gcc/genemit.c

   1 /* Generate code from machine description to emit insns as rtl.
   2    Copyright (C) 1987-2018 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)
  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);
 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);
 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)", GET_MODE_NAME (GET_MODE (XEXP (x, 0))),
 167                                                      REGNO (XEXP (x, 0)));
 168           return;
 169         }
 170       break;
 171
 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     case CONST_FIXED:
 199     case CONST_WIDE_INT:
 200       /* These shouldn't be written in MD files.  Instead, the appropriate
 201          routines in varasm.c should be called.  */
 202       gcc_unreachable ();
 203
 204     default:
 205       break;
 206     }
 207
 208   printf ("gen_rtx_");
 209   print_code (code);
 210   printf (" (");
 211   if (!always_void_p (code))
 212     {
 213       printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
 214       sep = ",\n\t";
 215     }
 216
 217   fmt = GET_RTX_FORMAT (code);
 218   len = GET_RTX_LENGTH (code);
 219   for (i = 0; i < len; i++)
 220     {
 221       if (fmt[i] == '0')
 222         break;
 223       fputs (sep, stdout);
 224       switch (fmt[i])
 225         {
 226         case 'e': case 'u':
 227           gen_exp (XEXP (x, i), subroutine_type, used);
 228           break;
 229
 230         case 'i':
 231           printf ("%u", XINT (x, i));
 232           break;
 233
 234         case 'r':
 235           printf ("%u", REGNO (x));
 236           break;
 237
 238         case 'p':
 239           /* We don't have a way of parsing polynomial offsets yet,
 240              and hopefully never will.  */
 241           printf ("%d", SUBREG_BYTE (x).to_constant ());
 242           break;
 243
 244         case 's':
 245           printf ("\"%s\"", XSTR (x, i));
 246           break;
 247
 248         case 'E':
 249           {
 250             int j;
 251             printf ("gen_rtvec (%d", XVECLEN (x, i));
 252             for (j = 0; j < XVECLEN (x, i); j++)
 253               {
 254                 printf (",\n\t\t");
 255                 gen_exp (XVECEXP (x, i, j), subroutine_type, used);
 256               }
 257             printf (")");
 258             break;
 259           }
 260
 261         default:
 262           gcc_unreachable ();
 263         }
 264       sep = ",\n\t";
 265     }
 266   printf (")");
 267 }
 268
 269 /* Output code to emit the instruction patterns in VEC, with each element
 270    becoming a separate instruction.  USED is as for gen_exp.  */
 271
 272 static void
 273 gen_emit_seq (rtvec vec, char *used)
 274 {
 275   for (int i = 0, len = GET_NUM_ELEM (vec); i < len; ++i)
 276     {
 277       bool last_p = (i == len - 1);
 278       rtx next = RTVEC_ELT (vec, i);
 279       if (const char *name = get_emit_function (next))
 280         {
 281           printf ("  %s (", name);
 282           gen_exp (next, DEFINE_EXPAND, used);
 283           printf (");\n");
 284           if (!last_p && needs_barrier_p (next))
 285             printf ("  emit_barrier ();");
 286         }
 287       else
 288         {
 289           printf ("  emit (");
 290           gen_exp (next, DEFINE_EXPAND, used);
 291           printf (", %s);\n", last_p ? "false" : "true");
 292         }
 293     }
 294 }
 295 \f
 296 /* Emit the given C code to the output file.  The code is allowed to
 297    fail if CAN_FAIL_P.  NAME describes what we're generating,
 298    for use in error messages.  */
 299
 300 static void
 301 emit_c_code (const char *code, bool can_fail_p, const char *name)
