gcc/genextract.c

   1 /* Generate code from machine description to extract operands from insn as rtl.
   2    Copyright (C) 1987, 91, 92, 93, 97, 1998 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC 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 2, or (at your option)
   9 any later version.
  10
  11 GNU CC 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 GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21
  22 #include "hconfig.h"
  23 #include "system.h"
  24 #include "rtl.h"
  25 #include "obstack.h"
  26 #include "insn-config.h"
  27
  28 static struct obstack obstack;
  29 struct obstack *rtl_obstack = &obstack;
  30
  31 #define obstack_chunk_alloc xmalloc
  32 #define obstack_chunk_free free
  33
  34 /* Names for patterns.  Need to allow linking with print-rtl.  */
  35 char **insn_name_ptr;
  36
  37 /* This structure contains all the information needed to describe one
  38    set of extractions methods.  Each method may be used by more than
  39    one pattern if the operands are in the same place.
  40
  41    The string for each operand describes that path to the operand and
  42    contains `0' through `9' when going into an expression and `a' through
  43    `z' when going into a vector.  We assume here that only the first operand
  44    of an rtl expression is a vector.  genrecog.c makes the same assumption
  45    (and uses the same representation) and it is currently true.  */
  46
  47 struct extraction
  48 {
  49   int op_count;
  50   char *oplocs[MAX_RECOG_OPERANDS];
  51   int dup_count;
  52   char *duplocs[MAX_DUP_OPERANDS];
  53   int dupnums[MAX_DUP_OPERANDS];
  54   struct code_ptr *insns;
  55   struct extraction *next;
  56 };
  57
  58 /* Holds a single insn code that use an extraction method.  */
  59
  60 struct code_ptr
  61 {
  62   int insn_code;
  63   struct code_ptr *next;
  64 };
  65
  66 static struct extraction *extractions;
  67
  68 /* Number instruction patterns handled, starting at 0 for first one.  */
  69
  70 static int insn_code_number;
  71
  72 /* Records the large operand number in this insn.  */
  73
  74 static int op_count;
  75
  76 /* Records the location of any operands using the string format described
  77    above.  */
  78
  79 static char *oplocs[MAX_RECOG_OPERANDS];
  80
  81 /* Number the occurrences of MATCH_DUP in each instruction,
  82    starting at 0 for the first occurrence.  */
  83
  84 static int dup_count;
  85
  86 /* Records the location of any MATCH_DUP operands.  */
  87
  88 static char *duplocs[MAX_DUP_OPERANDS];
  89
  90 /* Record the operand number of any MATCH_DUPs.  */
  91
  92 static int dupnums[MAX_DUP_OPERANDS];
  93
  94 /* Record the list of insn_codes for peepholes.  */
  95
  96 static struct code_ptr *peepholes;
  97
  98 static void walk_rtx PROTO ((rtx, char *));
  99 static void print_path PROTO ((char *));
 100 char *xmalloc PROTO ((unsigned));
 101 char *xrealloc PROTO ((char *, unsigned));
 102 static void fatal ();
 103 static char *copystr PROTO ((char *));
 104 static void mybzero ();
 105 void fancy_abort PROTO ((void));
 106 \f
 107 static void
 108 gen_insn (insn)
 109      rtx insn;
 110 {
 111   register int i;
 112   register struct extraction *p;
 113   register struct code_ptr *link;
 114
 115   op_count = 0;
 116   dup_count = 0;
 117
 118   /* No operands seen so far in this pattern.  */
 119   mybzero (oplocs, sizeof oplocs);
 120
 121   /* Walk the insn's pattern, remembering at all times the path
 122      down to the walking point.  */
 123
 124   if (XVECLEN (insn, 1) == 1)
 125     walk_rtx (XVECEXP (insn, 1, 0), "");
 126   else
 127     for (i = XVECLEN (insn, 1) - 1; i >= 0; i--)
 128       {
 129         char *path = (char *) alloca (2);
 130
 131         path[0] = 'a' + i;
 132         path[1] = 0;
 133
 134         walk_rtx (XVECEXP (insn, 1, i), path);
 135       }
 136
 137   link = (struct code_ptr *) xmalloc (sizeof (struct code_ptr));
