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
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 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 "iq2000-desc.h"
37 #include "iq2000-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);
47 static void print_keyword
48   (CGEN_CPU_DESC, void *, CGEN_KEYWORD *, long, unsigned int);
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 *, char *, unsigned);
53 static int default_print_insn
54   (CGEN_CPU_DESC, bfd_vma, disassemble_info *);
55 static int read_insn
56   (CGEN_CPU_DESC, bfd_vma, disassemble_info *, char *, int, CGEN_EXTRACT_INFO *,
57    unsigned long *);
58 
59 /* -- disassembler routines inserted here */
60 
61 
62 void iq2000_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
iq2000_cgen_print_operand(cd,opindex,xinfo,fields,attrs,pc,length)82 iq2000_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 IQ2000_OPERAND_BASE :
96       print_keyword (cd, info, & iq2000_cgen_opval_gr_names, fields->f_rs, 0);
97       break;
98     case IQ2000_OPERAND_BASEOFF :
99       print_address (cd, info, fields->f_imm, 0, pc, length);
100       break;
101     case IQ2000_OPERAND_BITNUM :
102       print_normal (cd, info, fields->f_rt, 0, pc, length);
103       break;
104     case IQ2000_OPERAND_BYTECOUNT :
105       print_normal (cd, info, fields->f_bytecount, 0, pc, length);
106       break;
107     case IQ2000_OPERAND_CAM_Y :
108       print_normal (cd, info, fields->f_cam_y, 0, pc, length);
109       break;
110     case IQ2000_OPERAND_CAM_Z :
111       print_normal (cd, info, fields->f_cam_z, 0, pc, length);
112       break;
113     case IQ2000_OPERAND_CM_3FUNC :
114       print_normal (cd, info, fields->f_cm_3func, 0, pc, length);
115       break;
116     case IQ2000_OPERAND_CM_3Z :
117       print_normal (cd, info, fields->f_cm_3z, 0, pc, length);
118       break;
119     case IQ2000_OPERAND_CM_4FUNC :
120       print_normal (cd, info, fields->f_cm_4func, 0, pc, length);
121       break;
122     case IQ2000_OPERAND_CM_4Z :
123       print_normal (cd, info, fields->f_cm_4z, 0, pc, length);
124       break;
125     case IQ2000_OPERAND_COUNT :
126       print_normal (cd, info, fields->f_count, 0, pc, length);
127       break;
128     case IQ2000_OPERAND_EXECODE :
129       print_normal (cd, info, fields->f_excode, 0, pc, length);
130       break;
131     case IQ2000_OPERAND_F_INDEX :
132       print_normal (cd, info, fields->f_index, 0, pc, length);
133       break;
134     case IQ2000_OPERAND_HI16 :
135       print_normal (cd, info, fields->f_imm, 0, pc, length);
136       break;
137     case IQ2000_OPERAND_IMM :
138       print_normal (cd, info, fields->f_imm, 0, pc, length);
139       break;
140     case IQ2000_OPERAND_JMPTARG :
141       print_address (cd, info, fields->f_jtarg, 0|(1<<CGEN_OPERAND_ABS_ADDR), pc, length);
142       break;
143     case IQ2000_OPERAND_JMPTARGQ10 :
144       print_address (cd, info, fields->f_jtargq10, 0|(1<<CGEN_OPERAND_ABS_ADDR), pc, length);
145       break;
146     case IQ2000_OPERAND_LO16 :
147       print_normal (cd, info, fields->f_imm, 0, pc, length);
148       break;
149     case IQ2000_OPERAND_MASK :
150       print_normal (cd, info, fields->f_mask, 0, pc, length);
151       break;
152     case IQ2000_OPERAND_MASKL :
153       print_normal (cd, info, fields->f_maskl, 0, pc, length);
154       break;
155     case IQ2000_OPERAND_MASKQ10 :
156       print_normal (cd, info, fields->f_maskq10, 0, pc, length);
157       break;
158     case IQ2000_OPERAND_MASKR :
159       print_normal (cd, info, fields->f_rs, 0, pc, length);
160       break;
161     case IQ2000_OPERAND_MLO16 :
162       print_normal (cd, info, fields->f_imm, 0, pc, length);
163       break;
164     case IQ2000_OPERAND_OFFSET :
165       print_address (cd, info, fields->f_offset, 0|(1<<CGEN_OPERAND_PCREL_ADDR), pc, length);
166       break;
167     case IQ2000_OPERAND_RD :
168       print_keyword (cd, info, & iq2000_cgen_opval_gr_names, fields->f_rd, 0);
169       break;
170     case IQ2000_OPERAND_RD_RS :
171       print_keyword (cd, info, & iq2000_cgen_opval_gr_names, fields->f_rd_rs, 0|(1<<CGEN_OPERAND_VIRTUAL));
172       break;
173     case IQ2000_OPERAND_RD_RT :
174       print_keyword (cd, info, & iq2000_cgen_opval_gr_names, fields->f_rd_rt, 0|(1<<CGEN_OPERAND_VIRTUAL));
