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some more optimizations
[picodrive.git] / cpu / Cyclone / Disa / Disa.c
CommitLineData
cc68a136 1\r
2// Dave's Disa 68000 Disassembler\r
3#ifndef __GNUC__\r
4#pragma warning(disable:4115)\r
5#endif\r
6#include <stdio.h>\r
7#include <string.h>\r
8#include "Disa.h"\r
9\r
10unsigned int DisaPc=0;\r
11char *DisaText=NULL; // Text buffer to write in\r
12static char Tasm[]="bwl?";\r
13static char Comment[64]="";\r
14unsigned short (CPU_CALL *DisaWord)(unsigned int a)=NULL;\r
15\r
16static unsigned int DisaLong(unsigned int a)\r
17{\r
18 unsigned int d=0;\r
19 if (DisaWord==NULL) return d;\r
20\r
21 d= DisaWord(a)<<16;\r
22 d|=DisaWord(a+2)&0xffff;\r
23 return d;\r
24}\r
25\r
26// Get text version of the effective address\r
27int DisaGetEa(char *t,int ea,int size)\r
28{\r
29 ea&=0x3f; t[0]=0;\r
30 if ((ea&0x38)==0x00) { sprintf(t,"d%d",ea ); return 0; } // 000rrr\r
31 if ((ea&0x38)==0x08) { sprintf(t,"a%d",ea&7); return 0; } // 001rrr\r
32 if ((ea&0x38)==0x10) { sprintf(t,"(a%d)",ea&7); return 0; } // 010rrr\r
33 if ((ea&0x38)==0x18) { sprintf(t,"(a%d)+",ea&7); return 0; } // 011rrr\r
34 if ((ea&0x38)==0x20) { sprintf(t,"-(a%d)",ea&7); return 0; } // 100rrr\r
35 if ((ea&0x38)==0x28) { sprintf(t,"($%x,a%d)",DisaWord(DisaPc)&0xffff,ea&7); DisaPc+=2; return 0; } // 101rrr\r
36\r
37 if ((ea&0x38)==0x30)\r
38 {\r
39 // 110nnn - An + Disp + D/An\r
40 int areg=0,ext=0,off=0,da=0,reg=0,wol=0,scale=0;\r
41 ext=DisaWord(DisaPc)&0xffff;\r
42 \r
43 areg=ea&7;\r
44 off=ext&0xff; da =ext&0x8000?'a':'d';\r
45 reg=(ext>>12)&7; wol=ext&0x0800?'l':'w';\r
46 scale=1<<((ext>>9)&3);\r
47\r
48 if (scale<2) sprintf(t,"($%x,a%d,%c%d.%c)", off,areg,da,reg,wol);\r
49 else sprintf(t,"($%x,a%d,%c%d.%c*%d)",off,areg,da,reg,wol,scale); // 68020\r
50\r
51 DisaPc+=2;\r
52 return 0;\r
53 }\r
54\r
55 if (ea==0x38) { sprintf(t,"$%x.w",DisaWord(DisaPc)&0xffff); DisaPc+=2; return 0; } // 111000 - Absolute short\r
56 if (ea==0x39) { sprintf(t,"$%x.l",DisaLong(DisaPc)); DisaPc+=4; return 0; } // 111001 - Absolute long\r
57\r
58 if (ea==0x3a)\r
59 {\r
60 // 111010 - PC Relative\r
61 int ext=DisaWord(DisaPc)&0xffff;\r
62 sprintf(t,"($%x,pc)",ext);\r
63 sprintf(Comment,"; =%x",DisaPc+(short)ext); // Comment where pc+ext is\r
64 DisaPc+=2;\r
65 return 0;\r
66 }\r
67\r
68 if (ea==0x3b)\r
69 {\r
70 // 111011 - PC Relative + D/An\r
71 int ext=0,off=0,da=0,reg=0,wol=0,scale=0;\r
72 ext=DisaWord(DisaPc)&0xffff;\r
73 \r
74 off=ext&0xff; da =ext&0x8000?'a':'d';\r
75 reg=(ext>>12)&7; wol=ext&0x0800?'l':'w';\r
76 scale=1<<((ext>>9)&3);\r
77\r
78 if (scale<2) sprintf(t,"($%x,pc,%c%d.%c)", off,da,reg,wol);\r
79 else sprintf(t,"($%x,pc,%c%d.%c*%d)",off,da,reg,wol,scale); // 68020\r
80\r
81 sprintf(Comment,"; =%x",DisaPc+(char)off); // Comment where pc+ext is\r
82 DisaPc+=2;\r
83 return 0;\r
84 }\r
85\r
86 if (ea==0x3c)\r
87 {\r
88 // 111100 - Immediate\r
89 switch (size)\r
90 {\r
91 case 0: sprintf(t,"#$%x",DisaWord(DisaPc)&0x00ff); DisaPc+=2; return 0;\r