 302 {
 303   if (can_fail_p)
 304     printf ("#define FAIL return (end_sequence (), _val)\n");
 305   else
 306     printf ("#define FAIL _Pragma (\"GCC error \\\"%s cannot FAIL\\\"\")"
 307             " (void)0\n", name);
 308   printf ("#define DONE return (_val = get_insns (),"
 309           "end_sequence (), _val)\n");
 310
 311   rtx_reader_ptr->print_md_ptr_loc (code);
 312   printf ("%s\n", code);
 313
 314   printf ("#undef DONE\n");
 315   printf ("#undef FAIL\n");
 316 }
 317 \f
 318 /* Generate the `gen_...' function for a DEFINE_INSN.  */
 319
 320 static void
 321 gen_insn (md_rtx_info *info)
 322 {
 323   struct pattern_stats stats;
 324   int i;
 325
 326   /* See if the pattern for this insn ends with a group of CLOBBERs of (hard)
 327      registers or MATCH_SCRATCHes.  If so, store away the information for
 328      later.  */
 329
 330   rtx insn = info->def;
 331   if (XVEC (insn, 1))
 332     {
 333       int has_hard_reg = 0;
 334
 335       for (i = XVECLEN (insn, 1) - 1; i > 0; i--)
 336         {
 337           if (GET_CODE (XVECEXP (insn, 1, i)) != CLOBBER)
 338             break;
 339
 340           if (REG_P (XEXP (XVECEXP (insn, 1, i), 0)))
 341             has_hard_reg = 1;
 342           else if (GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != MATCH_SCRATCH)
 343             break;
 344         }
 345
 346       if (i != XVECLEN (insn, 1) - 1)
 347         {
 348           struct clobber_pat *p;
 349           struct clobber_ent *link = XNEW (struct clobber_ent);
 350           int j;
 351
 352           link->code_number = info->index;
 353
 354           /* See if any previous CLOBBER_LIST entry is the same as this
 355              one.  */
 356
 357           for (p = clobber_list; p; p = p->next)
 358             {
 359               if (p->first_clobber != i + 1
 360                   || XVECLEN (p->pattern, 1) != XVECLEN (insn, 1))
 361                 continue;
 362
 363               for (j = i + 1; j < XVECLEN (insn, 1); j++)
 364                 {
 365                   rtx old_rtx = XEXP (XVECEXP (p->pattern, 1, j), 0);
 366                   rtx new_rtx = XEXP (XVECEXP (insn, 1, j), 0);
 367
 368                   /* OLD and NEW_INSN are the same if both are to be a SCRATCH
 369                      of the same mode,
 370                      or if both are registers of the same mode and number.  */
 371                   if (! (GET_MODE (old_rtx) == GET_MODE (new_rtx)
 372                          && ((GET_CODE (old_rtx) == MATCH_SCRATCH
 373                               && GET_CODE (new_rtx) == MATCH_SCRATCH)
 374                              || (REG_P (old_rtx) && REG_P (new_rtx)
 375                                  && REGNO (old_rtx) == REGNO (new_rtx)))))
 376                     break;
 377                 }
 378
 379               if (j == XVECLEN (insn, 1))
 380                 break;
 381             }
 382
 383           if (p == 0)
 384             {
 385               p = XNEW (struct clobber_pat);
 386
 387               p->insns = 0;
 388               p->pattern = insn;
 389               p->first_clobber = i + 1;
 390               p->next = clobber_list;
 391               p->has_hard_reg = has_hard_reg;
 392               clobber_list = p;
 393             }
 394
 395           link->next = p->insns;
 396           p->insns = link;
 397         }
 398     }
 399
 400   /* Don't mention instructions whose names are the null string
 401      or begin with '*'.  They are in the machine description just
 402      to be recognized.  */
 403   if (XSTR (insn, 0)[0] == 0 || XSTR (insn, 0)[0] == '*')
 404     return;
 405