175       break;
176     case IQ2000_OPERAND_RS :
177       print_keyword (cd, info, & iq2000_cgen_opval_gr_names, fields->f_rs, 0);
178       break;
179     case IQ2000_OPERAND_RT :
180       print_keyword (cd, info, & iq2000_cgen_opval_gr_names, fields->f_rt, 0);
181       break;
182     case IQ2000_OPERAND_RT_RS :
183       print_keyword (cd, info, & iq2000_cgen_opval_gr_names, fields->f_rt_rs, 0|(1<<CGEN_OPERAND_VIRTUAL));
184       break;
185     case IQ2000_OPERAND_SHAMT :
186       print_normal (cd, info, fields->f_shamt, 0, pc, length);
187       break;
188 
189     default :
190       /* xgettext:c-format */
191       fprintf (stderr, _("Unrecognized field %d while printing insn.\n"),
192 	       opindex);
193     abort ();
194   }
195 }
196 
197 cgen_print_fn * const iq2000_cgen_print_handlers[] =
198 {
199   print_insn_normal,
200 };
201 
202 
203 void
iq2000_cgen_init_dis(cd)204 iq2000_cgen_init_dis (cd)
205      CGEN_CPU_DESC cd;
206 {
207   iq2000_cgen_init_opcode_table (cd);
208   iq2000_cgen_init_ibld_table (cd);
209   cd->print_handlers = & iq2000_cgen_print_handlers[0];
210   cd->print_operand = iq2000_cgen_print_operand;
211 }
212 
213 
214 /* Default print handler.  */
215 
216 static void
print_normal(CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,void * dis_info,long value,unsigned int attrs,bfd_vma pc ATTRIBUTE_UNUSED,int length ATTRIBUTE_UNUSED)217 print_normal (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
218 	      void *dis_info,
219 	      long value,
220 	      unsigned int attrs,
221 	      bfd_vma pc ATTRIBUTE_UNUSED,
222 	      int length ATTRIBUTE_UNUSED)
223 {
224   disassemble_info *info = (disassemble_info *) dis_info;
225 
226 #ifdef CGEN_PRINT_NORMAL
227   CGEN_PRINT_NORMAL (cd, info, value, attrs, pc, length);
228 #endif
229 
230   /* Print the operand as directed by the attributes.  */
231   if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_SEM_ONLY))
232     ; /* nothing to do */
233   else if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_SIGNED))
234     (*info->fprintf_func) (info->stream, "%ld", value);
235   else
236     (*info->fprintf_func) (info->stream, "0x%lx", value);
237 }
238 
239 /* Default address handler.  */
240 
241 static void
print_address(CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,void * dis_info,bfd_vma value,unsigned int attrs,bfd_vma pc ATTRIBUTE_UNUSED,int length ATTRIBUTE_UNUSED)242 print_address (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
243 	       void *dis_info,
244 	       bfd_vma value,
245 	       unsigned int attrs,
246 	       bfd_vma pc ATTRIBUTE_UNUSED,
247 	       int length ATTRIBUTE_UNUSED)
248 {
249   disassemble_info *info = (disassemble_info *) dis_info;
250 
251 #ifdef CGEN_PRINT_ADDRESS
252   CGEN_PRINT_ADDRESS (cd, info, value, attrs, pc, length);
253 #endif
254 
255   /* Print the operand as directed by the attributes.  */
256   if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_SEM_ONLY))
257     ; /* nothing to do */
258   else if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_PCREL_ADDR))
259     (*info->print_address_func) (value, info);
260   else if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_ABS_ADDR))
261     (*info->print_address_func) (value, info);
262   else if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_SIGNED))
263     (*info->fprintf_func) (info->stream, "%ld", (long) value);
264   else
265     (*info->fprintf_func) (info->stream, "0x%lx", (long) value);
266 }
267 
268 /* Keyword print handler.  */
269 
270 static void
print_keyword(CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,void * dis_info,CGEN_KEYWORD * keyword_table,long value,unsigned int attrs ATTRIBUTE_UNUSED)271 print_keyword (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
272 	       void *dis_info,
273 	       CGEN_KEYWORD *keyword_table,
274 	       long value,
275 	       unsigned int attrs ATTRIBUTE_UNUSED)
276 {
277   disassemble_info *info = (disassemble_info *) dis_info;
278   const CGEN_KEYWORD_ENTRY *ke;
279 
280   ke = cgen_keyword_lookup_value (keyword_table, value);
281   if (ke != NULL)
282     (*info->fprintf_func) (info->stream, "%s", ke->name);
283   else
284     (*info->fprintf_func) (info->stream, "???");
285 }
286 
287 /* Default insn printer.