92 case 1: sprintf(t,"#$%x",DisaWord(DisaPc)&0xffff); DisaPc+=2; return 0;\r
93 case 2: sprintf(t,"#$%x",DisaLong(DisaPc) ); DisaPc+=4; return 0;\r
94 }\r
95 return 1;\r
96 }\r
97\r
98// Unknown effective address\r
99 sprintf(t,"ea=(%d%d%d %d%d%d)",\r
100 (ea>>5)&1,(ea>>4)&1,(ea>>3)&1,\r
101 (ea>>2)&1,(ea>>1)&1, ea &1);\r
102 return 1;\r
103}\r
104\r
105static void GetOffset(char *text)\r
106{\r
107 int off=(short)DisaWord(DisaPc); DisaPc+=2;\r
108\r
109 if (off<0) sprintf(text,"-$%x",-off);\r
110 else sprintf(text,"$%x", off);\r
111}\r
112\r
113// ================ Opcodes 0x0000+ ================\r
114static int DisaArithImm(int op)\r
115{\r
116 // Or/And/Sub/Add/Eor/Cmp Immediate 0000ttt0 xxDDDddd (tt=type, xx=size extension, DDDddd=Dest ea)\r
117 int dea=0;\r
118 char seat[64]="",deat[64]="";\r
119 int type=0,size=0;\r
120 char *arith[8]={"or","and","sub","add","?","eor","cmp","?"};\r
121\r
122 type=(op>>9)&7; if (type==4 || type>=7) return 1;\r
123 size=(op>>6)&3; if (size>=3) return 1;\r
124 dea=op&0x3f; if (dea==0x3c) return 1;\r
125\r
126 DisaGetEa(seat,0x3c,size);\r
127 DisaGetEa(deat,dea, size);\r
128\r
129 sprintf(DisaText,"%si.%c %s, %s",arith[type],Tasm[size],seat,deat);\r
130 return 0;\r
131}\r
132\r
133// ================ Opcodes 0x0108+ ================\r
134static int DisaMovep(int op)\r
135{\r
136 // movep.x (Aa),Dn - 0000nnn1 dx001aaa nn\r
137 int dn=0,dir=0,size=0,an=0;\r
138 char offset[32]="";\r
139\r
140 dn =(op>>9)&7;\r
141 dir =(op>>7)&1;\r
142 size=(op>>6)&1; size++;\r
143 an = op &7;\r
144\r
145 GetOffset(offset);\r
146 if (dir) sprintf(DisaText,"movep.%c d%d, (%s,a%d)",Tasm[size],dn,offset,an);\r
147 else sprintf(DisaText,"movep.%c (%s,a%d), d%d",Tasm[size],offset,an,dn);\r
148\r
149 return 0;\r
150}\r
151\r
152// ================ Opcodes 0x007c+ ================\r
153static int DisaArithSr(int op)\r
154{\r
155 // Ori/Andi/Eori $nnnn,sr 0000t0tx 0s111100\r
156 char *opcode[6]={"ori","andi","","","","eori"};\r
157 char seat[64]="";\r
158 int type=0,size=0;\r
159\r
160 type=(op>>9)&5;\r
161 size=(op>>6)&1;\r
162\r
163 DisaGetEa(seat,0x3c,size);\r
164 sprintf(DisaText,"%s.%c %s, %s", opcode[type], Tasm[size], seat, size?"sr":"ccr");\r
165\r
166 return 0;\r
167}\r
168\r
169// ================ Opcodes 0x0100+ ================\r
170static int DisaBtstReg(int op)\r
171{\r
172 // Btst/Bchg/Bclr/Bset 0000nnn1 tteeeeee (nn=reg number, eeeeee=Dest ea)\r
173 int type=0;\r
174 int sea=0,dea=0;\r
175 char seat[64]="",deat[64]="";\r
176 char *opcode[4]={"btst","bchg","bclr","bset"};\r
177\r
178 sea =(op>>9)&7;\r
179 type=(op>>6)&3;\r
180 dea= op&0x3f;\r
181\r
182 if ((dea&0x38)==0x08) return 1; // movep\r
183 DisaGetEa(seat,sea,0);\r
184 DisaGetEa(deat,dea,0);\r
185\r
186 sprintf(DisaText,"%s %s, %s",opcode[type],seat,deat);\r
187 return 0;\r
188}\r
189\r
190// ================ Opcodes 0x0800+ ================\r
191static int DisaBtstImm(int op)\r
192{\r