 406   printf ("/* %s:%d */\n", info->loc.filename, info->loc.lineno);
 407
 408   /* Find out how many operands this function has.  */
 409   get_pattern_stats (&stats, XVEC (insn, 1));
 410   if (stats.max_dup_opno > stats.max_opno)
 411     fatal_at (info->loc, "match_dup operand number has no match_operand");
 412
 413   /* Output the function name and argument declarations.  */
 414   printf ("rtx\ngen_%s (", XSTR (insn, 0));
 415   if (stats.num_generator_args)
 416     for (i = 0; i < stats.num_generator_args; i++)
 417       if (i)
 418         printf (",\n\trtx operand%d ATTRIBUTE_UNUSED", i);
 419       else
 420         printf ("rtx operand%d ATTRIBUTE_UNUSED", i);
 421   else
 422     printf ("void");
 423   printf (")\n");
 424   printf ("{\n");
 425
 426   /* Output code to construct and return the rtl for the instruction body.  */
 427
 428   rtx pattern = add_implicit_parallel (XVEC (insn, 1));
 429   /* ??? This is the traditional behavior, but seems suspect.  */
 430   char *used = (XVECLEN (insn, 1) == 1
 431                 ? NULL
 432                 : XCNEWVEC (char, stats.num_generator_args));
 433   printf ("  return ");
 434   gen_exp (pattern, DEFINE_INSN, used);
 435   printf (";\n}\n\n");
 436   XDELETEVEC (used);
 437 }
 438 \f
 439 /* Generate the `gen_...' function for a DEFINE_EXPAND.  */
 440
 441 static void
 442 gen_expand (md_rtx_info *info)
 443 {
 444   struct pattern_stats stats;
 445   int i;
 446   char *used;
 447
 448   rtx expand = info->def;
 449   if (strlen (XSTR (expand, 0)) == 0)
 450     fatal_at (info->loc, "define_expand lacks a name");
 451   if (XVEC (expand, 1) == 0)
 452     fatal_at (info->loc, "define_expand for %s lacks a pattern",
 453               XSTR (expand, 0));
 454
 455   /* Find out how many operands this function has.  */
 456   get_pattern_stats (&stats, XVEC (expand, 1));
 457   if (stats.min_scratch_opno != -1
 458       && stats.min_scratch_opno <= MAX (stats.max_opno, stats.max_dup_opno))
 459     fatal_at (info->loc, "define_expand for %s needs to have match_scratch "
 460                          "numbers above all other operands", XSTR (expand, 0));
 461
 462   /* Output the function name and argument declarations.  */
 463   printf ("rtx\ngen_%s (", XSTR (expand, 0));
 464   if (stats.num_generator_args)
 465     for (i = 0; i < stats.num_generator_args; i++)
 466       if (i)
 467         printf (",\n\trtx operand%d", i);
 468       else
 469         printf ("rtx operand%d", i);
 470   else
 471     printf ("void");
 472   printf (")\n");
 473   printf ("{\n");
 474
 475   /* If we don't have any C code to write, only one insn is being written,
 476      and no MATCH_DUPs are present, we can just return the desired insn
 477      like we do for a DEFINE_INSN.  This saves memory.  */
 478   if ((XSTR (expand, 3) == 0 || *XSTR (expand, 3) == '\0')
 479       && stats.max_opno >= stats.max_dup_opno
 480       && XVECLEN (expand, 1) == 1)
 481     {
 482       printf ("  return ");
 483       gen_exp (XVECEXP (expand, 1, 0), DEFINE_EXPAND, NULL);
 484       printf (";\n}\n\n");
 485       return;
 486     }
 487
 488   /* For each operand referred to only with MATCH_DUPs,
 489      make a local variable.  */
 490   for (i = stats.num_generator_args; i <= stats.max_dup_opno; i++)
 491     printf ("  rtx operand%d;\n", i);
 492   printf ("  rtx_insn *_val = 0;\n");
 493   printf ("  start_sequence ();\n");
 494
 495   /* The fourth operand of DEFINE_EXPAND is some code to be executed
 496      before the actual construction.
 497      This code expects to refer to `operands'
 498      just as the output-code in a DEFINE_INSN does,
 499      but here `operands' is an automatic array.