288 
289    DIS_INFO is defined as `void *' so the disassembler needn't know anything
290    about disassemble_info.  */
291 
292 static void
print_insn_normal(CGEN_CPU_DESC cd,void * dis_info,const CGEN_INSN * insn,CGEN_FIELDS * fields,bfd_vma pc,int length)293 print_insn_normal (CGEN_CPU_DESC cd,
294 		   void *dis_info,
295 		   const CGEN_INSN *insn,
296 		   CGEN_FIELDS *fields,
297 		   bfd_vma pc,
298 		   int length)
299 {
300   const CGEN_SYNTAX *syntax = CGEN_INSN_SYNTAX (insn);
301   disassemble_info *info = (disassemble_info *) dis_info;
302   const CGEN_SYNTAX_CHAR_TYPE *syn;
303 
304   CGEN_INIT_PRINT (cd);
305 
306   for (syn = CGEN_SYNTAX_STRING (syntax); *syn; ++syn)
307     {
308       if (CGEN_SYNTAX_MNEMONIC_P (*syn))
309 	{
310 	  (*info->fprintf_func) (info->stream, "%s", CGEN_INSN_MNEMONIC (insn));
311 	  continue;
312 	}
313       if (CGEN_SYNTAX_CHAR_P (*syn))
314 	{
315 	  (*info->fprintf_func) (info->stream, "%c", CGEN_SYNTAX_CHAR (*syn));
316 	  continue;
317 	}
318 
319       /* We have an operand.  */
320       iq2000_cgen_print_operand (cd, CGEN_SYNTAX_FIELD (*syn), info,
321 				 fields, CGEN_INSN_ATTRS (insn), pc, length);
322     }
323 }
324 
325 /* Subroutine of print_insn. Reads an insn into the given buffers and updates
326    the extract info.
327    Returns 0 if all is well, non-zero otherwise.  */
328 
329 static int
read_insn(CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,bfd_vma pc,disassemble_info * info,char * buf,int buflen,CGEN_EXTRACT_INFO * ex_info,unsigned long * insn_value)330 read_insn (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
331 	   bfd_vma pc,
332 	   disassemble_info *info,
333 	   char *buf,
334 	   int buflen,
335 	   CGEN_EXTRACT_INFO *ex_info,
336 	   unsigned long *insn_value)
337 {
338   int status = (*info->read_memory_func) (pc, buf, buflen, info);
339   if (status != 0)
340     {
341       (*info->memory_error_func) (status, pc, info);
342       return -1;
343     }
344 
345   ex_info->dis_info = info;
346   ex_info->valid = (1 << buflen) - 1;
347   ex_info->insn_bytes = buf;
348 
349   *insn_value = bfd_get_bits (buf, buflen * 8, info->endian == BFD_ENDIAN_BIG);
350   return 0;
351 }
352 
353 /* Utility to print an insn.
354    BUF is the base part of the insn, target byte order, BUFLEN bytes long.
355    The result is the size of the insn in bytes or zero for an unknown insn
356    or -1 if an error occurs fetching data (memory_error_func will have
357    been called).  */
358 
359 static int
print_insn(CGEN_CPU_DESC cd,bfd_vma pc,disassemble_info * info,char * buf,unsigned int buflen)360 print_insn (CGEN_CPU_DESC cd,
361 	    bfd_vma pc,
362 	    disassemble_info *info,
363 	    char *buf,
364 	    unsigned int buflen)
365 {
366   CGEN_INSN_INT insn_value;
367   const CGEN_INSN_LIST *insn_list;
368   CGEN_EXTRACT_INFO ex_info;
369   int basesize;
370 
371   /* Extract base part of instruction, just in case CGEN_DIS_* uses it. */
372   basesize = cd->base_insn_bitsize < buflen * 8 ?