193 // Btst/Bchg/Bclr/Bset 00001000 tteeeeee 00 nn (eeeeee=ea, nn=bit number)\r
194 int type=0;\r
195 char seat[64]="",deat[64]="";\r
196 char *opcode[4]={"btst","bchg","bclr","bset"};\r
197\r
198 type=(op>>6)&3;\r
199 DisaGetEa(seat, 0x3c,0);\r
200 DisaGetEa(deat,op&0x3f,0);\r
201\r
202 sprintf(DisaText,"%s %s, %s",opcode[type],seat,deat);\r
203 return 0;\r
204}\r
205\r
206// ================ Opcodes 0x1000+ ================\r
207static int DisaMove(int op)\r
208{\r
209 // Move 00xxdddD DDssssss (xx=size extension, ssssss=Source EA, DDDddd=Dest ea)\r
210 int sea=0,dea=0;\r
211 char inst[64]="",seat[64]="",deat[64]="";\r
212 char *movea="";\r
213 int size=0;\r
214\r
215 if ((op&0x01c0)==0x0040) movea="a"; // See if it's a movea opcode\r
216\r
217 // Find size extension\r
218 switch (op&0x3000)\r
219 {\r
220 case 0x1000: size=0; break;\r
221 case 0x3000: size=1; break;\r
222 case 0x2000: size=2; break;\r
223 default: return 1;\r
224 }\r
225\r
226 sea = op&0x003f;\r
227 DisaGetEa(seat,sea,size);\r
228 \r
229 dea =(op&0x01c0)>>3;\r
230 dea|=(op&0x0e00)>>9;\r
231 DisaGetEa(deat,dea,size);\r
232\r
233 sprintf(inst,"move%s.%c",movea,Tasm[size]);\r
234 sprintf(DisaText,"%s %s, %s",inst,seat,deat);\r
235 return 0;\r
236}\r
237\r
238// ================ Opcodes 0x4000+ ================\r
239static int DisaNeg(int op)\r
240{\r
241 // 01000tt0 xxeeeeee (tt=negx/clr/neg/not, xx=size, eeeeee=EA)\r
242 char eat[64]="";\r
243 int type=0,size=0;\r
244 char *opcode[4]={"negx","clr","neg","not"};\r
245\r
246 type=(op>>9)&3;\r
247 size=(op>>6)&3; if (size>=3) return 1;\r
248 DisaGetEa(eat,op&0x3f,size);\r
249\r
250 sprintf(DisaText,"%s.%c %s",opcode[type],Tasm[size],eat);\r
251 return 0;\r
252}\r
253\r
254// ================ Opcodes 0x40c0+ ================\r
255static int DisaMoveSr(int op)\r
256{\r
257 // 01000tt0 11eeeeee (tt=type, xx=size, eeeeee=EA)\r
258 int type=0,ea=0;\r
259 char eat[64]="";\r
260\r
261 type=(op>>9)&3;\r
262 ea=op&0x3f;\r
263 DisaGetEa(eat,ea,1);\r
264\r
265 switch (type)\r
266 {\r
267 default: sprintf(DisaText,"move sr, %s", eat); break;\r
268 case 1: sprintf(DisaText,"move ccr, %s",eat); break;\r
269 case 2: sprintf(DisaText,"move %s, ccr",eat); break;\r
270 case 3: sprintf(DisaText,"move %s, sr", eat); break;\r
271 }\r
272 return 0;\r
273}\r
274\r
275// ================ Opcodes 0x41c0+ ================\r
276static int DisaLea(int op)\r
277{\r
278 // Lea 0100nnn1 11eeeeee (eeeeee=ea)\r
279 int sea=0,dea=0;\r
280 char seat[64]="",deat[64]="";\r
281\r
282 sea=op&0x003f;\r
283 DisaGetEa(seat,sea,0);\r
284\r
285 dea=(op>>9)&7; dea|=8;\r
286 DisaGetEa(deat,dea,2);\r
287\r
288 sprintf(DisaText,"lea %s, %s",seat,deat);\r
289 return 0;\r
290}\r
291\r
292static int MakeRegList(char *list,int mask,int ea)\r
293{\r
294 int reverse=0,i=0,low=0,len=0;\r
295\r
296 if ((ea&0x38)==0x20) reverse=1; // -(An), bitfield is reversed\r
297\r
298 mask&=0xffff; list[0]=0;\r
299\r
300 for (i=0;i<17;i++)\r
301 {\r
302 int bit=0;\r
303 \r
304 // Mask off bit i:\r
