xref: /netbsd-src/external/gpl3/binutils.old/dist/opcodes/arc-dis.c (revision d909946ca08dceb44d7d0f22ec9488679695d976)
1 /* Instruction printing code for the ARC.
2    Copyright 1994, 1995, 1997, 1998, 2000, 2001, 2002, 2005, 2007, 2009,
3    2010, 2012 Free Software Foundation, Inc.
4    Contributed by Doug Evans (dje@cygnus.com).
5 
6    This file is part of libopcodes.
7 
8    This library is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3, or (at your option)
11    any later version.
12 
13    It is distributed in the hope that it will be useful, but WITHOUT
14    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
16    License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with this program; if not, write to the Free Software
20    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21    MA 02110-1301, USA.  */
22 
23 #include "sysdep.h"
24 #include "libiberty.h"
25 #include "dis-asm.h"
26 #include "opcode/arc.h"
27 #include "elf-bfd.h"
28 #include "elf/arc.h"
29 #include "opintl.h"
30 
31 #include <stdarg.h>
32 #include "arc-dis.h"
33 #include "arc-ext.h"
34 
35 #ifndef dbg
36 #define dbg (0)
37 #endif
38 
39 /* Classification of the opcodes for the decoder to print
40    the instructions.  */
41 
42 typedef enum
43 {
44   CLASS_A4_ARITH,
45   CLASS_A4_OP3_GENERAL,
46   CLASS_A4_FLAG,
47   /* All branches other than JC.  */
48   CLASS_A4_BRANCH,
49   CLASS_A4_JC ,
50   /* All loads other than immediate
51      indexed loads.  */
52   CLASS_A4_LD0,
53   CLASS_A4_LD1,
54   CLASS_A4_ST,
55   CLASS_A4_SR,
56   /* All single operand instructions.  */
57   CLASS_A4_OP3_SUBOPC3F,
58   CLASS_A4_LR
59 } a4_decoding_class;
60 
61 #define BIT(word,n)	((word) & (1 << n))
62 #define BITS(word,s,e)  (((word) >> s) & ((1 << (e + 1 - s)) - 1))
63 #define OPCODE(word)	(BITS ((word), 27, 31))
64 #define FIELDA(word)	(BITS ((word), 21, 26))
65 #define FIELDB(word)	(BITS ((word), 15, 20))
66 #define FIELDC(word)	(BITS ((word),  9, 14))
67 
68 /* FIELD D is signed.  */
69 #define FIELDD(word)	((BITS ((word), 0, 8) ^ 0x100) - 0x100)
70 
71 #define PUT_NEXT_WORD_IN(a)						\
72   do									\
73     {									\
74       if (is_limm == 1 && !NEXT_WORD (1))				\
75         mwerror (state, _("Illegal limm reference in last instruction!\n")); \
76       a = state->words[1];						\
77     }									\
78   while (0)
79 
80 #define CHECK_FLAG_COND_NULLIFY()				\
81   do								\
82     {								\
83       if (is_shimm == 0)					\
84         {							\
85           flag = BIT (state->words[0], 8);			\
86           state->nullifyMode = BITS (state->words[0], 5, 6);	\
87           cond = BITS (state->words[0], 0, 4);			\
88         }							\
89     }								\
90   while (0)
91 
92 #define CHECK_COND()				\
93   do						\
94     {						\
95       if (is_shimm == 0)			\
96         cond = BITS (state->words[0], 0, 4);	\
97     }						\
98   while (0)
99 
100 #define CHECK_FIELD(field)			\
101   do						\
102     {						\
103       if (field == 62)				\
104         {					\
105           is_limm++;				\
106 	  field##isReg = 0;			\
107 	  PUT_NEXT_WORD_IN (field);		\
108 	  limm_value = field;			\
109 	}					\
110       else if (field > 60)			\
111         {					\
112 	  field##isReg = 0;			\
113 	  is_shimm++;				\
114 	  flag = (field == 61);			\
115 	  field = FIELDD (state->words[0]);	\
116 	}					\
117     }						\
118   while (0)
119 
120 #define CHECK_FIELD_A()				\
121   do						\
122     {						\
123       fieldA = FIELDA (state->words[0]);	\
124       if (fieldA > 60)				\
125         {					\
126 	  fieldAisReg = 0;			\
127 	  fieldA = 0;				\
128 	}					\
129     }						\
130   while (0)
131 
132 #define CHECK_FIELD_B()				\
133   do						\
134     {						\
135       fieldB = FIELDB (state->words[0]);	\
136       CHECK_FIELD (fieldB);			\
137     }						\
138   while (0)
139 
140 #define CHECK_FIELD_C()				\
141   do						\
142     {						\
143       fieldC = FIELDC (state->words[0]);	\
144       CHECK_FIELD (fieldC);			\
145     }						\
