gcc/genemit.c

   1 /* Generate code from machine description to emit insns as rtl.
   2    Copyright (C) 1987-2021 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     case CC0:
 173       printf ("cc0_rtx");
 174       return;
 175
 176     case CONST_INT:
 177       if (INTVAL (x) == 0)
 178         printf ("const0_rtx");
 179       else if (INTVAL (x) == 1)
 180         printf ("const1_rtx");
 181       else if (INTVAL (x) == -1)
 182         printf ("constm1_rtx");
 183       else if (-MAX_SAVED_CONST_INT <= INTVAL (x)
 184                && INTVAL (x) <= MAX_SAVED_CONST_INT)
 185         printf ("const_int_rtx[MAX_SAVED_CONST_INT + (%d)]",
 186                 (int) INTVAL (x));
 187       else if (INTVAL (x) == STORE_FLAG_VALUE)
 188         printf ("const_true_rtx");
 189       else
 190         {
 191           printf ("GEN_INT (");
 192           printf (HOST_WIDE_INT_PRINT_DEC_C, INTVAL (x));
 193           printf (")");
 194         }
 195       return;
 196
 197     case CONST_DOUBLE:
 198       /* Handle `const_double_zero' rtx.  */
 199       if (CONST_DOUBLE_REAL_VALUE (x)->cl == rvc_zero)
 200         {
 201           printf ("CONST_DOUBLE_ATOF (\"0\", %smode)",
 202                   GET_MODE_NAME (GET_MODE (x)));
 203           return;
 204         }
 205       /* Fall through.  */
 206     case CONST_FIXED:
 207     case CONST_WIDE_INT:
 208       /* These shouldn't be written in MD files.  Instead, the appropriate
 209          routines in varasm.c should be called.  */
 210       gcc_unreachable ();
 211
 212     default:
 213       break;
 214     }
 215
 216   printf ("gen_rtx_");
 217   print_code (code);
 218   printf (" (");
 219   if (!always_void_p (code))
 220     {
 221       printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
 222       sep = ",\n\t";
 223     }
 224
 225   fmt = GET_RTX_FORMAT (code);
 226   len = GET_RTX_LENGTH (code);
 227   for (i = 0; i < len; i++)
 228     {
 229       if (fmt[i] == '0')
 230         break;
 231       fputs (sep, stdout);
 232       switch (fmt[i])
 233         {
 234         case 'e': case 'u':
 235           gen_exp (XEXP (x, i), subroutine_type, used, info);
 236           break;
 237
 238         case 'i':
 239           printf ("%u", XINT (x, i));
 240           break;
 241
 242         case 'r':
 243           printf ("%u", REGNO (x));
 244           break;
 245
 246         case 'p':
 247           /* We don't have a way of parsing polynomial offsets yet,
 248              and hopefully never will.  */
 249           printf ("%d", SUBREG_BYTE (x).to_constant ());
 250           break;
 251
 252         case 's':
 253           printf ("\"%s\"", XSTR (x, i));
 254           break;
 255
 256         case 'E':
 257           {
 258             int j;
 259             printf ("gen_rtvec (%d", XVECLEN (x, i));
 260             for (j = 0; j < XVECLEN (x, i); j++)
 261               {
 262                 printf (",\n\t\t");
 263                 gen_exp (XVECEXP (x, i, j), subroutine_type, used, info);
 264               }
 265             printf (")");
 266             break;
 267           }
 268
 269         default:
 270           gcc_unreachable ();
 271         }
 272       sep = ",\n\t";
 273     }
 274   printf (")");
 275 }
 276
 277 /* Output code to emit the instruction patterns in VEC, with each element
 278    becoming a separate instruction.  USED is as for gen_exp.  */
 279
 280 static void
 281 gen_emit_seq (rtvec vec, char *used, md_rtx_info *info)
