opcodes/xstormy16-dis.c

   1 /* Disassembler interface for targets using CGEN. -*- C -*-
   2    CGEN: Cpu tools GENerator
   3
   4 THIS FILE IS MACHINE GENERATED WITH CGEN.
   5 - the resultant file is machine generated, cgen-dis.in isn't
   6
   7 Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2005
   8 Free Software Foundation, Inc.
   9
  10 This file is part of the GNU Binutils and GDB, the GNU debugger.
  11
  12 This program is free software; you can redistribute it and/or modify
  13 it under the terms of the GNU General Public License as published by
  14 the Free Software Foundation; either version 2, or (at your option)
  15 any later version.
  16
  17 This program is distributed in the hope that it will be useful,
  18 but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 GNU General Public License for more details.
  21
  22 You should have received a copy of the GNU General Public License
  23 along with this program; if not, write to the Free Software Foundation, Inc.,
  24 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
  25
  26 /* ??? Eventually more and more of this stuff can go to cpu-independent files.
  27    Keep that in mind.  */
  28
  29 #include "sysdep.h"
  30 #include <stdio.h>
  31 #include "ansidecl.h"
  32 #include "dis-asm.h"
  33 #include "bfd.h"
  34 #include "symcat.h"
  35 #include "libiberty.h"
  36 #include "xstormy16-desc.h"
  37 #include "xstormy16-opc.h"
  38 #include "opintl.h"
  39
  40 /* Default text to print if an instruction isn't recognized.  */
  41 #define UNKNOWN_INSN_MSG _("*unknown*")
  42
  43 static void print_normal
  44   (CGEN_CPU_DESC, void *, long, unsigned int, bfd_vma, int);
  45 static void print_address
  46   (CGEN_CPU_DESC, void *, bfd_vma, unsigned int, bfd_vma, int) ATTRIBUTE_UNUSED;
  47 static void print_keyword
  48   (CGEN_CPU_DESC, void *, CGEN_KEYWORD *, long, unsigned int) ATTRIBUTE_UNUSED;
  49 static void print_insn_normal
  50   (CGEN_CPU_DESC, void *, const CGEN_INSN *, CGEN_FIELDS *, bfd_vma, int);
  51 static int print_insn
  52   (CGEN_CPU_DESC, bfd_vma,  disassemble_info *, bfd_byte *, unsigned);
  53 static int default_print_insn
  54   (CGEN_CPU_DESC, bfd_vma, disassemble_info *) ATTRIBUTE_UNUSED;
  55 static int read_insn
  56   (CGEN_CPU_DESC, bfd_vma, disassemble_info *, bfd_byte *, int, CGEN_EXTRACT_INFO *,
  57    unsigned long *);
  58 \f
  59 /* -- disassembler routines inserted here */
  60
  61
  62 void xstormy16_cgen_print_operand
  63   PARAMS ((CGEN_CPU_DESC, int, PTR, CGEN_FIELDS *,
  64            void const *, bfd_vma, int));
  65
  66 /* Main entry point for printing operands.
  67    XINFO is a `void *' and not a `disassemble_info *' to not put a requirement
  68    of dis-asm.h on cgen.h.
  69
  70    This function is basically just a big switch statement.  Earlier versions
  71    used tables to look up the function to use, but
  72    - if the table contains both assembler and disassembler functions then
  73      the disassembler contains much of the assembler and vice-versa,
  74    - there's a lot of inlining possibilities as things grow,
  75    - using a switch statement avoids the function call overhead.
