xref: /netbsd-src/external/gpl3/gdb/dist/opcodes/cr16-dis.c (revision a5847cc334d9a7029f6352b847e9e8d71a0f9e0c)
1 /* Disassembler code for CR16.
2    Copyright 2007, 2008, 2009  Free Software Foundation, Inc.
3    Contributed by M R Swami Reddy (MR.Swami.Reddy@nsc.com).
4 
5    This file is part of GAS, GDB and the GNU binutils.
6 
7    This program is free software; you can redistribute it and/or modify it
8    under the terms of the GNU General Public License as published by the
9    Free Software Foundation; either version 3, or (at your option)
10    any later version.
11 
12    This program is distributed in the hope that it will be useful, but WITHOUT
13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15    more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program; if not, write to the Free Software Foundation,
19    Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
20 
21 #include "dis-asm.h"
22 #include "sysdep.h"
23 #include "opcode/cr16.h"
24 #include "libiberty.h"
25 
26 /* String to print when opcode was not matched.  */
27 #define ILLEGAL  "illegal"
28   /* Escape to 16-bit immediate.  */
29 #define ESCAPE_16_BIT  0xB
30 
31 /* Extract 'n_bits' from 'a' starting from offset 'offs'.  */
32 #define EXTRACT(a, offs, n_bits)                    \
33   (n_bits == 32 ? (((a) >> (offs)) & 0xffffffffL)   \
34   : (((a) >> (offs)) & ((1 << (n_bits)) -1)))
35 
36 /* Set Bit Mask - a mask to set all bits starting from offset 'offs'.  */
37 #define SBM(offs)  ((((1 << (32 - offs)) -1) << (offs)))
38 
39 typedef unsigned long dwordU;
40 typedef unsigned short wordU;
41 
42 typedef struct
43 {
44   dwordU val;
45   int nbits;
46 } parameter;
47 
48 /* Structure to map valid 'cinv' instruction options.  */
49 
50 typedef struct
51   {
52     /* Cinv printed string.  */
53     char *istr;
54     /* Value corresponding to the string.  */
55     char *ostr;
56   }
57 cinv_entry;
58 
59 /* CR16 'cinv' options mapping.  */
60 const cinv_entry cr16_cinvs[] =
61 {
62   {"cinv[i]",     "cinv    [i]"},
63   {"cinv[i,u]",   "cinv    [i,u]"},
64   {"cinv[d]",     "cinv    [d]"},
65   {"cinv[d,u]",   "cinv    [d,u]"},
66   {"cinv[d,i]",   "cinv    [d,i]"},
67   {"cinv[d,i,u]", "cinv    [d,i,u]"}
68 };
69 
70 /* Number of valid 'cinv' instruction options.  */
71 static int NUMCINVS = ARRAY_SIZE (cr16_cinvs);
72 
73 /* Enum to distinguish different registers argument types.  */
74 typedef enum REG_ARG_TYPE
75   {
76     /* General purpose register (r<N>).  */
77     REG_ARG = 0,
78     /*Processor register   */
79     P_ARG,
80   }
81 REG_ARG_TYPE;
82 
83 /* Current opcode table entry we're disassembling.  */
84 const inst *instruction;
85 /* Current instruction we're disassembling.  */
86 ins currInsn;
87 /* The current instruction is read into 3 consecutive words.  */
88 wordU words[3];
89 /* Contains all words in appropriate order.  */
90 ULONGLONG allWords;
91 /* Holds the current processed argument number.  */
92 int processing_argument_number;
93 /* Nonzero means a IMM4 instruction.  */
94 int imm4flag;
95 /* Nonzero means the instruction's original size is
96    incremented (escape sequence is used).  */
97 int size_changed;
98 
99 
100 /* Print the constant expression length.  */
101 
102 static char *
103 print_exp_len (int size)
104 {
105   switch (size)
106     {
107     case 4:
108     case 5:
109     case 6:
110     case 8:
111     case 14:
112     case 16:
113       return ":s";
114     case 20:
115     case 24:
116     case 32:
117       return ":m";
118     case 48:
119       return ":l";
120     default:
121       return "";
122     }
123 }
124 
125 
126 /* Retrieve the number of operands for the current assembled instruction.  */
