=0;\r |
18 | int type=0,sea=0,tea=0;\r |
19 | int size=0;\r |
20 | \r |
21 | type=(op>>6)&3;\r |
22 | // Get source and target EA\r |
23 | sea=(op>>9)&7;\r |
24 | tea=op&0x003f;\r |
25 | if (tea<0x10) size=2; // For registers, 32-bits\r |
26 | \r |
27 | if ((tea&0x38)==0x08) return 1; // movep\r |
28 | \r |
29 | // See if we can do this opcode:\r |
30 | if (EaCanRead(tea,0)==0) return 1;\r |
31 | if (type>0)\r |
32 | {\r |
33 | if (EaCanWrite(tea)==0) return 1;\r |
34 | }\r |
35 | \r |
36 | use=OpBase(op);\r |
37 | use&=~0x0e00; // Use same handler for all registers\r |
38 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
39 | \r |
40 | OpStart(op); Cycles=4;\r |
41 | if (tea<0x10) Cycles+=2;\r |
42 | if (type>0) Cycles+=4;\r |
43 | \r |
44 | ot(" mov r10,#1\n");\r |
45 | \r |
46 | EaCalc (0,0x0e00,sea,0);\r |
47 | EaRead (0, 0,sea,0);\r |
48 | ot(" bic r9,r9,#0x40000000 ;@ Blank Z flag\n");\r |
49 | ot(" mov r10,r10,lsl r0 ;@ Make bit mask\n");\r |
50 | ot("\n");\r |
51 | \r |
52 | EaCalc(11,0x003f,tea,size);\r |
53 | EaRead(11, 0,tea,size);\r |
54 | ot(" tst r0,r10 ;@ Do arithmetic\n");\r |
55 | ot(" orreq r9,r9,#0x40000000 ;@ Get Z flag\n");\r |
56 | ot("\n");\r |
57 | \r |
58 | if (type>0)\r |
59 | {\r |
60 | if (type==1) ot(" eor r1,r0,r10 ;@ Toggle bit\n");\r |
61 | if (type==2) ot(" bic r1,r0,r10 ;@ Clear bit\n");\r |
62 | if (type==3) ot(" orr r1,r0,r10 ;@ Set bit\n");\r |
63 | ot("\n");\r |
64 | EaWrite(11, 1,tea,size);\r |
65 | }\r |
66 | OpEnd();\r |
67 | \r |
68 | return 0;\r |
69 | }\r |
70 | \r |
71 | // --------------------- Opcodes 0x0800+ ---------------------\r |
72 | // Emit a Btst/Bchg/Bclr/Bset (Immediate) opcode 00001000 ttaaaaaa nn\r |
73 | int OpBtstImm(int op)\r |
74 | {\r |
75 | int type=0,sea=0,tea=0;\r |
76 | int use=0;\r |
77 | int size=0;\r |
78 | \r |
79 | type=(op>>6)&3;\r |
80 | // Get source and target EA\r |
81 | sea= 0x003c;\r |
82 | tea=op&0x003f;\r |
83 | if (tea<0x10) size=2; // For registers, 32-bits\r |
84 | \r |
85 | // See if we can do this opcode:\r |
86 | if (EaCanRead(tea,0)==0) return 1;\r |
87 | if (type>0)\r |
88 | {\r |
89 | if (EaCanWrite(tea)==0) return 1;\r |
90 | }\r |
91 | \r |
92 | use=OpBase(op);\r |
93 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
94 | \r |
95 | OpStart(op); Cycles=4;\r |
96 | if (type<3 && tea<0x10) Cycles+=2;\r |
97 | if (type>0) Cycles+=4;\r |
98 | \r |
99 | ot(" mov r10,#1\n");\r |
100 | ot("\n");\r |
101 | EaCalc ( 0,0x0000,sea,0);\r |
102 | EaRead ( 0, 0,sea,0);\r |
103 | ot(" bic r9,r9,#0x40000000 ;@ Blank Z flag\n");\r |
104 | ot(" mov r10,r10,lsl r0 ;@ Make bit mask\n");\r |
105 | ot("\n");\r |
106 | \r |
107 | EaCalc (11,0x003f,tea,size);\r |
108 | EaRead (11, 0,tea,size);\r |
109 | ot(" tst r0,r10 ;@ Do arithmetic\n");\r |
110 | ot(" orreq r9,r9,#0x40000000 ;@ Get Z flag\n");\r |
111 | ot("\n");\r |
112 | \r |
113 | if (type>0)\r |
114 | {\r |
115 | if (type==1) ot(" eor r1,r0,r10 ;@ Toggle bit\n");\r |
116 | if (type==2) ot(" bic r1,r0,r10 ;@ Clear bit\n");\r |
