xref: /netbsd-src/external/gpl3/gdb/dist/opcodes/arc-dis.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
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 	  strcat (state->commentBuffer, state->comm[i]);
430 	}
431     }
432 }
433 
434 #define write_comments2(x) write_comments_ (state, x, is_limm, limm_value)
435 #define write_comments()   write_comments2 (0)
436 
437 static const char *condName[] =
438 {
439   /* 0..15.  */
440   ""   , "z"  , "nz" , "p"  , "n"  , "c"  , "nc" , "v"  ,
441   "nv" , "gt" , "ge" , "lt" , "le" , "hi" , "ls" , "pnz"
442 };
443 
444 static void
445 write_instr_name_(struct arcDisState * state,
446 		  const char * instrName,
447 		  int cond,
448 		  int condCodeIsPartOfName,
449 		  int flag,
450 		  int signExtend,
451 		  int addrWriteBack,
452 		  int directMem)
453 {
454   strcpy (state->instrBuffer, instrName);
455 
456   if (cond > 0)
457     {
458       const char *cc = 0;
459 
460       if (!condCodeIsPartOfName)
461 	strcat (state->instrBuffer, ".");
462 
463       if (cond < 16)
464 	cc = condName[cond];
465       else
466 	cc = cond_code_name (state, cond);
467 
468       if (!cc)
469 	cc = "???";
470 
471       strcat (state->instrBuffer, cc);
472     }
473 
474   if (flag)
475     strcat (state->instrBuffer, ".f");
476 
477   switch (state->nullifyMode)
478     {
479     case BR_exec_always:
480       strcat (state->instrBuffer, ".d");
481       break;
482     case BR_exec_when_jump:
483       strcat (state->instrBuffer, ".jd");
484       break;
485     }
486 
487   if (signExtend)
488     strcat (state->instrBuffer, ".x");
489 
490   if (addrWriteBack)
491     strcat (state->instrBuffer, ".a");
492 
493   if (directMem)
494     strcat (state->instrBuffer, ".di");
495 }
496 
497 #define write_instr_name()						\
498   do									\
499     {									\
500       write_instr_name_(state, instrName,cond, condCodeIsPartOfName,	\
501 			flag, signExtend, addrWriteBack, directMem);	\
502       formatString[0] = '\0';						\
503     }									\
504   while (0)
505 
506 enum
507 {
508   op_LD0 = 0, op_LD1 = 1, op_ST  = 2, op_3   = 3,
509   op_BC  = 4, op_BLC = 5, op_LPC = 6, op_JC  = 7,
510   op_ADD = 8, op_ADC = 9, op_SUB = 10, op_SBC = 11,
511   op_AND = 12, op_OR  = 13, op_BIC = 14, op_XOR = 15
512 };
513 
514 extern disassemble_info tm_print_insn_info;
515 
516 static int
517 dsmOneArcInst (bfd_vma addr, struct arcDisState * state)
518 {
519   int condCodeIsPartOfName = 0;
520   a4_decoding_class decodingClass;
521   const char * instrName;
522   int repeatsOp = 0;
523   int fieldAisReg = 1;
524   int fieldBisReg = 1;
525   int fieldCisReg = 1;
526   int fieldA;
527   int fieldB;
528   int fieldC = 0;
529   int flag = 0;
530   int cond = 0;
531   int is_shimm = 0;
532   int is_limm = 0;
533   long limm_value = 0;
534   int signExtend = 0;
535   int addrWriteBack = 0;
536   int directMem = 0;
537   int is_linked = 0;
538   int offset = 0;
539   int usesAuxReg = 0;
540   int flags;
541   int ignoreFirstOpd;
542   char formatString[60];
543 
544   state->instructionLen = 4;
545   state->nullifyMode = BR_exec_when_no_jump;
546   state->opWidth = 12;
547   state->isBranch = 0;
548 
549   state->_mem_load = 0;
550   state->_ea_present = 0;
551   state->_load_len = 0;