127 
128 static int
129 get_number_of_operands (void)
130 {
131   int i;
132 
133   for (i = 0; instruction->operands[i].op_type && i < MAX_OPERANDS; i++)
134     ;
135 
136   return i;
137 }
138 
139 /* Return the bit size for a given operand.  */
140 
141 static int
142 getbits (operand_type op)
143 {
144   if (op < MAX_OPRD)
145     return cr16_optab[op].bit_size;
146 
147   return 0;
148 }
149 
150 /* Return the argument type of a given operand.  */
151 
152 static argtype
153 getargtype (operand_type op)
154 {
155   if (op < MAX_OPRD)
156     return cr16_optab[op].arg_type;
157 
158   return nullargs;
159 }
160 
161 /* Given a 'CC' instruction constant operand, return its corresponding
162    string. This routine is used when disassembling the 'CC' instruction.  */
163 
164 static char *
165 getccstring (unsigned cc_insn)
166 {
167   return (char *) cr16_b_cond_tab[cc_insn];
168 }
169 
170 
171 /* Given a 'cinv' instruction constant operand, return its corresponding
172    string. This routine is used when disassembling the 'cinv' instruction. */
173 
174 static char *
175 getcinvstring (const char *str)
176 {
177   const cinv_entry *cinv;
178 
179   for (cinv = cr16_cinvs; cinv < (cr16_cinvs + NUMCINVS); cinv++)
180     if (strcmp (cinv->istr, str) == 0)
181       return cinv->ostr;
182 
183   return ILLEGAL;
184 }
185 
186 /* Given the trap index in dispatch table, return its name.
187    This routine is used when disassembling the 'excp' instruction.  */
188 
189 static char *
190 gettrapstring (unsigned int trap_index)
191 {
192   const trap_entry *trap;
193 
194   for (trap = cr16_traps; trap < cr16_traps + NUMTRAPS; trap++)
195     if (trap->entry == trap_index)
196       return trap->name;
197 
198   return ILLEGAL;
199 }
200 
201 /* Given a register enum value, retrieve its name.  */
202 
203 static char *
204 getregname (reg r)
205 {
206   const reg_entry * regentry = cr16_regtab + r;
207 
208   if (regentry->type != CR16_R_REGTYPE)
209     return ILLEGAL;
210 
211   return regentry->name;
212 }
213 
214 /* Given a register pair enum value, retrieve its name.  */
215 
216 static char *
217 getregpname (reg r)
218 {
219   const reg_entry * regentry = cr16_regptab + r;
220 
221   if (regentry->type != CR16_RP_REGTYPE)
222     return ILLEGAL;
223 
224   return regentry->name;
225 }
226 
227 /* Given a index register pair enum value, retrieve its name.  */
228 
229 static char *
230 getidxregpname (reg r)
231 {
232   const reg_entry * regentry;
233 
234   switch (r)
235    {
236    case 0: r = 0; break;
237    case 1: r = 2; break;
238    case 2: r = 4; break;
239    case 3: r = 6; break;
240    case 4: r = 8; break;
241    case 5: r = 10; break;
242    case 6: r = 3; break;
243    case 7: r = 5; break;
244    default:
245      break;
246    }
247 
248   regentry = cr16_regptab + r;
249 
250   if (regentry->type != CR16_RP_REGTYPE)
251     return ILLEGAL;
252 
253   return regentry->name;
254 }
255 
256 /* Getting a processor register name.  */
257 
258 static char *
259 getprocregname (int reg_index)
260 {
261   const reg_entry *r;
262 
263   for (r = cr16_pregtab; r < cr16_pregtab + NUMPREGS; r++)
264     if (r->image == reg_index)
265       return r->name;
266 
267   return "ILLEGAL REGISTER";
268 }
269 
270 /* Getting a processor register name - 32 bit size.  */
271 
272 static char *
273 getprocpregname (int reg_index)
274 {
275   const reg_entry *r;
276 
277   for (r = cr16_pregptab; r < cr16_pregptab + NUMPREGPS; r++)
278     if (r->image == reg_index)
279       return r->name;
280 
281   return "ILLEGAL REGISTER";
282 }
283 
284 /* START and END are relating 'allWords' struct, which is 48 bits size.