305 if (reverse) bit=0x8000>>i; else bit=1<<i;\r
306 bit&=mask;\r
307\r
308 if (bit==0 || i==8)\r
309 {\r
310 // low to i-1 are a continuous section, add it:\r
311 char add[16]="";\r
312 int ad=low&8?'a':'d';\r
313 if (low==i-1) sprintf(add,"%c%d/", ad,low&7);\r
314 if (low< i-1) sprintf(add,"%c%d-%c%d/",ad,low&7, ad,(i-1)&7);\r
315 strcat(list,add);\r
316\r
317 low=i; // Next section\r
318 }\r
319\r
320 if (bit==0) low=i+1;\r
321 }\r
322\r
323 // Knock off trailing '/'\r
324 len=strlen(list);\r
325 if (len>0) if (list[len-1]=='/') list[len-1]=0; \r
326 return 0;\r
327}\r
328\r
329// ================ Opcodes 0x4840+ ================\r
330static int DisaSwap(int op)\r
331{\r
332 // Swap, 01001000 01000nnn swap Dn\r
333 sprintf(DisaText,"swap d%d",op&7);\r
334 return 0;\r
335}\r
336\r
337// ================ Opcodes 0x4850+ ================\r
338static int DisaPea(int op)\r
339{\r
340 // Pea 01001000 01eeeeee (eeeeee=ea) pea \r
341 int ea=0;\r
342 char eat[64]="";\r
343\r
344 ea=op&0x003f; if (ea<0x10) return 1; // swap opcode\r
345 DisaGetEa(eat,ea,2);\r
346\r
347 sprintf(DisaText,"pea %s",eat);\r
348 return 0;\r
349}\r
350\r
351// ================ Opcodes 0x4880+ ================\r
352static int DisaExt(int op)\r
353{\r
354 // Ext 01001000 1x000nnn (x=size, eeeeee=EA)\r
355 char eat[64]="";\r
356 int size=0;\r
357\r
358 size=(op>>6)&1; size++;\r
359 DisaGetEa(eat,op&0x3f,size);\r
360\r
361 sprintf(DisaText,"ext.%c %s",Tasm[size],eat);\r
362 return 0;\r
363}\r
364\r
365// ================ Opcodes 0x4890+ ================\r
366static int DisaMovem(int op)\r
367{\r
368 // Movem 01001d00 1xeeeeee regmask d=direction, x=size, eeeeee=EA\r
369 int dir=0,size=0;\r
370 int ea=0,mask=0;\r
371 char list[64]="",eat[64]="";\r
372\r
373 dir=(op>>10)&1;\r
374 size=((op>>6)&1)+1;\r
375 ea=op&0x3f; if (ea<0x10) return 1; // ext opcode\r
376\r
377 mask=DisaWord(DisaPc)&0xffff; DisaPc+=2;\r
378\r
379 MakeRegList(list,mask,ea); // Turn register mask into text\r
380 DisaGetEa(eat,ea,size);\r
381\r
382 if (dir) sprintf(DisaText,"movem.%c %s, %s",Tasm[size],eat,list);\r
383 else sprintf(DisaText,"movem.%c %s, %s",Tasm[size],list,eat);\r
384 return 0;\r
385}\r
386\r
387// ================ Opcodes 0x4e40+ ================\r
388static int DisaTrap(int op)\r
389{\r
390 sprintf(DisaText,"trap #%d",op&0xf);\r
391 return 0;\r
392}\r
393\r
394// ================ Opcodes 0x4e50+ ================\r
395static int DisaLink(int op)\r
396{\r
397 // Link opcode, 01001110 01010nnn dd link An,#offset\r
398 char eat[64]="";\r
399 char offset[32]="";\r
400\r
401 DisaGetEa(eat,(op&7)|8,0);\r
402 GetOffset(offset);\r
403\r
404 sprintf(DisaText,"link %s,#%s",eat,offset);\r
405\r
406 return 0;\r
407}\r
408\r
409// ================ Opcodes 0x4e58+ ================\r
410static int DisaUnlk(int op)\r
411{\r
412 // Link opcode, 01001110 01011nnn dd unlk An\r
413 char eat[64]="";\r
414\r
415 DisaGetEa(eat,(op&7)|8,0);\r
416 sprintf(DisaText,"unlk %s",eat);\r
