gcc/genextract.c

   1 /* Generate code from machine description to extract operands from insn as rtl.
   2    Copyright (C) 1987-2017 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20
  21 #include "bconfig.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tm.h"
  25 #include "rtl.h"
  26 #include "errors.h"
  27 #include "read-md.h"
  28 #include "gensupport.h"
  29
  30 /* This structure contains all the information needed to describe one
  31    set of extractions methods.  Each method may be used by more than
  32    one pattern if the operands are in the same place.
  33
  34    The string for each operand describes that path to the operand and
  35    contains `0' through `9' when going into an expression and `a' through
  36    `z' when going into a vector.  We assume here that only the first operand
  37    of an rtl expression is a vector.  genrecog.c makes the same assumption
  38    (and uses the same representation) and it is currently true.  */
  39
  40 typedef char *locstr;
  41
  42 struct extraction
  43 {
  44   unsigned int op_count;
  45   unsigned int dup_count;
  46   locstr *oplocs;
  47   locstr *duplocs;
  48   int *dupnums;
  49   struct code_ptr *insns;
  50   struct extraction *next;
  51 };
  52
  53 /* Holds a single insn code that uses an extraction method.  */
  54 struct code_ptr
  55 {
  56   int insn_code;
  57   struct code_ptr *next;
  58 };
  59
  60 /* All extractions needed for this machine description.  */
  61 static struct extraction *extractions;
  62
  63 /* All insn codes for old-style peepholes.  */
  64 static struct code_ptr *peepholes;
  65
  66 /* This structure is used by gen_insn and walk_rtx to accumulate the
  67    data that will be used to produce an extractions structure.  */
  68
  69
  70 struct accum_extract
  71 {
  72   accum_extract () : oplocs (10), duplocs (10), dupnums (10), pathstr (20) {}
  73
  74   auto_vec<locstr> oplocs;
  75   auto_vec<locstr> duplocs;
  76   auto_vec<int> dupnums;
  77   auto_vec<char> pathstr;
  78 };
  79
  80 /* Forward declarations.  */
  81 static void walk_rtx (md_rtx_info *, rtx, struct accum_extract *);
  82
  83 static void
  84 gen_insn (md_rtx_info *info)
  85 {
  86   int i;
  87   unsigned int op_count, dup_count, j;
  88   struct extraction *p;
  89   struct code_ptr *link;
  90   struct accum_extract acc;
  91
  92   /* Walk the insn's pattern, remembering at all times the path
  93      down to the walking point.  */
  94
  95   rtx insn = info->def;
  96   if (XVECLEN (insn, 1) == 1)
  97     walk_rtx (info, XVECEXP (insn, 1, 0), &acc);
  98   else
  99     for (i = XVECLEN (insn, 1) - 1; i >= 0; i--)
 100       {
 101         acc.pathstr.safe_push ('a' + i);
 102         walk_rtx (info, XVECEXP (insn, 1, i), &acc);
 103         acc.pathstr.pop ();
 104       }
 105
 106   link = XNEW (struct code_ptr);
 107   link->insn_code = info->index;
 108
 109   /* See if we find something that already had this extraction method.  */
 110
 111   op_count = acc.oplocs.length ();
 112   dup_count = acc.duplocs.length ();
 113   gcc_assert (dup_count == acc.dupnums.length ());
 114
 115   for (p = extractions; p; p = p->next)
 116     {
 117       if (p->op_count != op_count || p->dup_count != dup_count)
 118         continue;
 119
 120       for (j = 0; j < op_count; j++)
 121         {
 122           char *a = p->oplocs[j];
 123           char *b = acc.oplocs[j];
 124           if (a != b && (!a || !b || strcmp (a, b)))
 125             break;
 126         }
 127
 128       if (j != op_count)
 129         continue;
 130
 131       for (j = 0; j < dup_count; j++)
 132         if (p->dupnums[j] != acc.dupnums[j]
 133             || strcmp (p->duplocs[j], acc.duplocs[j]))