285 
286                           START|--------|END
287              +---------+---------+---------+---------+
288              |         |   V    |     A    |   L     |
289              +---------+---------+---------+---------+
290                        0         16        32        48
291     words                  [0]       [1]       [2]      */
292 
293 static parameter
294 makelongparameter (ULONGLONG val, int start, int end)
295 {
296   parameter p;
297 
298   p.val = (dwordU) EXTRACT (val, 48 - end, end - start);
299   p.nbits = end - start;
300   return p;
301 }
302 
303 /* Build a mask of the instruction's 'constant' opcode,
304    based on the instruction's printing flags.  */
305 
306 static unsigned long
307 build_mask (void)
308 {
309   unsigned long mask = SBM (instruction->match_bits);
310 
311   /* Adjust mask for bcond with 32-bit size instruction.  */
312   if ((IS_INSN_MNEMONIC("b") && instruction->size == 2))
313     mask = 0xff0f0000;
314 
315   return mask;
316 }
317 
318 /* Search for a matching opcode. Return 1 for success, 0 for failure.  */
319 
320 static int
321 match_opcode (void)
322 {
323   unsigned long mask;
324   /* The instruction 'constant' opcode doewsn't exceed 32 bits.  */
325   unsigned long doubleWord = (words[1] + (words[0] << 16)) & 0xffffffff;
326 
327   /* Start searching from end of instruction table.  */
328   instruction = &cr16_instruction[NUMOPCODES - 2];
329 
330   /* Loop over instruction table until a full match is found.  */
331   while (instruction >= cr16_instruction)
332     {
333       mask = build_mask ();
334       /* Adjust mask for bcond with 32-bit size instruction */
335       if ((IS_INSN_MNEMONIC("b") && instruction->size == 2))
336         mask = 0xff0f0000;
337 
338       if ((doubleWord & mask) == BIN (instruction->match,
339                                       instruction->match_bits))
340         return 1;
341       else
342         instruction--;
343     }
344   return 0;
345 }
346 
347 /* Set the proper parameter value for different type of arguments.  */
348 
349 static void
350 make_argument (argument * a, int start_bits)
351 {
352   int inst_bit_size;
353   parameter p;
354 
355   if ((instruction->size == 3) && a->size >= 16)
356     inst_bit_size = 48;
357   else
358     inst_bit_size = 32;
359 
360   switch (a->type)
361     {
362     case arg_r:
363       p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),
364                              inst_bit_size - start_bits);
365       a->r = p.val;
366       break;
367 
368     case arg_rp:
369       p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),
370                              inst_bit_size - start_bits);
371       a->rp = p.val;
372       break;
373 
374     case arg_pr:
375       p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),
376                              inst_bit_size - start_bits);
377       a->pr = p.val;
378       break;
379 
380     case arg_prp:
381       p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),
382                              inst_bit_size - start_bits);
383       a->prp = p.val;
384       break;
385 
386     case arg_ic:
387       p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),
388                              inst_bit_size - start_bits);
389       a->constant = p.val;
390       break;
391 
392     case arg_cc:
393       p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),
394                              inst_bit_size - start_bits);
395 
396       a->cc = p.val;
397       break;
398 
399     case arg_idxr:
400       if ((IS_INSN_MNEMONIC ("cbitb"))
401 	  || (IS_INSN_MNEMONIC ("sbitb"))