 282 {
 283   for (int i = 0, len = GET_NUM_ELEM (vec); i < len; ++i)
 284     {
 285       bool last_p = (i == len - 1);
 286       rtx next = RTVEC_ELT (vec, i);
 287       if (const char *name = get_emit_function (next))
 288         {
 289           printf ("  %s (", name);
 290           gen_exp (next, DEFINE_EXPAND, used, info);
 291           printf (");\n");
 292           if (!last_p && needs_barrier_p (next))
 293             printf ("  emit_barrier ();");
 294         }
 295       else
 296         {
 297           printf ("  emit (");
 298           gen_exp (next, DEFINE_EXPAND, used, info);
 299           printf (", %s);\n", last_p ? "false" : "true");
 300         }
 301     }
 302 }
 303 \f
 304 /* Emit the given C code to the output file.  The code is allowed to
 305    fail if CAN_FAIL_P.  NAME describes what we're generating,
 306    for use in error messages.  */
 307
 308 static void
 309 emit_c_code (const char *code, bool can_fail_p, const char *name)
 310 {
 311   if (can_fail_p)
 312     printf ("#define FAIL return (end_sequence (), _val)\n");
 313   else
 314     printf ("#define FAIL _Pragma (\"GCC error \\\"%s cannot FAIL\\\"\")"
 315             " (void)0\n", name);
 316   printf ("#define DONE return (_val = get_insns (), "
 317           "end_sequence (), _val)\n");
 318
 319   rtx_reader_ptr->print_md_ptr_loc (code);
 320   printf ("%s\n", code);
 321
 322   printf ("#undef DONE\n");
 323   printf ("#undef FAIL\n");
 324 }
 325 \f
 326 /* Generate the `gen_...' function for a DEFINE_INSN.  */
 327
 328 static void
 329 gen_insn (md_rtx_info *info)
 330 {
 331   struct pattern_stats stats;
 332   int i;
 333
 334   /* See if the pattern for this insn ends with a group of CLOBBERs of (hard)
 335      registers or MATCH_SCRATCHes.  If so, store away the information for
 336      later.  */
 337
 338   rtx insn = info->def;
 339   if (XVEC (insn, 1))
 340     {
 341       int has_hard_reg = 0;
 342
 343       for (i = XVECLEN (insn, 1) - 1; i > 0; i--)
 344         {
 345           if (GET_CODE (XVECEXP (insn, 1, i)) != CLOBBER)
 346             break;
 347
 348           if (REG_P (XEXP (XVECEXP (insn, 1, i), 0)))
 349             has_hard_reg = 1;
 350           else if (GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != MATCH_SCRATCH)
 351             break;
 352         }
 353
 354       if (i != XVECLEN (insn, 1) - 1)
 355         {
 356           struct clobber_pat *p;
 357           struct clobber_ent *link = XNEW (struct clobber_ent);
 358           int j;
 359
 360           link->code_number = info->index;
 361
 362           /* See if any previous CLOBBER_LIST entry is the same as this
 363              one.  */
 364
 365           for (p = clobber_list; p; p = p->next)
 366             {
 367               if (p->first_clobber != i + 1
 368                   || XVECLEN (p->pattern, 1) != XVECLEN (insn, 1))
 369                 continue;
 370
 371               for (j = i + 1; j < XVECLEN (insn, 1); j++)
 372                 {
 373                   rtx old_rtx = XEXP (XVECEXP (p->pattern, 1, j), 0);
 374                   rtx new_rtx = XEXP (XVECEXP (insn, 1, j), 0);
 375
 376                   /* OLD and NEW_INSN are the same if both are to be a SCRATCH
 377                      of the same mode,
 378                      or if both are registers of the same mode and number.  */
 379                   if (! (GET_CODE (old_rtx) == GET_CODE (new_rtx)
