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