opcodes/i960c-asm.c

   1 /* Assembler interface for targets using CGEN. -*- C -*-
   2    CGEN: Cpu tools GENerator
   3
   4 THIS FILE IS USED TO GENERATE i960c-asm.c.
   5
   6 Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
   7
   8 This file is part of the GNU Binutils and GDB, the GNU debugger.
   9
  10 This program is free software; you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation; either version 2, or (at your option)
  13 any later version.
  14
  15 This program is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with this program; if not, write to the Free Software Foundation, Inc.,
  22 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  23
  24 #include "sysdep.h"
  25 #include <ctype.h>
  26 #include <stdio.h>
  27 #include "ansidecl.h"
  28 #include "bfd.h"
  29 #include "symcat.h"
  30 #include "i960c-opc.h"
  31 #include "opintl.h"
  32
  33 #undef min
  34 #define min(a,b) ((a) < (b) ? (a) : (b))
  35 #undef max
  36 #define max(a,b) ((a) > (b) ? (a) : (b))
  37
  38 #undef INLINE
  39 #ifdef __GNUC__
  40 #define INLINE __inline__
  41 #else
  42 #define INLINE
  43 #endif
  44
  45 /* Used by the ifield rtx function.  */
  46 #define FLD(f) (fields->f)
  47
  48 static const char * insert_normal
  49      PARAMS ((CGEN_OPCODE_DESC, long, unsigned int, unsigned int, unsigned int,
  50               unsigned int, unsigned int, unsigned int, CGEN_INSN_BYTES_PTR));
  51 static const char * parse_insn_normal
  52      PARAMS ((CGEN_OPCODE_DESC, const CGEN_INSN *,
  53               const char **, CGEN_FIELDS *));
  54 static const char * insert_insn_normal
  55      PARAMS ((CGEN_OPCODE_DESC, const CGEN_INSN *,
  56               CGEN_FIELDS *, CGEN_INSN_BYTES_PTR, bfd_vma));
  57 \f
  58 /* -- assembler routines inserted here */
  59
  60 /* Main entry point for operand parsing.
  61
  62    This function is basically just a big switch statement.  Earlier versions
  63    used tables to look up the function to use, but
  64    - if the table contains both assembler and disassembler functions then
  65      the disassembler contains much of the assembler and vice-versa,
  66    - there's a lot of inlining possibilities as things grow,
  67    - using a switch statement avoids the function call overhead.
  68
  69    This function could be moved into `parse_insn_normal', but keeping it
  70    separate makes clear the interface between `parse_insn_normal' and each of
  71    the handlers.
  72 */
  73
  74 const char *
  75 i960_cgen_parse_operand (od, opindex, strp, fields)
  76      CGEN_OPCODE_DESC od;
  77      int opindex;
  78      const char ** strp;
  79      CGEN_FIELDS * fields;
  80 {
  81   const char * errmsg;
  82
  83   switch (opindex)
  84     {
  85     case I960_OPERAND_SRC1 :
  86       errmsg = cgen_parse_keyword (od, strp, & i960_cgen_opval_h_gr, & fields->f_src1);
  87       break;
  88     case I960_OPERAND_SRC2 :
  89       errmsg = cgen_parse_keyword (od, strp, & i960_cgen_opval_h_gr, & fields->f_src2);
  90       break;
  91     case I960_OPERAND_DST :
  92       errmsg = cgen_parse_keyword (od, strp, & i960_cgen_opval_h_gr, & fields->f_srcdst);