 380                          && GET_MODE (old_rtx) == GET_MODE (new_rtx)
 381                          && ((GET_CODE (old_rtx) == MATCH_SCRATCH
 382                               && GET_CODE (new_rtx) == MATCH_SCRATCH)
 383                              || (REG_P (old_rtx) && REG_P (new_rtx)
 384                                  && REGNO (old_rtx) == REGNO (new_rtx)))))
 385                     break;
 386                 }
 387
 388               if (j == XVECLEN (insn, 1))
 389                 break;
 390             }
 391
 392           if (p == 0)
 393             {
 394               p = XNEW (struct clobber_pat);
 395
 396               p->insns = 0;
 397               p->pattern = insn;
 398               p->first_clobber = i + 1;
 399               p->next = clobber_list;
 400               p->has_hard_reg = has_hard_reg;
 401               clobber_list = p;
 402             }
 403
 404           link->next = p->insns;
 405           p->insns = link;
 406         }
 407     }
 408
 409   /* Don't mention instructions whose names are the null string
 410      or begin with '*'.  They are in the machine description just
 411      to be recognized.  */
 412   if (XSTR (insn, 0)[0] == 0 || XSTR (insn, 0)[0] == '*')
 413     return;
 414
 415   printf ("/* %s:%d */\n", info->loc.filename, info->loc.lineno);
 416
 417   /* Find out how many operands this function has.  */
 418   get_pattern_stats (&stats, XVEC (insn, 1));
 419   if (stats.max_dup_opno > stats.max_opno)
 420     fatal_at (info->loc, "match_dup operand number has no match_operand");
 421
 422   /* Output the function name and argument declarations.  */
 423   printf ("rtx\ngen_%s (", XSTR (insn, 0));
 424   if (stats.num_generator_args)
 425     for (i = 0; i < stats.num_generator_args; i++)
 426       if (i)
 427         printf (",\n\trtx operand%d ATTRIBUTE_UNUSED", i);
 428       else
 429         printf ("rtx operand%d ATTRIBUTE_UNUSED", i);
 430   else
 431     printf ("void");
 432   printf (")\n");
 433   printf ("{\n");
 434
 435   /* Output code to construct and return the rtl for the instruction body.  */
 436
 437   rtx pattern = add_implicit_parallel (XVEC (insn, 1));
 438   /* ??? This is the traditional behavior, but seems suspect.  */
 439   char *used = (XVECLEN (insn, 1) == 1
 440                 ? NULL
 441                 : XCNEWVEC (char, stats.num_generator_args));
 442   printf ("  return ");
 443   gen_exp (pattern, DEFINE_INSN, used, info);
 444   printf (";\n}\n\n");
 445   XDELETEVEC (used);
 446 }
 447 \f
 448 /* Generate the `gen_...' function for a DEFINE_EXPAND.  */
 449
 450 static void
 451 gen_expand (md_rtx_info *info)
 452 {
 453   struct pattern_stats stats;
 454   int i;
 455   char *used;
 456
 457   rtx expand = info->def;
 458   if (strlen (XSTR (expand, 0)) == 0)
 459     fatal_at (info->loc, "define_expand lacks a name");
 460   if (XVEC (expand, 1) == 0)
 461     fatal_at (info->loc, "define_expand for %s lacks a pattern",
 462               XSTR (expand, 0));
 463
 464   /* Find out how many operands this function has.  */
 465   get_pattern_stats (&stats, XVEC (expand, 1));
 466   if (stats.min_scratch_opno != -1
 467       && stats.min_scratch_opno <= MAX (stats.max_opno, stats.max_dup_opno))
 468     fatal_at (info->loc, "define_expand for %s needs to have match_scratch "
 469                          "numbers above all other operands", XSTR (expand, 0));
 470
 471   /* Output the function name and argument declarations.  */