 138   link->insn_code = insn_code_number;
 139
 140   /* See if we find something that already had this extraction method.  */
 141
 142   for (p = extractions; p; p = p->next)
 143     {
 144       if (p->op_count != op_count || p->dup_count != dup_count)
 145         continue;
 146
 147       for (i = 0; i < op_count; i++)
 148         if (p->oplocs[i] != oplocs[i]
 149             && ! (p->oplocs[i] != 0 && oplocs[i] != 0
 150                   && ! strcmp (p->oplocs[i], oplocs[i])))
 151           break;
 152
 153       if (i != op_count)
 154         continue;
 155
 156       for (i = 0; i < dup_count; i++)
 157         if (p->dupnums[i] != dupnums[i]
 158             || strcmp (p->duplocs[i], duplocs[i]))
 159           break;
 160
 161       if (i != dup_count)
 162         continue;
 163
 164       /* This extraction is the same as ours.  Just link us in.  */
 165       link->next = p->insns;
 166       p->insns = link;
 167       return;
 168     }
 169
 170   /* Otherwise, make a new extraction method.  */
 171
 172   p = (struct extraction *) xmalloc (sizeof (struct extraction));
 173   p->op_count = op_count;
 174   p->dup_count = dup_count;
 175   p->next = extractions;
 176   extractions = p;
 177   p->insns = link;
 178   link->next = 0;
 179
 180   for (i = 0; i < op_count; i++)
 181     p->oplocs[i] = oplocs[i];
 182
 183   for (i = 0; i < dup_count; i++)
 184     p->dupnums[i] = dupnums[i], p->duplocs[i] = duplocs[i];
 185 }
 186 \f
 187 static void
 188 walk_rtx (x, path)
 189      rtx x;
 190      char *path;
 191 {
 192   register RTX_CODE code;
 193   register int i;
 194   register int len;
 195   register char *fmt;
 196   int depth = strlen (path);
 197   char *newpath;
 198
 199   if (x == 0)
 200     return;
 201
 202   code = GET_CODE (x);
 203
 204   switch (code)
 205     {
 206     case PC:
 207     case CC0:
 208     case CONST_INT:
 209     case SYMBOL_REF:
 210       return;
 211
 212     case MATCH_OPERAND:
 213     case MATCH_SCRATCH:
 214       oplocs[XINT (x, 0)] = copystr (path);
 215       op_count = MAX (op_count, XINT (x, 0) + 1);
 216       break;
 217
 218     case MATCH_DUP:
 219     case MATCH_PAR_DUP:
 220       duplocs[dup_count] = copystr (path);
 221       dupnums[dup_count] = XINT (x, 0);
 222       dup_count++;
 223       break;
 224
 225     case MATCH_OP_DUP:
 226       duplocs[dup_count] = copystr (path);
 227       dupnums[dup_count] = XINT (x, 0);
 228       dup_count++;
 229
 230       newpath = (char *) alloca (depth + 2);
 231       strcpy (newpath, path);
 232       newpath[depth + 1] = 0;
 233
 234       for (i = XVECLEN (x, 1) - 1; i >= 0; i--)
 235         {
 236           newpath[depth] = '0' + i;
 237           walk_rtx (XVECEXP (x, 1, i), newpath);
 238         }
 239       return;
 240
 241     case MATCH_OPERATOR:
 242       oplocs[XINT (x, 0)] = copystr (path);
 243       op_count = MAX (op_count, XINT (x, 0) + 1);
 244
 245       newpath = (char *) alloca (depth + 2);
 246       strcpy (newpath, path);
 247       newpath[depth + 1] = 0;
 248
 249       for (i = XVECLEN (x, 2) - 1; i >= 0; i--)
 250         {
 251           newpath[depth] = '0' + i;
 252           walk_rtx (XVECEXP (x, 2, i), newpath);
 253         }
 254       return;
 255
 256     case MATCH_PARALLEL:
 257       oplocs[XINT (x, 0)] = copystr (path);
 258       op_count = MAX (op_count, XINT (x, 0) + 1);
 259
 260       newpath = (char *) alloca (depth + 2);
 261       strcpy (newpath, path);
 262       newpath[depth + 1] = 0;
 263
 264       for (i = XVECLEN (x, 2) - 1; i >= 0; i--)
 265         {
 266           newpath[depth] = 'a' + i;
 267           walk_rtx (XVECEXP (x, 2, i), newpath);
 268         }
 269       return;
 270
 271     case ADDRESS:
 272       walk_rtx (XEXP (x, 0), path);
 273       return;
 274
 275     default:
 276       break;
 277     }
 278
 279   newpath = (char *) alloca (depth + 2);
 280   strcpy (newpath, path);
 281   newpath[depth + 1] = 0;
