gcc/genemit.cc

   1 /* Generate code from machine description to emit insns as rtl.
   2    Copyright (C) 1987-2022 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
  31 /* Data structure for recording the patterns of insns that have CLOBBERs.
  32    We use this to output a function that adds these CLOBBERs to a
  33    previously-allocated PARALLEL expression.  */
  34
  35 struct clobber_pat
  36 {
  37   struct clobber_ent *insns;
  38   rtx pattern;
  39   int first_clobber;
  40   struct clobber_pat *next;
  41   int has_hard_reg;
  42 } *clobber_list;
  43
  44 /* Records one insn that uses the clobber list.  */
  45
  46 struct clobber_ent
  47 {
  48   int code_number;              /* Counts only insns.  */
  49   struct clobber_ent *next;
  50 };
  51
  52 static void output_peephole2_scratches  (rtx);
  53
  54 /* True for <X>_optab if that optab isn't allowed to fail.  */
  55 static bool nofail_optabs[NUM_OPTABS];
  56 \f
  57 static void
  58 print_code (RTX_CODE code)
  59 {
  60   const char *p1;
  61   for (p1 = GET_RTX_NAME (code); *p1; p1++)
  62     putchar (TOUPPER (*p1));
  63 }
  64
  65 static void
  66 gen_rtx_scratch (rtx x, enum rtx_code subroutine_type)
  67 {
  68   if (subroutine_type == DEFINE_PEEPHOLE2)
  69     {
  70       printf ("operand%d", XINT (x, 0));
  71     }
  72   else
  73     {
  74       printf ("gen_rtx_SCRATCH (%smode)", GET_MODE_NAME (GET_MODE (x)));
  75     }
  76 }
  77
  78 /* Print a C expression to construct an RTX just like X,
  79    substituting any operand references appearing within.  */
  80
  81 static void
  82 gen_exp (rtx x, enum rtx_code subroutine_type, char *used, md_rtx_info *info)
  83 {
  84   RTX_CODE code;
  85   int i;
  86   int len;
  87   const char *fmt;
  88   const char *sep = "";
  89
  90   if (x == 0)
  91     {
  92       printf ("NULL_RTX");
  93       return;
  94     }
  95
  96   code = GET_CODE (x);
  97
  98   switch (code)
  99     {
 100     case MATCH_OPERAND:
 101     case MATCH_DUP:
 102       if (used)
 103         {
 104           if (used[XINT (x, 0)])
 105             {
 106               printf ("copy_rtx (operand%d)", XINT (x, 0));
 107               return;
 108             }
 109           used[XINT (x, 0)] = 1;
 110         }
 111       printf ("operand%d", XINT (x, 0));
 112       return;
 113
 114     case MATCH_OP_DUP:
 115       printf ("gen_rtx_fmt_");
 116       for (i = 0; i < XVECLEN (x, 1); i++)
 117         printf ("e");
 118       printf (" (GET_CODE (operand%d), ", XINT (x, 0));
 119       if (GET_MODE (x) == VOIDmode)
 120         printf ("GET_MODE (operand%d)", XINT (x, 0));
 121       else
 122         printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
 123       for (i = 0; i < XVECLEN (x, 1); i++)
 124         {
 125           printf (",\n\t\t");
 126           gen_exp (XVECEXP (x, 1, i), subroutine_type, used, info);
 127         }
 128       printf (")");
 129       return;
 130
 131     case MATCH_OPERATOR:
 132       printf ("gen_rtx_fmt_");
 133       for (i = 0; i < XVECLEN (x, 2); i++)
 134         printf ("e");
 135       printf (" (GET_CODE (operand%d)", XINT (x, 0));
 136       printf (", %smode", GET_MODE_NAME (GET_MODE (x)));
 137       for (i = 0; i < XVECLEN (x, 2); i++)
 138         {
 139           printf (",\n\t\t");
 140           gen_exp (XVECEXP (x, 2, i), subroutine_type, used, info);
 141         }
 142       printf (")");
 143       return;
 144
 145     case MATCH_PARALLEL:
 146     case MATCH_PAR_DUP:
 147       printf ("operand%d", XINT (x, 0));
 148       return;
 149
 150     case MATCH_SCRATCH:
 151       gen_rtx_scratch (x, subroutine_type);
 152       return;
 153
 154     case PC:
 155       printf ("pc_rtx");
 156       return;
 157     case RETURN:
 158       printf ("ret_rtx");
 159       return;
 160     case SIMPLE_RETURN:
 161       printf ("simple_return_rtx");
 162       return;
 163     case CLOBBER:
 164       if (REG_P (XEXP (x, 0)))
