opcodes/crx-dis.c

   1 /* Disassembler code for CRX.
   2    Copyright 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
   3    Contributed by Tomer Levi, NSC, Israel.
   4    Written by Tomer Levi.
   5
   6    This file is part of the GNU opcodes library.
   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 "dis-asm.h"
  24 #include "sysdep.h"
  25 #include "opcode/crx.h"
  26
  27 /* String to print when opcode was not matched.  */
  28 #define ILLEGAL "illegal"
  29   /* Escape to 16-bit immediate.  */
  30 #define ESCAPE_16_BIT  0xE
  31
  32 /* Extract 'n_bits' from 'a' starting from offset 'offs'.  */
  33 #define EXTRACT(a, offs, n_bits)            \
  34   (n_bits == 32 ? (((a) >> (offs)) & 0xffffffffL)   \
  35   : (((a) >> (offs)) & ((1 << (n_bits)) -1)))
  36
  37 /* Set Bit Mask - a mask to set all bits starting from offset 'offs'.  */
  38 #define SBM(offs)  ((((1 << (32 - offs)) -1) << (offs)))
  39
  40 typedef unsigned long dwordU;
  41 typedef unsigned short wordU;
  42
  43 typedef struct
  44 {
  45   dwordU val;
  46   int nbits;
  47 } parameter;
  48
  49 /* Structure to hold valid 'cinv' instruction options.  */
  50
  51 typedef struct
  52   {
  53     /* Cinv printed string.  */
  54     char *str;
  55     /* Value corresponding to the string.  */
  56     unsigned int value;
  57   }
  58 cinv_entry;
  59
  60 /* CRX 'cinv' options.  */
  61 const cinv_entry crx_cinvs[] =
  62 {
  63   {"[i]", 2}, {"[i,u]", 3}, {"[d]", 4}, {"[d,u]", 5},
  64   {"[d,i]", 6}, {"[d,i,u]", 7}, {"[b]", 8},
  65   {"[b,i]", 10}, {"[b,i,u]", 11}, {"[b,d]", 12},
  66   {"[b,d,u]", 13}, {"[b,d,i]", 14}, {"[b,d,i,u]", 15}
  67 };
  68
  69 /* Enum to distinguish different registers argument types.  */
  70 typedef enum REG_ARG_TYPE
  71   {
  72     /* General purpose register (r<N>).  */
  73     REG_ARG = 0,
  74     /* User register (u<N>).  */
  75     USER_REG_ARG,
  76     /* CO-Processor register (c<N>).  */
  77     COP_ARG,
  78     /* CO-Processor special register (cs<N>).  */
  79     COPS_ARG
  80   }
  81 REG_ARG_TYPE;
  82
  83 /* Number of valid 'cinv' instruction options.  */
  84 int NUMCINVS = ((sizeof crx_cinvs)/(sizeof crx_cinvs[0]));
  85 /* Current opcode table entry we're disassembling.  */
  86 const inst *instruction;
  87 /* Current instruction we're disassembling.  */
  88 ins currInsn;
  89 /* The current instruction is read into 3 consecutive words.  */
  90 wordU words[3];
  91 /* Contains all words in appropriate order.  */
  92 ULONGLONG allWords;
  93 /* Holds the current processed argument number.  */
  94 int processing_argument_number;
  95 /* Nonzero means a CST4 instruction.  */
  96 int cst4flag;
  97 /* Nonzero means the instruction's original size is
  98    incremented (escape sequence is used).  */
  99 int size_changed;
 100
 101 static int get_number_of_operands (void);
 102 static argtype getargtype     (operand_type);
 103 static int getbits            (operand_type);
 104 static char *getregname       (reg);
 105 static char *getcopregname    (copreg, reg_type);
 106 static char * getprocregname  (int);
 107 static char *gettrapstring    (unsigned);
 108 static char *getcinvstring    (unsigned);
 109 static void getregliststring  (int, char *, enum REG_ARG_TYPE);
 110 static wordU get_word_at_PC   (bfd_vma, struct disassemble_info *);
 111 static void get_words_at_PC   (bfd_vma, struct disassemble_info *);
 112 static unsigned long build_mask (void);
 113 static int powerof2           (int);
 114 static int match_opcode       (void);
 115 static void make_instruction  (void);
 116 static void print_arguments   (ins *, bfd_vma, struct disassemble_info *);
 117 static void print_arg         (argument *, bfd_vma, struct disassemble_info *);
 118
 119 /* Retrieve the number of operands for the current assembled instruction.  */
 120
 121 static int
 122 get_number_of_operands (void)
 123 {
 124   int i;
 125
 126   for (i = 0; instruction->operands[i].op_type && i < MAX_OPERANDS; i++)
 127     ;
 128
 129   return i;
 130 }
 131
 132 /* Return the bit size for a given operand.  */
 133
 134 static int
 135 getbits (operand_type op)
 136 {
 137   if (op < MAX_OPRD)
 138     return crx_optab[op].bit_size;
 139   else
 140     return 0;
 141 }
 142
 143 /* Return the argument type of a given operand.  */
 144
 145 static argtype
 146 getargtype (operand_type op)
 147 {
 148   if (op < MAX_OPRD)
 149     return crx_optab[op].arg_type;
 150   else
 151     return nullargs;
 152 }
 153
 154 /* Given the trap index in dispatch table, return its name.
