gas/itbl-ops.c

   1 /* itbl-ops.c
   2    Copyright (C) 1997-2024 Free Software Foundation, Inc.
   3
   4    This file is part of GAS, the GNU Assembler.
   5
   6    GAS is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3, or (at your option)
   9    any later version.
  10
  11    GAS is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GAS; see the file COPYING.  If not, write to the Free
  18    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  19    02110-1301, USA.  */
  20
  21 /*======================================================================*/
  22 /*
  23  * Herein lies the support for dynamic specification of processor
  24  * instructions and registers.  Mnemonics, values, and formats for each
  25  * instruction and register are specified in an ascii file consisting of
  26  * table entries.  The grammar for the table is defined in the document
  27  * "Processor instruction table specification".
  28  *
  29  * Instructions use the gnu assembler syntax, with the addition of
  30  * allowing mnemonics for register.
  31  * Eg. "func $2,reg3,0x100,symbol ; comment"
  32  *      func - opcode name
  33  *      $n - register n
  34  *      reg3 - mnemonic for processor's register defined in table
  35  *      0xddd..d - immediate value
  36  *      symbol - address of label or external symbol
  37  *
  38  * First, itbl_parse reads in the table of register and instruction
  39  * names and formats, and builds a list of entries for each
  40  * processor/type combination.  lex and yacc are used to parse
  41  * the entries in the table and call functions defined here to
  42  * add each entry to our list.
  43  *
  44  * Then, when assembling or disassembling, these functions are called to
  45  * 1) get information on a processor's registers and
  46  * 2) assemble/disassemble an instruction.
  47  * To assemble(disassemble) an instruction, the function
  48  * itbl_assemble(itbl_disassemble) is called to search the list of
  49  * instruction entries, and if a match is found, uses the format
  50  * described in the instruction entry structure to complete the action.
  51  *
  52  * Eg. Suppose we have a Mips coprocessor "cop3" with data register "d2"
  53  * and we want to define function "pig" which takes two operands.
  54  *
  55  * Given the table entries:
  56  *      "p3 insn pig 0x1:24-21 dreg:20-16 immed:15-0"
  57  *      "p3 dreg d2 0x2"
  58  * and that the instruction encoding for coprocessor pz has encoding:
  59  *      #define MIPS_ENCODE_COP_NUM(z) ((0x21|(z<<1))<<25)
  60  *      #define ITBL_ENCODE_PNUM(pnum) MIPS_ENCODE_COP_NUM(pnum)
  61  *
  62  * a structure to describe the instruction might look something like:
  63  *      struct itbl_entry = {
  64  *      e_processor processor = e_p3
  65  *      e_type type = e_insn
  66  *      char *name = "pig"
  67  *      uint value = 0x1
  68  *      uint flags = 0
  69  *      struct itbl_range range = 24-21
  70  *      struct itbl_field *field = {
  71  *              e_type type = e_dreg
  72  *              struct itbl_range range = 20-16
  73  *              struct itbl_field *next = {
  74  *                      e_type type = e_immed
  75  *                      struct itbl_range range = 15-0
  76  *                      struct itbl_field *next = 0
  77  *                      };
  78  *              };
  79  *      struct itbl_entry *next = 0
  80  *      };
  81  *
  82  * And the assembler instructions:
  83  *      "pig d2,0x100"
  84  *      "pig $2,0x100"
  85  *
  86  * would both assemble to the hex value:
  87  *      "0x4e220100"
  88  *
  89  */
  90
  91 #include "as.h"
  92 #include "itbl-ops.h"
  93 #include <itbl-parse.h>
  94
  95 /* #define DEBUG */
  96
  97 #ifdef DEBUG
  98 #include <assert.h>
  99 #define ASSERT(x) gas_assert (x)
 100 #define DBG(x) printf x
 101 #else
 102 #define ASSERT(x)
 103 #define DBG(x)
 104 #endif
 105
 106 #ifndef min
 107 #define min(a,b) (a<b?a:b)
 108 #endif
 109
 110 int itbl_have_entries = 0;
 111
 112 /*======================================================================*/
 113 /* structures for keeping itbl format entries */
 114
 115 struct itbl_range {
 116   int sbit;                     /* mask starting bit position */
 117   int ebit;                     /* mask ending bit position */
 118 };
 119
 120 struct itbl_field {
 121   e_type type;                  /* dreg/creg/greg/immed/symb */
 122   struct itbl_range range;      /* field's bitfield range within instruction */
 123   unsigned long flags;          /* field flags */
 124   struct itbl_field *next;      /* next field in list */
 125 };
 126
 127 /* These structures define the instructions and registers for a processor.