117 | if (type==3) ot(" orr r1,r0,r10 ;@ Set bit\n");\r |
118 | ot("\n");\r |
119 | EaWrite(11, 1,tea,size);\r |
120 | }\r |
121 | \r |
122 | OpEnd();\r |
123 | \r |
124 | return 0;\r |
125 | }\r |
126 | \r |
127 | // --------------------- Opcodes 0x4000+ ---------------------\r |
128 | int OpNeg(int op)\r |
129 | {\r |
130 | // 01000tt0 xxeeeeee (tt=negx/clr/neg/not, xx=size, eeeeee=EA)\r |
131 | int type=0,size=0,ea=0,use=0;\r |
132 | \r |
133 | type=(op>>9)&3;\r |
134 | ea =op&0x003f;\r |
135 | size=(op>>6)&3; if (size>=3) return 1;\r |
136 | \r |
137 | switch (type)\r |
138 | {\r |
139 | case 1: case 2: case 3: break;\r |
140 | default: return 1; // todo\r |
141 | }\r |
142 | \r |
143 | // See if we can do this opcode:\r |
144 | if (EaCanRead (ea,size)==0) return 1;\r |
145 | if (EaCanWrite(ea )==0) return 1;\r |
146 | \r |
147 | use=OpBase(op);\r |
148 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
149 | \r |
150 | OpStart(op); Cycles=size<2?4:6;\r |
151 | \r |
152 | EaCalc (10,0x003f,ea,size);\r |
153 | \r |
154 | if (type!=1) EaRead (10,0,ea,size); // Don't need to read for 'clr'\r |
155 | if (type==1) ot("\n");\r |
156 | \r |
157 | if (type==1)\r |
158 | {\r |
159 | ot(";@ Clear:\n");\r |
160 | ot(" mov r1,#0\n");\r |
161 | ot(" mov r9,#0x40000000 ;@ NZCV=0100\n");\r |
162 | ot("\n");\r |
163 | }\r |
164 | \r |
165 | if (type==2)\r |
166 | {\r |
167 | ot(";@ Neg:\n");\r |
168 | ot(" rsbs r1,r0,#0\n");\r |
169 | OpGetFlags(1,1);\r |
170 | ot("\n");\r |
171 | }\r |
172 | \r |
173 | if (type==3)\r |
174 | {\r |
175 | ot(";@ Not:\n");\r |
176 | ot(" mvn r1,r0\n");\r |
177 | ot(" adds r1,r1,#0 ;@ Defines NZ, clears CV\n");\r |
178 | OpGetFlags(0,0);\r |
179 | ot("\n");\r |
180 | }\r |
181 | \r |
182 | EaWrite(10, 1,ea,size);\r |
183 | \r |
184 | OpEnd();\r |
185 | \r |
186 | return 0;\r |
187 | }\r |
188 | \r |
189 | // --------------------- Opcodes 0x4840+ ---------------------\r |
190 | // Swap, 01001000 01000nnn swap Dn\r |
191 | int OpSwap(int op)\r |
192 | {\r |
193 | int ea=0,use=0;\r |
194 | \r |
195 | ea=op&7;\r |
196 | use=op&~0x0007; // Use same opcode for all An\r |
197 | \r |
198 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
199 | \r |
200 | OpStart(op); Cycles=4;\r |
201 | \r |
202 | EaCalc (10,0x0007,ea,2);\r |
203 | EaRead (10, 0,ea,2);\r |
204 | \r |
205 | ot(" mov r1,r0,ror #16\n");\r |
206 | ot(" adds r1,r1,#0 ;@ Defines NZ, clears CV\n");\r |
207 | OpGetFlags(0,0);\r |
208 | \r |
209 | EaWrite(10, 1,8,2);\r |
210 | \r |
211 | OpEnd();\r |
212 | \r |
213 | return 0;\r |
214 | }\r |
215 | \r |
216 | // --------------------- Opcodes 0x4a00+ ---------------------\r |
217 | // Emit a Tst opcode, 01001010 xxeeeeee\r |
218 | int OpTst(int op)\r |
219 | {\r |
220 | int sea=0;\r |
221 | int size=0,use=0;\r |
222 | \r |
223 | sea=op&0x003f;\r |
224 | size=(op>>6)&3; if (size>=3) return 1;\r |
225 | \r |
226 | // See if we can do this opcode:\r |
227 | if (EaCanWrite(sea)==0) return 1;\r |
228 | \r |
229 | use=OpBase(op);\r |