 155    This routine is used when disassembling the 'excp' instruction.  */
 156
 157 static char *
 158 gettrapstring (unsigned int trap_index)
 159 {
 160   const trap_entry *trap;
 161
 162   for (trap = crx_traps; trap < crx_traps + NUMTRAPS; trap++)
 163     if (trap->entry == trap_index)
 164       return trap->name;
 165
 166   return ILLEGAL;
 167 }
 168
 169 /* Given a 'cinv' instruction constant operand, return its corresponding string.
 170    This routine is used when disassembling the 'cinv' instruction.  */
 171
 172 static char *
 173 getcinvstring (unsigned int num)
 174 {
 175   const cinv_entry *cinv;
 176
 177   for (cinv = crx_cinvs; cinv < (crx_cinvs + NUMCINVS); cinv++)
 178     if (cinv->value == num)
 179       return cinv->str;
 180
 181   return ILLEGAL;
 182 }
 183
 184 /* Given a register enum value, retrieve its name.  */
 185
 186 char *
 187 getregname (reg r)
 188 {
 189   const reg_entry * regentry = &crx_regtab[r];
 190
 191   if (regentry->type != CRX_R_REGTYPE)
 192     return ILLEGAL;
 193   else
 194     return regentry->name;
 195 }
 196
 197 /* Given a coprocessor register enum value, retrieve its name.  */
 198
 199 char *
 200 getcopregname (copreg r, reg_type type)
 201 {
 202   const reg_entry * regentry;
 203
 204   if (type == CRX_C_REGTYPE)
 205     regentry = &crx_copregtab[r];
 206   else if (type == CRX_CS_REGTYPE)
 207     regentry = &crx_copregtab[r+(cs0-c0)];
 208   else
 209     return ILLEGAL;
 210
 211   return regentry->name;
 212 }
 213
 214
 215 /* Getting a processor register name.  */
 216
 217 static char *
 218 getprocregname (int reg_index)
 219 {
 220   const reg_entry *r;
 221
 222   for (r = crx_regtab; r < crx_regtab + NUMREGS; r++)
 223     if (r->image == reg_index)
 224       return r->name;
 225
 226   return "ILLEGAL REGISTER";
 227 }
 228
 229 /* Get the power of two for a given integer.  */
 230
 231 static int
 232 powerof2 (int x)
 233 {
 234   int product, i;
 235
 236   for (i = 0, product = 1; i < x; i++)
 237     product *= 2;
 238
 239   return product;
 240 }
 241
 242 /* Transform a register bit mask to a register list.  */
 243
 244 void
 245 getregliststring (int mask, char *string, enum REG_ARG_TYPE core_cop)
 246 {
 247   char temp_string[5];
 248   int i;
 249
 250   string[0] = '{';
 251   string[1] = '\0';
 252
 253
 254   /* A zero mask means HI/LO registers.  */
 255   if (mask == 0)
 256     {
 257       if (core_cop == USER_REG_ARG)
 258         strcat (string, "ulo,uhi");
 259       else
 260         strcat (string, "lo,hi");
 261     }
 262   else
 263     {
 264       for (i = 0; i < 16; i++)
 265         {
 266           if (mask & 0x1)
 267             {
 268               switch (core_cop)
 269               {
 270               case REG_ARG:
 271                 sprintf (temp_string, "r%d", i);
 272                 break;
 273               case USER_REG_ARG:
 274                 sprintf (temp_string, "u%d", i);
 275                 break;
 276               case COP_ARG:
 277                 sprintf (temp_string, "c%d", i);
 278                 break;
 279               case COPS_ARG:
 280                 sprintf (temp_string, "cs%d", i);
 281                 break;
 282               default:
 283                 break;
 284               }
 285               strcat (string, temp_string);
 286               if (mask & 0xfffe)
 287                 strcat (string, ",");
 288             }
 289           mask >>= 1;
 290         }
 291     }
 292
 293   strcat (string, "}");
 294 }
 295
 296 /* START and END are relating 'allWords' struct, which is 48 bits size.