 472   printf ("rtx\ngen_%s (", XSTR (expand, 0));
 473   if (stats.num_generator_args)
 474     for (i = 0; i < stats.num_generator_args; i++)
 475       if (i)
 476         printf (",\n\trtx operand%d", i);
 477       else
 478         printf ("rtx operand%d", i);
 479   else
 480     printf ("void");
 481   printf (")\n");
 482   printf ("{\n");
 483
 484   /* If we don't have any C code to write, only one insn is being written,
 485      and no MATCH_DUPs are present, we can just return the desired insn
 486      like we do for a DEFINE_INSN.  This saves memory.  */
 487   if ((XSTR (expand, 3) == 0 || *XSTR (expand, 3) == '\0')
 488       && stats.max_opno >= stats.max_dup_opno
 489       && XVECLEN (expand, 1) == 1)
 490     {
 491       printf ("  return ");
 492       gen_exp (XVECEXP (expand, 1, 0), DEFINE_EXPAND, NULL, info);
 493       printf (";\n}\n\n");
 494       return;
 495     }
 496
 497   /* For each operand referred to only with MATCH_DUPs,
 498      make a local variable.  */
 499   for (i = stats.num_generator_args; i <= stats.max_dup_opno; i++)
 500     printf ("  rtx operand%d;\n", i);
 501   printf ("  rtx_insn *_val = 0;\n");
 502   printf ("  start_sequence ();\n");
 503
 504   /* The fourth operand of DEFINE_EXPAND is some code to be executed
 505      before the actual construction.
 506      This code expects to refer to `operands'
 507      just as the output-code in a DEFINE_INSN does,
 508      but here `operands' is an automatic array.
 509      So copy the operand values there before executing it.  */
 510   if (XSTR (expand, 3) && *XSTR (expand, 3))
 511     {
 512       printf ("  {\n");
 513       if (stats.num_operand_vars > 0)
 514         printf ("    rtx operands[%d];\n", stats.num_operand_vars);
 515
 516       /* Output code to copy the arguments into `operands'.  */
 517       for (i = 0; i < stats.num_generator_args; i++)
 518         printf ("    operands[%d] = operand%d;\n", i, i);
 519
 520       /* Output the special code to be executed before the sequence
 521          is generated.  */
 522       optab_pattern p;
 523       bool can_fail_p = true;
 524       if (find_optab (&p, XSTR (expand, 0)))
 525         {
 526           gcc_assert (p.op < NUM_OPTABS);
 527           if (nofail_optabs[p.op])
 528             can_fail_p = false;
 529         }
 530       emit_c_code (XSTR (expand, 3), can_fail_p, XSTR (expand, 0));
 531
 532       /* Output code to copy the arguments back out of `operands'
 533          (unless we aren't going to use them at all).  */
 534       if (XVEC (expand, 1) != 0)
 535         {
 536           for (i = 0; i <= MAX (stats.max_opno, stats.max_dup_opno); i++)
 537             {
 538               printf ("    operand%d = operands[%d];\n", i, i);
 539               printf ("    (void) operand%d;\n", i);
 540             }
 541         }
 542       printf ("  }\n");
 543     }
 544
 545   used = XCNEWVEC (char, stats.num_operand_vars);
 546   gen_emit_seq (XVEC (expand, 1), used, info);
 547   XDELETEVEC (used);
 548
 549   /* Call `get_insns' to extract the list of all the
 550      insns emitted within this gen_... function.  */
 551
 552   printf ("  _val = get_insns ();\n");
 553   printf ("  end_sequence ();\n");
 554   printf ("  return _val;\n}\n\n");
 555 }
 556
 557 /* Like gen_expand, but generates insns resulting from splitting SPLIT.  */
 558
 559 static void
 560 gen_split (md_rtx_info *info)
 561 {
 562   struct pattern_stats stats;
 563   int i;