417\r
418 return 0;\r
419}\r
420\r
421// ================ Opcodes 0x4e60+ ================\r
422static int DisaMoveUsp(int op)\r
423{\r
424 // Move USP opcode, 01001110 0110dnnn move An to/from USP (d=direction)\r
425 int ea=0,dir=0;\r
426 char eat[64]="";\r
427\r
428 dir=(op>>3)&1;\r
429 ea=(op&7)|8;\r
430 DisaGetEa(eat,ea,0);\r
431\r
432 if (dir) sprintf(DisaText,"move usp, %s",eat);\r
433 else sprintf(DisaText,"move %s, usp",eat);\r
434 return 0;\r
435}\r
436\r
437// ================ Opcodes 0x4e70+ ================\r
438static int Disa4E70(int op)\r
439{\r
440 char *inst[8]={"reset","nop","stop","rte","rtd","rts","trapv","rtr"};\r
441 int n=0;\r
442\r
443 n=op&7;\r
444\r
445 sprintf(DisaText,"%s",inst[n]);\r
446\r
447 //todo - 'stop' with 16 bit data\r
448 \r
449 return 0;\r
450}\r
451\r
452// ================ Opcodes 0x4a00+ ================\r
453static int DisaTst(int op)\r
454{\r
455 // Tst 01001010 xxeeeeee (eeeeee=ea)\r
456 int ea=0;\r
457 char eat[64]="";\r
458 int size=0;\r
459\r
460 ea=op&0x003f;\r
461 DisaGetEa(eat,ea,0);\r
462 size=(op>>6)&3; if (size>=3) return 1;\r
463\r
464 sprintf(DisaText,"tst.%c %s",Tasm[size],eat);\r
465 return 0;\r
466}\r
467\r
468// ================ Opcodes 0x4e80+ ================\r
469static int DisaJsr(int op)\r
470{\r
471 // Jsr/Jmp 0100 1110 1mEE Eeee (eeeeee=ea m=1=jmp)\r
472 int sea=0;\r
473 char seat[64]="";\r
474\r
475 sea=op&0x003f;\r
476 DisaGetEa(seat,sea,0);\r
477\r
478 sprintf(DisaText,"j%s %s", op&0x40?"mp":"sr", seat);\r
479 return 0;\r
480}\r
481\r
482// ================ Opcodes 0x5000+ ================\r
483static int DisaAddq(int op)\r
484{\r
485 // 0101nnnt xxeeeeee (nnn=#8,1-7 t=addq/subq xx=size, eeeeee=EA)\r
486 int num=0,type=0,size=0,ea=0;\r
487 char eat[64]="";\r
488\r
489 num =(op>>9)&7; if (num==0) num=8;\r
490 type=(op>>8)&1;\r
491 size=(op>>6)&3; if (size>=3) return 1;\r
492 ea = op&0x3f;\r
493\r
494 DisaGetEa(eat,ea,size);\r
495\r
496 sprintf(DisaText,"%s.%c #%d, %s",type?"subq":"addq",Tasm[size],num,eat);\r
497 return 0;\r
498}\r
499\r
500// ================ Opcodes 0x50c0+ ================\r
501static int DisaSet(int op)\r
502{\r
503 // 0101cccc 11eeeeee (sxx ea)\r
504 static char *cond[16]=\r
505 {"t" ,"f", "hi","ls","cc","cs","ne","eq",\r
506 "vc","vs","pl","mi","ge","lt","gt","le"};\r
507 char *cc="";\r
508 int ea=0;\r
509 char eat[64]="";\r
510\r
511 cc=cond[(op>>8)&0xf]; // Get condition code\r
512 ea=op&0x3f;\r
513 if ((ea&0x38)==0x08) return 1; // dbra, not scc\r
514\r
515 DisaGetEa(eat,ea,0);\r
516 sprintf(DisaText,"s%s %s",cc,eat);\r
517 return 0;\r
518}\r
519\r
520// ================ Opcodes 0x50c8+ ================\r
521static int DisaDbra(int op)\r
522{\r
523 // 0101cccc 11001nnn offset (dbra/dbxx Rn,offset)\r
524 int dea=0; char deat[64]="";\r
525 int pc=0,Offset=0;\r
526\r
527 static char *BraCode[16]=\r
528 {"bt" ,"bra","bhi","bls","bcc","bcs","bne","beq",\r
529 "bvc","bvs","bpl","bmi","bge","blt","bgt","ble"};\r
530 char *Bra="";\r