 500      So copy the operand values there before executing it.  */
 501   if (XSTR (expand, 3) && *XSTR (expand, 3))
 502     {
 503       printf ("  {\n");
 504       if (stats.num_operand_vars > 0)
 505         printf ("    rtx operands[%d];\n", stats.num_operand_vars);
 506
 507       /* Output code to copy the arguments into `operands'.  */
 508       for (i = 0; i < stats.num_generator_args; i++)
 509         printf ("    operands[%d] = operand%d;\n", i, i);
 510
 511       /* Output the special code to be executed before the sequence
 512          is generated.  */
 513       optab_pattern p;
 514       bool can_fail_p = true;
 515       if (find_optab (&p, XSTR (expand, 0)))
 516         {
 517           gcc_assert (p.op < NUM_OPTABS);
 518           if (nofail_optabs[p.op])
 519             can_fail_p = false;
 520         }
 521       emit_c_code (XSTR (expand, 3), can_fail_p, XSTR (expand, 0));
 522
 523       /* Output code to copy the arguments back out of `operands'
 524          (unless we aren't going to use them at all).  */
 525       if (XVEC (expand, 1) != 0)
 526         {
 527           for (i = 0; i <= MAX (stats.max_opno, stats.max_dup_opno); i++)
 528             {
 529               printf ("    operand%d = operands[%d];\n", i, i);
 530               printf ("    (void) operand%d;\n", i);
 531             }
 532         }
 533       printf ("  }\n");
 534     }
 535
 536   used = XCNEWVEC (char, stats.num_operand_vars);
 537   gen_emit_seq (XVEC (expand, 1), used);
 538   XDELETEVEC (used);
 539
 540   /* Call `get_insns' to extract the list of all the
 541      insns emitted within this gen_... function.  */
 542
 543   printf ("  _val = get_insns ();\n");
 544   printf ("  end_sequence ();\n");
 545   printf ("  return _val;\n}\n\n");
 546 }
 547
 548 /* Like gen_expand, but generates insns resulting from splitting SPLIT.  */
 549
 550 static void
 551 gen_split (md_rtx_info *info)
 552 {
 553   struct pattern_stats stats;
 554   int i;
 555   rtx split = info->def;
 556   const char *const name =
 557     ((GET_CODE (split) == DEFINE_PEEPHOLE2) ? "peephole2" : "split");
 558   const char *unused;
 559   char *used;
 560
 561   if (XVEC (split, 0) == 0)
 562     fatal_at (info->loc, "%s lacks a pattern",
 563               GET_RTX_NAME (GET_CODE (split)));
 564   else if (XVEC (split, 2) == 0)
 565     fatal_at (info->loc, "%s lacks a replacement pattern",
 566               GET_RTX_NAME (GET_CODE (split)));
 567
 568   /* Find out how many operands this function has.  */
 569
 570   get_pattern_stats (&stats, XVEC (split, 2));
 571   unused = (stats.num_operand_vars == 0 ? " ATTRIBUTE_UNUSED" : "");
 572   used = XCNEWVEC (char, stats.num_operand_vars);
 573
 574   /* Output the prototype, function name and argument declarations.  */
 575   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 576     {
 577       printf ("extern rtx_insn *gen_%s_%d (rtx_insn *, rtx *);\n",
 578               name, info->index);
 579       printf ("rtx_insn *\ngen_%s_%d (rtx_insn *curr_insn ATTRIBUTE_UNUSED,"
 580               " rtx *operands%s)\n",
 581               name, info->index, unused);
 582     }
 583   else
 584     {
 585       printf ("extern rtx_insn *gen_split_%d (rtx_insn *, rtx *);\n",
 586               info->index);
 587       printf ("rtx_insn *\ngen_split_%d "
 588               "(rtx_insn *curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
 589               info->index, unused);
 590     }
 591   printf ("{\n");
 592
 593   /* Declare all local variables.  */
 594   for (i = 0; i < stats.num_operand_vars; i++)
 595     printf ("  rtx operand%d;\n", i);
 596   printf ("  rtx_insn *_val = NULL;\n");
 597
 598   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 599     output_peephole2_scratches (split);
 600
 601   printf ("  if (dump_file)\n");
 602   printf ("    fprintf (dump_file, \"Splitting with gen_%s_%d\\n\");\n",