 165         {
 166           printf ("gen_hard_reg_clobber (%smode, %i)",
 167                   GET_MODE_NAME (GET_MODE (XEXP (x, 0))),
 168                   REGNO (XEXP (x, 0)));
 169           return;
 170         }
 171       break;
 172
 173     case CONST_INT:
 174       if (INTVAL (x) == 0)
 175         printf ("const0_rtx");
 176       else if (INTVAL (x) == 1)
 177         printf ("const1_rtx");
 178       else if (INTVAL (x) == -1)
 179         printf ("constm1_rtx");
 180       else if (-MAX_SAVED_CONST_INT <= INTVAL (x)
 181                && INTVAL (x) <= MAX_SAVED_CONST_INT)
 182         printf ("const_int_rtx[MAX_SAVED_CONST_INT + (%d)]",
 183                 (int) INTVAL (x));
 184       else if (INTVAL (x) == STORE_FLAG_VALUE)
 185         printf ("const_true_rtx");
 186       else
 187         {
 188           printf ("GEN_INT (");
 189           printf (HOST_WIDE_INT_PRINT_DEC_C, INTVAL (x));
 190           printf (")");
 191         }
 192       return;
 193
 194     case CONST_DOUBLE:
 195       /* Handle `const_double_zero' rtx.  */
 196       if (CONST_DOUBLE_REAL_VALUE (x)->cl == rvc_zero)
 197         {
 198           printf ("CONST_DOUBLE_ATOF (\"0\", %smode)",
 199                   GET_MODE_NAME (GET_MODE (x)));
 200           return;
 201         }
 202       /* Fall through.  */
 203     case CONST_FIXED:
 204     case CONST_WIDE_INT:
 205       /* These shouldn't be written in MD files.  Instead, the appropriate
 206          routines in varasm.cc should be called.  */
 207       gcc_unreachable ();
 208
 209     default:
 210       break;
 211     }
 212
 213   printf ("gen_rtx_");
 214   print_code (code);
 215   printf (" (");
 216   if (!always_void_p (code))
 217     {
 218       printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
 219       sep = ",\n\t";
 220     }
 221
 222   fmt = GET_RTX_FORMAT (code);
 223   len = GET_RTX_LENGTH (code);
 224   for (i = 0; i < len; i++)
 225     {
 226       if (fmt[i] == '0')
 227         break;
 228       fputs (sep, stdout);
 229       switch (fmt[i])
 230         {
 231         case 'e': case 'u':
 232           gen_exp (XEXP (x, i), subroutine_type, used, info);
 233           break;
 234
 235         case 'i':
 236           printf ("%u", XINT (x, i));
 237           break;
 238
 239         case 'r':
 240           printf ("%u", REGNO (x));
 241           break;
 242
 243         case 'p':
 244           /* We don't have a way of parsing polynomial offsets yet,
 245              and hopefully never will.  */
 246           printf ("%d", SUBREG_BYTE (x).to_constant ());
 247           break;
 248
 249         case 's':
 250           printf ("\"%s\"", XSTR (x, i));
 251           break;
 252
 253         case 'E':
 254           {
 255             int j;
 256             printf ("gen_rtvec (%d", XVECLEN (x, i));
 257             for (j = 0; j < XVECLEN (x, i); j++)
 258               {
 259                 printf (",\n\t\t");
 260                 gen_exp (XVECEXP (x, i, j), subroutine_type, used, info);
 261               }
 262             printf (")");
 263             break;
 264           }
 265
 266         default:
 267           gcc_unreachable ();
 268         }
 269       sep = ",\n\t";
 270     }
 271   printf (")");
 272 }
 273
 274 /* Output code to emit the instruction patterns in VEC, with each element
 275    becoming a separate instruction.  USED is as for gen_exp.  */
 276
 277 static void
 278 gen_emit_seq (rtvec vec, char *used, md_rtx_info *info)
 279 {
 280   for (int i = 0, len = GET_NUM_ELEM (vec); i < len; ++i)
 281     {
 282       bool last_p = (i == len - 1);
 283       rtx next = RTVEC_ELT (vec, i);
 284       if (const char *name = get_emit_function (next))
 285         {
 286           printf ("  %s (", name);
 287           gen_exp (next, DEFINE_EXPAND, used, info);
 288           printf (");\n");
 289           if (!last_p && needs_barrier_p (next))
 290             printf ("  emit_barrier ();");