402 	  || (IS_INSN_MNEMONIC ("tbitb")))
403 	p = makelongparameter (allWords, 8, 9);
404       else
405 	p = makelongparameter (allWords, 9, 10);
406       a->i_r = p.val;
407       p = makelongparameter (allWords, inst_bit_size - a->size, inst_bit_size);
408       a->constant = p.val;
409       break;
410 
411     case arg_idxrp:
412       p = makelongparameter (allWords, start_bits + 12, start_bits + 13);
413       a->i_r = p.val;
414       p = makelongparameter (allWords, start_bits + 13, start_bits + 16);
415       a->rp = p.val;
416       if (inst_bit_size > 32)
417 	{
418 	  p = makelongparameter (allWords, inst_bit_size - start_bits - 12,
419 				 inst_bit_size);
420 	  a->constant = ((p.val & 0xffff) | (p.val >> 8 & 0xf0000));
421 	}
422       else if (instruction->size == 2)
423 	{
424 	  p = makelongparameter (allWords, inst_bit_size - 22, inst_bit_size);
425 	  a->constant = (p.val & 0xf) | (((p.val >>20) & 0x3) << 4)
426 	    | ((p.val >>14 & 0x3) << 6) | (((p.val >>7) & 0x1f) <<7);
427 	}
428       else if (instruction->size == 1 && a->size == 0)
429 	a->constant = 0;
430 
431       break;
432 
433     case arg_rbase:
434       p = makelongparameter (allWords, inst_bit_size, inst_bit_size);
435       a->constant = p.val;
436       p = makelongparameter (allWords, inst_bit_size - (start_bits + 4),
437                              inst_bit_size - start_bits);
438       a->r = p.val;
439       break;
440 
441     case arg_cr:
442       p = makelongparameter (allWords, start_bits + 12, start_bits + 16);
443       a->r = p.val;
444       p = makelongparameter (allWords, inst_bit_size - 16, inst_bit_size);
445       a->constant = p.val;
446       break;
447 
448     case arg_crp:
449       if (instruction->size == 1)
450 	p = makelongparameter (allWords, 12, 16);
451       else
452 	p = makelongparameter (allWords, start_bits + 12, start_bits + 16);
453       a->rp = p.val;
454 
455       if (inst_bit_size > 32)
456 	{
457 	  p = makelongparameter (allWords, inst_bit_size - start_bits - 12,
458 				 inst_bit_size);
459 	  a->constant = ((p.val & 0xffff) | (p.val >> 8 & 0xf0000));
460 	}
461       else if (instruction->size == 2)
462 	{
463 	  p = makelongparameter (allWords, inst_bit_size - 16, inst_bit_size);
464 	  a->constant = p.val;
465 	}
466       else if (instruction->size == 1 && a->size != 0)
467 	{
468 	  p = makelongparameter (allWords, 4, 8);
469 	  if (IS_INSN_MNEMONIC ("loadw")
470 	      || IS_INSN_MNEMONIC ("loadd")
471 	      || IS_INSN_MNEMONIC ("storw")
472 	      || IS_INSN_MNEMONIC ("stord"))
473 	    a->constant = (p.val * 2);
474 	  else
475 	    a->constant = p.val;
476 	}
477       else /* below case for 0x0(reg pair) */
478 	a->constant = 0;
479 
480       break;
481 
482     case arg_c:
483 
484       if ((IS_INSN_TYPE (BRANCH_INS))
485 	  || (IS_INSN_MNEMONIC ("bal"))
486 	  || (IS_INSN_TYPE (CSTBIT_INS))
487 	  || (IS_INSN_TYPE (LD_STOR_INS)))
488 	{
489 	  switch (a->size)
490 	    {
491 	    case 8 :
492 	      p = makelongparameter (allWords, 0, start_bits);
493 	      a->constant = ((((p.val&0xf00)>>4)) | (p.val&0xf));
494 	      break;
495 
496 	    case 24:
497 	      if (instruction->size == 3)
498 		{
499 		  p = makelongparameter (allWords, 16, inst_bit_size);
500 		  a->constant = ((((p.val>>16)&0xf) << 20)
501 				 | (((p.val>>24)&0xf) << 16)
502 				 | (p.val & 0xffff));
503 		}
504 	      else if (instruction->size == 2)
505 		{
506 		  p = makelongparameter (allWords, 8, inst_bit_size);
507 		  a->constant = p.val;
508 		}
509 	      break;
510 
511 	    default:
512 	      p = makelongparameter (allWords, inst_bit_size - (start_bits +
