gcc/genextract.c

   1 /* Generate code from machine description to extract operands from insn as rtl.
   2    Copyright (C) 1987, 1991, 1992, 1993, 1997, 1998, 1999, 2000, 2003,
   3    2004, 2005
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 2, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING.  If not, write to the Free
  20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  21 02110-1301, USA.  */
  22
  23
  24 #include "bconfig.h"
  25 #include "system.h"
  26 #include "coretypes.h"
  27 #include "tm.h"
  28 #include "rtl.h"
  29 #include "errors.h"
  30 #include "gensupport.h"
  31 #include "vec.h"
  32
  33 /* This structure contains all the information needed to describe one
  34    set of extractions methods.  Each method may be used by more than
  35    one pattern if the operands are in the same place.
  36
  37    The string for each operand describes that path to the operand and
  38    contains `0' through `9' when going into an expression and `a' through
  39    `z' when going into a vector.  We assume here that only the first operand
  40    of an rtl expression is a vector.  genrecog.c makes the same assumption
  41    (and uses the same representation) and it is currently true.  */
  42
  43 typedef char *locstr;
  44
  45 struct extraction
  46 {
  47   unsigned int op_count;
  48   unsigned int dup_count;
  49   locstr *oplocs;
  50   locstr *duplocs;
  51   int *dupnums;
  52   struct code_ptr *insns;
  53   struct extraction *next;
  54 };
  55
  56 /* Holds a single insn code that uses an extraction method.  */
  57 struct code_ptr
  58 {
  59   int insn_code;
  60   struct code_ptr *next;
  61 };
  62
  63 /* All extractions needed for this machine description.  */
  64 static struct extraction *extractions;
  65
  66 /* All insn codes for old-style peepholes.  */
  67 static struct code_ptr *peepholes;
  68
  69 /* This structure is used by gen_insn and walk_rtx to accumulate the
  70    data that will be used to produce an extractions structure.  */
  71
  72 DEF_VEC_I(int);
  73 DEF_VEC_I(char);
  74 DEF_VEC_P(locstr);
  75 DEF_VEC_ALLOC_I(int,heap);
  76 DEF_VEC_ALLOC_I(char,heap);
  77 DEF_VEC_ALLOC_P(locstr,heap);
  78
  79 struct accum_extract
  80 {
  81   VEC(locstr,heap) *oplocs;
  82   VEC(locstr,heap) *duplocs;
  83   VEC(int,heap)    *dupnums;
  84   VEC(char,heap)   *pathstr;
  85 };
  86
  87 /* Forward declarations.  */
  88 static void walk_rtx (rtx, struct accum_extract *);
  89
  90 static void
  91 gen_insn (rtx insn, int insn_code_number)
  92 {
  93   int i;
  94   unsigned int op_count, dup_count, j;
  95   struct extraction *p;
  96   struct code_ptr *link;
  97   struct accum_extract acc;
  98
  99   acc.oplocs  = VEC_alloc (locstr,heap, 10);
 100   acc.duplocs = VEC_alloc (locstr,heap, 10);
 101   acc.dupnums = VEC_alloc (int,heap,    10);
 102   acc.pathstr = VEC_alloc (char,heap,   20);
 103
 104   /* Walk the insn's pattern, remembering at all times the path
 105      down to the walking point.  */
 106
 107   if (XVECLEN (insn, 1) == 1)
 108     walk_rtx (XVECEXP (insn, 1, 0), &acc);
 109   else
 110     for (i = XVECLEN (insn, 1) - 1; i >= 0; i--)
 111       {
 112         VEC_safe_push (char,heap, acc.pathstr, 'a' + i);
 113         walk_rtx (XVECEXP (insn, 1, i), &acc);
 114         VEC_pop (char, acc.pathstr);
 115       }
 116
 117   link = XNEW (struct code_ptr);
 118   link->insn_code = insn_code_number;
 119
 120   /* See if we find something that already had this extraction method.  */
 121
 122   op_count = VEC_length (locstr, acc.oplocs);
 123   dup_count = VEC_length (locstr, acc.duplocs);
 124   gcc_assert (dup_count == VEC_length (int, acc.dupnums));
 125
 126   for (p = extractions; p; p = p->next)
 127     {
 128       if (p->op_count != op_count || p->dup_count != dup_count)
 129         continue;
 130
 131       for (j = 0; j < op_count; j++)