 291         }
 292       else
 293         {
 294           printf ("  emit (");
 295           gen_exp (next, DEFINE_EXPAND, used, info);
 296           printf (", %s);\n", last_p ? "false" : "true");
 297         }
 298     }
 299 }
 300 \f
 301 /* Emit the given C code to the output file.  The code is allowed to
 302    fail if CAN_FAIL_P.  NAME describes what we're generating,
 303    for use in error messages.  */
 304
 305 static void
 306 emit_c_code (const char *code, bool can_fail_p, const char *name)
 307 {
 308   if (can_fail_p)
 309     printf ("#define FAIL return (end_sequence (), _val)\n");
 310   else
 311     printf ("#define FAIL _Pragma (\"GCC error \\\"%s cannot FAIL\\\"\")"
 312             " (void)0\n", name);
 313   printf ("#define DONE return (_val = get_insns (), "
 314           "end_sequence (), _val)\n");
 315
 316   rtx_reader_ptr->print_md_ptr_loc (code);
 317   printf ("%s\n", code);
 318
 319   printf ("#undef DONE\n");
 320   printf ("#undef FAIL\n");
 321 }
 322 \f
 323 /* Generate the `gen_...' function for a DEFINE_INSN.  */
 324
 325 static void
 326 gen_insn (md_rtx_info *info)
 327 {
 328   struct pattern_stats stats;
 329   int i;
 330
 331   /* See if the pattern for this insn ends with a group of CLOBBERs of (hard)
 332      registers or MATCH_SCRATCHes.  If so, store away the information for
 333      later.  */
 334
 335   rtx insn = info->def;
 336   if (XVEC (insn, 1))
 337     {
 338       int has_hard_reg = 0;
 339
 340       for (i = XVECLEN (insn, 1) - 1; i > 0; i--)
 341         {
 342           if (GET_CODE (XVECEXP (insn, 1, i)) != CLOBBER)
 343             break;
 344
 345           if (REG_P (XEXP (XVECEXP (insn, 1, i), 0)))
 346             has_hard_reg = 1;
 347           else if (GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != MATCH_SCRATCH)
 348             break;
 349         }
 350
 351       if (i != XVECLEN (insn, 1) - 1)
 352         {
 353           struct clobber_pat *p;
 354           struct clobber_ent *link = XNEW (struct clobber_ent);
 355           int j;
 356
 357           link->code_number = info->index;
 358
 359           /* See if any previous CLOBBER_LIST entry is the same as this
 360              one.  */
 361
 362           for (p = clobber_list; p; p = p->next)
 363             {
 364               if (p->first_clobber != i + 1
 365                   || XVECLEN (p->pattern, 1) != XVECLEN (insn, 1))
 366                 continue;
 367
 368               for (j = i + 1; j < XVECLEN (insn, 1); j++)
 369                 {
 370                   rtx old_rtx = XEXP (XVECEXP (p->pattern, 1, j), 0);
 371                   rtx new_rtx = XEXP (XVECEXP (insn, 1, j), 0);
 372
 373                   /* OLD and NEW_INSN are the same if both are to be a SCRATCH
 374                      of the same mode,
 375                      or if both are registers of the same mode and number.  */
 376                   if (! (GET_CODE (old_rtx) == GET_CODE (new_rtx)
 377                          && GET_MODE (old_rtx) == GET_MODE (new_rtx)
 378                          && ((GET_CODE (old_rtx) == MATCH_SCRATCH
 379                               && GET_CODE (new_rtx) == MATCH_SCRATCH)
 380                              || (REG_P (old_rtx) && REG_P (new_rtx)
 381                                  && REGNO (old_rtx) == REGNO (new_rtx)))))
 382                     break;
 383                 }
 384
 385               if (j == XVECLEN (insn, 1))
 386                 break;
 387             }
 388
 389           if (p == 0)
 390             {
 391               p = XNEW (struct clobber_pat);
 392
 393               p->insns = 0;
 394               p->pattern = insn;
 395               p->first_clobber = i + 1;
 396               p->next = clobber_list;
 397               p->has_hard_reg = has_hard_reg;
 398               clobber_list = p;
 399             }
 400
 401           link->next = p->insns;
 402           p->insns = link;
 403         }
 404     }
 405