 128  * If the type is an instruction, the structure defines the format of an
 129  * instruction where the fields are the list of operands.
 130  * The flags field below uses the same values as those defined in the
 131  * gnu assembler and are machine specific.  */
 132 struct itbl_entry {
 133   e_processor processor;        /* processor number */
 134   e_type type;                  /* dreg/creg/greg/insn */
 135   char *name;                   /* mnemonic name for insn/register */
 136   unsigned long value;          /* opcode/instruction mask/register number */
 137   unsigned long flags;          /* effects of the instruction */
 138   struct itbl_range range;      /* bit range within instruction for value */
 139   struct itbl_field *fields;    /* list of operand definitions (if any) */
 140   struct itbl_entry *next;      /* next entry */
 141 };
 142
 143 /* local data and structures */
 144
 145 static int itbl_num_opcodes = 0;
 146 /* Array of entries for each processor and entry type */
 147 static struct itbl_entry *entries[e_nprocs][e_ntypes];
 148
 149 /* local prototypes */
 150 static unsigned long build_opcode (struct itbl_entry *e);
 151 static e_type get_type (int yytype);
 152 static e_processor get_processor (int yyproc);
 153 static struct itbl_entry **get_entries (e_processor processor,
 154                                         e_type type);
 155 static struct itbl_entry *find_entry_byname (e_processor processor,
 156                                         e_type type, char *name);
 157 static struct itbl_entry *find_entry_byval (e_processor processor,
 158                         e_type type, unsigned long val, struct itbl_range *r);
 159 static struct itbl_entry *alloc_entry (e_processor processor,
 160                 e_type type, char *name, unsigned long value);
 161 static unsigned long apply_range (unsigned long value, struct itbl_range r);
 162 static unsigned long extract_range (unsigned long value, struct itbl_range r);
 163 static struct itbl_field *alloc_field (e_type type, int sbit,
 164                                         int ebit, unsigned long flags);
 165
 166 /*======================================================================*/
 167 /* Interfaces to the parser */
 168
 169 /* Open the table and use lex and yacc to parse the entries.
 170  * Return 1 for failure; 0 for success.  */
 171
 172 int
 173 itbl_parse (char *insntbl)
 174 {
 175   extern FILE *yyin;
 176   extern int yyparse (void);
 177
 178   yyin = fopen (insntbl, FOPEN_RT);
 179   if (yyin == 0)
 180     {
 181       printf ("Can't open processor instruction specification file \"%s\"\n",
 182               insntbl);
 183       return 1;
 184     }
 185
 186   while (yyparse ())
 187     ;
 188
 189   fclose (yyin);
 190   itbl_have_entries = 1;
 191   return 0;
 192 }
 193
 194 /* Add a register entry */
 195
 196 struct itbl_entry *
 197 itbl_add_reg (int yyprocessor, int yytype, char *regname,
 198               int regnum)
 199 {
 200   return alloc_entry (get_processor (yyprocessor), get_type (yytype), regname,
 201                       (unsigned long) regnum);
 202 }
 203
 204 /* Add an instruction entry */
 205
 206 struct itbl_entry *
 207 itbl_add_insn (int yyprocessor, char *name, unsigned long value,
 208                int sbit, int ebit, unsigned long flags)
 209 {
 210   struct itbl_entry *e;
 211   e = alloc_entry (get_processor (yyprocessor), e_insn, name, value);
 212   if (e)
 213     {
 214       e->range.sbit = sbit;
 215       e->range.ebit = ebit;
 216       e->flags = flags;
 217       itbl_num_opcodes++;
 218     }
 219   return e;
 220 }
 221
 222 /* Add an operand to an instruction entry */
 223
 224 struct itbl_field *
 225 itbl_add_operand (struct itbl_entry *e, int yytype, int sbit,
 226                   int ebit, unsigned long flags)
 227 {
 228   struct itbl_field *f, **last_f;
 229   if (!e)
 230     return 0;
 231   /* Add to end of fields' list.  */
 232   f = alloc_field (get_type (yytype), sbit, ebit, flags);
 233   if (f)
 234     {
 235       last_f = &e->fields;