 132         {
 133           char *a = p->oplocs[j];
 134           char *b = VEC_index (locstr, acc.oplocs, j);
 135           if (a != b && (!a || !b || strcmp (a, b)))
 136             break;
 137         }
 138
 139       if (j != op_count)
 140         continue;
 141
 142       for (j = 0; j < dup_count; j++)
 143         if (p->dupnums[j] != VEC_index (int, acc.dupnums, j)
 144             || strcmp (p->duplocs[j], VEC_index (locstr, acc.duplocs, j)))
 145           break;
 146
 147       if (j != dup_count)
 148         continue;
 149
 150       /* This extraction is the same as ours.  Just link us in.  */
 151       link->next = p->insns;
 152       p->insns = link;
 153       goto done;
 154     }
 155
 156   /* Otherwise, make a new extraction method.  We stash the arrays
 157      after the extraction structure in memory.  */
 158
 159   p = xmalloc (sizeof (struct extraction)
 160                + op_count*sizeof (char *)
 161                + dup_count*sizeof (char *)
 162                + dup_count*sizeof (int));
 163   p->op_count = op_count;
 164   p->dup_count = dup_count;
 165   p->next = extractions;
 166   extractions = p;
 167   p->insns = link;
 168   link->next = 0;
 169
 170   p->oplocs = (char **)((char *)p + sizeof (struct extraction));
 171   p->duplocs = p->oplocs + op_count;
 172   p->dupnums = (int *)(p->duplocs + dup_count);
 173
 174   memcpy(p->oplocs,  VEC_address(locstr,acc.oplocs),   op_count*sizeof(locstr));
 175   memcpy(p->duplocs, VEC_address(locstr,acc.duplocs), dup_count*sizeof(locstr));
 176   memcpy(p->dupnums, VEC_address(int,   acc.dupnums), dup_count*sizeof(int));
 177
 178  done:
 179   VEC_free (locstr,heap, acc.oplocs);
 180   VEC_free (locstr,heap, acc.duplocs);
 181   VEC_free (int,heap,    acc.dupnums);
 182   VEC_free (char,heap,   acc.pathstr);
 183 }
 184 \f
 185 /* Helper subroutine of walk_rtx: given a VEC(locstr), an index, and a
 186    string, insert the string at the index, which should either already
 187    exist and be NULL, or not yet exist within the vector.  In the latter
 188    case the vector is enlarged as appropriate.  */
 189 static void
 190 VEC_safe_set_locstr (VEC(locstr,heap) **vp, unsigned int ix, char *str)
 191 {
 192   if (ix < VEC_length (locstr, *vp))
 193     {
 194       gcc_assert (VEC_index (locstr, *vp, ix) == 0);
 195       VEC_replace (locstr, *vp, ix, str);
 196     }
 197   else
 198     {
 199       while (ix > VEC_length (locstr, *vp))
 200         VEC_safe_push (locstr, heap, *vp, 0);
 201       VEC_safe_push (locstr, heap, *vp, str);
 202     }
 203 }
 204
 205 /* Another helper subroutine of walk_rtx: given a VEC(char), convert it
 206    to a NUL-terminated string in malloc memory.  */
 207 static char *
 208 VEC_char_to_string (VEC(char,heap) *v)
 209 {
 210   size_t n = VEC_length (char, v);
 211   char *s = XNEWVEC (char, n + 1);
 212   memcpy (s, VEC_address (char, v), n);
 213   s[n] = '\0';
 214   return s;
 215 }
 216
 217 static void
 218 walk_rtx (rtx x, struct accum_extract *acc)
 219 {
 220   RTX_CODE code;
 221   int i, len, base;
 222   const char *fmt;
 223
 224   if (x == 0)
 225     return;
 226
 227   code = GET_CODE (x);
 228   switch (code)
 229     {
 230     case PC:
 231     case CC0:
 232     case CONST_INT:
 233     case SYMBOL_REF:
 234       return;
 235
 236     case MATCH_OPERAND:
 237     case MATCH_SCRATCH:
 238       VEC_safe_set_locstr (&acc->oplocs, XINT (x, 0),
 239                            VEC_char_to_string (acc->pathstr));
 240       break;
 241
 242     case MATCH_OPERATOR:
 243     case MATCH_PARALLEL:
 244       VEC_safe_set_locstr (&acc->oplocs, XINT (x, 0),
 245                            VEC_char_to_string (acc->pathstr));
 246
 247       base = (code == MATCH_OPERATOR ? '0' : 'a');
 248       for (i = XVECLEN (x, 2) - 1; i >= 0; i--)
 249         {
 250           VEC_safe_push (char,heap, acc->pathstr, base + i);