  93       break;
  94     case I960_OPERAND_LIT1 :
  95       errmsg = cgen_parse_unsigned_integer (od, strp, I960_OPERAND_LIT1, &fields->f_src1);
  96       break;
  97     case I960_OPERAND_LIT2 :
  98       errmsg = cgen_parse_unsigned_integer (od, strp, I960_OPERAND_LIT2, &fields->f_src2);
  99       break;
 100     case I960_OPERAND_ST_SRC :
 101       errmsg = cgen_parse_keyword (od, strp, & i960_cgen_opval_h_gr, & fields->f_srcdst);
 102       break;
 103     case I960_OPERAND_ABASE :
 104       errmsg = cgen_parse_keyword (od, strp, & i960_cgen_opval_h_gr, & fields->f_abase);
 105       break;
 106     case I960_OPERAND_OFFSET :
 107       errmsg = cgen_parse_unsigned_integer (od, strp, I960_OPERAND_OFFSET, &fields->f_offset);
 108       break;
 109     case I960_OPERAND_SCALE :
 110       errmsg = cgen_parse_unsigned_integer (od, strp, I960_OPERAND_SCALE, &fields->f_scale);
 111       break;
 112     case I960_OPERAND_INDEX :
 113       errmsg = cgen_parse_keyword (od, strp, & i960_cgen_opval_h_gr, & fields->f_index);
 114       break;
 115     case I960_OPERAND_OPTDISP :
 116       errmsg = cgen_parse_unsigned_integer (od, strp, I960_OPERAND_OPTDISP, &fields->f_optdisp);
 117       break;
 118     case I960_OPERAND_BR_SRC1 :
 119       errmsg = cgen_parse_keyword (od, strp, & i960_cgen_opval_h_gr, & fields->f_br_src1);
 120       break;
 121     case I960_OPERAND_BR_SRC2 :
 122       errmsg = cgen_parse_keyword (od, strp, & i960_cgen_opval_h_gr, & fields->f_br_src2);
 123       break;
 124     case I960_OPERAND_BR_DISP :
 125       {
 126         bfd_vma value;
 127         errmsg = cgen_parse_address (od, strp, I960_OPERAND_BR_DISP, 0, NULL,  & value);
 128         fields->f_br_disp = value;
 129       }
 130       break;
 131     case I960_OPERAND_BR_LIT1 :
 132       errmsg = cgen_parse_unsigned_integer (od, strp, I960_OPERAND_BR_LIT1, &fields->f_br_src1);
 133       break;
 134     case I960_OPERAND_CTRL_DISP :
 135       {
 136         bfd_vma value;
 137         errmsg = cgen_parse_address (od, strp, I960_OPERAND_CTRL_DISP, 0, NULL,  & value);
 138         fields->f_ctrl_disp = value;
 139       }
 140       break;
 141
 142     default :
 143       /* xgettext:c-format */
 144       fprintf (stderr, _("Unrecognized field %d while parsing.\n"), opindex);
 145       abort ();
 146   }
 147
 148   return errmsg;
 149 }
 150
 151 /* Main entry point for operand insertion.
 152
 153    This function is basically just a big switch statement.  Earlier versions
 154    used tables to look up the function to use, but
 155    - if the table contains both assembler and disassembler functions then
 156      the disassembler contains much of the assembler and vice-versa,
 157    - there's a lot of inlining possibilities as things grow,
 158    - using a switch statement avoids the function call overhead.
 159
 160    This function could be moved into `parse_insn_normal', but keeping it
 161    separate makes clear the interface between `parse_insn_normal' and each of
 162    the handlers.  It's also needed by GAS to insert operands that couldn't be
 163    resolved during parsing.