 603           name, info->index);
 604
 605   printf ("  start_sequence ();\n");
 606
 607   /* The fourth operand of DEFINE_SPLIT is some code to be executed
 608      before the actual construction.  */
 609
 610   if (XSTR (split, 3))
 611     emit_c_code (XSTR (split, 3), true, name);
 612
 613   /* Output code to copy the arguments back out of `operands'  */
 614   for (i = 0; i < stats.num_operand_vars; i++)
 615     {
 616       printf ("  operand%d = operands[%d];\n", i, i);
 617       printf ("  (void) operand%d;\n", i);
 618     }
 619
 620   gen_emit_seq (XVEC (split, 2), used);
 621
 622   /* Call `get_insns' to make a list of all the
 623      insns emitted within this gen_... function.  */
 624
 625   printf ("  _val = get_insns ();\n");
 626   printf ("  end_sequence ();\n");
 627   printf ("  return _val;\n}\n\n");
 628
 629   free (used);
 630 }
 631 \f
 632 /* Write a function, `add_clobbers', that is given a PARALLEL of sufficient
 633    size for the insn and an INSN_CODE, and inserts the required CLOBBERs at
 634    the end of the vector.  */
 635
 636 static void
 637 output_add_clobbers (void)
 638 {
 639   struct clobber_pat *clobber;
 640   struct clobber_ent *ent;
 641   int i;
 642
 643   printf ("\n\nvoid\nadd_clobbers (rtx pattern ATTRIBUTE_UNUSED, int insn_code_number)\n");
 644   printf ("{\n");
 645   printf ("  switch (insn_code_number)\n");
 646   printf ("    {\n");
 647
 648   for (clobber = clobber_list; clobber; clobber = clobber->next)
 649     {
 650       for (ent = clobber->insns; ent; ent = ent->next)
 651         printf ("    case %d:\n", ent->code_number);
 652
 653       for (i = clobber->first_clobber; i < XVECLEN (clobber->pattern, 1); i++)
 654         {
 655           printf ("      XVECEXP (pattern, 0, %d) = ", i);
 656           gen_exp (XVECEXP (clobber->pattern, 1, i),
 657                    GET_CODE (clobber->pattern), NULL);
 658           printf (";\n");
 659         }
 660
 661       printf ("      break;\n\n");
 662     }
 663
 664   printf ("    default:\n");
 665   printf ("      gcc_unreachable ();\n");
 666   printf ("    }\n");
 667   printf ("}\n");
 668 }
 669 \f
 670 /* Write a function, `added_clobbers_hard_reg_p' that is given an insn_code
 671    number that will have clobbers added (as indicated by `recog') and returns
 672    1 if those include a clobber of a hard reg or 0 if all of them just clobber
 673    SCRATCH.  */
 674
 675 static void
 676 output_added_clobbers_hard_reg_p (void)
 677 {
 678   struct clobber_pat *clobber;
 679   struct clobber_ent *ent;
 680   int clobber_p, used;
 681
 682   printf ("\n\nint\nadded_clobbers_hard_reg_p (int insn_code_number)\n");
 683   printf ("{\n");
 684   printf ("  switch (insn_code_number)\n");
 685   printf ("    {\n");
 686
 687   for (clobber_p = 0; clobber_p <= 1; clobber_p++)
 688     {
 689       used = 0;
 690       for (clobber = clobber_list; clobber; clobber = clobber->next)
 691         if (clobber->has_hard_reg == clobber_p)
 692           for (ent = clobber->insns; ent; ent = ent->next)
 693             {
 694               printf ("    case %d:\n", ent->code_number);
 695               used++;
 696             }
 697
 698       if (used)
 699         printf ("      return %d;\n\n", clobber_p);
 700     }
 701
 702   printf ("    default:\n");
 703   printf ("      gcc_unreachable ();\n");
 704   printf ("    }\n");
 705   printf ("}\n");
 706 }
 707 \f
 708 /* Generate code to invoke find_free_register () as needed for the
 709    scratch registers used by the peephole2 pattern in SPLIT.  */
 710
 711 static void
 712 output_peephole2_scratches (rtx split)
 713 {
 714   int i;
 715   int insn_nr = 0;
 716   bool first = true;
 717
 718   for (i = 0; i < XVECLEN (split, 0); i++)
 719     {
 720       rtx elt = XVECEXP (split, 0, i);
 721       if (GET_CODE (elt) == MATCH_SCRATCH)
 722         {
 723           int last_insn_nr = insn_nr;
 724           int cur_insn_nr = insn_nr;