373                                      cd->base_insn_bitsize : buflen * 8;
374   insn_value = cgen_get_insn_value (cd, buf, basesize);
375 
376 
377   /* Fill in ex_info fields like read_insn would.  Don't actually call
378      read_insn, since the incoming buffer is already read (and possibly
379      modified a la m32r).  */
380   ex_info.valid = (1 << buflen) - 1;
381   ex_info.dis_info = info;
382   ex_info.insn_bytes = buf;
383 
384   /* The instructions are stored in hash lists.
385      Pick the first one and keep trying until we find the right one.  */
386 
387   insn_list = CGEN_DIS_LOOKUP_INSN (cd, buf, insn_value);
388   while (insn_list != NULL)
389     {
390       const CGEN_INSN *insn = insn_list->insn;
391       CGEN_FIELDS fields;
392       int length;
393       unsigned long insn_value_cropped;
394 
395 #ifdef CGEN_VALIDATE_INSN_SUPPORTED
396       /* Not needed as insn shouldn't be in hash lists if not supported.  */
397       /* Supported by this cpu?  */
398       if (! iq2000_cgen_insn_supported (cd, insn))
399         {
400           insn_list = CGEN_DIS_NEXT_INSN (insn_list);
401 	  continue;
402         }
403 #endif
404 
405       /* Basic bit mask must be correct.  */
406       /* ??? May wish to allow target to defer this check until the extract
407 	 handler.  */
408 
409       /* Base size may exceed this instruction's size.  Extract the
410          relevant part from the buffer. */
411       if ((unsigned) (CGEN_INSN_BITSIZE (insn) / 8) < buflen &&
412 	  (unsigned) (CGEN_INSN_BITSIZE (insn) / 8) <= sizeof (unsigned long))
413 	insn_value_cropped = bfd_get_bits (buf, CGEN_INSN_BITSIZE (insn),
414 					   info->endian == BFD_ENDIAN_BIG);
415       else
416 	insn_value_cropped = insn_value;
417 
418       if ((insn_value_cropped & CGEN_INSN_BASE_MASK (insn))
419 	  == CGEN_INSN_BASE_VALUE (insn))
420 	{
421 	  /* Printing is handled in two passes.  The first pass parses the
422 	     machine insn and extracts the fields.  The second pass prints
423 	     them.  */
424 
425 	  /* Make sure the entire insn is loaded into insn_value, if it
426 	     can fit.  */
427 	  if (((unsigned) CGEN_INSN_BITSIZE (insn) > cd->base_insn_bitsize) &&
428 	      (unsigned) (CGEN_INSN_BITSIZE (insn) / 8) <= sizeof (unsigned long))
429 	    {
430 	      unsigned long full_insn_value;
431 	      int rc = read_insn (cd, pc, info, buf,
432 				  CGEN_INSN_BITSIZE (insn) / 8,
433 				  & ex_info, & full_insn_value);
434 	      if (rc != 0)
435 		return rc;
436 	      length = CGEN_EXTRACT_FN (cd, insn)
437 		(cd, insn, &ex_info, full_insn_value, &fields, pc);
438 	    }
439 	  else
440 	    length = CGEN_EXTRACT_FN (cd, insn)
441 	      (cd, insn, &ex_info, insn_value_cropped, &fields, pc);
442 
443 	  /* length < 0 -> error */
444 	  if (length < 0)
445 	    return length;
446 	  if (length > 0)
447 	    {
448 	      CGEN_PRINT_FN (cd, insn) (cd, info, insn, &fields, pc, length);
449 	      /* length is in bits, result is in bytes */
450 	      return length / 8;
451 	    }
452 	}
453 
454       insn_list = CGEN_DIS_NEXT_INSN (insn_list);
455     }
456 
457   return 0;
458 }
459 
460 /* Default value for CGEN_PRINT_INSN.
461    The result is the size of the insn in bytes or zero for an unknown insn
462    or -1 if an error occured fetching bytes.  */
463 
464 #ifndef CGEN_PRINT_INSN
465 #define CGEN_PRINT_INSN default_print_insn
466 #endif
467 
468 static int
default_print_insn(CGEN_CPU_DESC cd,bfd_vma pc,disassemble_info * info)469 default_print_insn (CGEN_CPU_DESC cd, bfd_vma pc, disassemble_info *info)
470 {
471   char buf[CGEN_MAX_INSN_SIZE];
472   int buflen;
473   int status;
474 
475   /* Attempt to read the base part of the insn.  */
476   buflen = cd->base_insn_bitsize / 8;
477   status = (*info->read_memory_func) (pc, buf, buflen, info);
478 
479   /* Try again with the minimum part, if min < base.  */
480   if (status != 0 && (cd->min_insn_bitsize < cd->base_insn_bitsize))
481     {
482       buflen = cd->min_insn_bitsize / 8;
483       status = (*info->read_memory_func) (pc, buf, buflen, info);
484     }
485 
486   if (status != 0)
487     {
488       (*info->memory_error_func) (status, pc, info);
489       return -1;
490     }
491 
492   return print_insn (cd, pc, info, buf, buflen);
493 }
494 
495 /* Main entry point.