230 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
231 | \r |
232 | OpStart(op); Cycles=4;\r |
233 | \r |
234 | EaCalc ( 0,0x003f,sea,size);\r |
235 | EaRead ( 0, 0,sea,size);\r |
236 | \r |
237 | ot(" adds r0,r0,#0 ;@ Defines NZ, clears CV\n");\r |
238 | ot(" mrs r9,cpsr ;@ r9=flags\n");\r |
239 | ot("\n");\r |
240 | \r |
241 | OpEnd();\r |
242 | return 0;\r |
243 | }\r |
244 | \r |
245 | // --------------------- Opcodes 0x4880+ ---------------------\r |
246 | // Emit an Ext opcode, 01001000 1x000nnn\r |
247 | int OpExt(int op)\r |
248 | {\r |
249 | int ea=0;\r |
250 | int size=0,use=0;\r |
251 | int shift=0;\r |
252 | \r |
253 | ea=op&0x0007;\r |
254 | size=(op>>6)&1;\r |
255 | shift=32-(8<<size);\r |
256 | \r |
257 | use=OpBase(op);\r |
258 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
259 | \r |
260 | OpStart(op); Cycles=4;\r |
261 | \r |
262 | EaCalc (10,0x0007,ea,size+1);\r |
263 | EaRead (10, 0,ea,size+1);\r |
264 | \r |
265 | ot(" mov r0,r0,asl #%d\n",shift);\r |
266 | ot(" adds r0,r0,#0 ;@ Defines NZ, clears CV\n");\r |
267 | ot(" mrs r9,cpsr ;@ r9=flags\n");\r |
268 | ot(" mov r1,r0,asr #%d\n",shift);\r |
269 | ot("\n");\r |
270 | \r |
271 | EaWrite(10, 1,ea,size+1);\r |
272 | \r |
273 | OpEnd();\r |
274 | return 0;\r |
275 | }\r |
276 | \r |
277 | // --------------------- Opcodes 0x50c0+ ---------------------\r |
278 | // Emit a Set cc opcode, 0101cccc 11eeeeee\r |
279 | int OpSet(int op)\r |
280 | {\r |
281 | int cc=0,ea=0;\r |
282 | int size=0,use=0;\r |
283 | char *cond[16]=\r |
284 | {\r |
285 | "al","", "hi","ls","cc","cs","ne","eq",\r |
286 | "vc","vs","pl","mi","ge","lt","gt","le"\r |
287 | };\r |
288 | \r |
289 | cc=(op>>8)&15;\r |
290 | ea=op&0x003f;\r |
291 | \r |
292 | if ((ea&0x38)==0x08) return 1; // dbra, not scc\r |
293 | \r |
294 | // See if we can do this opcode:\r |
295 | if (EaCanWrite(ea)==0) return 1;\r |
296 | \r |
297 | use=OpBase(op);\r |
298 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
299 | \r |
300 | OpStart(op); Cycles=8;\r |
301 | \r |
302 | if (ea<0x10) Cycles=4;\r |
303 | \r |
304 | ot(" mov r1,#0\n");\r |
305 | \r |
306 | if (cc!=1)\r |
307 | {\r |
308 | ot(";@ Is the condition true?\n");\r |
309 | if ((cc&~1)==2) ot(" eor r9,r9,#0x20000000 ;@ Invert carry for hi/ls\n");\r |
310 | ot(" msr cpsr_flg,r9 ;@ ARM flags = 68000 flags\n");\r |
311 | if ((cc&~1)==2) ot(" eor r9,r9,#0x20000000 ;@ Invert carry for hi/ls\n");\r |
312 | ot(" mvn%s r1,r1\n",cond[cc]);\r |
313 | }\r |
314 | \r |
315 | if (ea<0x10) ot(" sub%s r5,r5,#2 ;@ Extra cycles\n",cond[cc]);\r |
316 | ot("\n");\r |
317 | \r |
318 | EaCalc (0,0x003f, ea,size);\r |
319 | EaWrite(0, 1, ea,size);\r |
320 | \r |
321 | OpEnd();\r |
322 | return 0;\r |
323 | }\r |
324 | \r |
325 | // Emit a Asr/Lsr/Roxr/Ror opcode\r |
326 | static int EmitAsr(int op,int type,int dir,int count,int size,int usereg)\r |
327 | {\r |
328 | char pct[8]="";\r |
329 | int shift=32-(8<<size);\r |
330 | \r |
331 | if (count>=1) sprintf(pct,"#%d",count); // Fixed count\r |