531\r
532 dea=op&7;\r
533 DisaGetEa(deat,dea,2);\r
534\r
535 // Get condition code\r
536 Bra=BraCode[(op>>8)&0xf];\r
537\r
538 // Get offset\r
539 pc=DisaPc;\r
540 Offset=(short)DisaWord(DisaPc); DisaPc+=2;\r
541\r
542 sprintf(DisaText,"d%s %s, %x",Bra,deat,pc+Offset);\r
543 return 0;\r
544}\r
545\r
546// ================ Opcodes 0x6000+ ================\r
547static int DisaBranch(int op)\r
548{\r
549 // Branch 0110cccc nn (cccc=condition)\r
550 int pc=0,Offset=0;\r
551\r
552 static char *BraCode[16]=\r
553 {"bra","bsr","bhi","bls","bcc","bcs","bne","beq",\r
554 "bvc","bvs","bpl","bmi","bge","blt","bgt","ble"};\r
555 char *Bra="";\r
556\r
557 // Get condition code\r
558 Bra=BraCode[(op>>8)&0x0f];\r
559\r
560 // Get offset\r
561 pc=DisaPc;\r
562 Offset=(char)(op&0xff);\r
563 if (Offset== 0) { Offset=(short)DisaWord(DisaPc); DisaPc+=2; }\r
564 else if (Offset==-1) { Offset= DisaLong(DisaPc); DisaPc+=4; }\r
565\r
566 sprintf(DisaText,"%s %x",Bra,pc+Offset);\r
567 return 0;\r
568}\r
569\r
570// ================ Opcodes 0x7000+ ================\r
571static int DisaMoveq(int op)\r
572{\r
573 // Moveq 0111rrr0 nn (rrr=Dest register, nn=data)\r
574\r
575 int dea=0; char deat[64]="";\r
576 char *inst="moveq";\r
577 int val=0;\r
578\r
579 dea=(op>>9)&7;\r
580 DisaGetEa(deat,dea,2);\r
581\r
582 val=(char)(op&0xff);\r
583 sprintf(DisaText,"%s #$%x, %s",inst,val,deat);\r
584 return 0;\r
585}\r
586\r
587// ================ Opcodes 0x8000+ ================\r
588static int DisaArithReg(int op)\r
589{\r
590 // 1t0tnnnd xxeeeeee (tt=type:or/sub/and/add xx=size, eeeeee=EA)\r
591 int type=0,size=0,dir=0,rea=0,ea=0;\r
592 char reat[64]="",eat[64]="";\r
593 char *opcode[]={"or","sub","","","and","add"};\r
594\r
595 type=(op>>12)&5;\r
596 rea =(op>> 9)&7;\r
597 dir =(op>> 8)&1;\r
598 size=(op>> 6)&3; if (size>=3) return 1;\r
599 ea = op&0x3f;\r
600\r
601 if (dir && ea<0x10) return 1; // addx opcode\r
602\r
603 DisaGetEa(reat,rea,size);\r
604 DisaGetEa( eat, ea,size);\r
605\r
606 if (dir) sprintf(DisaText,"%s.%c %s, %s",opcode[type],Tasm[size],reat,eat);\r
607 else sprintf(DisaText,"%s.%c %s, %s",opcode[type],Tasm[size],eat,reat);\r
608 return 0;\r
609}\r
610\r
611// ================ Opcodes 0x8100+ ================\r
612static int DisaAbcd(int op)\r
613{\r
614 // 1t00ddd1 0000asss - sbcd/abcd Ds,Dd or -(As),-(Ad)\r
615 int type=0;\r
616 int dn=0,addr=0,sn=0;\r
617 char *opcode[]={"sbcd","abcd"};\r
618\r
619 type=(op>>14)&1;\r
620 dn =(op>> 9)&7;\r
621 addr=(op>> 3)&1;\r
622 sn = op &7;\r
623\r
624 if (addr) sprintf(DisaText,"%s -(a%d), -(a%d)",opcode[type],sn,dn);\r
625 else sprintf(DisaText,"%s d%d, d%d", opcode[type],sn,dn);\r
626\r
627 return 0;\r
628}\r
629\r
630// ================ Opcodes 0x80c0+ ================\r
631static int DisaMul(int op)\r
632{\r
633 // Div/Mul: 1m00nnns 11eeeeee (m=Mul, nnn=Register Dn, s=signed, eeeeee=EA)\r
634 int type=0,rea=0,sign=0,ea=0,size=1;\r
635 char reat[64]="",eat[64]="";\r