 406   /* Don't mention instructions whose names are the null string
 407      or begin with '*'.  They are in the machine description just
 408      to be recognized.  */
 409   if (XSTR (insn, 0)[0] == 0 || XSTR (insn, 0)[0] == '*')
 410     return;
 411
 412   printf ("/* %s:%d */\n", info->loc.filename, info->loc.lineno);
 413
 414   /* Find out how many operands this function has.  */
 415   get_pattern_stats (&stats, XVEC (insn, 1));
 416   if (stats.max_dup_opno > stats.max_opno)
 417     fatal_at (info->loc, "match_dup operand number has no match_operand");
 418
 419   /* Output the function name and argument declarations.  */
 420   printf ("rtx\ngen_%s (", XSTR (insn, 0));
 421   if (stats.num_generator_args)
 422     for (i = 0; i < stats.num_generator_args; i++)
 423       if (i)
 424         printf (",\n\trtx operand%d ATTRIBUTE_UNUSED", i);
 425       else
 426         printf ("rtx operand%d ATTRIBUTE_UNUSED", i);
 427   else
 428     printf ("void");
 429   printf (")\n");
 430   printf ("{\n");
 431
 432   /* Output code to construct and return the rtl for the instruction body.  */
 433
 434   rtx pattern = add_implicit_parallel (XVEC (insn, 1));
 435   /* ??? This is the traditional behavior, but seems suspect.  */
 436   char *used = (XVECLEN (insn, 1) == 1
 437                 ? NULL
 438                 : XCNEWVEC (char, stats.num_generator_args));
 439   printf ("  return ");
 440   gen_exp (pattern, DEFINE_INSN, used, info);
 441   printf (";\n}\n\n");
 442   XDELETEVEC (used);
 443 }
 444 \f
 445 /* Generate the `gen_...' function for a DEFINE_EXPAND.  */
 446
 447 static void
 448 gen_expand (md_rtx_info *info)
 449 {
 450   struct pattern_stats stats;
 451   int i;
 452   char *used;
 453
 454   rtx expand = info->def;
 455   if (strlen (XSTR (expand, 0)) == 0)
 456     fatal_at (info->loc, "define_expand lacks a name");
 457   if (XVEC (expand, 1) == 0)
 458     fatal_at (info->loc, "define_expand for %s lacks a pattern",
 459               XSTR (expand, 0));
 460
 461   /* Find out how many operands this function has.  */
 462   get_pattern_stats (&stats, XVEC (expand, 1));
 463   if (stats.min_scratch_opno != -1
 464       && stats.min_scratch_opno <= MAX (stats.max_opno, stats.max_dup_opno))
 465     fatal_at (info->loc, "define_expand for %s needs to have match_scratch "
 466                          "numbers above all other operands", XSTR (expand, 0));
 467
 468   /* Output the function name and argument declarations.  */
 469   printf ("rtx\ngen_%s (", XSTR (expand, 0));
 470   if (stats.num_generator_args)
 471     for (i = 0; i < stats.num_generator_args; i++)
 472       if (i)
 473         printf (",\n\trtx operand%d", i);
 474       else
 475         printf ("rtx operand%d", i);
 476   else
 477     printf ("void");
 478   printf (")\n");
 479   printf ("{\n");
 480
 481   /* If we don't have any C code to write, only one insn is being written,
 482      and no MATCH_DUPs are present, we can just return the desired insn
 483      like we do for a DEFINE_INSN.  This saves memory.  */
 484   if ((XSTR (expand, 3) == 0 || *XSTR (expand, 3) == '\0')
 485       && stats.max_opno >= stats.max_dup_opno
 486       && XVECLEN (expand, 1) == 1)
 487     {
 488       printf ("  return ");
 489       gen_exp (XVECEXP (expand, 1, 0), DEFINE_EXPAND, NULL, info);
 490       printf (";\n}\n\n");
 491       return;
 492     }
 493
 494   /* For each operand referred to only with MATCH_DUPs,
 495      make a local variable.  */
 496   for (i = stats.num_generator_args; i <= stats.max_dup_opno; i++)
 497     printf ("  rtx operand%d;\n", i);
 498   printf ("  rtx_insn *_val = 0;\n");
 499   printf ("  start_sequence ();\n");
 500
 501   /* The fourth operand of DEFINE_EXPAND is some code to be executed
 502      before the actual construction.
 503      This code expects to refer to `operands'
 504      just as the output-code in a DEFINE_INSN does,
 505      but here `operands' is an automatic array.