 297
 298                           START|--------|END
 299             +---------+---------+---------+---------+
 300             |         |    V    |     A   |   L     |
 301             +---------+---------+---------+---------+
 302                       0         16        32        48
 303     words                 [0]       [1]       [2]       */
 304
 305 static parameter
 306 makelongparameter (ULONGLONG val, int start, int end)
 307 {
 308   parameter p;
 309
 310   p.val = (dwordU) EXTRACT(val, 48 - end, end - start);
 311   p.nbits = end - start;
 312   return p;
 313 }
 314
 315 /* Build a mask of the instruction's 'constant' opcode,
 316    based on the instruction's printing flags.  */
 317
 318 static unsigned long
 319 build_mask (void)
 320 {
 321   unsigned int print_flags;
 322   unsigned long mask;
 323
 324   print_flags = instruction->flags & FMT_CRX;
 325   switch (print_flags)
 326     {
 327       case FMT_1:
 328         mask = 0xF0F00000;
 329         break;
 330       case FMT_2:
 331         mask = 0xFFF0FF00;
 332         break;
 333       case FMT_3:
 334         mask = 0xFFF00F00;
 335         break;
 336       case FMT_4:
 337         mask = 0xFFF0F000;
 338         break;
 339       case FMT_5:
 340         mask = 0xFFF0FFF0;
 341         break;
 342       default:
 343         mask = SBM(instruction->match_bits);
 344         break;
 345     }
 346
 347   return mask;
 348 }
 349
 350 /* Search for a matching opcode. Return 1 for success, 0 for failure.  */
 351
 352 static int
 353 match_opcode (void)
 354 {
 355   unsigned long mask;
 356
 357   /* The instruction 'constant' opcode doewsn't exceed 32 bits.  */
 358   unsigned long doubleWord = (words[1] + (words[0] << 16)) & 0xffffffff;
 359
 360   /* Start searching from end of instruction table.  */
 361   instruction = &crx_instruction[NUMOPCODES - 2];
 362
 363   /* Loop over instruction table until a full match is found.  */
 364   while (instruction >= crx_instruction)
 365     {
 366       mask = build_mask ();
 367       if ((doubleWord & mask) == BIN(instruction->match, instruction->match_bits))
 368         return 1;
 369       else
 370         instruction--;
 371     }
 372   return 0;
 373 }
 374
 375 /* Set the proper parameter value for different type of arguments.  */
 376
 377 static void
 378 make_argument (argument * a, int start_bits)
 379 {
 380   int inst_bit_size, total_size;
 381   parameter p;
 382
 383   if ((instruction->size == 3) && a->size >= 16)
 384     inst_bit_size = 48;
 385   else
 386     inst_bit_size = 32;
 387
 388   switch (a->type)
 389     {
 390     case arg_copr:
 391     case arg_copsr:
 392       p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),
 393                              inst_bit_size - start_bits);
 394       a->cr = p.val;
 395       break;
 396
 397     case arg_r:
 398       p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),
 399                              inst_bit_size - start_bits);
 400       a->r = p.val;
 401       break;
 402
 403     case arg_ic:
 404       p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),
 405                              inst_bit_size - start_bits);
 406
 407       if ((p.nbits == 4) && cst4flag)
 408         {
 409           if (IS_INSN_TYPE (CMPBR_INS) && (p.val == ESCAPE_16_BIT))
 410             {
 411               /* A special case, where the value is actually stored
 412                  in the last 4 bits.  */
 413               p = makelongparameter (allWords, 44, 48);
 414               /* The size of the instruction should be incremented.  */
 415               size_changed = 1;
 416             }
 417
 418           if (p.val == 6)
 419             p.val = -1;
 420           else if (p.val == 13)
 421             p.val = 48;
 422           else if (p.val == 5)
 423             p.val = -4;
 424           else if (p.val == 10)