 236       while (*last_f)
 237         last_f = &(*last_f)->next;
 238       *last_f = f;
 239       f->next = 0;
 240     }
 241   return f;
 242 }
 243
 244 /*======================================================================*/
 245 /* Interfaces for assembler and disassembler */
 246
 247 #ifndef STAND_ALONE
 248 static void append_insns_as_macros (void);
 249
 250 /* Initialize for gas.  */
 251
 252 void
 253 itbl_init (void)
 254 {
 255   struct itbl_entry *e, **es;
 256   e_processor procn;
 257   e_type type;
 258
 259   if (!itbl_have_entries)
 260     return;
 261
 262   /* Since register names don't have a prefix, put them in the symbol table so
 263      they can't be used as symbols.  This simplifies argument parsing as
 264      we can let gas parse registers for us.  */
 265   /* Use symbol_create instead of symbol_new so we don't try to
 266      output registers into the object file's symbol table.  */
 267
 268   for (type = e_regtype0; type < e_nregtypes; type++)
 269     for (procn = e_p0; procn < e_nprocs; procn++)
 270       {
 271         es = get_entries (procn, type);
 272         for (e = *es; e; e = e->next)
 273           {
 274             symbol_table_insert (symbol_create (e->name, reg_section,
 275                                                 &zero_address_frag, e->value));
 276           }
 277       }
 278   append_insns_as_macros ();
 279 }
 280
 281 /* Append insns to opcodes table and increase number of opcodes
 282  * Structure of opcodes table:
 283  * struct itbl_opcode
 284  * {
 285  *   const char *name;
 286  *   const char *args;          - string describing the arguments.
 287  *   unsigned long match;       - opcode, or ISA level if pinfo=INSN_MACRO
 288  *   unsigned long mask;        - opcode mask, or macro id if pinfo=INSN_MACRO
 289  *   unsigned long pinfo;       - insn flags, or INSN_MACRO
 290  * };
 291  * examples:
 292  *      {"li",      "t,i",  0x34000000, 0xffe00000, WR_t    },
 293  *      {"li",      "t,I",  0,    (int) M_LI,   INSN_MACRO  },
 294  */
 295
 296 static char *form_args (struct itbl_entry *e);
 297 static void
 298 append_insns_as_macros (void)
 299 {
 300   struct ITBL_OPCODE_STRUCT *new_opcodes, *o;
 301   struct itbl_entry *e, **es;
 302   int n, size, new_num_opcodes;
 303 #ifdef USE_MACROS
 304   int id;
 305 #endif
 306
 307   if (!itbl_have_entries)
 308     return;
 309
 310   if (!itbl_num_opcodes)        /* no new instructions to add! */
 311     {
 312       return;
 313     }
 314   DBG (("previous num_opcodes=%d\n", ITBL_NUM_OPCODES));
 315
 316   new_num_opcodes = ITBL_NUM_OPCODES + itbl_num_opcodes;
 317   ASSERT (new_num_opcodes >= itbl_num_opcodes);
 318
 319   size = sizeof (struct ITBL_OPCODE_STRUCT) * ITBL_NUM_OPCODES;
 320   ASSERT (size >= 0);
 321   DBG (("I get=%d\n", size / sizeof (ITBL_OPCODES[0])));
 322
 323   /* FIXME since ITBL_OPCODES could be a static table,
 324                 we can't realloc or delete the old memory.  */
 325   new_opcodes = XNEWVEC (struct ITBL_OPCODE_STRUCT, new_num_opcodes);
 326   if (!new_opcodes)
 327     {
 328       printf (_("Unable to allocate memory for new instructions\n"));
 329       return;
 330     }
 331   if (size)                     /* copy preexisting opcodes table */
 332     memcpy (new_opcodes, ITBL_OPCODES, size);
 333
 334   /* FIXME! some NUMOPCODES are calculated expressions.
 335                 These need to be changed before itbls can be supported.  */
 336
 337 #ifdef USE_MACROS
 338   id = ITBL_NUM_MACROS;         /* begin the next macro id after the last */
 339 #endif
 340   o = &new_opcodes[ITBL_NUM_OPCODES];   /* append macro to opcodes list */
 341   for (n = e_p0; n < e_nprocs; n++)
 342     {
 343       es = get_entries (n, e_insn);
 344       for (e = *es; e; e = e->next)
 345         {
 346           /* name,    args,   mask,       match,  pinfo
 347                  * {"li",      "t,i",  0x34000000, 0xffe00000, WR_t    },
 348                  * {"li",      "t,I",  0,    (int) M_LI,   INSN_MACRO  },
 349                  * Construct args from itbl_fields.