 251           walk_rtx (XVECEXP (x, 2, i), acc);
 252           VEC_pop (char, acc->pathstr);
 253         }
 254       return;
 255
 256     case MATCH_DUP:
 257     case MATCH_PAR_DUP:
 258     case MATCH_OP_DUP:
 259       VEC_safe_push (locstr,heap, acc->duplocs,
 260                      VEC_char_to_string (acc->pathstr));
 261       VEC_safe_push (int,heap, acc->dupnums, XINT (x, 0));
 262
 263       if (code == MATCH_DUP)
 264         break;
 265
 266       base = (code == MATCH_OP_DUP ? '0' : 'a');
 267       for (i = XVECLEN (x, 1) - 1; i >= 0; i--)
 268         {
 269           VEC_safe_push (char,heap, acc->pathstr, base + i);
 270           walk_rtx (XVECEXP (x, 1, i), acc);
 271           VEC_pop (char, acc->pathstr);
 272         }
 273       return;
 274
 275     default:
 276       break;
 277     }
 278
 279   fmt = GET_RTX_FORMAT (code);
 280   len = GET_RTX_LENGTH (code);
 281   for (i = 0; i < len; i++)
 282     {
 283       if (fmt[i] == 'e' || fmt[i] == 'u')
 284         {
 285           VEC_safe_push (char,heap, acc->pathstr, '0' + i);
 286           walk_rtx (XEXP (x, i), acc);
 287           VEC_pop (char, acc->pathstr);
 288         }
 289       else if (fmt[i] == 'E')
 290         {
 291           int j;
 292           for (j = XVECLEN (x, i) - 1; j >= 0; j--)
 293             {
 294               VEC_safe_push (char,heap, acc->pathstr, 'a' + j);
 295               walk_rtx (XVECEXP (x, i, j), acc);
 296               VEC_pop (char, acc->pathstr);
 297             }
 298         }
 299     }
 300 }
 301
 302 /* Given a PATH, representing a path down the instruction's
 303    pattern from the root to a certain point, output code to
 304    evaluate to the rtx at that point.  */
 305
 306 static void
 307 print_path (const char *path)
 308 {
 309   int len = strlen (path);
 310   int i;
 311
 312   if (len == 0)
 313     {
 314       /* Don't emit "pat", since we may try to take the address of it,
 315          which isn't what is intended.  */
 316       fputs ("PATTERN (insn)", stdout);
 317       return;
 318     }
 319
 320   /* We first write out the operations (XEXP or XVECEXP) in reverse
 321      order, then write "pat", then the indices in forward order.  */
 322
 323   for (i = len - 1; i >= 0 ; i--)
 324     {
 325       if (ISLOWER (path[i]))
 326         fputs ("XVECEXP (", stdout);
 327       else if (ISDIGIT (path[i]))
 328         fputs ("XEXP (", stdout);
 329       else
 330         gcc_unreachable ();
 331     }
 332
 333   fputs ("pat", stdout);
 334
 335   for (i = 0; i < len; i++)
 336     {
 337       if (ISLOWER (path[i]))
 338         printf (", 0, %d)", path[i] - 'a');
 339       else if (ISDIGIT(path[i]))
 340         printf (", %d)", path[i] - '0');
 341       else
 342         gcc_unreachable ();
 343     }
 344 }
 345 \f
 346 static void
 347 print_header (void)
 348 {
 349   /* N.B. Code below avoids putting squiggle braces in column 1 inside
 350      a string, because this confuses some editors' syntax highlighting
 351      engines.  */
 352
 353   puts ("\
 354 /* Generated automatically by the program `genextract'\n\
 355    from the machine description file `md'.  */\n\
 356 \n\
 357 #include \"config.h\"\n\
 358 #include \"system.h\"\n\
 359 #include \"coretypes.h\"\n\
 360 #include \"tm.h\"\n\
 361 #include \"rtl.h\"\n\
 362 #include \"insn-config.h\"\n\
 363 #include \"recog.h\"\n\
 364 #include \"toplev.h\"\n\
 365 \n\
 366 /* This variable is used as the \"location\" of any missing operand\n\
 367    whose numbers are skipped by a given pattern.  */\n\
 368 static rtx junk ATTRIBUTE_UNUSED;\n");
 369
 370   puts ("\
 371 void\n\
 372 insn_extract (rtx insn)\n{\n\
 373   rtx *ro = recog_data.operand;\n\
 374   rtx **ro_loc = recog_data.operand_loc;\n\
 375   rtx pat = PATTERN (insn);\n\
 376   int i ATTRIBUTE_UNUSED; /* only for peepholes */\n\
 377 \n\