  76
  77    This function could be moved into `print_insn_normal', but keeping it
  78    separate makes clear the interface between `print_insn_normal' and each of
  79    the handlers.  */
  80
  81 void
  82 xstormy16_cgen_print_operand (cd, opindex, xinfo, fields, attrs, pc, length)
  83      CGEN_CPU_DESC cd;
  84      int opindex;
  85      PTR xinfo;
  86      CGEN_FIELDS *fields;
  87      void const *attrs ATTRIBUTE_UNUSED;
  88      bfd_vma pc;
  89      int length;
  90 {
  91  disassemble_info *info = (disassemble_info *) xinfo;
  92
  93   switch (opindex)
  94     {
  95     case XSTORMY16_OPERAND_RB :
  96       print_keyword (cd, info, & xstormy16_cgen_opval_gr_Rb_names, fields->f_Rb, 0);
  97       break;
  98     case XSTORMY16_OPERAND_RBJ :
  99       print_keyword (cd, info, & xstormy16_cgen_opval_gr_Rb_names, fields->f_Rbj, 0);
 100       break;
 101     case XSTORMY16_OPERAND_RD :
 102       print_keyword (cd, info, & xstormy16_cgen_opval_gr_names, fields->f_Rd, 0);
 103       break;
 104     case XSTORMY16_OPERAND_RDM :
 105       print_keyword (cd, info, & xstormy16_cgen_opval_gr_names, fields->f_Rdm, 0);
 106       break;
 107     case XSTORMY16_OPERAND_RM :
 108       print_keyword (cd, info, & xstormy16_cgen_opval_gr_names, fields->f_Rm, 0);
 109       break;
 110     case XSTORMY16_OPERAND_RS :
 111       print_keyword (cd, info, & xstormy16_cgen_opval_gr_names, fields->f_Rs, 0);
 112       break;
 113     case XSTORMY16_OPERAND_ABS24 :
 114       print_normal (cd, info, fields->f_abs24, 0|(1<<CGEN_OPERAND_ABS_ADDR)|(1<<CGEN_OPERAND_VIRTUAL), pc, length);
 115       break;
 116     case XSTORMY16_OPERAND_BCOND2 :
 117       print_keyword (cd, info, & xstormy16_cgen_opval_h_branchcond, fields->f_op2, 0);
 118       break;
 119     case XSTORMY16_OPERAND_BCOND5 :
 120       print_keyword (cd, info, & xstormy16_cgen_opval_h_branchcond, fields->f_op5, 0);
 121       break;
 122     case XSTORMY16_OPERAND_HMEM8 :
 123       print_normal (cd, info, fields->f_hmem8, 0|(1<<CGEN_OPERAND_ABS_ADDR), pc, length);
 124       break;
 125     case XSTORMY16_OPERAND_IMM12 :
 126       print_normal (cd, info, fields->f_imm12, 0|(1<<CGEN_OPERAND_SIGNED), pc, length);
 127       break;
 128     case XSTORMY16_OPERAND_IMM16 :
 129       print_normal (cd, info, fields->f_imm16, 0|(1<<CGEN_OPERAND_SIGN_OPT), pc, length);
 130       break;
 131     case XSTORMY16_OPERAND_IMM2 :
 132       print_normal (cd, info, fields->f_imm2, 0, pc, length);
 133       break;
 134     case XSTORMY16_OPERAND_IMM3 :
 135       print_normal (cd, info, fields->f_imm3, 0, pc, length);
 136       break;
 137     case XSTORMY16_OPERAND_IMM3B :
 138       print_normal (cd, info, fields->f_imm3b, 0, pc, length);
 139       break;
 140     case XSTORMY16_OPERAND_IMM4 :
 141       print_normal (cd, info, fields->f_imm4, 0, pc, length);
 142       break;
 143     case XSTORMY16_OPERAND_IMM8 :
 144       print_normal (cd, info, fields->f_imm8, 0, pc, length);
 145       break;
 146     case XSTORMY16_OPERAND_IMM8SMALL :
 147       print_normal (cd, info, fields->f_imm8, 0, pc, length);
 148       break;
 149     case XSTORMY16_OPERAND_LMEM8 :
 150       print_normal (cd, info, fields->f_lmem8, 0|(1<<CGEN_OPERAND_ABS_ADDR), pc, length);
 151       break;
 152     case XSTORMY16_OPERAND_REL12 :
 153       print_normal (cd, info, fields->f_rel12, 0|(1<<CGEN_OPERAND_PCREL_ADDR), pc, length);
 154       break;
 155     case XSTORMY16_OPERAND_REL12A :
 156       print_normal (cd, info, fields->f_rel12a, 0|(1<<CGEN_OPERAND_PCREL_ADDR), pc, length);
 157       break;
 158     case XSTORMY16_OPERAND_REL8_2 :
 159       print_normal (cd, info, fields->f_rel8_2, 0|(1<<CGEN_OPERAND_PCREL_ADDR), pc, length);