 425             p.val = 32;
 426           else if (p.val == 11)
 427             p.val = 20;
 428           else if (p.val == 9)
 429             p.val = 16;
 430         }
 431
 432       a->constant = p.val;
 433       break;
 434
 435     case arg_idxr:
 436       a->scale = 0;
 437       total_size = a->size + 10;  /* sizeof(rbase + ridx + scl2) = 10.  */
 438       p = makelongparameter (allWords, inst_bit_size - total_size,
 439                              inst_bit_size - (total_size - 4));
 440       a->r = p.val;
 441       p = makelongparameter (allWords, inst_bit_size - (total_size - 4),
 442                              inst_bit_size - (total_size - 8));
 443       a->i_r = p.val;
 444       p = makelongparameter (allWords, inst_bit_size - (total_size - 8),
 445                              inst_bit_size - (total_size - 10));
 446       a->scale = p.val;
 447       p = makelongparameter (allWords, inst_bit_size - (total_size - 10),
 448                              inst_bit_size);
 449       a->constant = p.val;
 450       break;
 451
 452     case arg_rbase:
 453       p = makelongparameter (allWords, inst_bit_size - (start_bits + 4),
 454                              inst_bit_size - start_bits);
 455       a->r = p.val;
 456       break;
 457
 458     case arg_cr:
 459       if (a->size <= 8)
 460         {
 461           p = makelongparameter (allWords, inst_bit_size - (start_bits + 4),
 462                                  inst_bit_size - start_bits);
 463           a->r = p.val;
 464           /* Case for opc4 r dispu rbase.  */
 465           p = makelongparameter (allWords, inst_bit_size - (start_bits + 8),
 466                                  inst_bit_size - (start_bits + 4));
 467         }
 468       else
 469         {
 470           /* The 'rbase' start_bits is always relative to a 32-bit data type.  */
 471           p = makelongparameter (allWords, 32 - (start_bits + 4),
 472                                  32 - start_bits);
 473           a->r = p.val;
 474           p = makelongparameter (allWords, 32 - start_bits,
 475                                  inst_bit_size);
 476         }
 477       if ((p.nbits == 4) && cst4flag)
 478         {
 479           if (instruction->flags & DISPUW4)
 480             p.val *= 2;
 481           else if (instruction->flags & DISPUD4)
 482             p.val *= 4;
 483         }
 484       a->constant = p.val;
 485       break;
 486
 487     case arg_c:
 488       p = makelongparameter (allWords, inst_bit_size - (start_bits + a->size),
 489                              inst_bit_size - start_bits);
 490       a->constant = p.val;
 491       break;
 492     default:
 493       break;
 494     }
 495 }
 496
 497 /*  Print a single argument.  */
 498
 499 static void
 500 print_arg (argument *a, bfd_vma memaddr, struct disassemble_info *info)
 501 {
 502   LONGLONG longdisp, mask;
 503   int sign_flag = 0;
 504   int relative = 0;
 505   bfd_vma number;
 506   int op_index = 0;
 507   char string[200];
 508   PTR stream = info->stream;
 509   fprintf_ftype func = info->fprintf_func;
 510
 511   switch (a->type)
 512     {
 513     case arg_copr:
 514       func (stream, "%s", getcopregname (a->cr, CRX_C_REGTYPE));
 515       break;
 516
 517     case arg_copsr:
 518       func (stream, "%s", getcopregname (a->cr, CRX_CS_REGTYPE));
 519       break;
 520
 521     case arg_r:
 522       if (IS_INSN_MNEMONIC ("mtpr") || IS_INSN_MNEMONIC ("mfpr"))
 523         func (stream, "%s", getprocregname (a->r));
 524       else
 525         func (stream, "%s", getregname (a->r));
 526       break;
 527
 528     case arg_ic:
 529       if (IS_INSN_MNEMONIC ("excp"))
 530         func (stream, "%s", gettrapstring (a->constant));
 531
 532       else if (IS_INSN_MNEMONIC ("cinv"))
 533         func (stream, "%s", getcinvstring (a->constant));
 534
 535       else if (INST_HAS_REG_LIST)