 350                 */
 351           o->name = e->name;
 352           o->args = strdup (form_args (e));
 353           o->mask = apply_range (e->value, e->range);
 354           /* FIXME how to catch during assembly? */
 355           /* mask to identify this insn */
 356           o->match = apply_range (e->value, e->range);
 357           o->pinfo = 0;
 358
 359 #ifdef USE_MACROS
 360           o->mask = id++;       /* FIXME how to catch during assembly? */
 361           o->match = 0;         /* for macros, the insn_isa number */
 362           o->pinfo = INSN_MACRO;
 363 #endif
 364
 365           /* Don't add instructions which caused an error */
 366           if (o->args)
 367             o++;
 368           else
 369             new_num_opcodes--;
 370         }
 371     }
 372   ITBL_OPCODES = new_opcodes;
 373   ITBL_NUM_OPCODES = new_num_opcodes;
 374
 375   /* FIXME
 376                 At this point, we can free the entries, as they should have
 377                 been added to the assembler's tables.
 378                 Don't free name though, since name is being used by the new
 379                 opcodes table.
 380
 381                 Eventually, we should also free the new opcodes table itself
 382                 on exit.
 383         */
 384 }
 385
 386 static char *
 387 form_args (struct itbl_entry *e)
 388 {
 389   static char s[31];
 390   char c = 0, *p = s;
 391   struct itbl_field *f;
 392
 393   ASSERT (e);
 394   for (f = e->fields; f; f = f->next)
 395     {
 396       switch (f->type)
 397         {
 398         case e_dreg:
 399           c = 'd';
 400           break;
 401         case e_creg:
 402           c = 't';
 403           break;
 404         case e_greg:
 405           c = 's';
 406           break;
 407         case e_immed:
 408           c = 'i';
 409           break;
 410         case e_addr:
 411           c = 'a';
 412           break;
 413         default:
 414           c = 0;                /* ignore; unknown field type */
 415         }
 416       if (c)
 417         {
 418           if (p != s)
 419             *p++ = ',';
 420           *p++ = c;
 421         }
 422     }
 423   *p = 0;
 424   return s;
 425 }
 426 #endif /* !STAND_ALONE */
 427
 428 /* Get processor's register name from val */
 429
 430 int
 431 itbl_get_reg_val (char *name, unsigned long *pval)
 432 {
 433   e_type t;
 434   e_processor p;
 435
 436   for (p = e_p0; p < e_nprocs; p++)
 437     {
 438       for (t = e_regtype0; t < e_nregtypes; t++)
 439         {
 440           if (itbl_get_val (p, t, name, pval))
 441             return 1;
 442         }
 443     }
 444   return 0;
 445 }
 446
 447 char *
 448 itbl_get_name (e_processor processor, e_type type, unsigned long val)
 449 {
 450   struct itbl_entry *r;
 451   /* type depends on instruction passed */
 452   r = find_entry_byval (processor, type, val, 0);
 453   if (r)
 454     return r->name;
 455   else
 456     return 0;                   /* error; invalid operand */
 457 }
 458
 459 /* Get processor's register value from name */
 460
 461 int
 462 itbl_get_val (e_processor processor, e_type type, char *name,
 463               unsigned long *pval)
 464 {
 465   struct itbl_entry *r;
 466   /* type depends on instruction passed */
 467   r = find_entry_byname (processor, type, name);
 468   if (r == NULL)
 469     return 0;
 470   *pval = r->value;
 471   return 1;
 472 }
 473
 474 /* Assemble instruction "name" with operands "s".