 164 */
 165
 166 const char *
 167 i960_cgen_insert_operand (od, opindex, fields, buffer, pc)
 168      CGEN_OPCODE_DESC od;
 169      int opindex;
 170      CGEN_FIELDS * fields;
 171      CGEN_INSN_BYTES_PTR buffer;
 172      bfd_vma pc;
 173 {
 174   const char * errmsg;
 175   unsigned int total_length = CGEN_FIELDS_BITSIZE (fields);
 176
 177   switch (opindex)
 178     {
 179     case I960_OPERAND_SRC1 :
 180       errmsg = insert_normal (od, fields->f_src1, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 27, 5, 32, total_length, buffer);
 181       break;
 182     case I960_OPERAND_SRC2 :
 183       errmsg = insert_normal (od, fields->f_src2, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 13, 5, 32, total_length, buffer);
 184       break;
 185     case I960_OPERAND_DST :
 186       errmsg = insert_normal (od, fields->f_srcdst, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 8, 5, 32, total_length, buffer);
 187       break;
 188     case I960_OPERAND_LIT1 :
 189       errmsg = insert_normal (od, fields->f_src1, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 27, 5, 32, total_length, buffer);
 190       break;
 191     case I960_OPERAND_LIT2 :
 192       errmsg = insert_normal (od, fields->f_src2, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 13, 5, 32, total_length, buffer);
 193       break;
 194     case I960_OPERAND_ST_SRC :
 195       errmsg = insert_normal (od, fields->f_srcdst, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 8, 5, 32, total_length, buffer);
 196       break;
 197     case I960_OPERAND_ABASE :
 198       errmsg = insert_normal (od, fields->f_abase, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 13, 5, 32, total_length, buffer);
 199       break;
 200     case I960_OPERAND_OFFSET :
 201       errmsg = insert_normal (od, fields->f_offset, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 20, 12, 32, total_length, buffer);
 202       break;
 203     case I960_OPERAND_SCALE :
 204       errmsg = insert_normal (od, fields->f_scale, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 22, 3, 32, total_length, buffer);
 205       break;
 206     case I960_OPERAND_INDEX :
 207       errmsg = insert_normal (od, fields->f_index, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 27, 5, 32, total_length, buffer);
 208       break;
 209     case I960_OPERAND_OPTDISP :
 210       errmsg = insert_normal (od, fields->f_optdisp, 0|(1<<CGEN_OPERAND_UNSIGNED), 32, 0, 32, 32, total_length, buffer);
 211       break;
 212     case I960_OPERAND_BR_SRC1 :
 213       errmsg = insert_normal (od, fields->f_br_src1, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 8, 5, 32, total_length, buffer);
 214       break;
 215     case I960_OPERAND_BR_SRC2 :
 216       errmsg = insert_normal (od, fields->f_br_src2, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 13, 5, 32, total_length, buffer);
 217       break;
 218     case I960_OPERAND_BR_DISP :
 219       {
 220         long value = fields->f_br_disp;
 221         value = ((int) (((value) - (pc))) >> (2));
 222         errmsg = insert_normal (od, value, 0|(1<<CGEN_OPERAND_PCREL_ADDR), 0, 19, 11, 32, total_length, buffer);
 223       }
 224       break;
 225     case I960_OPERAND_BR_LIT1 :
 226       errmsg = insert_normal (od, fields->f_br_src1, 0|(1<<CGEN_OPERAND_UNSIGNED), 0, 8, 5, 32, total_length, buffer);
 227       break;
 228     case I960_OPERAND_CTRL_DISP :
 229       {
 230         long value = fields->f_ctrl_disp;
 231         value = ((int) (((value) - (pc))) >> (2));
 232         errmsg = insert_normal (od, value, 0|(1<<CGEN_OPERAND_PCREL_ADDR), 0, 8, 22, 32, total_length, buffer);
 233       }
 234       break;
 235
 236     default :
 237       /* xgettext:c-format */
 238       fprintf (stderr, _("Unrecognized field %d while building insn.\n"),
 239                opindex);
 240       abort ();
 241   }
 242
 243   return errmsg;
 244 }
 245
 246 cgen_parse_fn * const i960_cgen_parse_handlers[] =
 247 {
 248   0, /* default */
 249   parse_insn_normal,
 250 };
 251
 252 cgen_insert_fn * const i960_cgen_insert_handlers[] =