496    Print one instruction from PC on INFO->STREAM.
497    Return the size of the instruction (in bytes).  */
498 
499 typedef struct cpu_desc_list {
500   struct cpu_desc_list *next;
501   int isa;
502   int mach;
503   int endian;
504   CGEN_CPU_DESC cd;
505 } cpu_desc_list;
506 
507 int
print_insn_iq2000(bfd_vma pc,disassemble_info * info)508 print_insn_iq2000 (bfd_vma pc, disassemble_info *info)
509 {
510   static cpu_desc_list *cd_list = 0;
511   cpu_desc_list *cl = 0;
512   static CGEN_CPU_DESC cd = 0;
513   static int prev_isa;
514   static int prev_mach;
515   static int prev_endian;
516   int length;
517   int isa,mach;
518   int endian = (info->endian == BFD_ENDIAN_BIG
519 		? CGEN_ENDIAN_BIG
520 		: CGEN_ENDIAN_LITTLE);
521   enum bfd_architecture arch;
522 
523   /* ??? gdb will set mach but leave the architecture as "unknown" */
524 #ifndef CGEN_BFD_ARCH
525 #define CGEN_BFD_ARCH bfd_arch_iq2000
526 #endif
527   arch = info->arch;
528   if (arch == bfd_arch_unknown)
529     arch = CGEN_BFD_ARCH;
530 
531   /* There's no standard way to compute the machine or isa number
532      so we leave it to the target.  */
533 #ifdef CGEN_COMPUTE_MACH
534   mach = CGEN_COMPUTE_MACH (info);
535 #else
536   mach = info->mach;
537 #endif
538 
539 #ifdef CGEN_COMPUTE_ISA
540   isa = CGEN_COMPUTE_ISA (info);
541 #else
542   isa = info->insn_sets;
543 #endif
544 
545   /* If we've switched cpu's, try to find a handle we've used before */
546   if (cd
547       && (isa != prev_isa
548 	  || mach != prev_mach
549 	  || endian != prev_endian))
550     {
551       cd = 0;
552       for (cl = cd_list; cl; cl = cl->next)
553 	{
554 	  if (cl->isa == isa &&
555 	      cl->mach == mach &&
556 	      cl->endian == endian)
557 	    {
558 	      cd = cl->cd;
559 	      break;
560 	    }
561 	}
562     }
563 
564   /* If we haven't initialized yet, initialize the opcode table.  */
565   if (! cd)
566     {
567       const bfd_arch_info_type *arch_type = bfd_lookup_arch (arch, mach);
568       const char *mach_name;
569 
570       if (!arch_type)
571 	abort ();
572       mach_name = arch_type->printable_name;
573 
574       prev_isa = isa;
575       prev_mach = mach;
576       prev_endian = endian;
577       cd = iq2000_cgen_cpu_open (CGEN_CPU_OPEN_ISAS, prev_isa,
578 				 CGEN_CPU_OPEN_BFDMACH, mach_name,
579 				 CGEN_CPU_OPEN_ENDIAN, prev_endian,
580 				 CGEN_CPU_OPEN_END);
581       if (!cd)
582 	abort ();
583 
584       /* save this away for future reference */
585       cl = xmalloc (sizeof (struct cpu_desc_list));
586       cl->cd = cd;
587       cl->isa = isa;
588       cl->mach = mach;
589       cl->endian = endian;
590       cl->next = cd_list;
591       cd_list = cl;
592 
593       iq2000_cgen_init_dis (cd);
594     }
595 
596   /* We try to have as much common code as possible.
597      But at this point some targets need to take over.  */
598   /* ??? Some targets may need a hook elsewhere.  Try to avoid this,
599      but if not possible try to move this hook elsewhere rather than
600      have two hooks.  */
601   length = CGEN_PRINT_INSN (cd, pc, info);
602   if (length > 0)
603     return length;
604   if (length < 0)
605     return -1;
606 
607   (*info->fprintf_func) (info->stream, UNKNOWN_INSN_MSG);
608   return cd->default_insn_bitsize / 8;
609 }
610