146   while (0)
147 
148 #define IS_SMALL(x)                 (((field##x) < 256) && ((field##x) > -257))
149 #define IS_REG(x)                    (field##x##isReg)
150 #define WRITE_FORMAT_LB_Rx_RB(x)     WRITE_FORMAT (x, "[","]","","")
151 #define WRITE_FORMAT_x_COMMA_LB(x)   WRITE_FORMAT (x, "",",[","",",[")
152 #define WRITE_FORMAT_COMMA_x_RB(x)   WRITE_FORMAT (x, ",","]",",","]")
153 #define WRITE_FORMAT_x_RB(x)         WRITE_FORMAT (x, "","]","","]")
154 #define WRITE_FORMAT_COMMA_x(x)      WRITE_FORMAT (x, ",","",",","")
155 #define WRITE_FORMAT_x_COMMA(x)      WRITE_FORMAT (x, "",",","",",")
156 #define WRITE_FORMAT_x(x)            WRITE_FORMAT (x, "","","","")
157 #define WRITE_FORMAT(x,cb1,ca1,cb,ca) strcat (formatString,		\
158 				     (IS_REG (x) ? cb1"%r"ca1 :		\
159 				      usesAuxReg ? cb"%a"ca :		\
160 				      IS_SMALL (x) ? cb"%d"ca : cb"%h"ca))
161 #define WRITE_FORMAT_RB()	strcat (formatString, "]")
162 #define WRITE_COMMENT(str)	(state->comm[state->commNum++] = (str))
163 #define WRITE_NOP_COMMENT()	if (!fieldAisReg && !flag) WRITE_COMMENT ("nop");
164 
165 #define NEXT_WORD(x)	(offset += 4, state->words[x])
166 
167 #define add_target(x)	(state->targets[state->tcnt++] = (x))
168 
169 static char comment_prefix[] = "\t; ";
170 
171 static const char *
172 core_reg_name (struct arcDisState * state, int val)
173 {
174   if (state->coreRegName)
175     return (*state->coreRegName)(state->_this, val);
176   return 0;
177 }
178 
179 static const char *
180 aux_reg_name (struct arcDisState * state, int val)
181 {
182   if (state->auxRegName)
183     return (*state->auxRegName)(state->_this, val);
184   return 0;
185 }
186 
187 static const char *
188 cond_code_name (struct arcDisState * state, int val)
189 {
190   if (state->condCodeName)
191     return (*state->condCodeName)(state->_this, val);
192   return 0;
193 }
194 
195 static const char *
196 instruction_name (struct arcDisState * state,
197 		  int    op1,
198 		  int    op2,
199 		  int *  flags)
200 {
201   if (state->instName)
202     return (*state->instName)(state->_this, op1, op2, flags);
203   return 0;
204 }
205 
206 static void
207 mwerror (struct arcDisState * state, const char * msg)
208 {
209   if (state->err != 0)
210     (*state->err)(state->_this, (msg));
211 }
212 
213 static const char *
214 post_address (struct arcDisState * state, int addr)
215 {
216   static char id[3 * ARRAY_SIZE (state->addresses)];
217   int j, i = state->acnt;
218 
219   if (i < ((int) ARRAY_SIZE (state->addresses)))
220     {
221       state->addresses[i] = addr;
222       ++state->acnt;
223       j = i*3;
224       id[j+0] = '@';
225       id[j+1] = '0'+i;
226       id[j+2] = 0;
227 
228       return id + j;
229     }
230   return "";
231 }
232 
233 static void
234 arc_sprintf (struct arcDisState *state, char *buf, const char *format, ...)
235 {
236   char *bp;
237   const char *p;
238   int size, leading_zero, regMap[2];
239   va_list ap;
240 
241   va_start (ap, format);
242 
243   bp = buf;
244   *bp = 0;
245   p = format;
246   regMap[0] = 0;
247   regMap[1] = 0;
248 
249   while (1)
250     switch (*p++)
251       {
252       case 0:
253 	goto DOCOMM; /* (return)  */
254       default:
255 	*bp++ = p[-1];
256 	break;
257       case '%':
258 	size = 0;
259 	leading_zero = 0;
260       RETRY: ;
261 	switch (*p++)
262 	  {
263 	  case '0':
264 	  case '1':
265 	  case '2':
266 	  case '3':
267 	  case '4':
268 	  case '5':
269 	  case '6':
270 	  case '7':
271 	  case '8':
272 	  case '9':
273 	    {
274 	      /* size.  */
275 	      size = p[-1] - '0';
276 	      if (size == 0)
277 		leading_zero = 1; /* e.g. %08x  */
278 	      while (*p >= '0' && *p <= '9')
279 		{
280 		  size = size * 10 + *p - '0';
281 		  p++;
282 		}
283 	      goto RETRY;
284 	    }
285 #define inc_bp() bp = bp + strlen (bp)
286 
287 	  case 'h':
288 	    {
289 	      unsigned u = va_arg (ap, int);
290 
291 	      /* Hex.  We can change the format to 0x%08x in
292 		 one place, here, if we wish.