 134           break;
 135
 136       if (j != dup_count)
 137         continue;
 138
 139       /* This extraction is the same as ours.  Just link us in.  */
 140       link->next = p->insns;
 141       p->insns = link;
 142       return;
 143     }
 144
 145   /* Otherwise, make a new extraction method.  We stash the arrays
 146      after the extraction structure in memory.  */
 147
 148   p = XNEWVAR (struct extraction, sizeof (struct extraction)
 149                + op_count*sizeof (char *)
 150                + dup_count*sizeof (char *)
 151                + dup_count*sizeof (int));
 152   p->op_count = op_count;
 153   p->dup_count = dup_count;
 154   p->next = extractions;
 155   extractions = p;
 156   p->insns = link;
 157   link->next = 0;
 158
 159   p->oplocs = (char **)((char *)p + sizeof (struct extraction));
 160   p->duplocs = p->oplocs + op_count;
 161   p->dupnums = (int *)(p->duplocs + dup_count);
 162
 163   memcpy (p->oplocs, acc.oplocs.address (), op_count * sizeof (locstr));
 164   memcpy (p->duplocs, acc.duplocs.address (), dup_count * sizeof (locstr));
 165   memcpy (p->dupnums, acc.dupnums.address (), dup_count * sizeof (int));
 166 }
 167 \f
 168 /* Helper subroutine of walk_rtx: given a vec<locstr>, an index, and a
 169    string, insert the string at the index, which should either already
 170    exist and be NULL, or not yet exist within the vector.  In the latter
 171    case the vector is enlarged as appropriate.  INFO describes the
 172    containing define_* expression.  */
 173 static void
 174 VEC_safe_set_locstr (md_rtx_info *info, vec<locstr> *vp,
 175                      unsigned int ix, char *str)
 176 {
 177   if (ix < (*vp).length ())
 178     {
 179       if ((*vp)[ix])
 180         {
 181           message_at (info->loc, "repeated operand number %d", ix);
 182           have_error = 1;
 183         }
 184       else
 185         (*vp)[ix] = str;
 186     }
 187   else
 188     {
 189       while (ix > (*vp).length ())
 190         vp->safe_push (NULL);
 191       vp->safe_push (str);
 192     }
 193 }
 194
 195 /* Another helper subroutine of walk_rtx: given a vec<char>, convert it
 196    to a NUL-terminated string in malloc memory.  */
 197 static char *
 198 VEC_char_to_string (vec<char> v)
 199 {
 200   size_t n = v.length ();
 201   char *s = XNEWVEC (char, n + 1);
 202   memcpy (s, v.address (), n);
 203   s[n] = '\0';
 204   return s;
 205 }
 206
 207 static void
 208 walk_rtx (md_rtx_info *info, rtx x, struct accum_extract *acc)
 209 {
 210   RTX_CODE code;
 211   int i, len, base;
 212   const char *fmt;
 213
 214   if (x == 0)
 215     return;
 216
 217   code = GET_CODE (x);
 218   switch (code)
 219     {
 220     case PC:
 221     case CC0:
 222     case CONST_INT:
 223     case SYMBOL_REF:
 224       return;
 225
 226     case MATCH_OPERAND:
 227     case MATCH_SCRATCH:
 228       VEC_safe_set_locstr (info, &acc->oplocs, XINT (x, 0),
 229                            VEC_char_to_string (acc->pathstr));
 230       break;
 231
 232     case MATCH_OPERATOR:
 233     case MATCH_PARALLEL:
 234       VEC_safe_set_locstr (info, &acc->oplocs, XINT (x, 0),
 235                            VEC_char_to_string (acc->pathstr));
 236
 237       base = (code == MATCH_OPERATOR ? '0' : 'a');
 238       for (i = XVECLEN (x, 2) - 1; i >= 0; i--)
 239         {
 240           acc->pathstr.safe_push (base + i);
 241           walk_rtx (info, XVECEXP (x, 2, i), acc);
 242           acc->pathstr.pop ();
 243         }
 244       return;
 245
 246     case MATCH_DUP:
 247     case MATCH_PAR_DUP:
 248     case MATCH_OP_DUP:
 249       acc->duplocs.safe_push (VEC_char_to_string (acc->pathstr));