 536         {
 537           REG_ARG_TYPE reg_arg_type = IS_INSN_TYPE (COP_REG_INS) ?
 538                                  COP_ARG : IS_INSN_TYPE (COPS_REG_INS) ?
 539                                  COPS_ARG : (instruction->flags & USER_REG) ?
 540                                  USER_REG_ARG : REG_ARG;
 541
 542           if ((reg_arg_type == COP_ARG) || (reg_arg_type == COPS_ARG))
 543             {
 544                 /*  Check for proper argument number.  */
 545                 if (processing_argument_number == 2)
 546                   {
 547                     getregliststring (a->constant, string, reg_arg_type);
 548                     func (stream, "%s", string);
 549                   }
 550                 else
 551                   func (stream, "$0x%lx", a->constant);
 552             }
 553           else
 554             {
 555               getregliststring (a->constant, string, reg_arg_type);
 556               func (stream, "%s", string);
 557             }
 558         }
 559       else
 560         func (stream, "$0x%lx", a->constant);
 561       break;
 562
 563     case arg_idxr:
 564       func (stream, "0x%lx(%s,%s,%d)", a->constant, getregname (a->r),
 565             getregname (a->i_r), powerof2 (a->scale));
 566       break;
 567
 568     case arg_rbase:
 569       func (stream, "(%s)", getregname (a->r));
 570       break;
 571
 572     case arg_cr:
 573       func (stream, "0x%lx(%s)", a->constant, getregname (a->r));
 574
 575       if (IS_INSN_TYPE (LD_STOR_INS_INC))
 576         func (stream, "+");
 577       break;
 578
 579     case arg_c:
 580       /* Removed the *2 part as because implicit zeros are no more required.
 581          Have to fix this as this needs a bit of extension in terms of branchins.
 582          Have to add support for cmp and branch instructions.  */
 583       if (IS_INSN_TYPE (BRANCH_INS) || IS_INSN_MNEMONIC ("bal")
 584           || IS_INSN_TYPE (CMPBR_INS) || IS_INSN_TYPE (DCR_BRANCH_INS)
 585           || IS_INSN_TYPE (COP_BRANCH_INS))
 586         {
 587           relative = 1;
 588           longdisp = a->constant;
 589           longdisp <<= 1;
 590
 591           switch (a->size)
 592             {
 593             case 8:
 594             case 16:
 595             case 24:
 596             case 32:
 597               mask = ((LONGLONG)1 << a->size) - 1;
 598               if (longdisp & ((LONGLONG)1 << a->size))
 599                 {
 600                   sign_flag = 1;
 601                   longdisp = ~(longdisp) + 1;
 602                 }
 603               a->constant = (unsigned long int) (longdisp & mask);
 604               break;
 605             default:
 606               func (stream,
 607                     "Wrong offset used in branch/bal instruction");
 608               break;
 609             }
 610
 611         }
 612       /* For branch Neq instruction it is 2*offset + 2.  */
 613       else if (IS_INSN_TYPE (BRANCH_NEQ_INS))
 614         a->constant = 2 * a->constant + 2;
 615       else if (IS_INSN_TYPE (LD_STOR_INS_INC)
 616           || IS_INSN_TYPE (LD_STOR_INS)
 617           || IS_INSN_TYPE (STOR_IMM_INS)
 618           || IS_INSN_TYPE (CSTBIT_INS))
 619         {
 620           op_index = instruction->flags & REVERSE_MATCH ? 0 : 1;
 621           if (instruction->operands[op_index].op_type == abs16)
 622             a->constant |= 0xFFFF0000;
 623         }
 624       func (stream, "%s", "0x");
 625       number = (relative ? memaddr : 0)