293 		 We add underscores for easy reading.  */
294 	      if (u > 65536)
295 		sprintf (bp, "0x%x_%04x", u >> 16, u & 0xffff);
296 	      else
297 		sprintf (bp, "0x%x", u);
298 	      inc_bp ();
299 	    }
300 	    break;
301 	  case 'X': case 'x':
302 	    {
303 	      int val = va_arg (ap, int);
304 
305 	      if (size != 0)
306 		if (leading_zero)
307 		  sprintf (bp, "%0*x", size, val);
308 		else
309 		  sprintf (bp, "%*x", size, val);
310 	      else
311 		sprintf (bp, "%x", val);
312 	      inc_bp ();
313 	    }
314 	    break;
315 	  case 'd':
316 	    {
317 	      int val = va_arg (ap, int);
318 
319 	      if (size != 0)
320 		sprintf (bp, "%*d", size, val);
321 	      else
322 		sprintf (bp, "%d", val);
323 	      inc_bp ();
324 	    }
325 	    break;
326 	  case 'r':
327 	    {
328 	      /* Register.  */
329 	      int val = va_arg (ap, int);
330 
331 #define REG2NAME(num, name) case num: sprintf (bp, ""name); \
332   regMap[(num < 32) ? 0 : 1] |= 1 << (num - ((num < 32) ? 0 : 32)); break;
333 
334 	      switch (val)
335 		{
336 		  REG2NAME (26, "gp");
337 		  REG2NAME (27, "fp");
338 		  REG2NAME (28, "sp");
339 		  REG2NAME (29, "ilink1");
340 		  REG2NAME (30, "ilink2");
341 		  REG2NAME (31, "blink");
342 		  REG2NAME (60, "lp_count");
343 		default:
344 		  {
345 		    const char * ext;
346 
347 		    ext = core_reg_name (state, val);
348 		    if (ext)
349 		      sprintf (bp, "%s", ext);
350 		    else
351 		      sprintf (bp,"r%d",val);
352 		  }
353 		  break;
354 		}
355 	      inc_bp ();
356 	    } break;
357 
358 	  case 'a':
359 	    {
360 	      /* Aux Register.  */
361 	      int val = va_arg (ap, int);
362 
363 #define AUXREG2NAME(num, name) case num: sprintf (bp,name); break;
364 
365 	      switch (val)
366 		{
367 		  AUXREG2NAME (0x0, "status");
368 		  AUXREG2NAME (0x1, "semaphore");
369 		  AUXREG2NAME (0x2, "lp_start");
370 		  AUXREG2NAME (0x3, "lp_end");
371 		  AUXREG2NAME (0x4, "identity");
372 		  AUXREG2NAME (0x5, "debug");
373 		default:
374 		  {
375 		    const char *ext;
376 
377 		    ext = aux_reg_name (state, val);
378 		    if (ext)
379 		      sprintf (bp, "%s", ext);
380 		    else
381 		      arc_sprintf (state, bp, "%h", val);
382 		  }
383 		  break;
384 		}
385 	      inc_bp ();
386 	    }
387 	    break;
388 
389 	  case 's':
390 	    {
391 	      sprintf (bp, "%s", va_arg (ap, char *));
392 	      inc_bp ();
393 	    }
394 	    break;
395 
396 	  default:
397 	    fprintf (stderr, "?? format %c\n", p[-1]);
398 	    break;
399 	  }
400       }
401 
402  DOCOMM: *bp = 0;
403   va_end (ap);
404 }
405 
406 static void
407 write_comments_(struct arcDisState * state,
408 		int shimm,
409 		int is_limm,
410 		long limm_value)
411 {
412   if (state->commentBuffer != 0)
413     {
414       int i;
415 
416       if (is_limm)
417 	{
418 	  const char *name = post_address (state, limm_value + shimm);
419 
420 	  if (*name != 0)
421 	    WRITE_COMMENT (name);
422 	}
423       for (i = 0; i < state->commNum; i++)
424 	{
425 	  if (i == 0)
426 	    strcpy (state->commentBuffer, comment_prefix);
427 	  else
428 	    strcat (state->commentBuffer, ", ");
429 	  strncat (state->commentBuffer, state->comm[i],
430 		   sizeof (state->commentBuffer));
431 	}
432     }
433 }
434 
435 #define write_comments2(x) write_comments_ (state, x, is_limm, limm_value)
436 #define write_comments()   write_comments2 (0)
437 
438 static const char *condName[] =
439 {
440   /* 0..15.  */
441   ""   , "z"  , "nz" , "p"  , "n"  , "c"  , "nc" , "v"  ,
442   "nv" , "gt" , "ge" , "lt" , "le" , "hi" , "ls" , "pnz"
443 };
444 
445 static void
446 write_instr_name_(struct arcDisState * state,
447 		  const char * instrName,
448 		  int cond,
449 		  int condCodeIsPartOfName,
450 		  int flag,
451 		  int signExtend,
452 		  int addrWriteBack,
453 		  int directMem)
454 {
455   strcpy (state->instrBuffer, instrName);
456 
457   if (cond > 0)
458     {
459       const char *cc = 0;
460 
461       if (!condCodeIsPartOfName)
462 	strcat (state->instrBuffer, ".");
463 
464       if (cond < 16)
465 	cc = condName[cond];
466       else
467 	cc = cond_code_name (state, cond);
468 
469       if (!cc)