 160       break;
 161     case XSTORMY16_OPERAND_REL8_4 :
 162       print_normal (cd, info, fields->f_rel8_4, 0|(1<<CGEN_OPERAND_PCREL_ADDR), pc, length);
 163       break;
 164     case XSTORMY16_OPERAND_WS2 :
 165       print_keyword (cd, info, & xstormy16_cgen_opval_h_wordsize, fields->f_op2m, 0);
 166       break;
 167
 168     default :
 169       /* xgettext:c-format */
 170       fprintf (stderr, _("Unrecognized field %d while printing insn.\n"),
 171                opindex);
 172     abort ();
 173   }
 174 }
 175
 176 cgen_print_fn * const xstormy16_cgen_print_handlers[] =
 177 {
 178   print_insn_normal,
 179 };
 180
 181
 182 void
 183 xstormy16_cgen_init_dis (cd)
 184      CGEN_CPU_DESC cd;
 185 {
 186   xstormy16_cgen_init_opcode_table (cd);
 187   xstormy16_cgen_init_ibld_table (cd);
 188   cd->print_handlers = & xstormy16_cgen_print_handlers[0];
 189   cd->print_operand = xstormy16_cgen_print_operand;
 190 }
 191
 192 \f
 193 /* Default print handler.  */
 194
 195 static void
 196 print_normal (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
 197               void *dis_info,
 198               long value,
 199               unsigned int attrs,
 200               bfd_vma pc ATTRIBUTE_UNUSED,
 201               int length ATTRIBUTE_UNUSED)
 202 {
 203   disassemble_info *info = (disassemble_info *) dis_info;
 204
 205 #ifdef CGEN_PRINT_NORMAL
 206   CGEN_PRINT_NORMAL (cd, info, value, attrs, pc, length);
 207 #endif
 208
 209   /* Print the operand as directed by the attributes.  */
 210   if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_SEM_ONLY))
 211     ; /* nothing to do */
 212   else if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_SIGNED))
 213     (*info->fprintf_func) (info->stream, "%ld", value);
 214   else
 215     (*info->fprintf_func) (info->stream, "0x%lx", value);
 216 }
 217
 218 /* Default address handler.  */
 219
 220 static void
 221 print_address (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
 222                void *dis_info,
 223                bfd_vma value,
 224                unsigned int attrs,
 225                bfd_vma pc ATTRIBUTE_UNUSED,
 226                int length ATTRIBUTE_UNUSED)
 227 {
 228   disassemble_info *info = (disassemble_info *) dis_info;
 229
 230 #ifdef CGEN_PRINT_ADDRESS
 231   CGEN_PRINT_ADDRESS (cd, info, value, attrs, pc, length);
 232 #endif
 233
 234   /* Print the operand as directed by the attributes.  */
 235   if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_SEM_ONLY))
 236     ; /* nothing to do */
 237   else if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_PCREL_ADDR))
 238     (*info->print_address_func) (value, info);
 239   else if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_ABS_ADDR))
 240     (*info->print_address_func) (value, info);
 241   else if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_SIGNED))
 242     (*info->fprintf_func) (info->stream, "%ld", (long) value);
 243   else
 244     (*info->fprintf_func) (info->stream, "0x%lx", (long) value);
 245 }
 246
 247 /* Keyword print handler.  */
 248
 249 static void
 250 print_keyword (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
 251                void *dis_info,
 252                CGEN_KEYWORD *keyword_table,
 253                long value,
 254                unsigned int attrs ATTRIBUTE_UNUSED)
 255 {
 256   disassemble_info *info = (disassemble_info *) dis_info;
 257   const CGEN_KEYWORD_ENTRY *ke;
 258
 259   ke = cgen_keyword_lookup_value (keyword_table, value);
 260   if (ke != NULL)
 261     (*info->fprintf_func) (info->stream, "%s", ke->name);
 262   else
 263     (*info->fprintf_func) (info->stream, "???");
 264 }
 265 \f
 266 /* Default insn printer.