636 char *opcode[2]={"div","mul"};\r
637\r
638 type=(op>>14)&1; // div/mul\r
639 rea =(op>> 9)&7;\r
640 sign=(op>> 8)&1;\r
641 ea = op&0x3f;\r
642\r
643 DisaGetEa(reat,rea,size);\r
644 DisaGetEa( eat, ea,size);\r
645\r
646 sprintf(DisaText,"%s%c.%c %s, %s",opcode[type],sign?'s':'u',Tasm[size],eat,reat);\r
647 return 0;\r
648}\r
649\r
650// ================ Opcodes 0x90c0+ ================\r
651static int DisaAritha(int op)\r
652{\r
653 // Suba/Cmpa/Adda 1tt1nnnx 11eeeeee (tt=type, x=size, eeeeee=Source EA)\r
654 int type=0,size=0,sea=0,dea=0;\r
655 char seat[64]="",deat[64]="";\r
656 char *aritha[4]={"suba","cmpa","adda",""};\r
657\r
658 type=(op>>13)&3; if (type>=3) return 1;\r
659 size=(op>>8)&1; size++;\r
660 dea =(op>>9)&7; dea|=8; // Dest=An\r
661 sea = op&0x003f; // Source\r
662\r
663 DisaGetEa(seat,sea,size);\r
664 DisaGetEa(deat,dea,size);\r
665\r
666 sprintf(DisaText,"%s.%c %s, %s",aritha[type],Tasm[size],seat,deat);\r
667 return 0;\r
668}\r
669\r
670// ================ Opcodes 0xb000+ ================\r
671static int DisaCmpEor(int op)\r
672{\r
673 // Cmp/Eor 1011rrrt xxeeeeee (rrr=Dn, t=cmp/eor, xx=size extension, eeeeee=ea)\r
674 char reat[64]="",eat[64]="";\r
675 int type=0,size=0;\r
676\r
677 type=(op>>8)&1;\r
678 size=(op>>6)&3; if (size>=3) return 1;\r
679 DisaGetEa(reat,(op>>9)&7,size);\r
680 DisaGetEa(eat, op&0x3f, size);\r
681\r
682 if (type) sprintf(DisaText,"eor.%c %s, %s",Tasm[size],reat,eat);\r
683 else sprintf(DisaText,"cmp.%c %s, %s",Tasm[size],eat,reat);\r
684 return 0;\r
685}\r
686\r
687// ================ Opcodes 0xc140+ ================\r
688// 1100ttt1 01000sss exg ds,dt\r
689// 1100ttt1 01001sss exg as,at\r
690// 1100ttt1 10001sss exg as,dt\r
691static int DisaExg(int op)\r
692{\r
693 int tr=0,type=0,sr=0;\r
694\r
695 tr =(op>>9)&7;\r
696 type= op&0xf8;\r
697 sr = op&7;\r
698\r
699 if (type==0x40) sprintf(DisaText,"exg d%d, d%d",sr,tr);\r
700 else if (type==0x48) sprintf(DisaText,"exg a%d, a%d",sr,tr);\r
701 else if (type==0x88) sprintf(DisaText,"exg a%d, d%d",sr,tr);\r
702 else return 1;\r
703\r
704 return 0;\r
705}\r
706\r
707// ================ Opcodes 0xd100+ ================\r
708static int DisaAddx(int op)\r
709{\r
710 // 1t01ddd1 xx000sss addx\r
711 int type=0,size=0,dea=0,sea=0;\r
712 char deat[64]="",seat[64]="";\r
713 char *opcode[6]={"","subx","","","","addx"};\r
714\r
715 type=(op>>12)&5;\r
716 dea =(op>> 9)&7;\r
717 size=(op>> 6)&3; if (size>=3) return 1;\r
718 sea = op&0x3f;\r
719\r
720 DisaGetEa(deat,dea,size);\r
721 DisaGetEa(seat,sea,size);\r
722\r
723 sprintf(DisaText,"%s.%c %s, %s",opcode[type],Tasm[size],seat,deat);\r
724 return 0;\r
725}\r
726\r
727// ================ Opcodes 0xe000+ ================\r
728static char *AsrName[4]={"as","ls","rox","ro"};\r
729static int DisaAsr(int op)\r
730{\r
731 // Asr/l/Ror/l etc - 1110cccd xxuttnnn\r
732 // (ccc=count, d=direction xx=size extension, u=use reg for count, tt=type, nnn=register Dn)\r
733 int count=0,dir=0,size=0,usereg=0,type=0,num=0;\r