470 	cc = "???";
471 
472       strcat (state->instrBuffer, cc);
473     }
474 
475   if (flag)
476     strcat (state->instrBuffer, ".f");
477 
478   switch (state->nullifyMode)
479     {
480     case BR_exec_always:
481       strcat (state->instrBuffer, ".d");
482       break;
483     case BR_exec_when_jump:
484       strcat (state->instrBuffer, ".jd");
485       break;
486     }
487 
488   if (signExtend)
489     strcat (state->instrBuffer, ".x");
490 
491   if (addrWriteBack)
492     strcat (state->instrBuffer, ".a");
493 
494   if (directMem)
495     strcat (state->instrBuffer, ".di");
496 }
497 
498 #define write_instr_name()						\
499   do									\
500     {									\
501       write_instr_name_(state, instrName,cond, condCodeIsPartOfName,	\
502 			flag, signExtend, addrWriteBack, directMem);	\
503       formatString[0] = '\0';						\
504     }									\
505   while (0)
506 
507 enum
508 {
509   op_LD0 = 0, op_LD1 = 1, op_ST  = 2, op_3   = 3,
510   op_BC  = 4, op_BLC = 5, op_LPC = 6, op_JC  = 7,
511   op_ADD = 8, op_ADC = 9, op_SUB = 10, op_SBC = 11,
512   op_AND = 12, op_OR  = 13, op_BIC = 14, op_XOR = 15
513 };
514 
515 extern disassemble_info tm_print_insn_info;
516 
517 static int
518 dsmOneArcInst (bfd_vma addr, struct arcDisState * state)
519 {
520   int condCodeIsPartOfName = 0;
521   a4_decoding_class decodingClass;
522   const char * instrName;
523   int repeatsOp = 0;
524   int fieldAisReg = 1;
525   int fieldBisReg = 1;
526   int fieldCisReg = 1;
527   int fieldA;
528   int fieldB;
529   int fieldC = 0;
530   int flag = 0;
531   int cond = 0;
532   int is_shimm = 0;
533   int is_limm = 0;
534   long limm_value = 0;
535   int signExtend = 0;
536   int addrWriteBack = 0;
537   int directMem = 0;
538   int is_linked = 0;
539   int offset = 0;
540   int usesAuxReg = 0;
541   int flags;
542   int ignoreFirstOpd;
543   char formatString[60];
544 
545   state->instructionLen = 4;
546   state->nullifyMode = BR_exec_when_no_jump;
547   state->opWidth = 12;
548   state->isBranch = 0;
549 
550   state->_mem_load = 0;
551   state->_ea_present = 0;
552   state->_load_len = 0;
553   state->ea_reg1 = no_reg;
554   state->ea_reg2 = no_reg;
555   state->_offset = 0;
556 
557   if (! NEXT_WORD (0))
558     return 0;
559 
560   state->_opcode = OPCODE (state->words[0]);
561   instrName = 0;
562   decodingClass = CLASS_A4_ARITH; /* default!  */
563   repeatsOp = 0;
564   condCodeIsPartOfName=0;
565   state->commNum = 0;
566   state->tcnt = 0;
567   state->acnt = 0;
568   state->flow = noflow;
569   ignoreFirstOpd = 0;
570 
571   if (state->commentBuffer)
572     state->commentBuffer[0] = '\0';
573 
574   switch (state->_opcode)
575     {
576     case op_LD0:
577       switch (BITS (state->words[0],1,2))
578 	{
579 	case 0:
580 	  instrName = "ld";
581 	  state->_load_len = 4;
582 	  break;
583 	case 1:
584 	  instrName = "ldb";
585 	  state->_load_len = 1;
586 	  break;
587 	case 2:
588 	  instrName = "ldw";
589 	  state->_load_len = 2;
590 	  break;
591 	default:
592 	  instrName = "??? (0[3])";
593 	  state->flow = invalid_instr;
594 	  break;
595 	}
596       decodingClass = CLASS_A4_LD0;
597       break;
598 
599     case op_LD1:
600       if (BIT (state->words[0],13))
601 	{
602 	  instrName = "lr";
603 	  decodingClass = CLASS_A4_LR;
604 	}
605       else
606 	{
607 	  switch (BITS (state->words[0], 10, 11))
608 	    {
609 	    case 0:
610 	      instrName = "ld";
611 	      state->_load_len = 4;
612 	      break;
613 	    case 1:
614 	      instrName = "ldb";
615 	      state->_load_len = 1;
616 	      break;
617 	    case 2:
618 	      instrName = "ldw";
619 	      state->_load_len = 2;
620 	      break;
621 	    default:
622 	      instrName = "??? (1[3])";
623 	      state->flow = invalid_instr;
624 	      break;
625 	    }
626 	  decodingClass = CLASS_A4_LD1;
627 	}
628       break;
629 
630     case op_ST:
631       if (BIT (state->words[0], 25))
632 	{
633 	  instrName = "sr";
634 	  decodingClass = CLASS_A4_SR;
635 	}
636       else
637 	{
638 	  switch (BITS (state->words[0], 22, 23))
639 	    {
640 	    case 0:
641 	      instrName = "st";
642 	      break;
643 	    case 1:
644 	      instrName = "stb";