552   state->ea_reg1 = no_reg;
553   state->ea_reg2 = no_reg;
554   state->_offset = 0;
555 
556   if (! NEXT_WORD (0))
557     return 0;
558 
559   state->_opcode = OPCODE (state->words[0]);
560   instrName = 0;
561   decodingClass = CLASS_A4_ARITH; /* default!  */
562   repeatsOp = 0;
563   condCodeIsPartOfName=0;
564   state->commNum = 0;
565   state->tcnt = 0;
566   state->acnt = 0;
567   state->flow = noflow;
568   ignoreFirstOpd = 0;
569 
570   if (state->commentBuffer)
571     state->commentBuffer[0] = '\0';
572 
573   switch (state->_opcode)
574     {
575     case op_LD0:
576       switch (BITS (state->words[0],1,2))
577 	{
578 	case 0:
579 	  instrName = "ld";
580 	  state->_load_len = 4;
581 	  break;
582 	case 1:
583 	  instrName = "ldb";
584 	  state->_load_len = 1;
585 	  break;
586 	case 2:
587 	  instrName = "ldw";
588 	  state->_load_len = 2;
589 	  break;
590 	default:
591 	  instrName = "??? (0[3])";
592 	  state->flow = invalid_instr;
593 	  break;
594 	}
595       decodingClass = CLASS_A4_LD0;
596       break;
597 
598     case op_LD1:
599       if (BIT (state->words[0],13))
600 	{
601 	  instrName = "lr";
602 	  decodingClass = CLASS_A4_LR;
603 	}
604       else
605 	{
606 	  switch (BITS (state->words[0], 10, 11))
607 	    {
608 	    case 0:
609 	      instrName = "ld";
610 	      state->_load_len = 4;
611 	      break;
612 	    case 1:
613 	      instrName = "ldb";
614 	      state->_load_len = 1;
615 	      break;
616 	    case 2:
617 	      instrName = "ldw";
618 	      state->_load_len = 2;
619 	      break;
620 	    default:
621 	      instrName = "??? (1[3])";
622 	      state->flow = invalid_instr;
623 	      break;
624 	    }
625 	  decodingClass = CLASS_A4_LD1;
626 	}
627       break;
628 
629     case op_ST:
630       if (BIT (state->words[0], 25))
631 	{
632 	  instrName = "sr";
633 	  decodingClass = CLASS_A4_SR;
634 	}
635       else
636 	{
637 	  switch (BITS (state->words[0], 22, 23))
638 	    {
639 	    case 0:
640 	      instrName = "st";
641 	      break;
642 	    case 1:
643 	      instrName = "stb";
644 	      break;
645 	    case 2:
646 	      instrName = "stw";
647 	      break;
648 	    default:
649 	      instrName = "??? (2[3])";
650 	      state->flow = invalid_instr;
651 	      break;
652 	    }
653 	  decodingClass = CLASS_A4_ST;
654 	}
655       break;
656 
657     case op_3:
658       decodingClass = CLASS_A4_OP3_GENERAL;  /* default for opcode 3...  */
659       switch (FIELDC (state->words[0]))
660 	{
661 	case  0:
662 	  instrName = "flag";
663 	  decodingClass = CLASS_A4_FLAG;
664 	  break;
665 	case  1:
666 	  instrName = "asr";
667 	  break;
668 	case  2:
669 	  instrName = "lsr";
670 	  break;
671 	case  3:
672 	  instrName = "ror";
673 	  break;
674 	case  4:
675 	  instrName = "rrc";
676 	  break;
677 	case  5:
678 	  instrName = "sexb";
679 	  break;
680 	case  6:
681 	  instrName = "sexw";
682 	  break;
683 	case  7:
684 	  instrName = "extb";
685 	  break;
686 	case  8:
687 	  instrName = "extw";
688 	  break;
689 	case  0x3f:
690 	  {
691 	    decodingClass = CLASS_A4_OP3_SUBOPC3F;
692 	    switch (FIELDD (state->words[0]))
693 	      {
694 	      case 0:
695 		instrName = "brk";
696 		break;
697 	      case 1:
698 		instrName = "sleep";