 506      So copy the operand values there before executing it.  */
 507   if (XSTR (expand, 3) && *XSTR (expand, 3))
 508     {
 509       printf ("  {\n");
 510       if (stats.num_operand_vars > 0)
 511         printf ("    rtx operands[%d];\n", stats.num_operand_vars);
 512
 513       /* Output code to copy the arguments into `operands'.  */
 514       for (i = 0; i < stats.num_generator_args; i++)
 515         printf ("    operands[%d] = operand%d;\n", i, i);
 516
 517       /* Output the special code to be executed before the sequence
 518          is generated.  */
 519       optab_pattern p;
 520       bool can_fail_p = true;
 521       if (find_optab (&p, XSTR (expand, 0)))
 522         {
 523           gcc_assert (p.op < NUM_OPTABS);
 524           if (nofail_optabs[p.op])
 525             can_fail_p = false;
 526         }
 527       emit_c_code (XSTR (expand, 3), can_fail_p, XSTR (expand, 0));
 528
 529       /* Output code to copy the arguments back out of `operands'
 530          (unless we aren't going to use them at all).  */
 531       if (XVEC (expand, 1) != 0)
 532         {
 533           for (i = 0; i <= MAX (stats.max_opno, stats.max_dup_opno); i++)
 534             {
 535               printf ("    operand%d = operands[%d];\n", i, i);
 536               printf ("    (void) operand%d;\n", i);
 537             }
 538         }
 539       printf ("  }\n");
 540     }
 541
 542   used = XCNEWVEC (char, stats.num_operand_vars);
 543   gen_emit_seq (XVEC (expand, 1), used, info);
 544   XDELETEVEC (used);
 545
 546   /* Call `get_insns' to extract the list of all the
 547      insns emitted within this gen_... function.  */
 548
 549   printf ("  _val = get_insns ();\n");
 550   printf ("  end_sequence ();\n");
 551   printf ("  return _val;\n}\n\n");
 552 }
 553
 554 /* Like gen_expand, but generates insns resulting from splitting SPLIT.  */
 555
 556 static void
 557 gen_split (md_rtx_info *info)
 558 {
 559   struct pattern_stats stats;
 560   int i;
 561   rtx split = info->def;
 562   const char *const name =
 563     ((GET_CODE (split) == DEFINE_PEEPHOLE2) ? "peephole2" : "split");
 564   const char *unused;
 565   char *used;
 566
 567   if (XVEC (split, 0) == 0)
 568     fatal_at (info->loc, "%s lacks a pattern",
 569               GET_RTX_NAME (GET_CODE (split)));
 570   else if (XVEC (split, 2) == 0)
 571     fatal_at (info->loc, "%s lacks a replacement pattern",
 572               GET_RTX_NAME (GET_CODE (split)));
 573
 574   /* Find out how many operands this function has.  */
 575
 576   get_pattern_stats (&stats, XVEC (split, 2));
 577   unused = (stats.num_operand_vars == 0 ? " ATTRIBUTE_UNUSED" : "");
 578   used = XCNEWVEC (char, stats.num_operand_vars);
 579
 580   /* Output the prototype, function name and argument declarations.  */
 581   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 582     {
 583       printf ("extern rtx_insn *gen_%s_%d (rtx_insn *, rtx *);\n",
 584               name, info->index);
 585       printf ("rtx_insn *\ngen_%s_%d (rtx_insn *curr_insn ATTRIBUTE_UNUSED,"
 586               " rtx *operands%s)\n",
 587               name, info->index, unused);
 588     }
 589   else
 590     {
 591       printf ("extern rtx_insn *gen_split_%d (rtx_insn *, rtx *);\n",
 592               info->index);
 593       printf ("rtx_insn *\ngen_split_%d "
 594               "(rtx_insn *curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
 595               info->index, unused);
 596     }
 597   printf ("{\n");
 598
 599   /* Declare all local variables.  */
 600   for (i = 0; i < stats.num_operand_vars; i++)
 601     printf ("  rtx operand%d;\n", i);
 602   printf ("  rtx_insn *_val = NULL;\n");
 603
 604   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 605     output_peephole2_scratches (split);
 606
 607   const char *fn = info->loc.filename;
 608   for (const char *p = fn; *p; p++)
 609     if (*p == '/')
 610       fn = p + 1;
 611
 612   printf ("  if (dump_file)\n");