 253 {
 254   0, /* default */
 255   insert_insn_normal,
 256 };
 257
 258 void
 259 i960_cgen_init_asm (od)
 260      CGEN_OPCODE_DESC od;
 261 {
 262 }
 263
 264 \f
 265 #if ! CGEN_INT_INSN_P
 266
 267 /* Subroutine of insert_normal.  */
 268
 269 static INLINE void
 270 insert_1 (od, value, start, length, word_length, bufp)
 271      CGEN_OPCODE_DESC od;
 272      unsigned long value;
 273      int start,length,word_length;
 274      unsigned char *bufp;
 275 {
 276   unsigned long x,mask;
 277   int shift;
 278   int big_p = CGEN_OPCODE_INSN_ENDIAN (od) == CGEN_ENDIAN_BIG;
 279
 280   switch (word_length)
 281     {
 282     case 8:
 283       x = *bufp;
 284       break;
 285     case 16:
 286       if (big_p)
 287         x = bfd_getb16 (bufp);
 288       else
 289         x = bfd_getl16 (bufp);
 290       break;
 291     case 24:
 292       /* ??? This may need reworking as these cases don't necessarily
 293          want the first byte and the last two bytes handled like this.  */
 294       if (big_p)
 295         x = (bufp[0] << 16) | bfd_getb16 (bufp + 1);
 296       else
 297         x = bfd_getl16 (bufp) | (bufp[2] << 16);
 298       break;
 299     case 32:
 300       if (big_p)
 301         x = bfd_getb32 (bufp);
 302       else
 303         x = bfd_getl32 (bufp);
 304       break;
 305     default :
 306       abort ();
 307     }
 308
 309   /* Written this way to avoid undefined behaviour.  */
 310   mask = (((1L << (length - 1)) - 1) << 1) | 1;
 311   if (CGEN_INSN_LSB0_P)
 312     shift = (start + 1) - length;
 313   else
 314     shift = (word_length - (start + length));
 315   x = (x & ~(mask << shift)) | ((value & mask) << shift);
 316
 317   switch (word_length)
 318     {
 319     case 8:
 320       *bufp = x;
 321       break;
 322     case 16:
 323       if (big_p)
 324         bfd_putb16 (x, bufp);
 325       else
 326         bfd_putl16 (x, bufp);
 327       break;
 328     case 24:
 329       /* ??? This may need reworking as these cases don't necessarily
 330          want the first byte and the last two bytes handled like this.  */
 331       if (big_p)
 332         {
 333           bufp[0] = x >> 16;
 334           bfd_putb16 (x, bufp + 1);
 335         }
 336       else
 337         {
 338           bfd_putl16 (x, bufp);
 339           bufp[2] = x >> 16;
 340         }
 341       break;
 342     case 32:
 343       if (big_p)
 344         bfd_putb32 (x, bufp);
 345       else
 346         bfd_putl32 (x, bufp);
 347       break;
 348     default :
 349       abort ();
 350     }
 351 }
 352
 353 #endif /* ! CGEN_INT_INSN_P */
 354
 355 /* Default insertion routine.
 356
 357    ATTRS is a mask of the boolean attributes.
 358    WORD_OFFSET is the offset in bits from the start of the insn of the value.
 359    WORD_LENGTH is the length of the word in bits in which the value resides.
 360    START is the starting bit number in the word, architecture origin.
 361    LENGTH is the length of VALUE in bits.
 362    TOTAL_LENGTH is the total length of the insn in bits.
 363
 364    The result is an error message or NULL if success.  */
 365
 366 /* ??? This duplicates functionality with bfd's howto table and
 367    bfd_install_relocation.  */
 368 /* ??? This doesn't handle bfd_vma's.  Create another function when
 369    necessary.  */
 370
 371 static const char *
 372 insert_normal (od, value, attrs, word_offset, start, length, word_length,
 373                total_length, buffer)
 374      CGEN_OPCODE_DESC od;
 375      long value;
 376      unsigned int attrs;
 377      unsigned int word_offset, start, length, word_length, total_length;
 378      CGEN_INSN_BYTES_PTR buffer;
 379 {
 380   static char errbuf[100];
 381   /* Written this way to avoid undefined behaviour.  */
 382   unsigned long mask = (((1L << (length - 1)) - 1) << 1) | 1;
 383
 384   /* If LENGTH is zero, this operand doesn't contribute to the value.  */
 385   if (length == 0)
 386     return NULL;
 387
 388   if (CGEN_INT_INSN_P
 389       && word_offset != 0)
 390     abort ();
 391