 267
 268    DIS_INFO is defined as `void *' so the disassembler needn't know anything
 269    about disassemble_info.  */
 270
 271 static void
 272 print_insn_normal (CGEN_CPU_DESC cd,
 273                    void *dis_info,
 274                    const CGEN_INSN *insn,
 275                    CGEN_FIELDS *fields,
 276                    bfd_vma pc,
 277                    int length)
 278 {
 279   const CGEN_SYNTAX *syntax = CGEN_INSN_SYNTAX (insn);
 280   disassemble_info *info = (disassemble_info *) dis_info;
 281   const CGEN_SYNTAX_CHAR_TYPE *syn;
 282
 283   CGEN_INIT_PRINT (cd);
 284
 285   for (syn = CGEN_SYNTAX_STRING (syntax); *syn; ++syn)
 286     {
 287       if (CGEN_SYNTAX_MNEMONIC_P (*syn))
 288         {
 289           (*info->fprintf_func) (info->stream, "%s", CGEN_INSN_MNEMONIC (insn));
 290           continue;
 291         }
 292       if (CGEN_SYNTAX_CHAR_P (*syn))
 293         {
 294           (*info->fprintf_func) (info->stream, "%c", CGEN_SYNTAX_CHAR (*syn));
 295           continue;
 296         }
 297
 298       /* We have an operand.  */
 299       xstormy16_cgen_print_operand (cd, CGEN_SYNTAX_FIELD (*syn), info,
 300                                  fields, CGEN_INSN_ATTRS (insn), pc, length);
 301     }
 302 }
 303 \f
 304 /* Subroutine of print_insn. Reads an insn into the given buffers and updates
 305    the extract info.
 306    Returns 0 if all is well, non-zero otherwise.  */
 307
 308 static int
 309 read_insn (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
 310            bfd_vma pc,
 311            disassemble_info *info,
 312            bfd_byte *buf,
 313            int buflen,
 314            CGEN_EXTRACT_INFO *ex_info,
 315            unsigned long *insn_value)
 316 {
 317   int status = (*info->read_memory_func) (pc, buf, buflen, info);
 318   if (status != 0)
 319     {
 320       (*info->memory_error_func) (status, pc, info);
 321       return -1;
 322     }
 323
 324   ex_info->dis_info = info;
 325   ex_info->valid = (1 << buflen) - 1;
 326   ex_info->insn_bytes = buf;
 327
 328   *insn_value = bfd_get_bits (buf, buflen * 8, info->endian == BFD_ENDIAN_BIG);
 329   return 0;
 330 }
 331
 332 /* Utility to print an insn.
 333    BUF is the base part of the insn, target byte order, BUFLEN bytes long.
 334    The result is the size of the insn in bytes or zero for an unknown insn
 335    or -1 if an error occurs fetching data (memory_error_func will have
 336    been called).  */
 337
 338 static int
 339 print_insn (CGEN_CPU_DESC cd,
 340             bfd_vma pc,
 341             disassemble_info *info,
 342             bfd_byte *buf,
 343             unsigned int buflen)
 344 {
 345   CGEN_INSN_INT insn_value;
 346   const CGEN_INSN_LIST *insn_list;
 347   CGEN_EXTRACT_INFO ex_info;
 348   int basesize;
 349
 350   /* Extract base part of instruction, just in case CGEN_DIS_* uses it. */
 351   basesize = cd->base_insn_bitsize < buflen * 8 ?
 352                                      cd->base_insn_bitsize : buflen * 8;
 353   insn_value = cgen_get_insn_value (cd, buf, basesize);
 354
 355
 356   /* Fill in ex_info fields like read_insn would.  Don't actually call
 357      read_insn, since the incoming buffer is already read (and possibly
 358      modified a la m32r).  */
 359   ex_info.valid = (1 << buflen) - 1;
 360   ex_info.dis_info = info;
 361   ex_info.insn_bytes = buf;
 362
 363   /* The instructions are stored in hash lists.