 613   printf ("    fprintf (dump_file, \"Splitting with gen_%s_%d (%s:%d)\\n\");\n",
 614           name, info->index, fn, info->loc.lineno);
 615
 616   printf ("  start_sequence ();\n");
 617
 618   /* The fourth operand of DEFINE_SPLIT is some code to be executed
 619      before the actual construction.  */
 620
 621   if (XSTR (split, 3))
 622     emit_c_code (XSTR (split, 3), true, name);
 623
 624   /* Output code to copy the arguments back out of `operands'  */
 625   for (i = 0; i < stats.num_operand_vars; i++)
 626     {
 627       printf ("  operand%d = operands[%d];\n", i, i);
 628       printf ("  (void) operand%d;\n", i);
 629     }
 630
 631   gen_emit_seq (XVEC (split, 2), used, info);
 632
 633   /* Call `get_insns' to make a list of all the
 634      insns emitted within this gen_... function.  */
 635
 636   printf ("  _val = get_insns ();\n");
 637   printf ("  end_sequence ();\n");
 638   printf ("  return _val;\n}\n\n");
 639
 640   free (used);
 641 }
 642 \f
 643 /* Write a function, `add_clobbers', that is given a PARALLEL of sufficient
 644    size for the insn and an INSN_CODE, and inserts the required CLOBBERs at
 645    the end of the vector.  */
 646
 647 static void
 648 output_add_clobbers (md_rtx_info *info)
 649 {
 650   struct clobber_pat *clobber;
 651   struct clobber_ent *ent;
 652   int i;
 653
 654   printf ("\n\nvoid\nadd_clobbers (rtx pattern ATTRIBUTE_UNUSED, int insn_code_number)\n");
 655   printf ("{\n");
 656   printf ("  switch (insn_code_number)\n");
 657   printf ("    {\n");
 658
 659   for (clobber = clobber_list; clobber; clobber = clobber->next)
 660     {
 661       for (ent = clobber->insns; ent; ent = ent->next)
 662         printf ("    case %d:\n", ent->code_number);
 663
 664       for (i = clobber->first_clobber; i < XVECLEN (clobber->pattern, 1); i++)
 665         {
 666           printf ("      XVECEXP (pattern, 0, %d) = ", i);
 667           gen_exp (XVECEXP (clobber->pattern, 1, i),
 668                    GET_CODE (clobber->pattern), NULL, info);
 669           printf (";\n");
 670         }
 671
 672       printf ("      break;\n\n");
 673     }
 674
 675   printf ("    default:\n");
 676   printf ("      gcc_unreachable ();\n");
 677   printf ("    }\n");
 678   printf ("}\n");
 679 }
 680 \f
 681 /* Write a function, `added_clobbers_hard_reg_p' that is given an insn_code
 682    number that will have clobbers added (as indicated by `recog') and returns
 683    1 if those include a clobber of a hard reg or 0 if all of them just clobber
 684    SCRATCH.  */
 685
 686 static void
 687 output_added_clobbers_hard_reg_p (void)
 688 {
 689   struct clobber_pat *clobber;
 690   struct clobber_ent *ent;
 691   int clobber_p, used;
 692
 693   printf ("\n\nint\nadded_clobbers_hard_reg_p (int insn_code_number)\n");
 694   printf ("{\n");
 695   printf ("  switch (insn_code_number)\n");
 696   printf ("    {\n");
 697
 698   for (clobber_p = 0; clobber_p <= 1; clobber_p++)
 699     {
 700       used = 0;
 701       for (clobber = clobber_list; clobber; clobber = clobber->next)
 702         if (clobber->has_hard_reg == clobber_p)
 703           for (ent = clobber->insns; ent; ent = ent->next)
 704             {
 705               printf ("    case %d:\n", ent->code_number);
 706               used++;
 707             }
 708
 709       if (used)
 710         printf ("      return %d;\n\n", clobber_p);
 711     }
 712
 713   printf ("    default:\n");
 714   printf ("      gcc_unreachable ();\n");
 715   printf ("    }\n");
 716   printf ("}\n");
 717 }
 718 \f
 719 /* Generate code to invoke find_free_register () as needed for the
 720    scratch registers used by the peephole2 pattern in SPLIT.  */
 721
 722 static void
 723 output_peephole2_scratches (rtx split)
 724 {
 725   int i;
 726   int insn_nr = 0;
 727   bool first = true;
 728
 729   for (i = 0; i < XVECLEN (split, 0); i++)
 730     {
 731       rtx elt = XVECEXP (split, 0, i);
 732       if (GET_CODE (elt) == MATCH_SCRATCH)