 392   if (word_length > 32)
 393     abort ();
 394
 395   /* For architectures with insns smaller than the insn-base-bitsize,
 396      word_length may be too big.  */
 397 #if CGEN_MIN_INSN_BITSIZE < CGEN_BASE_INSN_BITSIZE
 398   if (word_offset == 0
 399       && word_length > total_length)
 400     word_length = total_length;
 401 #endif
 402
 403   /* Ensure VALUE will fit.  */
 404   if (CGEN_BOOL_ATTR (attrs, CGEN_OPERAND_UNSIGNED))
 405     {
 406       unsigned long maxval = mask;
 407       if ((unsigned long) value > maxval)
 408         {
 409           /* xgettext:c-format */
 410           sprintf (errbuf,
 411                    _("operand out of range (%lu not between 0 and %lu)"),
 412                    value, maxval);
 413           return errbuf;
 414         }
 415     }
 416   else
 417     {
 418       long minval = - (1L << (length - 1));
 419       long maxval = (1L << (length - 1)) - 1;
 420       if (value < minval || value > maxval)
 421         {
 422           sprintf
 423             /* xgettext:c-format */
 424             (errbuf, _("operand out of range (%ld not between %ld and %ld)"),
 425              value, minval, maxval);
 426           return errbuf;
 427         }
 428     }
 429
 430 #if CGEN_INT_INSN_P
 431
 432   {
 433     int shift;
 434
 435     if (CGEN_INSN_LSB0_P)
 436       shift = (start + 1) - length;
 437     else
 438       shift = word_length - (start + length);
 439     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
 440   }
 441
 442 #else /* ! CGEN_INT_INSN_P */
 443
 444   {
 445     unsigned char *bufp = (unsigned char *) buffer + word_offset / 8;
 446
 447     insert_1 (od, value, start, length, word_length, bufp);
 448   }
 449
 450 #endif /* ! CGEN_INT_INSN_P */
 451
 452   return NULL;
 453 }
 454 \f
 455 /* Default insn parser.
 456
 457    The syntax string is scanned and operands are parsed and stored in FIELDS.
 458    Relocs are queued as we go via other callbacks.
 459
 460    ??? Note that this is currently an all-or-nothing parser.  If we fail to
 461    parse the instruction, we return 0 and the caller will start over from
 462    the beginning.  Backtracking will be necessary in parsing subexpressions,
 463    but that can be handled there.  Not handling backtracking here may get
 464    expensive in the case of the m68k.  Deal with later.
 465
 466    Returns NULL for success, an error message for failure.
 467 */
 468
 469 static const char *
 470 parse_insn_normal (od, insn, strp, fields)
 471      CGEN_OPCODE_DESC od;
 472      const CGEN_INSN * insn;
 473      const char ** strp;
 474      CGEN_FIELDS * fields;
 475 {
 476   const CGEN_SYNTAX * syntax = CGEN_INSN_SYNTAX (insn);
 477   const char * str = *strp;
 478   const char * errmsg;
 479   const char * p;
 480   const unsigned char * syn;
 481 #ifdef CGEN_MNEMONIC_OPERANDS
 482   /* FIXME: wip */
 483   int past_opcode_p;
 484 #endif
 485
 486   /* For now we assume the mnemonic is first (there are no leading operands).
 487      We can parse it without needing to set up operand parsing.
 488      GAS's input scrubber will ensure mnemonics are lowercase, but we may
 489      not be called from GAS.  */
 490   p = CGEN_INSN_MNEMONIC (insn);
 491   while (*p && tolower (*p) == tolower (*str))
 492     ++p, ++str;
 493
 494   if (* p || (* str && !isspace (* str)))
 495     return _("unrecognized instruction");
 496
 497   CGEN_INIT_PARSE (od);
 498   cgen_init_parse_operand (od);
 499 #ifdef CGEN_MNEMONIC_OPERANDS
 500   past_opcode_p = 0;
 501 #endif
 502
 503   /* We don't check for (*str != '\0') here because we want to parse
 504      any trailing fake arguments in the syntax string.  */
 505   syn = CGEN_SYNTAX_STRING (syntax);
 506
 507   /* Mnemonics come first for now, ensure valid string.  */
 508   if (! CGEN_SYNTAX_MNEMONIC_P (* syn))
 509     abort ();
 510
 511   ++syn;
 512
 513   while (* syn != 0)
 514     {
 515       /* Non operand chars must match exactly.  */
 516       if (CGEN_SYNTAX_CHAR_P (* syn))
 517         {
 518           if (*str == CGEN_SYNTAX_CHAR (* syn))