 475  * name - name of instruction
 476  * s - operands
 477  * returns - long word for assembled instruction */
 478
 479 unsigned long
 480 itbl_assemble (char *name, char *s)
 481 {
 482   unsigned long opcode;
 483   struct itbl_entry *e = NULL;
 484   struct itbl_field *f;
 485   char *n;
 486   int processor;
 487
 488   if (!name || !*name)
 489     return 0;                   /* error!  must have an opcode name/expr */
 490
 491   /* find entry in list of instructions for all processors */
 492   for (processor = 0; processor < e_nprocs; processor++)
 493     {
 494       e = find_entry_byname (processor, e_insn, name);
 495       if (e)
 496         break;
 497     }
 498   if (!e)
 499     return 0;                   /* opcode not in table; invalid instruction */
 500   opcode = build_opcode (e);
 501
 502   /* parse opcode's args (if any) */
 503   for (f = e->fields; f; f = f->next)   /* for each arg, ...  */
 504     {
 505       struct itbl_entry *r;
 506       unsigned long value;
 507       if (!s || !*s)
 508         return 0;               /* error - not enough operands */
 509       n = itbl_get_field (&s);
 510       /* n should be in form $n or 0xhhh (are symbol names valid?? */
 511       switch (f->type)
 512         {
 513         case e_dreg:
 514         case e_creg:
 515         case e_greg:
 516           /* Accept either a string name
 517                          * or '$' followed by the register number */
 518           if (*n == '$')
 519             {
 520               n++;
 521               value = strtol (n, 0, 10);
 522               /* FIXME! could have "0l"... then what?? */
 523               if (value == 0 && *n != '0')
 524                 return 0;       /* error; invalid operand */
 525             }
 526           else
 527             {
 528               r = find_entry_byname (e->processor, f->type, n);
 529               if (r)
 530                 value = r->value;
 531               else
 532                 return 0;       /* error; invalid operand */
 533             }
 534           break;
 535         case e_addr:
 536           /* use assembler's symbol table to find symbol */
 537           /* FIXME!! Do we need this?
 538                                 if so, what about relocs??
 539                                 my_getExpression (&imm_expr, s);
 540                                 return 0;       /-* error; invalid operand *-/
 541                                 break;
 542                         */
 543           /* If not a symbol, fallthru to IMMED */
 544         case e_immed:
 545           if (*n == '0' && *(n + 1) == 'x')     /* hex begins 0x...  */
 546             {
 547               n += 2;
 548               value = strtol (n, 0, 16);
 549               /* FIXME! could have "0xl"... then what?? */
 550             }
 551           else
 552             {
 553               value = strtol (n, 0, 10);
 554               /* FIXME! could have "0l"... then what?? */
 555               if (value == 0 && *n != '0')
 556                 return 0;       /* error; invalid operand */
 557             }
 558           break;
 559         default:
 560           return 0;             /* error; invalid field spec */
 561         }
 562       opcode |= apply_range (value, f->range);
 563     }
 564   if (s && *s)
 565     return 0;                   /* error - too many operands */
 566   return opcode;                /* done! */
 567 }
 568
 569 /* Disassemble instruction "insn".
 570  * insn - instruction
 571  * s - buffer to hold disassembled instruction
 572  * returns - 1 if succeeded; 0 if failed
 573  */
 574
 575 int
 576 itbl_disassemble (char *s, unsigned long insn)
 577 {
 578   e_processor processor;
 579   struct itbl_entry *e;
 580   struct itbl_field *f;
 581
 582   if (!ITBL_IS_INSN (insn))
 583     return 0;                   /* error */
 584   processor = get_processor (ITBL_DECODE_PNUM (insn));
 585
 586   /* find entry in list */
 587   e = find_entry_byval (processor, e_insn, insn, 0);
 588   if (!e)
 589     return 0;                   /* opcode not in table; invalid instruction */
 590   strcpy (s, e->name);
 591
 592   /* Parse insn's args (if any).  */
 593   for (f = e->fields; f; f = f->next)   /* for each arg, ...  */
 594     {
 595       struct itbl_entry *r;
 596       unsigned long value;
 597       char s_value[20];
 598
 599       if (f == e->fields)       /* First operand is preceded by tab.  */
 600         strcat (s, "\t");
 601       else                      /* ','s separate following operands.  */
 602         strcat (s, ",");
 603       value = extract_range (insn, f->range);
 604       /* n should be in form $n or 0xhhh (are symbol names valid?? */
 605       switch (f->type)
 606         {
 607         case e_dreg:
 608         case e_creg:
 609         case e_greg:
 610           /* Accept either a string name
 611              or '$' followed by the register number.  */
 612           r = find_entry_byval (e->processor, f->type, value, &f->range);
 613           if (r)
 614             strcat (s, r->name);
 615           else
 616             {
 617               sprintf (s_value, "$%lu", value);
 618               strcat (s, s_value);
 619             }
 620           break;
 621         case e_addr:
 622           /* Use assembler's symbol table to find symbol.  */
 623           /* FIXME!! Do we need this?  If so, what about relocs??  */
 624           /* If not a symbol, fall through to IMMED.  */
 625         case e_immed:
 626           sprintf (s_value, "0x%lx", value);
 627           strcat (s, s_value);
 628           break;
 629         default:
 630           return 0;             /* error; invalid field spec */
 631         }
 632     }
 633   return 1;                     /* Done!  */
 634 }
 635
 636 /*======================================================================*/
 637 /*
 638  * Local functions for manipulating private structures containing
 639  * the names and format for the new instructions and registers
 640  * for each processor.