 564   rtx split = info->def;
 565   const char *const name =
 566     ((GET_CODE (split) == DEFINE_PEEPHOLE2) ? "peephole2" : "split");
 567   const char *unused;
 568   char *used;
 569
 570   if (XVEC (split, 0) == 0)
 571     fatal_at (info->loc, "%s lacks a pattern",
 572               GET_RTX_NAME (GET_CODE (split)));
 573   else if (XVEC (split, 2) == 0)
 574     fatal_at (info->loc, "%s lacks a replacement pattern",
 575               GET_RTX_NAME (GET_CODE (split)));
 576
 577   /* Find out how many operands this function has.  */
 578
 579   get_pattern_stats (&stats, XVEC (split, 2));
 580   unused = (stats.num_operand_vars == 0 ? " ATTRIBUTE_UNUSED" : "");
 581   used = XCNEWVEC (char, stats.num_operand_vars);
 582
 583   /* Output the prototype, function name and argument declarations.  */
 584   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 585     {
 586       printf ("extern rtx_insn *gen_%s_%d (rtx_insn *, rtx *);\n",
 587               name, info->index);
 588       printf ("rtx_insn *\ngen_%s_%d (rtx_insn *curr_insn ATTRIBUTE_UNUSED,"
 589               " rtx *operands%s)\n",
 590               name, info->index, unused);
 591     }
 592   else
 593     {
 594       printf ("extern rtx_insn *gen_split_%d (rtx_insn *, rtx *);\n",
 595               info->index);
 596       printf ("rtx_insn *\ngen_split_%d "
 597               "(rtx_insn *curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
 598               info->index, unused);
 599     }
 600   printf ("{\n");
 601
 602   /* Declare all local variables.  */
 603   for (i = 0; i < stats.num_operand_vars; i++)
 604     printf ("  rtx operand%d;\n", i);
 605   printf ("  rtx_insn *_val = NULL;\n");
 606
 607   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 608     output_peephole2_scratches (split);
 609
 610   const char *fn = info->loc.filename;
 611   for (const char *p = fn; *p; p++)
 612     if (*p == '/')
 613       fn = p + 1;
 614
 615   printf ("  if (dump_file)\n");
 616   printf ("    fprintf (dump_file, \"Splitting with gen_%s_%d (%s:%d)\\n\");\n",
 617           name, info->index, fn, info->loc.lineno);
 618
 619   printf ("  start_sequence ();\n");
 620
 621   /* The fourth operand of DEFINE_SPLIT is some code to be executed
 622      before the actual construction.  */
 623
 624   if (XSTR (split, 3))
 625     emit_c_code (XSTR (split, 3), true, name);
 626
 627   /* Output code to copy the arguments back out of `operands'  */
 628   for (i = 0; i < stats.num_operand_vars; i++)
 629     {
 630       printf ("  operand%d = operands[%d];\n", i, i);
 631       printf ("  (void) operand%d;\n", i);
 632     }
 633
 634   gen_emit_seq (XVEC (split, 2), used, info);
 635
 636   /* Call `get_insns' to make a list of all the
 637      insns emitted within this gen_... function.  */
 638
 639   printf ("  _val = get_insns ();\n");
 640   printf ("  end_sequence ();\n");
 641   printf ("  return _val;\n}\n\n");
 642
 643   free (used);
 644 }
 645 \f
 646 /* Write a function, `add_clobbers', that is given a PARALLEL of sufficient
 647    size for the insn and an INSN_CODE, and inserts the required CLOBBERs at
 648    the end of the vector.  */
 649
 650 static void
 651 output_add_clobbers (md_rtx_info *info)
 652 {
 653   struct clobber_pat *clobber;
 654   struct clobber_ent *ent;
 655   int i;
 656
 657   printf ("\n\nvoid\nadd_clobbers (rtx pattern ATTRIBUTE_UNUSED, int insn_code_number)\n");
 658   printf ("{\n");
 659   printf ("  switch (insn_code_number)\n");