699 		break;
700 	      case 2:
701 		instrName = "swi";
702 		break;
703 	      default:
704 		instrName = "???";
705 		state->flow=invalid_instr;
706 		break;
707 	      }
708 	  }
709 	  break;
710 
711 	  /* ARC Extension Library Instructions
712 	     NOTE: We assume that extension codes are these instrs.  */
713 	default:
714 	  instrName = instruction_name (state,
715 					state->_opcode,
716 					FIELDC (state->words[0]),
717 					&flags);
718 	  if (!instrName)
719 	    {
720 	      instrName = "???";
721 	      state->flow = invalid_instr;
722 	    }
723 	  if (flags & IGNORE_FIRST_OPD)
724 	    ignoreFirstOpd = 1;
725 	  break;
726 	}
727       break;
728 
729     case op_BC:
730       instrName = "b";
731     case op_BLC:
732       if (!instrName)
733 	instrName = "bl";
734     case op_LPC:
735       if (!instrName)
736 	instrName = "lp";
737     case op_JC:
738       if (!instrName)
739 	{
740 	  if (BITS (state->words[0],9,9))
741 	    {
742 	      instrName = "jl";
743 	      is_linked = 1;
744 	    }
745 	  else
746 	    {
747 	      instrName = "j";
748 	      is_linked = 0;
749 	    }
750 	}
751       condCodeIsPartOfName = 1;
752       decodingClass = ((state->_opcode == op_JC) ? CLASS_A4_JC : CLASS_A4_BRANCH );
753       state->isBranch = 1;
754       break;
755 
756     case op_ADD:
757     case op_ADC:
758     case op_AND:
759       repeatsOp = (FIELDC (state->words[0]) == FIELDB (state->words[0]));
760 
761       switch (state->_opcode)
762 	{
763 	case op_ADD:
764 	  instrName = (repeatsOp ? "asl" : "add");
765 	  break;
766 	case op_ADC:
767 	  instrName = (repeatsOp ? "rlc" : "adc");
768 	  break;
769 	case op_AND:
770 	  instrName = (repeatsOp ? "mov" : "and");
771 	  break;
772 	}
773       break;
774 
775     case op_SUB: instrName = "sub";
776       break;
777     case op_SBC: instrName = "sbc";
778       break;
779     case op_OR:  instrName = "or";
780       break;
781     case op_BIC: instrName = "bic";
782       break;
783 
784     case op_XOR:
785       if (state->words[0] == 0x7fffffff)
786 	{
787 	  /* NOP encoded as xor -1, -1, -1.   */
788 	  instrName = "nop";
789 	  decodingClass = CLASS_A4_OP3_SUBOPC3F;
790 	}
791       else
792 	instrName = "xor";
793       break;
794 
795     default:
796       instrName = instruction_name (state,state->_opcode,0,&flags);
797       /* if (instrName) printf("FLAGS=0x%x\n", flags);  */
798       if (!instrName)
799 	{
800 	  instrName = "???";
801 	  state->flow=invalid_instr;
802 	}
803       if (flags & IGNORE_FIRST_OPD)
804 	ignoreFirstOpd = 1;
805       break;
806     }
807 
808   fieldAisReg = fieldBisReg = fieldCisReg = 1; /* Assume regs for now.  */
809   flag = cond = is_shimm = is_limm = 0;
810   state->nullifyMode = BR_exec_when_no_jump;	/* 0  */
811   signExtend = addrWriteBack = directMem = 0;
812   usesAuxReg = 0;
813 
814   switch (decodingClass)
815     {
816     case CLASS_A4_ARITH:
817       CHECK_FIELD_A ();
818       CHECK_FIELD_B ();
819       if (!repeatsOp)
820 	CHECK_FIELD_C ();
821       CHECK_FLAG_COND_NULLIFY ();
822 
823       write_instr_name ();
824       if (!ignoreFirstOpd)
825 	{
826 	  WRITE_FORMAT_x (A);
827 	  WRITE_FORMAT_COMMA_x (B);
828 	  if (!repeatsOp)
829 	    WRITE_FORMAT_COMMA_x (C);