 725           int j;
 726           for (j = i + 1; j < XVECLEN (split, 0); j++)
 727             if (GET_CODE (XVECEXP (split, 0, j)) == MATCH_DUP)
 728               {
 729                 if (XINT (XVECEXP (split, 0, j), 0) == XINT (elt, 0))
 730                   last_insn_nr = cur_insn_nr;
 731               }
 732             else if (GET_CODE (XVECEXP (split, 0, j)) != MATCH_SCRATCH)
 733               cur_insn_nr++;
 734
 735           if (first)
 736             {
 737               printf ("  HARD_REG_SET _regs_allocated;\n");
 738               printf ("  CLEAR_HARD_REG_SET (_regs_allocated);\n");
 739               first = false;
 740             }
 741
 742           printf ("  if ((operands[%d] = peep2_find_free_register (%d, %d, \"%s\", %smode, &_regs_allocated)) == NULL_RTX)\n\
 743     return NULL;\n",
 744                   XINT (elt, 0),
 745                   insn_nr, last_insn_nr,
 746                   XSTR (elt, 1),
 747                   GET_MODE_NAME (GET_MODE (elt)));
 748
 749         }
 750       else if (GET_CODE (elt) != MATCH_DUP)
 751         insn_nr++;
 752     }
 753 }
 754
 755 /* Print "arg<N>" parameter declarations for each argument N of ONAME.  */
 756
 757 static void
 758 print_overload_arguments (overloaded_name *oname)
 759 {
 760   for (unsigned int i = 0; i < oname->arg_types.length (); ++i)
 761     printf ("%s%s arg%d", i == 0 ? "" : ", ", oname->arg_types[i], i);
 762 }
 763
 764 /* Print code to test whether INSTANCE should be chosen, given that
 765    argument N of the overload is available as "arg<N>".  */
 766
 767 static void
 768 print_overload_test (overloaded_instance *instance)
 769 {
 770   for (unsigned int i = 0; i < instance->arg_values.length (); ++i)
 771     printf ("%sarg%d == %s", i == 0 ? "  if (" : "\n      && ",
 772             i, instance->arg_values[i]);
 773   printf (")\n");
 774 }
 775
 776 /* Emit a maybe_code_for_* function for ONAME.  */
 777
 778 static void
 779 handle_overloaded_code_for (overloaded_name *oname)
 780 {
 781   /* Print the function prototype.  */
 782   printf ("\ninsn_code\nmaybe_code_for_%s (", oname->name);
 783   print_overload_arguments (oname);
 784   printf (")\n{\n");
 785
 786   /* Use a sequence of "if" statements for each instance.  */
 787   for (overloaded_instance *instance = oname->first_instance;
 788        instance; instance = instance->next)
 789     {
 790       print_overload_test (instance);
 791       printf ("    return CODE_FOR_%s;\n", instance->name);
 792     }
 793
 794   /* Return null if no match was found.  */
 795   printf ("  return CODE_FOR_nothing;\n}\n");
 796 }
 797
 798 /* Emit a maybe_gen_* function for ONAME.  */
 799
 800 static void
 801 handle_overloaded_gen (overloaded_name *oname)
 802 {
 803   /* All patterns must have the same number of operands.  */
 804   pattern_stats stats;
 805   get_pattern_stats (&stats, XVEC (oname->first_instance->insn, 1));
 806   for (overloaded_instance *instance = oname->first_instance->next;
 807        instance; instance = instance->next)
 808     {
 809       pattern_stats stats2;
 810       get_pattern_stats (&stats2, XVEC (instance->insn, 1));
 811       if (stats.num_generator_args != stats2.num_generator_args)
 812         fatal_at (get_file_location (instance->insn),
 813                   "inconsistent number of operands for '%s'; "
 814                   "this instance has %d, but previous instances had %d",
 815                   oname->name, stats2.num_generator_args,
 816                   stats.num_generator_args);
 817     }
 818
 819   /* Print the function prototype.  */
 820   printf ("\nrtx\nmaybe_gen_%s (", oname->name);
 821   print_overload_arguments (oname);
 822   for (int i = 0; i < stats.num_generator_args; ++i)
 823     printf (", rtx x%d", i);
 824   printf (")\n{\n");
 825
 826   /* Use maybe_code_for_*, instead of duplicating the selection logic here.  */