513 								a->size), inst_bit_size - start_bits);
514 	      a->constant = p.val;
515 	      break;
516 	    }
517 	}
518       else
519 	{
520 	  p = makelongparameter (allWords, inst_bit_size -
521 				 (start_bits + a->size),
522 				 inst_bit_size - start_bits);
523 	  a->constant = p.val;
524 	}
525       break;
526 
527     default:
528       break;
529     }
530 }
531 
532 /*  Print a single argument.  */
533 
534 static void
535 print_arg (argument *a, bfd_vma memaddr, struct disassemble_info *info)
536 {
537   LONGLONG longdisp, mask;
538   int sign_flag = 0;
539   int relative = 0;
540   bfd_vma number;
541   PTR stream = info->stream;
542   fprintf_ftype func = info->fprintf_func;
543 
544   switch (a->type)
545     {
546     case arg_r:
547       func (stream, "%s", getregname (a->r));
548       break;
549 
550     case arg_rp:
551       func (stream, "%s", getregpname (a->rp));
552       break;
553 
554     case arg_pr:
555       func (stream, "%s", getprocregname (a->pr));
556       break;
557 
558     case arg_prp:
559       func (stream, "%s", getprocpregname (a->prp));
560       break;
561 
562     case arg_cc:
563       func (stream, "%s", getccstring (a->cc));
564       func (stream, "%s", "\t");
565       break;
566 
567     case arg_ic:
568       if (IS_INSN_MNEMONIC ("excp"))
569 	{
570 	  func (stream, "%s", gettrapstring (a->constant));
571 	  break;
572 	}
573       else if ((IS_INSN_TYPE (ARITH_INS) || IS_INSN_TYPE (ARITH_BYTE_INS))
574 	       && ((instruction->size == 1) && (a->constant == 9)))
575 	func (stream, "$%d", -1);
576       else if (INST_HAS_REG_LIST)
577 	func (stream, "$0x%lx", a->constant +1);
578       else if (IS_INSN_TYPE (SHIFT_INS))
579 	{
580 	  longdisp = a->constant;
581 	  mask = ((LONGLONG)1 << a->size) - 1;
582 	  if (longdisp & ((LONGLONG)1 << (a->size -1)))
583 	    {
584 	      sign_flag = 1;
585 	      longdisp = ~(longdisp) + 1;
586 	    }
587 	  a->constant = (unsigned long int) (longdisp & mask);
588 	  func (stream, "$%d", ((int)(sign_flag ? -a->constant :
589 				      a->constant)));
590 	}
591       else
592 	func (stream, "$0x%lx", a->constant);
593       switch (a->size)
594 	{
595 	case 4  : case 5  : case 6  : case 8  :
596 	  func (stream, "%s", ":s"); break;
597 	case 16 : case 20 : func (stream, "%s", ":m"); break;
598 	case 24 : case 32 : func (stream, "%s", ":l"); break;
599 	default: break;
600 	}
601       break;
602 
603     case arg_idxr:
604       if (a->i_r == 0) func (stream, "[r12]");
605       if (a->i_r == 1) func (stream, "[r13]");
606       func (stream, "0x%lx", a->constant);
607       func (stream, "%s", print_exp_len (instruction->size * 16));
608       break;
609 
610     case arg_idxrp:
611       if (a->i_r == 0) func (stream, "[r12]");
612       if (a->i_r == 1) func (stream, "[r13]");
613       func (stream, "0x%lx", a->constant);
614       func (stream, "%s", print_exp_len (instruction->size * 16));
615       func (stream, "%s", getidxregpname (a->rp));
616       break;
617 
618     case arg_rbase:
619       func (stream, "(%s)", getregname (a->r));
620       break;
621 
622     case arg_cr:
623       func (stream, "0x%lx", a->constant);
624       func (stream, "%s", print_exp_len (instruction->size * 16));
625       func (stream, "(%s)", getregname (a->r));
626       break;
627 
628     case arg_crp:
629       func (stream, "0x%lx", a->constant);
630       func (stream, "%s", print_exp_len (instruction->size * 16));
631       func (stream, "%s", getregpname (a->rp));
632       break;
633 
634     case arg_c:
635       /*Removed the *2 part as because implicit zeros are no more required.