332 | \r |
333 | if (count<0)\r |
334 | {\r |
335 | ot(" mov r2,r8,lsr #9 ;@ Get 'n'\n");\r |
336 | ot(" and r2,r2,#7\n\n"); strcpy(pct,"r2");\r |
337 | }\r |
338 | \r |
339 | if (usereg)\r |
340 | {\r |
341 | ot(";@ Use Dn for count:\n");\r |
342 | ot(" ldr r2,[r7,r2,lsl #2]\n");\r |
343 | ot(" and r2,r2,#63\n");\r |
344 | ot("\n");\r |
345 | }\r |
346 | \r |
347 | // Take 2*n cycles:\r |
348 | if (count<0) ot(" sub r5,r5,r2,asl #1 ;@ Take 2*n cycles\n\n");\r |
349 | else Cycles+=count<<1;\r |
350 | \r |
351 | if (type<2)\r |
352 | {\r |
353 | // Asr/Lsr\r |
354 | if (dir==0 && size<2)\r |
355 | {\r |
356 | ot(";@ For shift right, also copy to lowest bits (to get carry bit):\n");\r |
357 | ot(" orr r0,r0,r0,lsr #%d\n",32-(8<<size));\r |
358 | ot("\n");\r |
359 | }\r |
360 | \r |
361 | ot(";@ Shift register:\n");\r |
362 | if (type==0) ot(" movs r0,r0,%s %s\n",dir?"asl":"asr",pct);\r |
363 | if (type==1) ot(" movs r0,r0,%s %s\n",dir?"lsl":"lsr",pct);\r |
364 | OpGetFlags(0,1);\r |
365 | ot("\n");\r |
366 | \r |
367 | if (size<2)\r |
368 | {\r |
369 | ot(";@ Check if result is zero:\n");\r |
370 | ot(" movs r2,r0,lsr #%d\n",shift);\r |
371 | ot(" orreq r9,r9,#0x40000000\n");\r |
372 | ot("\n");\r |
373 | }\r |
374 | }\r |
375 | \r |
376 | // --------------------------------------\r |
377 | if (type==2)\r |
378 | {\r |
379 | // Roxr\r |
380 | int wide=8<<size;\r |
381 | \r |
382 | if (shift) ot(" mov r0,r0,lsr #%d ;@ Shift down\n",shift);\r |
383 | \r |
384 | ot(";@ Rotate register through X:\n");\r |
385 | if (strcmp("r2",pct)!=0) { ot(" mov r2,%s\n",pct); strcpy(pct,"r2"); } // Get into register\r |
386 | \r |
387 | if (count!=8)\r |
388 | {\r |
389 | ot(";@ Reduce r2 until <0:\n");\r |
390 | ot("Reduce_%.4x%s\n",op,ms?"":":");\r |
391 | ot(" subs r2,r2,#%d\n",wide+1);\r |
392 | ot(" bpl Reduce_%.4x\n",op);\r |
393 | ot(" add r2,r2,#%d ;@ Now r2=0-%d\n",wide+1,wide);\r |
394 | ot("\n");\r |
395 | }\r |
396 | \r |
397 | if (dir) ot(" rsb r2,r2,#%d ;@ Reverse direction\n",wide+1);\r |
398 | \r |
399 | ot(";@ Rotate bits:\n");\r |
400 | ot(" mov r3,r0,lsr r2 ;@ Get right part\n");\r |
401 | ot(" rsb r2,r2,#%d\n",wide+1);\r |
402 | ot(" movs r0,r0,lsl r2 ;@ Get left part\n");\r |
403 | ot(" orr r0,r3,r0 ;@ r0=Rotated value\n");\r |
404 | \r |
405 | ot(";@ Insert X bit into r2-1:\n");\r |
406 | ot(" ldrb r3,[r7,#0x45]\n");\r |
407 | ot(" sub r2,r2,#1\n");\r |
408 | ot(" and r3,r3,#2\n");\r |
409 | ot(" mov r3,r3,lsr #1\n");\r |
410 | ot(" orr r0,r0,r3,lsl r2\n");\r |
411 | ot("\n");\r |
412 | \r |
413 | if (shift) ot(" movs r0,r0,lsl #%d ;@ Shift up and get correct NC flags\n",shift);\r |
414 | OpGetFlags(0,1);\r |
415 | ot("\n");\r |
416 | }\r |
417 | \r |
418 | // --------------------------------------\r |
419 | if (type==3)\r |
420 | {\r |
421 | // Ror\r |
422 | if (size<2)\r |
423 | {\r |
424 | ot(";@ Mirror value in whole 32 bits:\n");\r |
425 | if (size<=0) ot(" orr r0,r0,r0,lsr #8\n");\r |
426 | if (size<=1) ot(" orr r0,r0,r0,lsr #16\n");\r |