830 	  WRITE_NOP_COMMENT ();
831 	  arc_sprintf (state, state->operandBuffer, formatString,
832 		      fieldA, fieldB, fieldC);
833 	}
834       else
835 	{
836 	  WRITE_FORMAT_x (B);
837 	  if (!repeatsOp)
838 	    WRITE_FORMAT_COMMA_x (C);
839 	  arc_sprintf (state, state->operandBuffer, formatString,
840 		      fieldB, fieldC);
841 	}
842       write_comments ();
843       break;
844 
845     case CLASS_A4_OP3_GENERAL:
846       CHECK_FIELD_A ();
847       CHECK_FIELD_B ();
848       CHECK_FLAG_COND_NULLIFY ();
849 
850       write_instr_name ();
851       if (!ignoreFirstOpd)
852 	{
853 	  WRITE_FORMAT_x (A);
854 	  WRITE_FORMAT_COMMA_x (B);
855 	  WRITE_NOP_COMMENT ();
856 	  arc_sprintf (state, state->operandBuffer, formatString,
857 		      fieldA, fieldB);
858 	}
859       else
860 	{
861 	  WRITE_FORMAT_x (B);
862 	  arc_sprintf (state, state->operandBuffer, formatString, fieldB);
863 	}
864       write_comments ();
865       break;
866 
867     case CLASS_A4_FLAG:
868       CHECK_FIELD_B ();
869       CHECK_FLAG_COND_NULLIFY ();
870       flag = 0; /* This is the FLAG instruction -- it's redundant.  */
871 
872       write_instr_name ();
873       WRITE_FORMAT_x (B);
874       arc_sprintf (state, state->operandBuffer, formatString, fieldB);
875       write_comments ();
876       break;
877 
878     case CLASS_A4_BRANCH:
879       fieldA = BITS (state->words[0],7,26) << 2;
880       fieldA = (fieldA << 10) >> 10; /* Make it signed.  */
881       fieldA += addr + 4;
882       CHECK_FLAG_COND_NULLIFY ();
883       flag = 0;
884 
885       write_instr_name ();
886       /* This address could be a label we know. Convert it.  */
887       if (state->_opcode != op_LPC /* LP  */)
888 	{
889 	  add_target (fieldA); /* For debugger.  */
890 	  state->flow = state->_opcode == op_BLC /* BL  */
891 	    ? direct_call
892 	    : direct_jump;
893 	  /* indirect calls are achieved by "lr blink,[status];
894 	     lr dest<- func addr; j [dest]"  */
895 	}
896 
897       strcat (formatString, "%s"); /* Address/label name.  */
898       arc_sprintf (state, state->operandBuffer, formatString,
899 		  post_address (state, fieldA));
900       write_comments ();
901       break;
902 
903     case CLASS_A4_JC:
904       /* For op_JC -- jump to address specified.
905 	 Also covers jump and link--bit 9 of the instr. word
906 	 selects whether linked, thus "is_linked" is set above.  */
907       fieldA = 0;
908       CHECK_FIELD_B ();
909       CHECK_FLAG_COND_NULLIFY ();
910 
911       if (!fieldBisReg)
912 	{
913 	  fieldAisReg = 0;
914 	  fieldA = (fieldB >> 25) & 0x7F; /* Flags.  */
915 	  fieldB = (fieldB & 0xFFFFFF) << 2;
916 	  state->flow = is_linked ? direct_call : direct_jump;
917 	  add_target (fieldB);
918 	  /* Screwy JLcc requires .jd mode to execute correctly
919 	     but we pretend it is .nd (no delay slot).  */
920 	  if (is_linked && state->nullifyMode == BR_exec_when_jump)
921 	    state->nullifyMode = BR_exec_when_no_jump;
922 	}
923       else
924 	{
925 	  state->flow = is_linked ? indirect_call : indirect_jump;
926 	  /* We should also treat this as indirect call if NOT linked
927 	     but the preceding instruction was a "lr blink,[status]"
928 	     and we have a delay slot with "add blink,blink,2".