636 	Have to fix this as this needs a bit of extension in terms of branch
637 	instructions. */
638       if (IS_INSN_TYPE (BRANCH_INS) || IS_INSN_MNEMONIC ("bal"))
639 	{
640 	  relative = 1;
641 	  longdisp = a->constant;
642 	  /* REVISIT: To sync with WinIDEA and CR16 4.1tools, the below
643 	     line commented */
644 	  /* longdisp <<= 1; */
645 	  mask = ((LONGLONG)1 << a->size) - 1;
646 	  switch (a->size)
647 	    {
648 	    case 8  :
649 	      {
650 		longdisp <<= 1;
651 		if (longdisp & ((LONGLONG)1 << a->size))
652 		  {
653 		    sign_flag = 1;
654 		    longdisp = ~(longdisp) + 1;
655 		  }
656 		break;
657 	      }
658 	    case 16 :
659 	    case 24 :
660 	      {
661 		if (longdisp & 1)
662 		  {
663 		    sign_flag = 1;
664 		    longdisp = ~(longdisp) + 1;
665 		  }
666 		break;
667 	      }
668 	    default:
669 	      func (stream, "Wrong offset used in branch/bal instruction");
670 	      break;
671 	    }
672 	  a->constant = (unsigned long int) (longdisp & mask);
673 	}
674       /* For branch Neq instruction it is 2*offset + 2.  */
675       else if (IS_INSN_TYPE (BRANCH_NEQ_INS))
676 	a->constant = 2 * a->constant + 2;
677 
678       if ((!IS_INSN_TYPE (CSTBIT_INS)) && (!IS_INSN_TYPE (LD_STOR_INS)))
679 	(sign_flag) ? func (stream, "%s", "*-"): func (stream, "%s","*+");
680 
681       /* PR 10173: Avoid printing the 0x prefix twice.  */
682       if (info->num_symbols > 0)
683 	func (stream, "%s", "0x");
684       number = ((relative ? memaddr : 0) +
685 		(sign_flag ? ((- a->constant) & 0xffffffe) : a->constant));
686 
687       (*info->print_address_func) ((number & ((1 << 24) - 1)), info);
688 
689       func (stream, "%s", print_exp_len (instruction->size * 16));
690       break;
691 
692     default:
693       break;
694     }
695 }
696 
697 /* Print all the arguments of CURRINSN instruction.  */
698 
699 static void
700 print_arguments (ins *currentInsn, bfd_vma memaddr, struct disassemble_info *info)
701 {
702   int i;
703 
704   /* For "pop/push/popret RA instruction only.  */
705   if ((IS_INSN_MNEMONIC ("pop")
706        || (IS_INSN_MNEMONIC ("popret")
707 	   || (IS_INSN_MNEMONIC ("push"))))
708       && currentInsn->nargs == 1)
709     {
710       info->fprintf_func (info->stream, "RA");
711       return;
712     }
713 
714   for (i = 0; i < currentInsn->nargs; i++)
715     {
716       processing_argument_number = i;
717 
718       /* For "bal (ra), disp17" instruction only.  */
719       if ((IS_INSN_MNEMONIC ("bal")) && (i == 0) && instruction->size == 2)
720         {
721           info->fprintf_func (info->stream, "(ra),");
722           continue;
723         }
724 
725       if ((INST_HAS_REG_LIST) && (i == 2))
726         info->fprintf_func (info->stream, "RA");
727       else
728         print_arg (&currentInsn->arg[i], memaddr, info);
729 
730       if ((i != currentInsn->nargs - 1) && (!IS_INSN_MNEMONIC ("b")))
731         info->fprintf_func (info->stream, ",");
732     }
733 }
734 