427 | ot("\n");\r |
428 | }\r |
429 | \r |
430 | ot(";@ Rotate register:\n");\r |
431 | if (count<0)\r |
432 | {\r |
433 | if (dir) ot(" rsb r2,%s,#32\n",pct);\r |
434 | ot(" movs r0,r0,ror %s\n",pct);\r |
435 | }\r |
436 | else\r |
437 | {\r |
438 | int ror=count;\r |
439 | if (dir) ror=32-ror;\r |
440 | if (ror&31) ot(" movs r0,r0,ror #%d\n",ror);\r |
441 | }\r |
442 | \r |
443 | if (dir)\r |
444 | {\r |
445 | ot(";@ Get carry bit from bit 0:\n");\r |
446 | ot(" mov r9,#0\n");\r |
447 | ot(" ands r2,r0,#1\n");\r |
448 | ot(" orrne r9,r9,#0x20000000\n");\r |
449 | }\r |
450 | else\r |
451 | {\r |
452 | OpGetFlags(0,0);\r |
453 | }\r |
454 | ot("\n");\r |
455 | \r |
456 | }\r |
457 | // --------------------------------------\r |
458 | \r |
459 | return 0;\r |
460 | }\r |
461 | \r |
462 | // Emit a Asr/Lsr/Roxr/Ror opcode - 1110cccd xxuttnnn\r |
463 | // (ccc=count, d=direction xx=size extension, u=use reg for count, tt=type, nnn=register Dn)\r |
464 | int OpAsr(int op)\r |
465 | {\r |
466 | int ea=0,use=0;\r |
467 | int count=0,dir=0;\r |
468 | int size=0,usereg=0,type=0;\r |
469 | \r |
470 | ea=0;\r |
471 | count =(op>>9)&7;\r |
472 | dir =(op>>8)&1;\r |
473 | size =(op>>6)&3;\r |
474 | if (size>=3) return 1; // todo Asr EA\r |
475 | usereg=(op>>5)&1;\r |
476 | type =(op>>3)&3;\r |
477 | \r |
478 | if (usereg==0) count=((count-1)&7)+1; // because ccc=000 means 8\r |
479 | \r |
480 | // Use the same opcode for target registers:\r |
481 | use=op&~0x0007;\r |
482 | \r |
483 | // As long as count is not 8, use the same opcode for all shift counts::\r |
484 | if (usereg==0 && count!=8) { use|=0x0e00; count=-1; }\r |
485 | if (usereg) { use&=~0x0e00; count=-1; } // Use same opcode for all Dn\r |
486 | \r |
487 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
488 | \r |
489 | OpStart(op); Cycles=size<2?6:8;\r |
490 | \r |
491 | EaCalc(10,0x0007, ea,size);\r |
492 | EaRead(10, 0, ea,size,1);\r |
493 | \r |
494 | EmitAsr(op,type,dir,count, size,usereg);\r |
495 | \r |
496 | EaWrite(10, 0, ea,size,1);\r |
497 | \r |
498 | OpEnd();\r |
499 | \r |
500 | return 0;\r |
501 | }\r |
502 | \r |
503 | // Asr/l/Ror/l etc EA - 11100ttd 11eeeeee \r |
504 | int OpAsrEa(int op)\r |
505 | {\r |
506 | int use=0,type=0,dir=0,ea=0,size=1;\r |
507 | \r |
508 | type=(op>>9)&3;\r |
509 | dir =(op>>8)&1;\r |
510 | ea = op&0x3f;\r |
511 | \r |
512 | if (ea<0x10) return 1;\r |
513 | // See if we can do this opcode:\r |
514 | if (EaCanRead(ea,0)==0) return 1;\r |
515 | if (EaCanWrite(ea)==0) return 1;\r |
516 | \r |
517 | use=OpBase(op);\r |
518 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
519 | \r |
520 | OpStart(op); Cycles=8;\r |
521 | \r |
522 | EaCalc (10,0x003f,ea,size);\r |
523 | EaRead (10, 0,ea,size,1);\r |
524 | \r |
525 | EmitAsr(op,type,dir,1, size,0);\r |
526 | \r |
527 | ot(";@ Save shifted value back to EA:\n");\r |
528 | ot(" mov r1,r0\n");\r |
529 | EaWrite(10, 1,ea,size,1);\r |
530 | \r |
531 | OpEnd();\r |
532 | return 0;\r |
533 | }\r |