645 	      break;
646 	    case 2:
647 	      instrName = "stw";
648 	      break;
649 	    default:
650 	      instrName = "??? (2[3])";
651 	      state->flow = invalid_instr;
652 	      break;
653 	    }
654 	  decodingClass = CLASS_A4_ST;
655 	}
656       break;
657 
658     case op_3:
659       decodingClass = CLASS_A4_OP3_GENERAL;  /* default for opcode 3...  */
660       switch (FIELDC (state->words[0]))
661 	{
662 	case  0:
663 	  instrName = "flag";
664 	  decodingClass = CLASS_A4_FLAG;
665 	  break;
666 	case  1:
667 	  instrName = "asr";
668 	  break;
669 	case  2:
670 	  instrName = "lsr";
671 	  break;
672 	case  3:
673 	  instrName = "ror";
674 	  break;
675 	case  4:
676 	  instrName = "rrc";
677 	  break;
678 	case  5:
679 	  instrName = "sexb";
680 	  break;
681 	case  6:
682 	  instrName = "sexw";
683 	  break;
684 	case  7:
685 	  instrName = "extb";
686 	  break;
687 	case  8:
688 	  instrName = "extw";
689 	  break;
690 	case  0x3f:
691 	  {
692 	    decodingClass = CLASS_A4_OP3_SUBOPC3F;
693 	    switch (FIELDD (state->words[0]))
694 	      {
695 	      case 0:
696 		instrName = "brk";
697 		break;
698 	      case 1:
699 		instrName = "sleep";
700 		break;
701 	      case 2:
702 		instrName = "swi";
703 		break;
704 	      default:
705 		instrName = "???";
706 		state->flow=invalid_instr;
707 		break;
708 	      }
709 	  }
710 	  break;
711 
712 	  /* ARC Extension Library Instructions
713 	     NOTE: We assume that extension codes are these instrs.  */
714 	default:
715 	  instrName = instruction_name (state,
716 					state->_opcode,
717 					FIELDC (state->words[0]),
718 					&flags);
719 	  if (!instrName)
720 	    {
721 	      instrName = "???";
722 	      state->flow = invalid_instr;
723 	    }
724 	  if (flags & IGNORE_FIRST_OPD)
725 	    ignoreFirstOpd = 1;
726 	  break;
727 	}
728       break;
729 
730     case op_BC:
731       instrName = "b";
732     case op_BLC:
733       if (!instrName)
734 	instrName = "bl";
735     case op_LPC:
736       if (!instrName)
737 	instrName = "lp";
738     case op_JC:
739       if (!instrName)
740 	{
741 	  if (BITS (state->words[0],9,9))
742 	    {
743 	      instrName = "jl";
744 	      is_linked = 1;
745 	    }
746 	  else
747 	    {
748 	      instrName = "j";
749 	      is_linked = 0;
750 	    }
751 	}
752       condCodeIsPartOfName = 1;
753       decodingClass = ((state->_opcode == op_JC) ? CLASS_A4_JC : CLASS_A4_BRANCH );
754       state->isBranch = 1;
755       break;
756 
757     case op_ADD:
758     case op_ADC:
759     case op_AND:
760       repeatsOp = (FIELDC (state->words[0]) == FIELDB (state->words[0]));
761 
762       switch (state->_opcode)
763 	{
764 	case op_ADD:
765 	  instrName = (repeatsOp ? "asl" : "add");
766 	  break;
767 	case op_ADC:
768 	  instrName = (repeatsOp ? "rlc" : "adc");
769 	  break;
770 	case op_AND:
771 	  instrName = (repeatsOp ? "mov" : "and");
772 	  break;
773 	}
774       break;
775 
776     case op_SUB: instrName = "sub";
777       break;
778     case op_SBC: instrName = "sbc";
779       break;
780     case op_OR:  instrName = "or";
781       break;
782     case op_BIC: instrName = "bic";
783       break;
784 
785     case op_XOR:
786       if (state->words[0] == 0x7fffffff)
787 	{
788 	  /* NOP encoded as xor -1, -1, -1.   */
789 	  instrName = "nop";
790 	  decodingClass = CLASS_A4_OP3_SUBOPC3F;
791 	}
792       else
793 	instrName = "xor";
794       break;
795 
796     default:
797       instrName = instruction_name (state,state->_opcode,0,&flags);
798       /* if (instrName) printf("FLAGS=0x%x\n", flags);  */
799       if (!instrName)
800 	{
801 	  instrName = "???";
802 	  state->flow=invalid_instr;
803 	}
804       if (flags & IGNORE_FIRST_OPD)
805 	ignoreFirstOpd = 1;
806       break;
807     }
808 
809   fieldAisReg = fieldBisReg = fieldCisReg = 1; /* Assume regs for now.  */
810   flag = cond = is_shimm = is_limm = 0;
811   state->nullifyMode = BR_exec_when_no_jump;	/* 0  */
812   signExtend = addrWriteBack = directMem = 0;
813   usesAuxReg = 0;
814 
815   switch (decodingClass)
816     {
817     case CLASS_A4_ARITH:
818       CHECK_FIELD_A ();
819       CHECK_FIELD_B ();
820       if (!repeatsOp)