 250       acc->dupnums.safe_push (XINT (x, 0));
 251
 252       if (code == MATCH_DUP)
 253         break;
 254
 255       base = (code == MATCH_OP_DUP ? '0' : 'a');
 256       for (i = XVECLEN (x, 1) - 1; i >= 0; i--)
 257         {
 258           acc->pathstr.safe_push (base + i);
 259           walk_rtx (info, XVECEXP (x, 1, i), acc);
 260           acc->pathstr.pop ();
 261         }
 262       return;
 263
 264     default:
 265       break;
 266     }
 267
 268   fmt = GET_RTX_FORMAT (code);
 269   len = GET_RTX_LENGTH (code);
 270   for (i = 0; i < len; i++)
 271     {
 272       if (fmt[i] == 'e' || fmt[i] == 'u')
 273         {
 274           acc->pathstr.safe_push ('0' + i);
 275           walk_rtx (info, XEXP (x, i), acc);
 276           acc->pathstr.pop ();
 277         }
 278       else if (fmt[i] == 'E')
 279         {
 280           int j;
 281           for (j = XVECLEN (x, i) - 1; j >= 0; j--)
 282             {
 283               acc->pathstr.safe_push ('a' + j);
 284               walk_rtx (info, XVECEXP (x, i, j), acc);
 285               acc->pathstr.pop ();
 286             }
 287         }
 288     }
 289 }
 290
 291 /* Given a PATH, representing a path down the instruction's
 292    pattern from the root to a certain point, output code to
 293    evaluate to the rtx at that point.  */
 294
 295 static void
 296 print_path (const char *path)
 297 {
 298   int len = strlen (path);
 299   int i;
 300
 301   if (len == 0)
 302     {
 303       /* Don't emit "pat", since we may try to take the address of it,
 304          which isn't what is intended.  */
 305       fputs ("PATTERN (insn)", stdout);
 306       return;
 307     }
 308
 309   /* We first write out the operations (XEXP or XVECEXP) in reverse
 310      order, then write "pat", then the indices in forward order.  */
 311
 312   for (i = len - 1; i >= 0 ; i--)
 313     {
 314       if (ISLOWER (path[i]))
 315         fputs ("XVECEXP (", stdout);
 316       else if (ISDIGIT (path[i]))
 317         fputs ("XEXP (", stdout);
 318       else
 319         gcc_unreachable ();
 320     }
 321
 322   fputs ("pat", stdout);
 323
 324   for (i = 0; i < len; i++)
 325     {
 326       if (ISLOWER (path[i]))
 327         printf (", 0, %d)", path[i] - 'a');
 328       else if (ISDIGIT (path[i]))
 329         printf (", %d)", path[i] - '0');
 330       else
 331         gcc_unreachable ();
 332     }
 333 }
 334 \f
 335 static void
 336 print_header (void)
 337 {
 338   /* N.B. Code below avoids putting squiggle braces in column 1 inside
 339      a string, because this confuses some editors' syntax highlighting
 340      engines.  */
 341
 342   puts ("\
 343 /* Generated automatically by the program `genextract'\n\
 344    from the machine description file `md'.  */\n\
 345 \n\
 346 #define IN_TARGET_CODE 1\n\
 347 #include \"config.h\"\n\
 348 #include \"system.h\"\n\
 349 #include \"coretypes.h\"\n\
 350 #include \"tm.h\"\n\
 351 #include \"rtl.h\"\n\
 352 #include \"insn-config.h\"\n\
 353 #include \"recog.h\"\n\
 354 #include \"diagnostic-core.h\"\n\
 355 \n\
 356 /* This variable is used as the \"location\" of any missing operand\n\
 357    whose numbers are skipped by a given pattern.  */\n\
 358 static rtx junk ATTRIBUTE_UNUSED;\n");
 359
 360   puts ("\
 361 void\n\
 362 insn_extract (rtx_insn *insn)\n{\n\
 363   rtx *ro = recog_data.operand;\n\
 364   rtx **ro_loc = recog_data.operand_loc;\n\
 365   rtx pat = PATTERN (insn);\n\
 366   int i ATTRIBUTE_UNUSED; /* only for peepholes */\n\
 367 \n\
 368   if (flag_checking)\n\
 369     {\n\
 370       memset (ro, 0xab, sizeof (*ro) * MAX_RECOG_OPERANDS);\n\
 371       memset (ro_loc, 0xab, sizeof (*ro_loc) * MAX_RECOG_OPERANDS);\n\
 372     }\n");
 373