929 	     For now we can't detect such.  */
930 	  state->register_for_indirect_jump = fieldB;
931 	}
932 
933       write_instr_name ();
934       strcat (formatString,
935 	      IS_REG (B) ? "[%r]" : "%s"); /* Address/label name.  */
936       if (fieldA != 0)
937 	{
938 	  fieldAisReg = 0;
939 	  WRITE_FORMAT_COMMA_x (A);
940 	}
941       if (IS_REG (B))
942 	arc_sprintf (state, state->operandBuffer, formatString, fieldB, fieldA);
943       else
944 	arc_sprintf (state, state->operandBuffer, formatString,
945 		    post_address (state, fieldB), fieldA);
946       write_comments ();
947       break;
948 
949     case CLASS_A4_LD0:
950       /* LD instruction.
951 	 B and C can be regs, or one (both?) can be limm.  */
952       CHECK_FIELD_A ();
953       CHECK_FIELD_B ();
954       CHECK_FIELD_C ();
955       if (dbg)
956 	printf ("5:b reg %d %d c reg %d %d  \n",
957 		fieldBisReg,fieldB,fieldCisReg,fieldC);
958       state->_offset = 0;
959       state->_ea_present = 1;
960       if (fieldBisReg)
961 	state->ea_reg1 = fieldB;
962       else
963 	state->_offset += fieldB;
964       if (fieldCisReg)
965 	state->ea_reg2 = fieldC;
966       else
967 	state->_offset += fieldC;
968       state->_mem_load = 1;
969 
970       directMem     = BIT (state->words[0], 5);
971       addrWriteBack = BIT (state->words[0], 3);
972       signExtend    = BIT (state->words[0], 0);
973 
974       write_instr_name ();
975       WRITE_FORMAT_x_COMMA_LB(A);
976       if (fieldBisReg || fieldB != 0)
977 	WRITE_FORMAT_x_COMMA (B);
978       else
979 	fieldB = fieldC;
980 
981       WRITE_FORMAT_x_RB (C);
982       arc_sprintf (state, state->operandBuffer, formatString,
983 		  fieldA, fieldB, fieldC);
984       write_comments ();
985       break;
986 
987     case CLASS_A4_LD1:
988       /* LD instruction.  */
989       CHECK_FIELD_B ();
990       CHECK_FIELD_A ();
991       fieldC = FIELDD (state->words[0]);
992 
993       if (dbg)
994 	printf ("6:b reg %d %d c 0x%x  \n",
995 		fieldBisReg, fieldB, fieldC);
996       state->_ea_present = 1;
997       state->_offset = fieldC;
998       state->_mem_load = 1;
999       if (fieldBisReg)
1000 	state->ea_reg1 = fieldB;
1001       /* Field B is either a shimm (same as fieldC) or limm (different!)