 827   printf ("  insn_code code = maybe_code_for_%s (", oname->name);
 828   for (unsigned int i = 0; i < oname->arg_types.length (); ++i)
 829     printf ("%sarg%d", i == 0 ? "" : ", ", i);
 830   printf (");\n"
 831           "  if (code != CODE_FOR_nothing)\n"
 832           "    return GEN_FCN (code) (");
 833   for (int i = 0; i < stats.num_generator_args; ++i)
 834     printf ("%sx%d", i == 0 ? "" : ", ", i);
 835   printf (");\n"
 836           "  else\n"
 837           "    return NULL_RTX;\n"
 838           "}\n");
 839 }
 840
 841 int
 842 main (int argc, const char **argv)
 843 {
 844   progname = "genemit";
 845
 846   if (!init_rtx_reader_args (argc, argv))
 847     return (FATAL_EXIT_CODE);
 848
 849 #define DEF_INTERNAL_OPTAB_FN(NAME, FLAGS, OPTAB, TYPE) \
 850   nofail_optabs[OPTAB##_optab] = true;
 851 #include "internal-fn.def"
 852
 853   /* Assign sequential codes to all entries in the machine description
 854      in parallel with the tables in insn-output.c.  */
 855
 856   printf ("/* Generated automatically by the program `genemit'\n\
 857 from the machine description file `md'.  */\n\n");
 858
 859   printf ("#define IN_TARGET_CODE 1\n");
 860   printf ("#include \"config.h\"\n");
 861   printf ("#include \"system.h\"\n");
 862   printf ("#include \"coretypes.h\"\n");
 863   printf ("#include \"backend.h\"\n");
 864   printf ("#include \"predict.h\"\n");
 865   printf ("#include \"tree.h\"\n");
 866   printf ("#include \"rtl.h\"\n");
 867   printf ("#include \"alias.h\"\n");
 868   printf ("#include \"varasm.h\"\n");
 869   printf ("#include \"stor-layout.h\"\n");
 870   printf ("#include \"calls.h\"\n");
 871   printf ("#include \"memmodel.h\"\n");
 872   printf ("#include \"tm_p.h\"\n");
 873   printf ("#include \"flags.h\"\n");
 874   printf ("#include \"insn-config.h\"\n");
 875   printf ("#include \"expmed.h\"\n");
 876   printf ("#include \"dojump.h\"\n");
 877   printf ("#include \"explow.h\"\n");
 878   printf ("#include \"emit-rtl.h\"\n");
 879   printf ("#include \"stmt.h\"\n");
 880   printf ("#include \"expr.h\"\n");
 881   printf ("#include \"insn-codes.h\"\n");
 882   printf ("#include \"optabs.h\"\n");
 883   printf ("#include \"dfp.h\"\n");
 884   printf ("#include \"output.h\"\n");
 885   printf ("#include \"recog.h\"\n");
 886   printf ("#include \"df.h\"\n");
 887   printf ("#include \"resource.h\"\n");
 888   printf ("#include \"reload.h\"\n");
 889   printf ("#include \"diagnostic-core.h\"\n");
 890   printf ("#include \"regs.h\"\n");
 891   printf ("#include \"tm-constrs.h\"\n");
 892   printf ("#include \"ggc.h\"\n");
 893   printf ("#include \"target.h\"\n\n");
 894
 895   /* Read the machine description.  */
 896
 897   md_rtx_info info;
 898   while (read_md_rtx (&info))
 899     switch (GET_CODE (info.def))
 900       {
 901       case DEFINE_INSN:
 902         gen_insn (&info);
 903         break;
 904
 905       case DEFINE_EXPAND:
 906         printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
 907         gen_expand (&info);
 908         break;
 909
 910       case DEFINE_SPLIT:
 911         printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
 912         gen_split (&info);
 913         break;
 914
 915       case DEFINE_PEEPHOLE2:
 916         printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
 917         gen_split (&info);
 918         break;
 919
 920       default:
 921         break;
 922       }
 923
 924   /* Write out the routines to add CLOBBERs to a pattern and say whether they
 925      clobber a hard reg.  */
 926   output_add_clobbers ();
 927   output_added_clobbers_hard_reg_p ();
 928
 929   for (overloaded_name *oname = rtx_reader_ptr->get_overloads ();
 930        oname; oname = oname->next)
 931     {
 932       handle_overloaded_code_for (oname);
 933       handle_overloaded_gen (oname);
 934     }
 935
 936   fflush (stdout);
 937   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 938 }