734\r
735 count =(op>>9)&7;\r
736 dir =(op>>8)&1;\r
737 size =(op>>6)&3; if (size>=3) return 1; // todo Asr EA\r
738 usereg=(op>>5)&1;\r
739 type =(op>>3)&3;\r
740 num = op &7; // Register number\r
741\r
742 if (usereg==0) count=((count-1)&7)+1; // because ccc=000 means 8\r
743\r
744 sprintf(DisaText,"%s%c.%c %c%d, d%d",\r
745 AsrName[type], dir?'l':'r', Tasm[size],\r
746 usereg?'d':'#', count, num);\r
747 return 0;\r
748}\r
749\r
750static int DisaAsrEa(int op)\r
751{\r
752 // Asr/l/Ror/l etc EA - 11100ttd 11eeeeee \r
753 int type=0,dir=0,size=1;\r
754 char eat[64]="";\r
755\r
756 type=(op>>9)&3;\r
757 dir =(op>>8)&1;\r
758 DisaGetEa(eat,op&0x3f,size);\r
759\r
760 sprintf(DisaText,"%s%c.w %s", AsrName[type], dir?'l':'r', eat);\r
761 return 0;\r
762}\r
763\r
764// =================================================================\r
765\r
766static int TryOp(int op)\r
767{\r
768 if ((op&0xf100)==0x0000) DisaArithImm(op); // Ori/And/Sub/Add/Eor/Cmp Immediate\r
769 if ((op&0xf5bf)==0x003c) DisaArithSr(op); // Ori/Andi/Eori $nnnn,sr\r
770 if ((op&0xf100)==0x0100) DisaBtstReg(op);\r
771 if ((op&0xf138)==0x0108) DisaMovep(op);\r
772 if ((op&0xff00)==0x0800) DisaBtstImm(op); // Btst/Bchg/Bclr/Bset\r
773 if ((op&0xc000)==0x0000) DisaMove(op);\r
774 if ((op&0xf900)==0x4000) DisaNeg(op); // Negx/Clr/Neg/Not\r
775 if ((op&0xf1c0)==0x41c0) DisaLea(op);\r
776 if ((op&0xf9c0)==0x40c0) DisaMoveSr(op);\r
777 if ((op&0xfff8)==0x4840) DisaSwap(op);\r
778 if ((op&0xffc0)==0x4840) DisaPea(op);\r
779 if ((op&0xffb8)==0x4880) DisaExt(op);\r
780 if ((op&0xfb80)==0x4880) DisaMovem(op);\r
781 if ((op&0xff00)==0x4a00) DisaTst(op);\r
782 if ((op&0xfff0)==0x4e40) DisaTrap(op);\r
783 if ((op&0xfff8)==0x4e50) DisaLink(op);\r
784 if ((op&0xfff8)==0x4e58) DisaUnlk(op);\r
785 if ((op&0xfff0)==0x4e60) DisaMoveUsp(op);\r
786 if ((op&0xfff8)==0x4e70) Disa4E70(op);\r
787 if ((op&0xff80)==0x4e80) DisaJsr(op);\r
788 if ((op&0xf000)==0x5000) DisaAddq(op);\r
789 if ((op&0xf0c0)==0x50c0) DisaSet(op);\r
790 if ((op&0xf0f8)==0x50c8) DisaDbra(op);\r
791 if ((op&0xf000)==0x6000) DisaBranch(op);\r
792 if ((op&0xa000)==0x8000) DisaArithReg(op); // Or/Sub/And/Add\r
793 if ((op&0xb1f0)==0x8100) DisaAbcd(op);\r
794 if ((op&0xb130)==0x9100) DisaAddx(op);\r
795 if ((op&0xb0c0)==0x80c0) DisaMul(op);\r
796 if ((op&0xf100)==0x7000) DisaMoveq(op);\r
797 if ((op&0x90c0)==0x90c0) DisaAritha(op);\r
798 if ((op&0xf000)==0xb000) DisaCmpEor(op);\r
799 if ((op&0xf130)==0xc100) DisaExg(op);\r
800 if ((op&0xf000)==0xe000) DisaAsr(op);\r
801 if ((op&0xf8c0)==0xe0c0) DisaAsrEa(op);\r
802\r
803 // Unknown opcoode\r
804 return 0;\r
805}\r
806\r
807int DisaGet()\r
808{\r
809 int op=0;\r
810 if (DisaWord==NULL) return 1;\r
811\r
812 Comment[0]=0;\r
813 DisaText[0]=0; // Assume opcode unknown\r
814\r
815 op=DisaWord(DisaPc)&0xffff; DisaPc+=2;\r
816 TryOp(op);\r
817 strcat(DisaText,Comment);\r
818\r
819 // Unknown opcoode\r
820 return 0;\r
821}\r
fast MegaDrive/MegaCD/32X emulator