735 /* Build the instruction's arguments.  */
736 
737 static void
738 make_instruction (void)
739 {
740   int i;
741   unsigned int shift;
742 
743   for (i = 0; i < currInsn.nargs; i++)
744     {
745       argument a;
746 
747       memset (&a, 0, sizeof (a));
748       a.type = getargtype (instruction->operands[i].op_type);
749       a.size = getbits (instruction->operands[i].op_type);
750       shift = instruction->operands[i].shift;
751 
752       make_argument (&a, shift);
753       currInsn.arg[i] = a;
754     }
755 
756   /* Calculate instruction size (in bytes).  */
757   currInsn.size = instruction->size + (size_changed ? 1 : 0);
758   /* Now in bits.  */
759   currInsn.size *= 2;
760 }
761 
762 /* Retrieve a single word from a given memory address.  */
763 
764 static wordU
765 get_word_at_PC (bfd_vma memaddr, struct disassemble_info *info)
766 {
767   bfd_byte buffer[4];
768   int status;
769   wordU insn = 0;
770 
771   status = info->read_memory_func (memaddr, buffer, 2, info);
772 
773   if (status == 0)
774     insn = (wordU) bfd_getl16 (buffer);
775 
776   return insn;
777 }
778 
779 /* Retrieve multiple words (3) from a given memory address.  */
780 
781 static void
782 get_words_at_PC (bfd_vma memaddr, struct disassemble_info *info)
783 {
784   int i;
785   bfd_vma mem;
786 
787   for (i = 0, mem = memaddr; i < 3; i++, mem += 2)
788     words[i] = get_word_at_PC (mem, info);
789 
790   allWords =
791     ((ULONGLONG) words[0] << 32) + ((unsigned long) words[1] << 16) + words[2];
792 }
793 
794 /* Prints the instruction by calling print_arguments after proper matching.  */
795 
796 int
797 print_insn_cr16 (bfd_vma memaddr, struct disassemble_info *info)
798 {
799   int is_decoded;     /* Nonzero means instruction has a match.  */
800 
801   /* Initialize global variables.  */
802   imm4flag = 0;
803   size_changed = 0;
804 
805   /* Retrieve the encoding from current memory location.  */
806   get_words_at_PC (memaddr, info);
807   /* Find a matching opcode in table.  */
808   is_decoded = match_opcode ();
809   /* If found, print the instruction's mnemonic and arguments.  */
810   if (is_decoded > 0 && (words[0] << 16 || words[1]) != 0)
811     {
812       if (strneq (instruction->mnemonic, "cinv", 4))
813         info->fprintf_func (info->stream,"%s", getcinvstring (instruction->mnemonic));
814       else
815         info->fprintf_func (info->stream, "%s", instruction->mnemonic);
816 
817       if (((currInsn.nargs = get_number_of_operands ()) != 0)
818 	  && ! (IS_INSN_MNEMONIC ("b")))
819         info->fprintf_func (info->stream, "\t");
820       make_instruction ();
821       /* For push/pop/pushrtn with RA instructions.  */
822       if ((INST_HAS_REG_LIST) && ((words[0] >> 7) & 0x1))
823         currInsn.nargs +=1;
824       print_arguments (&currInsn, memaddr, info);
825       return currInsn.size;
826     }
827 
828   /* No match found.  */
829   info->fprintf_func (info->stream,"%s ",ILLEGAL);
830   return 2;
831 }
832