 374   puts ("\
 375   switch (INSN_CODE (insn))\n\
 376     {\n\
 377     default:\n\
 378       /* Control reaches here if insn_extract has been called with an\n\
 379          unrecognizable insn (code -1), or an insn whose INSN_CODE\n\
 380          corresponds to a DEFINE_EXPAND in the machine description;\n\
 381          either way, a bug.  */\n\
 382       if (INSN_CODE (insn) < 0)\n\
 383         fatal_insn (\"unrecognizable insn:\", insn);\n\
 384       else\n\
 385         fatal_insn (\"insn with invalid code number:\", insn);\n");
 386 }
 387
 388 int
 389 main (int argc, const char **argv)
 390 {
 391   unsigned int i;
 392   struct extraction *p;
 393   struct code_ptr *link;
 394   const char *name;
 395
 396   progname = "genextract";
 397
 398   if (!init_rtx_reader_args (argc, argv))
 399     return (FATAL_EXIT_CODE);
 400
 401   /* Read the machine description.  */
 402
 403   md_rtx_info info;
 404   while (read_md_rtx (&info))
 405     switch (GET_CODE (info.def))
 406       {
 407       case DEFINE_INSN:
 408         gen_insn (&info);
 409         break;
 410
 411       case DEFINE_PEEPHOLE:
 412         {
 413           struct code_ptr *link = XNEW (struct code_ptr);
 414
 415           link->insn_code = info.index;
 416           link->next = peepholes;
 417           peepholes = link;
 418         }
 419         break;
 420
 421       default:
 422         break;
 423     }
 424
 425   if (have_error)
 426     return FATAL_EXIT_CODE;
 427
 428   print_header ();
 429
 430   /* Write out code to handle peepholes and the insn_codes that it should
 431      be called for.  */
 432   if (peepholes)
 433     {
 434       for (link = peepholes; link; link = link->next)
 435         printf ("    case %d:\n", link->insn_code);
 436
 437       /* The vector in the insn says how many operands it has.
 438          And all it contains are operands.  In fact, the vector was
 439          created just for the sake of this function.  We need to set the
 440          location of the operands for sake of simplifications after
 441          extraction, like eliminating subregs.  */
 442       puts ("      for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)\n"
 443             "          ro[i] = *(ro_loc[i] = &XVECEXP (pat, 0, i));\n"
 444             "      break;\n");
 445     }
 446
 447   /* Write out all the ways to extract insn operands.  */
 448   for (p = extractions; p; p = p->next)
 449     {
 450       for (link = p->insns; link; link = link->next)
 451         {
 452           i = link->insn_code;
 453           name = get_insn_name (i);
 454           if (name)
 455             printf ("    case %d:  /* %s */\n", i, name);
 456           else
 457             printf ("    case %d:\n", i);
 458         }
 459
 460       for (i = 0; i < p->op_count; i++)
 461         {
 462           if (p->oplocs[i] == 0)
 463             {
 464               printf ("      ro[%d] = const0_rtx;\n", i);
 465               printf ("      ro_loc[%d] = &junk;\n", i);
 466             }
 467           else
 468             {
 469               printf ("      ro[%d] = *(ro_loc[%d] = &", i, i);
 470               print_path (p->oplocs[i]);
 471               puts (");");
 472             }
 473         }
 474
 475       for (i = 0; i < p->dup_count; i++)
 476         {
 477           printf ("      recog_data.dup_loc[%d] = &", i);
 478           print_path (p->duplocs[i]);
 479           puts (";");
 480           printf ("      recog_data.dup_num[%d] = %d;\n", i, p->dupnums[i]);
 481         }
 482
 483       puts ("      break;\n");
 484     }
 485
 486   puts ("    }\n}");
 487   fflush (stdout);
 488   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 489 }