 733         {
 734           int last_insn_nr = insn_nr;
 735           int cur_insn_nr = insn_nr;
 736           int j;
 737           for (j = i + 1; j < XVECLEN (split, 0); j++)
 738             if (GET_CODE (XVECEXP (split, 0, j)) == MATCH_DUP)
 739               {
 740                 if (XINT (XVECEXP (split, 0, j), 0) == XINT (elt, 0))
 741                   last_insn_nr = cur_insn_nr;
 742               }
 743             else if (GET_CODE (XVECEXP (split, 0, j)) != MATCH_SCRATCH)
 744               cur_insn_nr++;
 745
 746           if (first)
 747             {
 748               printf ("  HARD_REG_SET _regs_allocated;\n");
 749               printf ("  CLEAR_HARD_REG_SET (_regs_allocated);\n");
 750               first = false;
 751             }
 752
 753           printf ("  if ((operands[%d] = peep2_find_free_register (%d, %d, \"%s\", %smode, &_regs_allocated)) == NULL_RTX)\n\
 754     return NULL;\n",
 755                   XINT (elt, 0),
 756                   insn_nr, last_insn_nr,
 757                   XSTR (elt, 1),
 758                   GET_MODE_NAME (GET_MODE (elt)));
 759
 760         }
 761       else if (GET_CODE (elt) != MATCH_DUP)
 762         insn_nr++;
 763     }
 764 }
 765
 766 /* Print "arg<N>" parameter declarations for each argument N of ONAME.  */
 767
 768 static void
 769 print_overload_arguments (overloaded_name *oname)
 770 {
 771   for (unsigned int i = 0; i < oname->arg_types.length (); ++i)
 772     printf ("%s%s arg%d", i == 0 ? "" : ", ", oname->arg_types[i], i);
 773 }
 774
 775 /* Print code to test whether INSTANCE should be chosen, given that
 776    argument N of the overload is available as "arg<N>".  */
 777
 778 static void
 779 print_overload_test (overloaded_instance *instance)
 780 {
 781   for (unsigned int i = 0; i < instance->arg_values.length (); ++i)
 782     printf ("%sarg%d == %s", i == 0 ? "  if (" : "\n      && ",
 783             i, instance->arg_values[i]);
 784   printf (")\n");
 785 }
 786
 787 /* Emit a maybe_code_for_* function for ONAME.  */
 788
 789 static void
 790 handle_overloaded_code_for (overloaded_name *oname)
 791 {
 792   /* Print the function prototype.  */
 793   printf ("\ninsn_code\nmaybe_code_for_%s (", oname->name);
 794   print_overload_arguments (oname);
 795   printf (")\n{\n");
 796
 797   /* Use a sequence of "if" statements for each instance.  */
 798   for (overloaded_instance *instance = oname->first_instance;
 799        instance; instance = instance->next)
 800     {
 801       print_overload_test (instance);
 802       printf ("    return CODE_FOR_%s;\n", instance->name);
 803     }
 804
 805   /* Return null if no match was found.  */
 806   printf ("  return CODE_FOR_nothing;\n}\n");
 807 }
 808
 809 /* Emit a maybe_gen_* function for ONAME.  */
 810
 811 static void
 812 handle_overloaded_gen (overloaded_name *oname)
 813 {
 814   unsigned HOST_WIDE_INT seen = 0;
 815   /* All patterns must have the same number of operands.  */
 816   for (overloaded_instance *instance = oname->first_instance->next;
 817        instance; instance = instance->next)
 818     {
 819       pattern_stats stats;
 820       get_pattern_stats (&stats, XVEC (instance->insn, 1));
 821       unsigned HOST_WIDE_INT mask
 822         = HOST_WIDE_INT_1U << stats.num_generator_args;
 823       if (seen & mask)
 824         continue;
 825
 826       seen |= mask;
 827
 828       /* Print the function prototype.  */
 829       printf ("\nrtx\nmaybe_gen_%s (", oname->name);
 830       print_overload_arguments (oname);
 831       for (int i = 0; i < stats.num_generator_args; ++i)
 832         printf (", rtx x%d", i);
 833       printf (")\n{\n");
 834
 835       /* Use maybe_code_for_*, instead of duplicating the selection
 836          logic here.  */
 837       printf ("  insn_code code = maybe_code_for_%s (", oname->name);
 838       for (unsigned int i = 0; i < oname->arg_types.length (); ++i)
 839         printf ("%sarg%d", i == 0 ? "" : ", ", i);