 660   printf ("    {\n");
 661
 662   for (clobber = clobber_list; clobber; clobber = clobber->next)
 663     {
 664       for (ent = clobber->insns; ent; ent = ent->next)
 665         printf ("    case %d:\n", ent->code_number);
 666
 667       for (i = clobber->first_clobber; i < XVECLEN (clobber->pattern, 1); i++)
 668         {
 669           printf ("      XVECEXP (pattern, 0, %d) = ", i);
 670           gen_exp (XVECEXP (clobber->pattern, 1, i),
 671                    GET_CODE (clobber->pattern), NULL, info);
 672           printf (";\n");
 673         }
 674
 675       printf ("      break;\n\n");
 676     }
 677
 678   printf ("    default:\n");
 679   printf ("      gcc_unreachable ();\n");
 680   printf ("    }\n");
 681   printf ("}\n");
 682 }
 683 \f
 684 /* Write a function, `added_clobbers_hard_reg_p' that is given an insn_code
 685    number that will have clobbers added (as indicated by `recog') and returns
 686    1 if those include a clobber of a hard reg or 0 if all of them just clobber
 687    SCRATCH.  */
 688
 689 static void
 690 output_added_clobbers_hard_reg_p (void)
 691 {
 692   struct clobber_pat *clobber;
 693   struct clobber_ent *ent;
 694   int clobber_p, used;
 695
 696   printf ("\n\nint\nadded_clobbers_hard_reg_p (int insn_code_number)\n");
 697   printf ("{\n");
 698   printf ("  switch (insn_code_number)\n");
 699   printf ("    {\n");
 700
 701   for (clobber_p = 0; clobber_p <= 1; clobber_p++)
 702     {
 703       used = 0;
 704       for (clobber = clobber_list; clobber; clobber = clobber->next)
 705         if (clobber->has_hard_reg == clobber_p)
 706           for (ent = clobber->insns; ent; ent = ent->next)
 707             {
 708               printf ("    case %d:\n", ent->code_number);
 709               used++;
 710             }
 711
 712       if (used)
 713         printf ("      return %d;\n\n", clobber_p);
 714     }
 715
 716   printf ("    default:\n");
 717   printf ("      gcc_unreachable ();\n");
 718   printf ("    }\n");
 719   printf ("}\n");
 720 }
 721 \f
 722 /* Generate code to invoke find_free_register () as needed for the
 723    scratch registers used by the peephole2 pattern in SPLIT.  */
 724
 725 static void
 726 output_peephole2_scratches (rtx split)
 727 {
 728   int i;
 729   int insn_nr = 0;
 730   bool first = true;
 731
 732   for (i = 0; i < XVECLEN (split, 0); i++)
 733     {
 734       rtx elt = XVECEXP (split, 0, i);
 735       if (GET_CODE (elt) == MATCH_SCRATCH)
 736         {
 737           int last_insn_nr = insn_nr;
 738           int cur_insn_nr = insn_nr;
 739           int j;
 740           for (j = i + 1; j < XVECLEN (split, 0); j++)
 741             if (GET_CODE (XVECEXP (split, 0, j)) == MATCH_DUP)
 742               {
 743                 if (XINT (XVECEXP (split, 0, j), 0) == XINT (elt, 0))
 744                   last_insn_nr = cur_insn_nr;
 745               }
 746             else if (GET_CODE (XVECEXP (split, 0, j)) != MATCH_SCRATCH)
 747               cur_insn_nr++;
 748
 749           if (first)
 750             {
 751               printf ("  HARD_REG_SET _regs_allocated;\n");
 752               printf ("  CLEAR_HARD_REG_SET (_regs_allocated);\n");
 753               first = false;
 754             }
 755
 756           printf ("  if ((operands[%d] = peep2_find_free_register (%d, %d, \"%s\", %smode, &_regs_allocated)) == NULL_RTX)\n\
 757     return NULL;\n",
 758                   XINT (elt, 0),