 378 #ifdef ENABLE_CHECKING\n\
 379   memset (ro, 0xab, sizeof (*ro) * MAX_RECOG_OPERANDS);\n\
 380   memset (ro_loc, 0xab, sizeof (*ro_loc) * MAX_RECOG_OPERANDS);\n\
 381 #endif\n");
 382
 383   puts ("\
 384   switch (INSN_CODE (insn))\n\
 385     {\n\
 386     default:\n\
 387       /* Control reaches here if insn_extract has been called with an\n\
 388          unrecognizable insn (code -1), or an insn whose INSN_CODE\n\
 389          corresponds to a DEFINE_EXPAND in the machine description;\n\
 390          either way, a bug.  */\n\
 391       if (INSN_CODE (insn) < 0)\n\
 392         fatal_insn (\"unrecognizable insn:\", insn);\n\
 393       else\n\
 394         fatal_insn (\"insn with invalid code number:\", insn);\n");
 395 }
 396
 397 int
 398 main (int argc, char **argv)
 399 {
 400   rtx desc;
 401   unsigned int i;
 402   struct extraction *p;
 403   struct code_ptr *link;
 404   const char *name;
 405   int insn_code_number;
 406   int line_no;
 407
 408   progname = "genextract";
 409
 410   if (init_md_reader_args (argc, argv) != SUCCESS_EXIT_CODE)
 411     return (FATAL_EXIT_CODE);
 412
 413   /* Read the machine description.  */
 414
 415   while ((desc = read_md_rtx (&line_no, &insn_code_number)) != NULL)
 416     {
 417        if (GET_CODE (desc) == DEFINE_INSN)
 418          gen_insn (desc, insn_code_number);
 419
 420       else if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 421         {
 422           struct code_ptr *link = XNEW (struct code_ptr);
 423
 424           link->insn_code = insn_code_number;
 425           link->next = peepholes;
 426           peepholes = link;
 427         }
 428     }
 429
 430   print_header ();
 431
 432   /* Write out code to handle peepholes and the insn_codes that it should
 433      be called for.  */
 434   if (peepholes)
 435     {
 436       for (link = peepholes; link; link = link->next)
 437         printf ("    case %d:\n", link->insn_code);
 438
 439       /* The vector in the insn says how many operands it has.
 440          And all it contains are operands.  In fact, the vector was
 441          created just for the sake of this function.  We need to set the
 442          location of the operands for sake of simplifications after
 443          extraction, like eliminating subregs.  */
 444       puts ("      for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)\n"
 445             "          ro[i] = *(ro_loc[i] = &XVECEXP (pat, 0, i));\n"
 446             "      break;\n");
 447     }
 448
 449   /* Write out all the ways to extract insn operands.  */
 450   for (p = extractions; p; p = p->next)
 451     {
 452       for (link = p->insns; link; link = link->next)
 453         {
 454           i = link->insn_code;
 455           name = get_insn_name (i);
 456           if (name)
 457             printf ("    case %d:  /* %s */\n", i, name);
 458           else
 459             printf ("    case %d:\n", i);
 460         }
 461
 462       for (i = 0; i < p->op_count; i++)
 463         {
 464           if (p->oplocs[i] == 0)
 465             {
 466               printf ("      ro[%d] = const0_rtx;\n", i);
 467               printf ("      ro_loc[%d] = &junk;\n", i);
 468             }
 469           else
 470             {
 471               printf ("      ro[%d] = *(ro_loc[%d] = &", i, i);
 472               print_path (p->oplocs[i]);
 473               puts (");");
 474             }
 475         }
 476
 477       for (i = 0; i < p->dup_count; i++)
 478         {
 479           printf ("      recog_data.dup_loc[%d] = &", i);
 480           print_path (p->duplocs[i]);
 481           puts (";");
 482           printf ("      recog_data.dup_num[%d] = %d;\n", i, p->dupnums[i]);
 483         }
 484
 485       puts ("      break;\n");
 486     }
 487
 488   puts ("    }\n}");
 489   fflush (stdout);
 490   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 491 }