821 	CHECK_FIELD_C ();
822       CHECK_FLAG_COND_NULLIFY ();
823 
824       write_instr_name ();
825       if (!ignoreFirstOpd)
826 	{
827 	  WRITE_FORMAT_x (A);
828 	  WRITE_FORMAT_COMMA_x (B);
829 	  if (!repeatsOp)
830 	    WRITE_FORMAT_COMMA_x (C);
831 	  WRITE_NOP_COMMENT ();
832 	  arc_sprintf (state, state->operandBuffer, formatString,
833 		      fieldA, fieldB, fieldC);
834 	}
835       else
836 	{
837 	  WRITE_FORMAT_x (B);
838 	  if (!repeatsOp)
839 	    WRITE_FORMAT_COMMA_x (C);
840 	  arc_sprintf (state, state->operandBuffer, formatString,
841 		      fieldB, fieldC);
842 	}
843       write_comments ();
844       break;
845 
846     case CLASS_A4_OP3_GENERAL:
847       CHECK_FIELD_A ();
848       CHECK_FIELD_B ();
849       CHECK_FLAG_COND_NULLIFY ();
850 
851       write_instr_name ();
852       if (!ignoreFirstOpd)
853 	{
854 	  WRITE_FORMAT_x (A);
855 	  WRITE_FORMAT_COMMA_x (B);
856 	  WRITE_NOP_COMMENT ();
857 	  arc_sprintf (state, state->operandBuffer, formatString,
858 		      fieldA, fieldB);
859 	}
860       else
861 	{
862 	  WRITE_FORMAT_x (B);
863 	  arc_sprintf (state, state->operandBuffer, formatString, fieldB);
864 	}
865       write_comments ();
866       break;
867 
868     case CLASS_A4_FLAG:
869       CHECK_FIELD_B ();
870       CHECK_FLAG_COND_NULLIFY ();
871       flag = 0; /* This is the FLAG instruction -- it's redundant.  */
872 
873       write_instr_name ();
874       WRITE_FORMAT_x (B);
875       arc_sprintf (state, state->operandBuffer, formatString, fieldB);
876       write_comments ();
877       break;
878 
879     case CLASS_A4_BRANCH:
880       fieldA = BITS (state->words[0],7,26) << 2;
881       fieldA = (fieldA << 10) >> 10; /* Make it signed.  */
882       fieldA += addr + 4;
883       CHECK_FLAG_COND_NULLIFY ();
884       flag = 0;
885 
886       write_instr_name ();
887       /* This address could be a label we know. Convert it.  */
888       if (state->_opcode != op_LPC /* LP  */)
889 	{
890 	  add_target (fieldA); /* For debugger.  */
891 	  state->flow = state->_opcode == op_BLC /* BL  */
892 	    ? direct_call
893 	    : direct_jump;
894 	  /* indirect calls are achieved by "lr blink,[status];
895 	     lr dest<- func addr; j [dest]"  */
896 	}
897 
898       strcat (formatString, "%s"); /* Address/label name.  */
899       arc_sprintf (state, state->operandBuffer, formatString,
900 		  post_address (state, fieldA));
901       write_comments ();
902       break;
903 
904     case CLASS_A4_JC:
905       /* For op_JC -- jump to address specified.
906 	 Also covers jump and link--bit 9 of the instr. word
907 	 selects whether linked, thus "is_linked" is set above.  */
908       fieldA = 0;
909       CHECK_FIELD_B ();
910       CHECK_FLAG_COND_NULLIFY ();
911 
912       if (!fieldBisReg)
913 	{
914 	  fieldAisReg = 0;
915 	  fieldA = (fieldB >> 25) & 0x7F; /* Flags.  */
916 	  fieldB = (fieldB & 0xFFFFFF) << 2;
917 	  state->flow = is_linked ? direct_call : direct_jump;
918 	  add_target (fieldB);
919 	  /* Screwy JLcc requires .jd mode to execute correctly
920 	     but we pretend it is .nd (no delay slot).  */
921 	  if (is_linked && state->nullifyMode == BR_exec_when_jump)
922 	    state->nullifyMode = BR_exec_when_no_jump;
923 	}
924       else
925 	{
926 	  state->flow = is_linked ? indirect_call : indirect_jump;
927 	  /* We should also treat this as indirect call if NOT linked
928 	     but the preceding instruction was a "lr blink,[status]"
929 	     and we have a delay slot with "add blink,blink,2".
930 	     For now we can't detect such.  */
931 	  state->register_for_indirect_jump = fieldB;
932 	}
933 
934       write_instr_name ();
935       strcat (formatString,
936 	      IS_REG (B) ? "[%r]" : "%s"); /* Address/label name.  */
937       if (fieldA != 0)
938 	{
939 	  fieldAisReg = 0;
940 	  WRITE_FORMAT_COMMA_x (A);
941 	}
942       if (IS_REG (B))
943 	arc_sprintf (state, state->operandBuffer, formatString, fieldB, fieldA);
944       else
945 	arc_sprintf (state, state->operandBuffer, formatString,
946 		    post_address (state, fieldB), fieldA);
947       write_comments ();
948       break;
949 
950     case CLASS_A4_LD0:
951       /* LD instruction.