 759                   insn_nr, last_insn_nr,
 760                   XSTR (elt, 1),
 761                   GET_MODE_NAME (GET_MODE (elt)));
 762
 763         }
 764       else if (GET_CODE (elt) != MATCH_DUP)
 765         insn_nr++;
 766     }
 767 }
 768
 769 /* Print "arg<N>" parameter declarations for each argument N of ONAME.  */
 770
 771 static void
 772 print_overload_arguments (overloaded_name *oname)
 773 {
 774   for (unsigned int i = 0; i < oname->arg_types.length (); ++i)
 775     printf ("%s%s arg%d", i == 0 ? "" : ", ", oname->arg_types[i], i);
 776 }
 777
 778 /* Print code to test whether INSTANCE should be chosen, given that
 779    argument N of the overload is available as "arg<N>".  */
 780
 781 static void
 782 print_overload_test (overloaded_instance *instance)
 783 {
 784   for (unsigned int i = 0; i < instance->arg_values.length (); ++i)
 785     printf ("%sarg%d == %s", i == 0 ? "  if (" : "\n      && ",
 786             i, instance->arg_values[i]);
 787   printf (")\n");
 788 }
 789
 790 /* Emit a maybe_code_for_* function for ONAME.  */
 791
 792 static void
 793 handle_overloaded_code_for (overloaded_name *oname)
 794 {
 795   /* Print the function prototype.  */
 796   printf ("\ninsn_code\nmaybe_code_for_%s (", oname->name);
 797   print_overload_arguments (oname);
 798   printf (")\n{\n");
 799
 800   /* Use a sequence of "if" statements for each instance.  */
 801   for (overloaded_instance *instance = oname->first_instance;
 802        instance; instance = instance->next)
 803     {
 804       print_overload_test (instance);
 805       printf ("    return CODE_FOR_%s;\n", instance->name);
 806     }
 807
 808   /* Return null if no match was found.  */
 809   printf ("  return CODE_FOR_nothing;\n}\n");
 810 }
 811
 812 /* Emit a maybe_gen_* function for ONAME.  */
 813
 814 static void
 815 handle_overloaded_gen (overloaded_name *oname)
 816 {
 817   unsigned HOST_WIDE_INT seen = 0;
 818   /* All patterns must have the same number of operands.  */
 819   for (overloaded_instance *instance = oname->first_instance->next;
 820        instance; instance = instance->next)
 821     {
 822       pattern_stats stats;
 823       get_pattern_stats (&stats, XVEC (instance->insn, 1));
 824       unsigned HOST_WIDE_INT mask
 825         = HOST_WIDE_INT_1U << stats.num_generator_args;
 826       if (seen & mask)
 827         continue;
 828
 829       seen |= mask;
 830
 831       /* Print the function prototype.  */
 832       printf ("\nrtx\nmaybe_gen_%s (", oname->name);
 833       print_overload_arguments (oname);
 834       for (int i = 0; i < stats.num_generator_args; ++i)
 835         printf (", rtx x%d", i);
 836       printf (")\n{\n");
 837
 838       /* Use maybe_code_for_*, instead of duplicating the selection
 839          logic here.  */
 840       printf ("  insn_code code = maybe_code_for_%s (", oname->name);
 841       for (unsigned int i = 0; i < oname->arg_types.length (); ++i)
 842         printf ("%sarg%d", i == 0 ? "" : ", ", i);
 843       printf (");\n"
 844               "  if (code != CODE_FOR_nothing)\n"
 845               "    {\n"
 846               "      gcc_assert (insn_data[code].n_generator_args == %d);\n"
 847               "      return GEN_FCN (code) (", stats.num_generator_args);
 848       for (int i = 0; i < stats.num_generator_args; ++i)
 849         printf ("%sx%d", i == 0 ? "" : ", ", i);
 850       printf (");\n"
 851               "    }\n"
 852               "  else\n"
 853               "    return NULL_RTX;\n"