 364      Pick the first one and keep trying until we find the right one.  */
 365
 366   insn_list = CGEN_DIS_LOOKUP_INSN (cd, (char *) buf, insn_value);
 367   while (insn_list != NULL)
 368     {
 369       const CGEN_INSN *insn = insn_list->insn;
 370       CGEN_FIELDS fields;
 371       int length;
 372       unsigned long insn_value_cropped;
 373
 374 #ifdef CGEN_VALIDATE_INSN_SUPPORTED
 375       /* Not needed as insn shouldn't be in hash lists if not supported.  */
 376       /* Supported by this cpu?  */
 377       if (! xstormy16_cgen_insn_supported (cd, insn))
 378         {
 379           insn_list = CGEN_DIS_NEXT_INSN (insn_list);
 380           continue;
 381         }
 382 #endif
 383
 384       /* Basic bit mask must be correct.  */
 385       /* ??? May wish to allow target to defer this check until the extract
 386          handler.  */
 387
 388       /* Base size may exceed this instruction's size.  Extract the
 389          relevant part from the buffer. */
 390       if ((unsigned) (CGEN_INSN_BITSIZE (insn) / 8) < buflen &&
 391           (unsigned) (CGEN_INSN_BITSIZE (insn) / 8) <= sizeof (unsigned long))
 392         insn_value_cropped = bfd_get_bits (buf, CGEN_INSN_BITSIZE (insn),
 393                                            info->endian == BFD_ENDIAN_BIG);
 394       else
 395         insn_value_cropped = insn_value;
 396
 397       if ((insn_value_cropped & CGEN_INSN_BASE_MASK (insn))
 398           == CGEN_INSN_BASE_VALUE (insn))
 399         {
 400           /* Printing is handled in two passes.  The first pass parses the
 401              machine insn and extracts the fields.  The second pass prints
 402              them.  */
 403
 404           /* Make sure the entire insn is loaded into insn_value, if it
 405              can fit.  */
 406           if (((unsigned) CGEN_INSN_BITSIZE (insn) > cd->base_insn_bitsize) &&
 407               (unsigned) (CGEN_INSN_BITSIZE (insn) / 8) <= sizeof (unsigned long))
 408             {
 409               unsigned long full_insn_value;
 410               int rc = read_insn (cd, pc, info, buf,
 411                                   CGEN_INSN_BITSIZE (insn) / 8,
 412                                   & ex_info, & full_insn_value);
 413               if (rc != 0)
 414                 return rc;
 415               length = CGEN_EXTRACT_FN (cd, insn)
 416                 (cd, insn, &ex_info, full_insn_value, &fields, pc);
 417             }
 418           else
 419             length = CGEN_EXTRACT_FN (cd, insn)
 420               (cd, insn, &ex_info, insn_value_cropped, &fields, pc);
 421
 422           /* length < 0 -> error */
 423           if (length < 0)
 424             return length;
 425           if (length > 0)
 426             {
 427               CGEN_PRINT_FN (cd, insn) (cd, info, insn, &fields, pc, length);
 428               /* length is in bits, result is in bytes */
 429               return length / 8;
 430             }
 431         }
 432
 433       insn_list = CGEN_DIS_NEXT_INSN (insn_list);
 434     }
 435
 436   return 0;
 437 }
 438
 439 /* Default value for CGEN_PRINT_INSN.
 440    The result is the size of the insn in bytes or zero for an unknown insn
 441    or -1 if an error occured fetching bytes.  */
 442
 443 #ifndef CGEN_PRINT_INSN
 444 #define CGEN_PRINT_INSN default_print_insn
 445 #endif
 446
 447 static int
 448 default_print_insn (CGEN_CPU_DESC cd, bfd_vma pc, disassemble_info *info)
 449 {
 450   bfd_byte buf[CGEN_MAX_INSN_SIZE];
 451   int buflen;
 452   int status;
 453
 454   /* Attempt to read the base part of the insn.  */
 455   buflen = cd->base_insn_bitsize / 8;
 456   status = (*info->read_memory_func) (pc, buf, buflen, info);
 457
 458   /* Try again with the minimum part, if min < base.  */
 459   if (status != 0 && (cd->min_insn_bitsize < cd->base_insn_bitsize))
 460     {
 461       buflen = cd->min_insn_bitsize / 8;
 462       status = (*info->read_memory_func) (pc, buf, buflen, info);
 463     }
 464
 465   if (status != 0)
 466     {
 467       (*info->memory_error_func) (status, pc, info);
 468       return -1;
 469     }
 470
 471   return print_insn (cd, pc, info, buf, buflen);
 472 }
 473
 474 /* Main entry point.