 519             {
 520 #ifdef CGEN_MNEMONIC_OPERANDS
 521               if (* syn == ' ')
 522                 past_opcode_p = 1;
 523 #endif
 524               ++ syn;
 525               ++ str;
 526             }
 527           else
 528             {
 529               /* Syntax char didn't match.  Can't be this insn.  */
 530               /* FIXME: would like to return something like
 531                  "expected char `c'" */
 532               return _("syntax error");
 533             }
 534           continue;
 535         }
 536
 537       /* We have an operand of some sort.  */
 538       errmsg = i960_cgen_parse_operand (od, CGEN_SYNTAX_FIELD (*syn),
 539                                           &str, fields);
 540       if (errmsg)
 541         return errmsg;
 542
 543       /* Done with this operand, continue with next one.  */
 544       ++ syn;
 545     }
 546
 547   /* If we're at the end of the syntax string, we're done.  */
 548   if (* syn == '\0')
 549     {
 550       /* FIXME: For the moment we assume a valid `str' can only contain
 551          blanks now.  IE: We needn't try again with a longer version of
 552          the insn and it is assumed that longer versions of insns appear
 553          before shorter ones (eg: lsr r2,r3,1 vs lsr r2,r3).  */
 554       while (isspace (* str))
 555         ++ str;
 556
 557       if (* str != '\0')
 558         return _("junk at end of line"); /* FIXME: would like to include `str' */
 559
 560       return NULL;
 561     }
 562
 563   /* We couldn't parse it.  */
 564   return _("unrecognized instruction");
 565 }
 566
 567 /* Default insn builder (insert handler).
 568    The instruction is recorded in CGEN_INT_INSN_P byte order
 569    (meaning that if CGEN_INT_INSN_P BUFFER is an int * and thus the value is
 570    recorded in host byte order, otherwise BUFFER is an array of bytes and the
 571    value is recorded in target byte order).
 572    The result is an error message or NULL if success.  */
 573
 574 static const char *
 575 insert_insn_normal (od, insn, fields, buffer, pc)
 576      CGEN_OPCODE_DESC od;
 577      const CGEN_INSN * insn;
 578      CGEN_FIELDS * fields;
 579      CGEN_INSN_BYTES_PTR buffer;
 580      bfd_vma pc;
 581 {
 582   const CGEN_SYNTAX * syntax = CGEN_INSN_SYNTAX (insn);
 583   unsigned long value;
 584   const unsigned char * syn;
 585
 586   CGEN_INIT_INSERT (od);
 587   value = CGEN_INSN_BASE_VALUE (insn);
 588
 589   /* If we're recording insns as numbers (rather than a string of bytes),
 590      target byte order handling is deferred until later.  */
 591
 592 #if CGEN_INT_INSN_P
 593
 594   *buffer = value;
 595
 596 #else
 597
 598   cgen_put_insn_value (od, buffer, min (CGEN_BASE_INSN_BITSIZE,
 599                                         CGEN_FIELDS_BITSIZE (fields)),
 600                        value);
 601
 602 #endif /* ! CGEN_INT_INSN_P */
 603
 604   /* ??? It would be better to scan the format's fields.
 605      Still need to be able to insert a value based on the operand though;
 606      e.g. storing a branch displacement that got resolved later.
 607      Needs more thought first.  */
 608
 609   for (syn = CGEN_SYNTAX_STRING (syntax); * syn != '\0'; ++ syn)
 610     {
 611       const char *errmsg;
 612
 613       if (CGEN_SYNTAX_CHAR_P (* syn))
 614         continue;
 615
 616       errmsg = i960_cgen_insert_operand (od, CGEN_SYNTAX_FIELD (*syn),
 617                                            fields, buffer, pc);
 618       if (errmsg)
 619         return errmsg;
 620     }
 621
 622   return NULL;
 623 }
 624 \f
 625 /* Main entry point.
 626    This routine is called for each instruction to be assembled.
 627    STR points to the insn to be assembled.
 628    We assume all necessary tables have been initialized.
 629    The assembled instruction, less any fixups, is stored in BUF.
 630    Remember that if CGEN_INT_INSN_P then BUF is an int and thus the value
 631    still needs to be converted to target byte order, otherwise BUF is an array
 632    of bytes in target byte order.