952 	 B and C can be regs, or one (both?) can be limm.  */
953       CHECK_FIELD_A ();
954       CHECK_FIELD_B ();
955       CHECK_FIELD_C ();
956       if (dbg)
957 	printf ("5:b reg %d %d c reg %d %d  \n",
958 		fieldBisReg,fieldB,fieldCisReg,fieldC);
959       state->_offset = 0;
960       state->_ea_present = 1;
961       if (fieldBisReg)
962 	state->ea_reg1 = fieldB;
963       else
964 	state->_offset += fieldB;
965       if (fieldCisReg)
966 	state->ea_reg2 = fieldC;
967       else
968 	state->_offset += fieldC;
969       state->_mem_load = 1;
970 
971       directMem     = BIT (state->words[0], 5);
972       addrWriteBack = BIT (state->words[0], 3);
973       signExtend    = BIT (state->words[0], 0);
974 
975       write_instr_name ();
976       WRITE_FORMAT_x_COMMA_LB(A);
977       if (fieldBisReg || fieldB != 0)
978 	WRITE_FORMAT_x_COMMA (B);
979       else
980 	fieldB = fieldC;
981 
982       WRITE_FORMAT_x_RB (C);
983       arc_sprintf (state, state->operandBuffer, formatString,
984 		  fieldA, fieldB, fieldC);
985       write_comments ();
986       break;
987 
988     case CLASS_A4_LD1:
989       /* LD instruction.  */
990       CHECK_FIELD_B ();
991       CHECK_FIELD_A ();
992       fieldC = FIELDD (state->words[0]);
993 
994       if (dbg)
995 	printf ("6:b reg %d %d c 0x%x  \n",
996 		fieldBisReg, fieldB, fieldC);
997       state->_ea_present = 1;
998       state->_offset = fieldC;
999       state->_mem_load = 1;
1000       if (fieldBisReg)
1001 	state->ea_reg1 = fieldB;
1002       /* Field B is either a shimm (same as fieldC) or limm (different!)
1003 	 Say ea is not present, so only one of us will do the name lookup.  */
1004       else
1005 	state->_offset += fieldB, state->_ea_present = 0;
1006 
1007       directMem     = BIT (state->words[0],14);
1008       addrWriteBack = BIT (state->words[0],12);
1009       signExtend    = BIT (state->words[0],9);
1010 
1011       write_instr_name ();
1012       WRITE_FORMAT_x_COMMA_LB (A);
1013       if (!fieldBisReg)
1014 	{
1015 	  fieldB = state->_offset;
1016 	  WRITE_FORMAT_x_RB (B);
1017 	}
1018       else
1019 	{
1020 	  WRITE_FORMAT_x (B);
1021 	  if (fieldC != 0 && !BIT (state->words[0],13))
1022 	    {
1023 	      fieldCisReg = 0;
1024 	      WRITE_FORMAT_COMMA_x_RB (C);
1025 	    }
1026 	  else
1027 	    WRITE_FORMAT_RB ();
1028 	}
1029       arc_sprintf (state, state->operandBuffer, formatString,
1030 		  fieldA, fieldB, fieldC);
1031       write_comments ();
1032       break;
1033 
1034     case CLASS_A4_ST:
1035       /* ST instruction.  */
1036       CHECK_FIELD_B();
1037       CHECK_FIELD_C();
1038       fieldA = FIELDD(state->words[0]); /* shimm  */
1039 
1040       /* [B,A offset]  */
1041       if (dbg) printf("7:b reg %d %x off %x\n",
1042 		      fieldBisReg,fieldB,fieldA);
1043       state->_ea_present = 1;
1044       state->_offset = fieldA;
1045       if (fieldBisReg)
1046 	state->ea_reg1 = fieldB;
1047       /* Field B is either a shimm (same as fieldA) or limm (different!)