1002 	 Say ea is not present, so only one of us will do the name lookup.  */
1003       else
1004 	state->_offset += fieldB, state->_ea_present = 0;
1005 
1006       directMem     = BIT (state->words[0],14);
1007       addrWriteBack = BIT (state->words[0],12);
1008       signExtend    = BIT (state->words[0],9);
1009 
1010       write_instr_name ();
1011       WRITE_FORMAT_x_COMMA_LB (A);
1012       if (!fieldBisReg)
1013 	{
1014 	  fieldB = state->_offset;
1015 	  WRITE_FORMAT_x_RB (B);
1016 	}
1017       else
1018 	{
1019 	  WRITE_FORMAT_x (B);
1020 	  if (fieldC != 0 && !BIT (state->words[0],13))
1021 	    {
1022 	      fieldCisReg = 0;
1023 	      WRITE_FORMAT_COMMA_x_RB (C);
1024 	    }
1025 	  else
1026 	    WRITE_FORMAT_RB ();
1027 	}
1028       arc_sprintf (state, state->operandBuffer, formatString,
1029 		  fieldA, fieldB, fieldC);
1030       write_comments ();
1031       break;
1032 
1033     case CLASS_A4_ST:
1034       /* ST instruction.  */
1035       CHECK_FIELD_B();
1036       CHECK_FIELD_C();
1037       fieldA = FIELDD(state->words[0]); /* shimm  */
1038 
1039       /* [B,A offset]  */
1040       if (dbg) printf("7:b reg %d %x off %x\n",
1041 		      fieldBisReg,fieldB,fieldA);
1042       state->_ea_present = 1;
1043       state->_offset = fieldA;
1044       if (fieldBisReg)
1045 	state->ea_reg1 = fieldB;
1046       /* Field B is either a shimm (same as fieldA) or limm (different!)
1047 	 Say ea is not present, so only one of us will do the name lookup.
1048 	 (for is_limm we do the name translation here).  */
1049       else
1050 	state->_offset += fieldB, state->_ea_present = 0;
1051 
1052       directMem     = BIT (state->words[0], 26);
1053       addrWriteBack = BIT (state->words[0], 24);
1054 
1055       write_instr_name ();
1056       WRITE_FORMAT_x_COMMA_LB(C);
1057 
1058       if (!fieldBisReg)
1059 	{
1060 	  fieldB = state->_offset;
1061 	  WRITE_FORMAT_x_RB (B);
1062 	}
1063       else
1064 	{
1065 	  WRITE_FORMAT_x (B);
1066 	  if (fieldBisReg && fieldA != 0)
1067 	    {
1068 	      fieldAisReg = 0;
1069 	      WRITE_FORMAT_COMMA_x_RB(A);
1070 	    }
1071 	  else
1072 	    WRITE_FORMAT_RB();
1073 	}
1074       arc_sprintf (state, state->operandBuffer, formatString,
1075 		  fieldC, fieldB, fieldA);
1076       write_comments2 (fieldA);
1077       break;
1078 
1079     case CLASS_A4_SR:
1080       /* SR instruction  */
1081       CHECK_FIELD_B();
1082       CHECK_FIELD_C();
1083 
1084       write_instr_name ();
1085       WRITE_FORMAT_x_COMMA_LB(C);
1086       /* Try to print B as an aux reg if it is not a core reg.  */
1087       usesAuxReg = 1;
1088       WRITE_FORMAT_x (B);
1089       WRITE_FORMAT_RB ();
1090       arc_sprintf (state, state->operandBuffer, formatString, fieldC, fieldB);
1091       write_comments ();
1092       break;
1093 
1094     case CLASS_A4_OP3_SUBOPC3F:
1095       write_instr_name ();
1096       state->operandBuffer[0] = '\0';
1097       break;
1098 
1099     case CLASS_A4_LR:
1100       /* LR instruction */
1101       CHECK_FIELD_A ();
1102       CHECK_FIELD_B ();
1103 
1104       write_instr_name ();
1105       WRITE_FORMAT_x_COMMA_LB (A);
1106       /* Try to print B as an aux reg if it is not a core reg. */
1107       usesAuxReg = 1;
1108       WRITE_FORMAT_x (B);
1109       WRITE_FORMAT_RB ();
1110       arc_sprintf (state, state->operandBuffer, formatString, fieldA, fieldB);
1111       write_comments ();
1112       break;
1113 
1114     default:
1115       mwerror (state, "Bad decoding class in ARC disassembler");
1116       break;
1117     }
1118 
1119   state->_cond = cond;
1120   return state->instructionLen = offset;
1121 }
1122 
1123 
1124 /* Returns the name the user specified core extension register.  */
1125 
1126 static const char *
1127 _coreRegName(void * arg ATTRIBUTE_UNUSED, int regval)
1128 {
1129   return arcExtMap_coreRegName (regval);
1130 }
1131 
1132 /* Returns the name the user specified AUX extension register.  */
1133 
1134 static const char *
1135 _auxRegName(void *_this ATTRIBUTE_UNUSED, int regval)
1136 {
1137   return arcExtMap_auxRegName(regval);
1138 }
1139 
1140 /* Returns the name the user specified condition code name.  */
1141 
1142 static const char *
1143 _condCodeName(void *_this ATTRIBUTE_UNUSED, int regval)
1144 {
1145   return arcExtMap_condCodeName(regval);
1146 }
1147 
1148 /* Returns the name the user specified extension instruction.  */
1149 
1150 static const char *
1151 _instName (void *_this ATTRIBUTE_UNUSED, int majop, int minop, int *flags)
1152 {
1153   return arcExtMap_instName(majop, minop, flags);
1154 }
1155 
1156 /* Decode an instruction returning the size of the instruction
1157    in bytes or zero if unrecognized.  */
1158 
1159 static int
1160 decodeInstr (bfd_vma            address, /* Address of this instruction.  */
1161 	     disassemble_info * info)
1162 {
1163   int status;
1164   bfd_byte buffer[4];
1165   struct arcDisState s;		/* ARC Disassembler state.  */
1166   void *stream = info->stream; 	/* Output stream.  */
1167   fprintf_ftype func = info->fprintf_func;
1168 
1169   memset (&s, 0, sizeof(struct arcDisState));
1170 
1171   /* read first instruction  */
1172   status = (*info->read_memory_func) (address, buffer, 4, info);
1173   if (status != 0)
1174     {
1175       (*info->memory_error_func) (status, address, info);
1176       return 0;
1177     }
1178   if (info->endian == BFD_ENDIAN_LITTLE)
1179     s.words[0] = bfd_getl32(buffer);
1180   else
1181     s.words[0] = bfd_getb32(buffer);
1182   /* Always read second word in case of limm.  */
1183 
1184   /* We ignore the result since last insn may not have a limm.  */
1185   status = (*info->read_memory_func) (address + 4, buffer, 4, info);
1186   if (info->endian == BFD_ENDIAN_LITTLE)
1187     s.words[1] = bfd_getl32(buffer);
1188   else
1189     s.words[1] = bfd_getb32(buffer);
1190 
1191   s._this = &s;
1192   s.coreRegName = _coreRegName;
1193   s.auxRegName = _auxRegName;
1194   s.condCodeName = _condCodeName;
1195   s.instName = _instName;
1196 
1197   /* Disassemble.  */
1198   dsmOneArcInst (address, & s);
1199 
1200   /* Display the disassembly instruction.  */
1201   (*func) (stream, "%08lx ", s.words[0]);
1202   (*func) (stream, "    ");
1203   (*func) (stream, "%-10s ", s.instrBuffer);
1204 
1205   if (__TRANSLATION_REQUIRED (s))
1206     {
1207       bfd_vma addr = s.addresses[s.operandBuffer[1] - '0'];
1208 
1209       (*info->print_address_func) ((bfd_vma) addr, info);
1210       (*func) (stream, "\n");
1211     }
1212   else
1213     (*func) (stream, "%s",s.operandBuffer);
1214 
1215   return s.instructionLen;
1216 }
1217 
1218 /* Return the print_insn function to use.
1219    Side effect: load (possibly empty) extension section  */
1220 
1221 disassembler_ftype
1222 arc_get_disassembler (void *ptr)
1223 {
1224   if (ptr)
1225     build_ARC_extmap ((struct bfd *) ptr);
1226   return decodeInstr;
1227 }
1228