 626                + (sign_flag ? -a->constant : a->constant);
 627       (*info->print_address_func) (number, info);
 628       break;
 629     default:
 630       break;
 631     }
 632 }
 633
 634 /* Print all the arguments of CURRINSN instruction.  */
 635
 636 static void
 637 print_arguments (ins *currentInsn, bfd_vma memaddr, struct disassemble_info *info)
 638 {
 639   int i;
 640
 641   for (i = 0; i < currentInsn->nargs; i++)
 642     {
 643       processing_argument_number = i;
 644
 645       print_arg (&currentInsn->arg[i], memaddr, info);
 646
 647       if (i != currentInsn->nargs - 1)
 648         info->fprintf_func (info->stream, ", ");
 649     }
 650 }
 651
 652 /* Build the instruction's arguments.  */
 653
 654 static void
 655 make_instruction (void)
 656 {
 657   int i;
 658   unsigned int shift;
 659
 660   for (i = 0; i < currInsn.nargs; i++)
 661     {
 662       argument a;
 663
 664       memset (&a, 0, sizeof (a));
 665       a.type = getargtype (instruction->operands[i].op_type);
 666       if (instruction->operands[i].op_type == cst4
 667           || instruction->operands[i].op_type == rbase_dispu4)
 668         cst4flag = 1;
 669       a.size = getbits (instruction->operands[i].op_type);
 670       shift = instruction->operands[i].shift;
 671
 672       make_argument (&a, shift);
 673       currInsn.arg[i] = a;
 674     }
 675
 676   /* Calculate instruction size (in bytes).  */
 677   currInsn.size = instruction->size + (size_changed ? 1 : 0);
 678   /* Now in bits.  */
 679   currInsn.size *= 2;
 680 }
 681
 682 /* Retrieve a single word from a given memory address.  */
 683
 684 static wordU
 685 get_word_at_PC (bfd_vma memaddr, struct disassemble_info *info)
 686 {
 687   bfd_byte buffer[4];
 688   int status;
 689   wordU insn = 0;
 690
 691   status = info->read_memory_func (memaddr, buffer, 2, info);
 692
 693   if (status == 0)
 694     insn = (wordU) bfd_getl16 (buffer);
 695
 696   return insn;
 697 }
 698
 699 /* Retrieve multiple words (3) from a given memory address.  */
 700
 701 static void
 702 get_words_at_PC (bfd_vma memaddr, struct disassemble_info *info)
 703 {
 704   int i;
 705   bfd_vma mem;
 706
 707   for (i = 0, mem = memaddr; i < 3; i++, mem += 2)
 708     words[i] = get_word_at_PC (mem, info);
 709
 710   allWords =
 711     ((ULONGLONG) words[0] << 32) + ((unsigned long) words[1] << 16) + words[2];
 712 }
 713
 714 /* Prints the instruction by calling print_arguments after proper matching.  */
 715
 716 int
 717 print_insn_crx (memaddr, info)
 718      bfd_vma memaddr;
 719      struct disassemble_info *info;
 720 {
 721   int is_decoded;     /* Nonzero means instruction has a match.  */
 722
 723   /* Initialize global variables.  */
 724   cst4flag = 0;
 725   size_changed = 0;
 726
 727   /* Retrieve the encoding from current memory location.  */
 728   get_words_at_PC (memaddr, info);
 729   /* Find a matching opcode in table.  */
 730   is_decoded = match_opcode ();
 731   /* If found, print the instruction's mnemonic and arguments.  */
 732   if (is_decoded > 0 && (words[0] << 16 || words[1]) != 0)
 733     {
 734       info->fprintf_func (info->stream, "%s", instruction->mnemonic);
 735       if ((currInsn.nargs = get_number_of_operands ()) != 0)
 736         info->fprintf_func (info->stream, "\t");
 737       make_instruction ();
 738       print_arguments (&currInsn, memaddr, info);
 739       return currInsn.size;
 740     }
 741
 742   /* No match found.  */
 743   info->fprintf_func (info->stream,"%s ",ILLEGAL);
 744   return 2;
 745 }