 641  */
 642
 643 /* Calculate instruction's opcode and function values from entry */
 644
 645 static unsigned long
 646 build_opcode (struct itbl_entry *e)
 647 {
 648   unsigned long opcode;
 649
 650   opcode = apply_range (e->value, e->range);
 651   opcode |= ITBL_ENCODE_PNUM (e->processor);
 652   return opcode;
 653 }
 654
 655 /* Calculate absolute value given the relative value and bit position range
 656  * within the instruction.
 657  * The range is inclusive where 0 is least significant bit.
 658  * A range of { 24, 20 } will have a mask of
 659  * bit   3           2            1
 660  * pos: 1098 7654 3210 9876 5432 1098 7654 3210
 661  * bin: 0000 0001 1111 0000 0000 0000 0000 0000
 662  * hex:    0    1    f    0    0    0    0    0
 663  * mask: 0x01f00000.
 664  */
 665
 666 static unsigned long
 667 apply_range (unsigned long rval, struct itbl_range r)
 668 {
 669   unsigned long mask;
 670   unsigned long aval;
 671   int len = MAX_BITPOS - r.sbit;
 672
 673   ASSERT (r.sbit >= r.ebit);
 674   ASSERT (MAX_BITPOS >= r.sbit);
 675   ASSERT (r.ebit >= 0);
 676
 677   /* create mask by truncating 1s by shifting */
 678   mask = 0xffffffff << len;
 679   mask = mask >> len;
 680   mask = mask >> r.ebit;
 681   mask = mask << r.ebit;
 682
 683   aval = (rval << r.ebit) & mask;
 684   return aval;
 685 }
 686
 687 /* Calculate relative value given the absolute value and bit position range
 688  * within the instruction.  */
 689
 690 static unsigned long
 691 extract_range (unsigned long aval, struct itbl_range r)
 692 {
 693   unsigned long mask;
 694   unsigned long rval;
 695   int len = MAX_BITPOS - r.sbit;
 696
 697   /* create mask by truncating 1s by shifting */
 698   mask = 0xffffffff << len;
 699   mask = mask >> len;
 700   mask = mask >> r.ebit;
 701   mask = mask << r.ebit;
 702
 703   rval = (aval & mask) >> r.ebit;
 704   return rval;
 705 }
 706
 707 /* Extract processor's assembly instruction field name from s;
 708  * forms are "n args" "n,args" or "n" */
 709 /* Return next argument from string pointer "s" and advance s.
 710  * delimiters are " ,()" */
 711
 712 char *
 713 itbl_get_field (char **S)
 714 {
 715   static char n[128];
 716   char *s;
 717   int len;
 718
 719   s = *S;
 720   if (!s || !*s)
 721     return 0;
 722   /* FIXME: This is a weird set of delimiters.  */
 723   len = strcspn (s, " \t,()");
 724   ASSERT (128 > len + 1);
 725   strncpy (n, s, len);
 726   n[len] = 0;
 727   if (s[len] == '\0')
 728     s = 0;                      /* no more args */
 729   else
 730     s += len + 1;               /* advance to next arg */
 731
 732   *S = s;
 733   return n;
 734 }
 735
 736 /* Search entries for a given processor and type
 737  * to find one matching the name "n".