 282
 283   fmt = GET_RTX_FORMAT (code);
 284   len = GET_RTX_LENGTH (code);
 285   for (i = 0; i < len; i++)
 286     {
 287       if (fmt[i] == 'e' || fmt[i] == 'u')
 288         {
 289           newpath[depth] = '0' + i;
 290           walk_rtx (XEXP (x, i), newpath);
 291         }
 292       else if (fmt[i] == 'E')
 293         {
 294           int j;
 295           for (j = XVECLEN (x, i) - 1; j >= 0; j--)
 296             {
 297               newpath[depth] = 'a' + j;
 298               walk_rtx (XVECEXP (x, i, j), newpath);
 299             }
 300         }
 301     }
 302 }
 303
 304 /* Given a PATH, representing a path down the instruction's
 305    pattern from the root to a certain point, output code to
 306    evaluate to the rtx at that point.  */
 307
 308 static void
 309 print_path (path)
 310      char *path;
 311 {
 312   register int len = strlen (path);
 313   register int i;
 314
 315   /* We first write out the operations (XEXP or XVECEXP) in reverse
 316      order, then write "insn", then the indices in forward order.  */
 317
 318   for (i = len - 1; i >=0 ; i--)
 319     {
 320       if (path[i] >= 'a' && path[i] <= 'z')
 321         printf ("XVECEXP (");
 322       else if (path[i] >= '0' && path[i] <= '9')
 323         printf ("XEXP (");
 324       else
 325         abort ();
 326     }
 327
 328   printf ("pat");
 329
 330   for (i = 0; i < len; i++)
 331     {
 332       if (path[i] >= 'a' && path[i] <= 'z')
 333         printf (", 0, %d)", path[i] - 'a');
 334       else if (path[i] >= '0' && path[i] <= '9')
 335         printf (", %d)", path[i] - '0');
 336       else
 337         abort ();
 338     }
 339 }
 340 \f
 341 char *
 342 xmalloc (size)
 343      unsigned size;
 344 {
 345   register char *val = (char *) malloc (size);
 346
 347   if (val == 0)
 348     fatal ("virtual memory exhausted");
 349   return val;
 350 }
 351
 352 char *
 353 xrealloc (ptr, size)
 354      char *ptr;
 355      unsigned size;
 356 {
 357   char *result = (char *) realloc (ptr, size);
 358   if (!result)
 359     fatal ("virtual memory exhausted");
 360   return result;
 361 }
 362
 363 static void
 364 fatal (s, a1, a2)
 365      char *s;
 366 {
 367   fprintf (stderr, "genextract: ");
 368   fprintf (stderr, s, a1, a2);
 369   fprintf (stderr, "\n");
 370   exit (FATAL_EXIT_CODE);
 371 }
 372
 373 /* More 'friendly' abort that prints the line and file.
 374    config.h can #define abort fancy_abort if you like that sort of thing.  */
 375
 376 void
 377 fancy_abort ()
 378 {
 379   fatal ("Internal gcc abort.");
 380 }
 381
 382 static char *
 383 copystr (s1)
 384      char *s1;
 385 {
 386   register char *tem;
 387
 388   if (s1 == 0)
 389     return 0;
 390
 391   tem = (char *) xmalloc (strlen (s1) + 1);
 392   strcpy (tem, s1);
 393
 394   return tem;
 395 }
 396
 397 static void
 398 mybzero (b, length)
 399      register char *b;
 400      register unsigned length;
 401 {
 402   while (length-- > 0)
 403     *b++ = 0;
 404 }
 405 \f
 406 int
 407 main (argc, argv)
 408      int argc;
 409      char **argv;
 410 {
 411   rtx desc;
 412   FILE *infile;
 413   register int c, i;
 414   struct extraction *p;
 415   struct code_ptr *link;
 416
 417   obstack_init (rtl_obstack);
 418
 419   if (argc <= 1)
 420     fatal ("No input file name.");
 421
 422   infile = fopen (argv[1], "r");
 423   if (infile == 0)
 424     {
 425       perror (argv[1]);
 426       exit (FATAL_EXIT_CODE);
 427     }
 428
 429   init_rtl ();
 430
 431   /* Assign sequential codes to all entries in the machine description
 432      in parallel with the tables in insn-output.c.  */
 433
 434   insn_code_number = 0;
 435
 436   printf ("/* Generated automatically by the program `genextract'\n\
 437 from the machine description file `md'.  */\n\n");
 438
 439   printf ("#include \"config.h\"\n");
 440   printf ("#include <stdio.h>\n");
 441   printf ("#include \"rtl.h\"\n\n");
 442