 475    Print one instruction from PC on INFO->STREAM.
 476    Return the size of the instruction (in bytes).  */
 477
 478 typedef struct cpu_desc_list {
 479   struct cpu_desc_list *next;
 480   int isa;
 481   int mach;
 482   int endian;
 483   CGEN_CPU_DESC cd;
 484 } cpu_desc_list;
 485
 486 int
 487 print_insn_xstormy16 (bfd_vma pc, disassemble_info *info)
 488 {
 489   static cpu_desc_list *cd_list = 0;
 490   cpu_desc_list *cl = 0;
 491   static CGEN_CPU_DESC cd = 0;
 492   static int prev_isa;
 493   static int prev_mach;
 494   static int prev_endian;
 495   int length;
 496   int isa,mach;
 497   int endian = (info->endian == BFD_ENDIAN_BIG
 498                 ? CGEN_ENDIAN_BIG
 499                 : CGEN_ENDIAN_LITTLE);
 500   enum bfd_architecture arch;
 501
 502   /* ??? gdb will set mach but leave the architecture as "unknown" */
 503 #ifndef CGEN_BFD_ARCH
 504 #define CGEN_BFD_ARCH bfd_arch_xstormy16
 505 #endif
 506   arch = info->arch;
 507   if (arch == bfd_arch_unknown)
 508     arch = CGEN_BFD_ARCH;
 509
 510   /* There's no standard way to compute the machine or isa number
 511      so we leave it to the target.  */
 512 #ifdef CGEN_COMPUTE_MACH
 513   mach = CGEN_COMPUTE_MACH (info);
 514 #else
 515   mach = info->mach;
 516 #endif
 517
 518 #ifdef CGEN_COMPUTE_ISA
 519   isa = CGEN_COMPUTE_ISA (info);
 520 #else
 521   isa = info->insn_sets;
 522 #endif
 523
 524   /* If we've switched cpu's, try to find a handle we've used before */
 525   if (cd
 526       && (isa != prev_isa
 527           || mach != prev_mach
 528           || endian != prev_endian))
 529     {
 530       cd = 0;
 531       for (cl = cd_list; cl; cl = cl->next)
 532         {
 533           if (cl->isa == isa &&
 534               cl->mach == mach &&
 535               cl->endian == endian)
 536             {
 537               cd = cl->cd;
 538               break;
 539             }
 540         }
 541     }
 542
 543   /* If we haven't initialized yet, initialize the opcode table.  */
 544   if (! cd)
 545     {
 546       const bfd_arch_info_type *arch_type = bfd_lookup_arch (arch, mach);
 547       const char *mach_name;
 548
 549       if (!arch_type)
 550         abort ();
 551       mach_name = arch_type->printable_name;
 552
 553       prev_isa = isa;
 554       prev_mach = mach;
 555       prev_endian = endian;
 556       cd = xstormy16_cgen_cpu_open (CGEN_CPU_OPEN_ISAS, prev_isa,
 557                                  CGEN_CPU_OPEN_BFDMACH, mach_name,
 558                                  CGEN_CPU_OPEN_ENDIAN, prev_endian,
 559                                  CGEN_CPU_OPEN_END);
 560       if (!cd)
 561         abort ();
 562
 563       /* save this away for future reference */
 564       cl = xmalloc (sizeof (struct cpu_desc_list));
 565       cl->cd = cd;
 566       cl->isa = isa;
 567       cl->mach = mach;
 568       cl->endian = endian;
 569       cl->next = cd_list;
 570       cd_list = cl;
 571
 572       xstormy16_cgen_init_dis (cd);
 573     }
 574
 575   /* We try to have as much common code as possible.
 576      But at this point some targets need to take over.  */
 577   /* ??? Some targets may need a hook elsewhere.  Try to avoid this,
 578      but if not possible try to move this hook elsewhere rather than
 579      have two hooks.  */
 580   length = CGEN_PRINT_INSN (cd, pc, info);
 581   if (length > 0)
 582     return length;
 583   if (length < 0)
 584     return -1;
 585
 586   (*info->fprintf_func) (info->stream, UNKNOWN_INSN_MSG);
 587   return cd->default_insn_bitsize / 8;
 588 }