 840       printf (");\n"
 841               "  if (code != CODE_FOR_nothing)\n"
 842               "    {\n"
 843               "      gcc_assert (insn_data[code].n_generator_args == %d);\n"
 844               "      return GEN_FCN (code) (", stats.num_generator_args);
 845       for (int i = 0; i < stats.num_generator_args; ++i)
 846         printf ("%sx%d", i == 0 ? "" : ", ", i);
 847       printf (");\n"
 848               "    }\n"
 849               "  else\n"
 850               "    return NULL_RTX;\n"
 851               "}\n");
 852     }
 853 }
 854
 855 int
 856 main (int argc, const char **argv)
 857 {
 858   progname = "genemit";
 859
 860   if (!init_rtx_reader_args (argc, argv))
 861     return (FATAL_EXIT_CODE);
 862
 863 #define DEF_INTERNAL_OPTAB_FN(NAME, FLAGS, OPTAB, TYPE) \
 864   nofail_optabs[OPTAB##_optab] = true;
 865 #include "internal-fn.def"
 866
 867   /* Assign sequential codes to all entries in the machine description
 868      in parallel with the tables in insn-output.cc.  */
 869
 870   printf ("/* Generated automatically by the program `genemit'\n\
 871 from the machine description file `md'.  */\n\n");
 872
 873   printf ("#define IN_TARGET_CODE 1\n");
 874   printf ("#include \"config.h\"\n");
 875   printf ("#include \"system.h\"\n");
 876   printf ("#include \"coretypes.h\"\n");
 877   printf ("#include \"backend.h\"\n");
 878   printf ("#include \"predict.h\"\n");
 879   printf ("#include \"tree.h\"\n");
 880   printf ("#include \"rtl.h\"\n");
 881   printf ("#include \"alias.h\"\n");
 882   printf ("#include \"varasm.h\"\n");
 883   printf ("#include \"stor-layout.h\"\n");
 884   printf ("#include \"calls.h\"\n");
 885   printf ("#include \"memmodel.h\"\n");
 886   printf ("#include \"tm_p.h\"\n");
 887   printf ("#include \"flags.h\"\n");
 888   printf ("#include \"insn-config.h\"\n");
 889   printf ("#include \"expmed.h\"\n");
 890   printf ("#include \"dojump.h\"\n");
 891   printf ("#include \"explow.h\"\n");
 892   printf ("#include \"emit-rtl.h\"\n");
 893   printf ("#include \"stmt.h\"\n");
 894   printf ("#include \"expr.h\"\n");
 895   printf ("#include \"insn-codes.h\"\n");
 896   printf ("#include \"optabs.h\"\n");
 897   printf ("#include \"dfp.h\"\n");
 898   printf ("#include \"output.h\"\n");
 899   printf ("#include \"recog.h\"\n");
 900   printf ("#include \"df.h\"\n");
 901   printf ("#include \"resource.h\"\n");
 902   printf ("#include \"reload.h\"\n");
 903   printf ("#include \"diagnostic-core.h\"\n");
 904   printf ("#include \"regs.h\"\n");
 905   printf ("#include \"tm-constrs.h\"\n");
 906   printf ("#include \"ggc.h\"\n");
 907   printf ("#include \"target.h\"\n\n");
 908
 909   /* Read the machine description.  */
 910
 911   md_rtx_info info;
 912   while (read_md_rtx (&info))
 913     switch (GET_CODE (info.def))
 914       {
 915       case DEFINE_INSN:
 916         gen_insn (&info);
 917         break;
 918
 919       case DEFINE_EXPAND:
 920         printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
 921         gen_expand (&info);
 922         break;
 923
 924       case DEFINE_SPLIT:
 925         printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
 926         gen_split (&info);
 927         break;
 928
 929       case DEFINE_PEEPHOLE2:
 930         printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
 931         gen_split (&info);
 932         break;
 933
 934       default:
 935         break;
 936       }
 937
 938   /* Write out the routines to add CLOBBERs to a pattern and say whether they
 939      clobber a hard reg.  */
 940   output_add_clobbers (&info);
 941   output_added_clobbers_hard_reg_p ();
 942
 943   for (overloaded_name *oname = rtx_reader_ptr->get_overloads ();
 944        oname; oname = oname->next)
 945     {
 946       handle_overloaded_code_for (oname);
 947       handle_overloaded_gen (oname);
 948     }
 949
 950   fflush (stdout);
 951   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 952 }