 738  * Return a pointer to the entry */
 739
 740 static struct itbl_entry *
 741 find_entry_byname (e_processor processor,
 742                    e_type type, char *n)
 743 {
 744   struct itbl_entry *e, **es;
 745
 746   es = get_entries (processor, type);
 747   for (e = *es; e; e = e->next) /* for each entry, ...  */
 748     {
 749       if (!strcmp (e->name, n))
 750         return e;
 751     }
 752   return 0;
 753 }
 754
 755 /* Search entries for a given processor and type
 756  * to find one matching the value "val" for the range "r".
 757  * Return a pointer to the entry.
 758  * This function is used for disassembling fields of an instruction.
 759  */
 760
 761 static struct itbl_entry *
 762 find_entry_byval (e_processor processor, e_type type,
 763                   unsigned long val, struct itbl_range *r)
 764 {
 765   struct itbl_entry *e, **es;
 766   unsigned long eval;
 767
 768   es = get_entries (processor, type);
 769   for (e = *es; e; e = e->next) /* for each entry, ...  */
 770     {
 771       if (processor != e->processor)
 772         continue;
 773       /* For insns, we might not know the range of the opcode,
 774          * so a range of 0 will allow this routine to match against
 775          * the range of the entry to be compared with.
 776          * This could cause ambiguities.
 777          * For operands, we get an extracted value and a range.
 778          */
 779       /* if range is 0, mask val against the range of the compared entry.  */
 780       if (r == 0)               /* if no range passed, must be whole 32-bits
 781                          * so create 32-bit value from entry's range */
 782         {
 783           eval = apply_range (e->value, e->range);
 784           val &= apply_range (0xffffffff, e->range);
 785         }
 786       else if ((r->sbit == e->range.sbit && r->ebit == e->range.ebit)
 787                || (e->range.sbit == 0 && e->range.ebit == 0))
 788         {
 789           eval = apply_range (e->value, *r);
 790           val = apply_range (val, *r);
 791         }
 792       else
 793         continue;
 794       if (val == eval)
 795         return e;
 796     }
 797   return 0;
 798 }
 799
 800 /* Return a pointer to the list of entries for a given processor and type.  */
 801
 802 static struct itbl_entry **
 803 get_entries (e_processor processor, e_type type)
 804 {
 805   return &entries[processor][type];
 806 }
 807
 808 /* Return an integral value for the processor passed from yyparse.  */
 809
 810 static e_processor
 811 get_processor (int yyproc)
 812 {
 813   /* translate from yacc's processor to enum */
 814   if (yyproc >= e_p0 && yyproc < e_nprocs)
 815     return (e_processor) yyproc;
 816   return e_invproc;             /* error; invalid processor */
 817 }
 818
 819 /* Return an integral value for the entry type passed from yyparse.  */
 820
 821 static e_type
 822 get_type (int yytype)
 823 {
 824   switch (yytype)
 825     {
 826       /* translate from yacc's type to enum */
 827     case INSN:
 828       return e_insn;
 829     case DREG:
 830       return e_dreg;
 831     case CREG:
 832       return e_creg;
 833     case GREG:
 834       return e_greg;
 835     case ADDR:
 836       return e_addr;
 837     case IMMED:
 838       return e_immed;
 839     default:
 840       return e_invtype;         /* error; invalid type */
 841     }
 842 }
 843
 844 /* Allocate and initialize an entry */
 845
 846 static struct itbl_entry *
 847 alloc_entry (e_processor processor, e_type type,
 848              char *name, unsigned long value)
 849 {
 850   struct itbl_entry *e, **es;
 851   if (!name)
 852     return 0;
 853   e = XNEW (struct itbl_entry);
 854   if (e)
 855     {
 856       memset (e, 0, sizeof (struct itbl_entry));
 857       e->name = xstrdup (name);
 858       e->processor = processor;
 859       e->type = type;
 860       e->value = value;
 861       es = get_entries (e->processor, e->type);
 862       e->next = *es;
 863       *es = e;
 864     }
 865   return e;
 866 }
 867
 868 /* Allocate and initialize an entry's field */
 869
 870 static struct itbl_field *
 871 alloc_field (e_type type, int sbit, int ebit,
 872              unsigned long flags)
 873 {
 874   struct itbl_field *f;
 875   f = XNEW (struct itbl_field);
 876   if (f)
 877     {
 878       memset (f, 0, sizeof (struct itbl_field));
 879       f->type = type;
 880       f->range.sbit = sbit;
 881       f->range.ebit = ebit;
 882       f->flags = flags;
 883     }
 884   return f;
 885 }