 443   /* This variable exists only so it can be the "location"
 444      of any missing operand whose numbers are skipped by a given pattern.  */
 445   printf ("static rtx junk;\n");
 446
 447   printf ("extern rtx recog_operand[];\n");
 448   printf ("extern rtx *recog_operand_loc[];\n");
 449   printf ("extern rtx *recog_dup_loc[];\n");
 450   printf ("extern char recog_dup_num[];\n");
 451
 452   printf ("void\ninsn_extract (insn)\n");
 453   printf ("     rtx insn;\n");
 454   printf ("{\n");
 455   printf ("  register rtx *ro = recog_operand;\n");
 456   printf ("  register rtx **ro_loc = recog_operand_loc;\n");
 457   printf ("  rtx pat = PATTERN (insn);\n");
 458   printf ("  int i;\n\n");
 459   printf ("  switch (INSN_CODE (insn))\n");
 460   printf ("    {\n");
 461   printf ("    case -1:\n");
 462   printf ("      fatal_insn_not_found (insn);\n\n");
 463
 464   /* Read the machine description.  */
 465
 466   while (1)
 467     {
 468       c = read_skip_spaces (infile);
 469       if (c == EOF)
 470         break;
 471       ungetc (c, infile);
 472
 473       desc = read_rtx (infile);
 474       if (GET_CODE (desc) == DEFINE_INSN)
 475         {
 476           gen_insn (desc);
 477           ++insn_code_number;
 478         }
 479
 480       else if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 481         {
 482           struct code_ptr *link
 483             = (struct code_ptr *) xmalloc (sizeof (struct code_ptr));
 484
 485           link->insn_code = insn_code_number;
 486           link->next = peepholes;
 487           peepholes = link;
 488           ++insn_code_number;
 489         }
 490
 491       else if (GET_CODE (desc) == DEFINE_EXPAND
 492                || GET_CODE (desc) == DEFINE_SPLIT)
 493         ++insn_code_number;
 494     }
 495
 496   /* Write out code to handle peepholes and the insn_codes that it should
 497      be called for.  */
 498   if (peepholes)
 499     {
 500       for (link = peepholes; link; link = link->next)
 501         printf ("    case %d:\n", link->insn_code);
 502
 503       /* The vector in the insn says how many operands it has.
 504          And all it contains are operands.  In fact, the vector was
 505          created just for the sake of this function.  */
 506       printf ("      for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)\n");
 507       printf ("          ro[i] = XVECEXP (pat, 0, i);\n");
 508       printf ("      break;\n\n");
 509     }
 510
 511   /* Write out all the ways to extract insn operands.  */
 512   for (p = extractions; p; p = p->next)
 513     {
 514       for (link = p->insns; link; link = link->next)
 515         printf ("    case %d:\n", link->insn_code);
 516
 517       for (i = 0; i < p->op_count; i++)
 518         {
 519           if (p->oplocs[i] == 0)
 520             {
 521               printf ("      ro[%d] = const0_rtx;\n", i);
 522               printf ("      ro_loc[%d] = &junk;\n", i);
 523             }
 524           else
 525             {
 526               printf ("      ro[%d] = *(ro_loc[%d] = &", i, i);
 527               print_path (p->oplocs[i]);
 528               printf (");\n");
 529             }
 530         }
 531
 532       for (i = 0; i < p->dup_count; i++)
 533         {
 534           printf ("      recog_dup_loc[%d] = &", i);
 535           print_path (p->duplocs[i]);
 536           printf (";\n");
 537           printf ("      recog_dup_num[%d] = %d;\n", i, p->dupnums[i]);
 538         }
 539
 540       printf ("      break;\n\n");
 541     }
 542
 543   /* This should never be reached.  Note that we would also reach this abort
 544    if we tried to extract something whose INSN_CODE was a DEFINE_EXPAND or
 545    DEFINE_SPLIT, but that is correct.  */
 546   printf ("    default:\n      abort ();\n");
 547
 548   printf ("    }\n}\n");
 549
 550   fflush (stdout);
 551   exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 552   /* NOTREACHED */
 553   return 0;
 554 }