 854               "}\n");
 855     }
 856 }
 857
 858 int
 859 main (int argc, const char **argv)
 860 {
 861   progname = "genemit";
 862
 863   if (!init_rtx_reader_args (argc, argv))
 864     return (FATAL_EXIT_CODE);
 865
 866 #define DEF_INTERNAL_OPTAB_FN(NAME, FLAGS, OPTAB, TYPE) \
 867   nofail_optabs[OPTAB##_optab] = true;
 868 #include "internal-fn.def"
 869
 870   /* Assign sequential codes to all entries in the machine description
 871      in parallel with the tables in insn-output.c.  */
 872
 873   printf ("/* Generated automatically by the program `genemit'\n\
 874 from the machine description file `md'.  */\n\n");
 875
 876   printf ("#define IN_TARGET_CODE 1\n");
 877   printf ("#include \"config.h\"\n");
 878   printf ("#include \"system.h\"\n");
 879   printf ("#include \"coretypes.h\"\n");
 880   printf ("#include \"backend.h\"\n");
 881   printf ("#include \"predict.h\"\n");
 882   printf ("#include \"tree.h\"\n");
 883   printf ("#include \"rtl.h\"\n");
 884   printf ("#include \"alias.h\"\n");
 885   printf ("#include \"varasm.h\"\n");
 886   printf ("#include \"stor-layout.h\"\n");
 887   printf ("#include \"calls.h\"\n");
 888   printf ("#include \"memmodel.h\"\n");
 889   printf ("#include \"tm_p.h\"\n");
 890   printf ("#include \"flags.h\"\n");
 891   printf ("#include \"insn-config.h\"\n");
 892   printf ("#include \"expmed.h\"\n");
 893   printf ("#include \"dojump.h\"\n");
 894   printf ("#include \"explow.h\"\n");
 895   printf ("#include \"emit-rtl.h\"\n");
 896   printf ("#include \"stmt.h\"\n");
 897   printf ("#include \"expr.h\"\n");
 898   printf ("#include \"insn-codes.h\"\n");
 899   printf ("#include \"optabs.h\"\n");
 900   printf ("#include \"dfp.h\"\n");
 901   printf ("#include \"output.h\"\n");
 902   printf ("#include \"recog.h\"\n");
 903   printf ("#include \"df.h\"\n");
 904   printf ("#include \"resource.h\"\n");
 905   printf ("#include \"reload.h\"\n");
 906   printf ("#include \"diagnostic-core.h\"\n");
 907   printf ("#include \"regs.h\"\n");
 908   printf ("#include \"tm-constrs.h\"\n");
 909   printf ("#include \"ggc.h\"\n");
 910   printf ("#include \"target.h\"\n\n");
 911
 912   /* Read the machine description.  */
 913
 914   md_rtx_info info;
 915   while (read_md_rtx (&info))
 916     switch (GET_CODE (info.def))
 917       {
 918       case DEFINE_INSN:
 919         gen_insn (&info);
 920         break;
 921
 922       case DEFINE_EXPAND:
 923         printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
 924         gen_expand (&info);
 925         break;
 926
 927       case DEFINE_SPLIT:
 928         printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
 929         gen_split (&info);
 930         break;
 931
 932       case DEFINE_PEEPHOLE2:
 933         printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
 934         gen_split (&info);
 935         break;
 936
 937       default:
 938         break;
 939       }
 940
 941   /* Write out the routines to add CLOBBERs to a pattern and say whether they
 942      clobber a hard reg.  */
 943   output_add_clobbers (&info);
 944   output_added_clobbers_hard_reg_p ();
 945
 946   for (overloaded_name *oname = rtx_reader_ptr->get_overloads ();
 947        oname; oname = oname->next)
 948     {
 949       handle_overloaded_code_for (oname);
 950       handle_overloaded_gen (oname);
 951     }
 952
 953   fflush (stdout);
 954   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 955 }