 633    The result is a pointer to the insn's entry in the opcode table,
 634    or NULL if an error occured (an error message will have already been
 635    printed).
 636
 637    Note that when processing (non-alias) macro-insns,
 638    this function recurses.  */
 639
 640 const CGEN_INSN *
 641 i960_cgen_assemble_insn (od, str, fields, buf, errmsg)
 642      CGEN_OPCODE_DESC od;
 643      const char * str;
 644      CGEN_FIELDS * fields;
 645      CGEN_INSN_BYTES_PTR buf;
 646      char ** errmsg;
 647 {
 648   const char * start;
 649   CGEN_INSN_LIST * ilist;
 650
 651   /* Skip leading white space.  */
 652   while (isspace (* str))
 653     ++ str;
 654
 655   /* The instructions are stored in hashed lists.
 656      Get the first in the list.  */
 657   ilist = CGEN_ASM_LOOKUP_INSN (od, str);
 658
 659   /* Keep looking until we find a match.  */
 660
 661   start = str;
 662   for ( ; ilist != NULL ; ilist = CGEN_ASM_NEXT_INSN (ilist))
 663     {
 664       const CGEN_INSN *insn = ilist->insn;
 665
 666 #if 0 /* not needed as unsupported opcodes shouldn't be in the hash lists */
 667       /* Is this insn supported by the selected cpu?  */
 668       if (! i960_cgen_insn_supported (od, insn))
 669         continue;
 670 #endif
 671
 672       /* If the RELAX attribute is set, this is an insn that shouldn't be
 673          chosen immediately.  Instead, it is used during assembler/linker
 674          relaxation if possible.  */
 675       if (CGEN_INSN_ATTR (insn, CGEN_INSN_RELAX) != 0)
 676         continue;
 677
 678       str = start;
 679
 680       /* Allow parse/insert handlers to obtain length of insn.  */
 681       CGEN_FIELDS_BITSIZE (fields) = CGEN_INSN_BITSIZE (insn);
 682
 683       if (! CGEN_PARSE_FN (insn) (od, insn, & str, fields))
 684         {
 685           /* ??? 0 is passed for `pc' */
 686           if (CGEN_INSERT_FN (insn) (od, insn, fields, buf, (bfd_vma) 0) != NULL)
 687             continue;
 688           /* It is up to the caller to actually output the insn and any
 689              queued relocs.  */
 690           return insn;
 691         }
 692
 693       /* Try the next entry.  */
 694     }
 695
 696   /* FIXME: We can return a better error message than this.
 697      Need to track why it failed and pick the right one.  */
 698   {
 699     static char errbuf[100];
 700     if (strlen (start) > 50)
 701       /* xgettext:c-format */
 702       sprintf (errbuf, _("bad instruction `%.50s...'"), start);
 703     else
 704       /* xgettext:c-format */
 705       sprintf (errbuf, _("bad instruction `%.50s'"), start);
 706
 707     *errmsg = errbuf;
 708     return NULL;
 709   }
 710 }
 711 \f
 712 #if 0 /* This calls back to GAS which we can't do without care.  */
 713
 714 /* Record each member of OPVALS in the assembler's symbol table.
 715    This lets GAS parse registers for us.
 716    ??? Interesting idea but not currently used.  */
 717
 718 /* Record each member of OPVALS in the assembler's symbol table.
 719    FIXME: Not currently used.  */
 720
 721 void
 722 i960_cgen_asm_hash_keywords (od, opvals)
 723      CGEN_OPCODE_DESC od;
 724      CGEN_KEYWORD * opvals;
 725 {
 726   CGEN_KEYWORD_SEARCH search = cgen_keyword_search_init (opvals, NULL);
 727   const CGEN_KEYWORD_ENTRY * ke;
 728
 729   while ((ke = cgen_keyword_search_next (& search)) != NULL)
 730     {
 731 #if 0 /* Unnecessary, should be done in the search routine.  */
 732       if (! i960_cgen_opval_supported (ke))
 733         continue;
 734 #endif
 735       cgen_asm_record_register (od, ke->name, ke->value);
 736     }
 737 }
 738
 739 #endif /* 0 */