1048 	 Say ea is not present, so only one of us will do the name lookup.
1049 	 (for is_limm we do the name translation here).  */
1050       else
1051 	state->_offset += fieldB, state->_ea_present = 0;
1052 
1053       directMem     = BIT (state->words[0], 26);
1054       addrWriteBack = BIT (state->words[0], 24);
1055 
1056       write_instr_name ();
1057       WRITE_FORMAT_x_COMMA_LB(C);
1058 
1059       if (!fieldBisReg)
1060 	{
1061 	  fieldB = state->_offset;
1062 	  WRITE_FORMAT_x_RB (B);
1063 	}
1064       else
1065 	{
1066 	  WRITE_FORMAT_x (B);
1067 	  if (fieldBisReg && fieldA != 0)
1068 	    {
1069 	      fieldAisReg = 0;
1070 	      WRITE_FORMAT_COMMA_x_RB(A);
1071 	    }
1072 	  else
1073 	    WRITE_FORMAT_RB();
1074 	}
1075       arc_sprintf (state, state->operandBuffer, formatString,
1076 		  fieldC, fieldB, fieldA);
1077       write_comments2 (fieldA);
1078       break;
1079 
1080     case CLASS_A4_SR:
1081       /* SR instruction  */
1082       CHECK_FIELD_B();
1083       CHECK_FIELD_C();
1084 
1085       write_instr_name ();
1086       WRITE_FORMAT_x_COMMA_LB(C);
1087       /* Try to print B as an aux reg if it is not a core reg.  */
1088       usesAuxReg = 1;
1089       WRITE_FORMAT_x (B);
1090       WRITE_FORMAT_RB ();
1091       arc_sprintf (state, state->operandBuffer, formatString, fieldC, fieldB);
1092       write_comments ();
1093       break;
1094 
1095     case CLASS_A4_OP3_SUBOPC3F:
1096       write_instr_name ();
1097       state->operandBuffer[0] = '\0';
1098       break;
1099 
1100     case CLASS_A4_LR:
1101       /* LR instruction */
1102       CHECK_FIELD_A ();
1103       CHECK_FIELD_B ();
1104 
1105       write_instr_name ();
1106       WRITE_FORMAT_x_COMMA_LB (A);
1107       /* Try to print B as an aux reg if it is not a core reg. */
1108       usesAuxReg = 1;
1109       WRITE_FORMAT_x (B);
1110       WRITE_FORMAT_RB ();
1111       arc_sprintf (state, state->operandBuffer, formatString, fieldA, fieldB);
1112       write_comments ();
1113       break;
1114 
1115     default:
1116       mwerror (state, "Bad decoding class in ARC disassembler");
1117       break;
1118     }
1119 
1120   state->_cond = cond;
1121   return state->instructionLen = offset;
1122 }
1123 
1124 
1125 /* Returns the name the user specified core extension register.  */
1126 
1127 static const char *
1128 _coreRegName(void * arg ATTRIBUTE_UNUSED, int regval)
1129 {
1130   return arcExtMap_coreRegName (regval);
1131 }
1132 
1133 /* Returns the name the user specified AUX extension register.  */
1134 
1135 static const char *
1136 _auxRegName(void *_this ATTRIBUTE_UNUSED, int regval)
1137 {
1138   return arcExtMap_auxRegName(regval);
1139 }
1140 
1141 /* Returns the name the user specified condition code name.  */
1142 
1143 static const char *
1144 _condCodeName(void *_this ATTRIBUTE_UNUSED, int regval)
1145 {
1146   return arcExtMap_condCodeName(regval);
1147 }
1148 
1149 /* Returns the name the user specified extension instruction.  */
1150 
1151 static const char *
1152 _instName (void *_this ATTRIBUTE_UNUSED, int majop, int minop, int *flags)
1153 {
1154   return arcExtMap_instName(majop, minop, flags);
1155 }
1156 
1157 /* Decode an instruction returning the size of the instruction
1158    in bytes or zero if unrecognized.  */
1159 
1160 static int
1161 decodeInstr (bfd_vma            address, /* Address of this instruction.  */
1162 	     disassemble_info * info)
1163 {
1164   int status;
1165   bfd_byte buffer[4];
1166   struct arcDisState s;		/* ARC Disassembler state.  */
1167   void *stream = info->stream; 	/* Output stream.  */
1168   fprintf_ftype func = info->fprintf_func;
1169 
1170   memset (&s, 0, sizeof(struct arcDisState));
1171 
1172   /* read first instruction  */
1173   status = (*info->read_memory_func) (address, buffer, 4, info);
1174   if (status != 0)
1175     {
1176       (*info->memory_error_func) (status, address, info);
1177       return 0;
1178     }
1179   if (info->endian == BFD_ENDIAN_LITTLE)
1180     s.words[0] = bfd_getl32(buffer);
1181   else
1182     s.words[0] = bfd_getb32(buffer);
1183   /* Always read second word in case of limm.  */
1184 
1185   /* We ignore the result since last insn may not have a limm.  */
1186   status = (*info->read_memory_func) (address + 4, buffer, 4, info);
1187   if (info->endian == BFD_ENDIAN_LITTLE)
1188     s.words[1] = bfd_getl32(buffer);
1189   else
1190     s.words[1] = bfd_getb32(buffer);
1191 
1192   s._this = &s;
1193   s.coreRegName = _coreRegName;
1194   s.auxRegName = _auxRegName;
1195   s.condCodeName = _condCodeName;
1196   s.instName = _instName;
1197 
1198   /* Disassemble.  */
1199   dsmOneArcInst (address, & s);
1200 
1201   /* Display the disassembly instruction.  */
1202   (*func) (stream, "%08lx ", s.words[0]);
1203   (*func) (stream, "    ");
1204   (*func) (stream, "%-10s ", s.instrBuffer);
1205 
1206   if (__TRANSLATION_REQUIRED (s))
1207     {
1208       bfd_vma addr = s.addresses[s.operandBuffer[1] - '0'];
1209 
1210       (*info->print_address_func) ((bfd_vma) addr, info);
1211       (*func) (stream, "\n");
1212     }
1213   else
1214     (*func) (stream, "%s",s.operandBuffer);
1215 
1216   return s.instructionLen;
1217 }
1218 
1219 /* Return the print_insn function to use.
1220    Side effect: load (possibly empty) extension section  */
1221 
1222 disassembler_ftype
1223 arc_get_disassembler (void *ptr)
1224 {
1225   if (ptr)
1226     build_ARC_extmap ((struct bfd *) ptr);
1227   return decodeInstr;
1228 }
1229