gcc/genemit.c

   1 /* Generate code from machine description to emit insns as rtl.
   2    Copyright (C) 1987-2015 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 static int insn_code_number;
  32 static int insn_index_number;
  33
  34 /* Data structure for recording the patterns of insns that have CLOBBERs.
  35    We use this to output a function that adds these CLOBBERs to a
  36    previously-allocated PARALLEL expression.  */
  37
  38 struct clobber_pat
  39 {
  40   struct clobber_ent *insns;
  41   rtx pattern;
  42   int first_clobber;
  43   struct clobber_pat *next;
  44   int has_hard_reg;
  45 } *clobber_list;
  46
  47 /* Records one insn that uses the clobber list.  */
  48
  49 struct clobber_ent
  50 {
  51   int code_number;              /* Counts only insns.  */
  52   struct clobber_ent *next;
  53 };
  54
  55 static void print_code                  (RTX_CODE);
  56 static void gen_exp                     (rtx, enum rtx_code, char *);
  57 static void gen_insn                    (rtx, int);
  58 static void gen_expand                  (rtx);
  59 static void gen_split                   (rtx);
  60 static void output_add_clobbers         (void);
  61 static void output_added_clobbers_hard_reg_p (void);
  62 static void gen_rtx_scratch             (rtx, enum rtx_code);
  63 static void output_peephole2_scratches  (rtx);
  64
  65 \f
  66 static void
  67 print_code (RTX_CODE code)
  68 {
  69   const char *p1;
  70   for (p1 = GET_RTX_NAME (code); *p1; p1++)
  71     putchar (TOUPPER (*p1));
  72 }
  73
  74 static void
  75 gen_rtx_scratch (rtx x, enum rtx_code subroutine_type)
  76 {
  77   if (subroutine_type == DEFINE_PEEPHOLE2)
  78     {
  79       printf ("operand%d", XINT (x, 0));
  80     }
  81   else
  82     {
  83       printf ("gen_rtx_SCRATCH (%smode)", GET_MODE_NAME (GET_MODE (x)));
  84     }
  85 }
  86
  87 /* Print a C expression to construct an RTX just like X,
  88    substituting any operand references appearing within.  */
  89
  90 static void
  91 gen_exp (rtx x, enum rtx_code subroutine_type, char *used)
  92 {
  93   RTX_CODE code;
  94   int i;
  95   int len;
  96   const char *fmt;
  97   const char *sep = "";
  98
  99   if (x == 0)
 100     {
 101       printf ("NULL_RTX");
 102       return;
 103     }
 104
 105   code = GET_CODE (x);
 106
 107   switch (code)
 108     {
 109     case MATCH_OPERAND:
 110     case MATCH_DUP:
 111       if (used)
 112         {
 113           if (used[XINT (x, 0)])
 114             {
 115               printf ("copy_rtx (operand%d)", XINT (x, 0));
 116               return;
 117             }
 118           used[XINT (x, 0)] = 1;
 119         }
 120       printf ("operand%d", XINT (x, 0));
 121       return;
 122
 123     case MATCH_OP_DUP:
 124       printf ("gen_rtx_fmt_");
 125       for (i = 0; i < XVECLEN (x, 1); i++)
 126         printf ("e");
 127       printf (" (GET_CODE (operand%d), ", XINT (x, 0));
 128       if (GET_MODE (x) == VOIDmode)
 129         printf ("GET_MODE (operand%d)", XINT (x, 0));
 130       else
 131         printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
 132       for (i = 0; i < XVECLEN (x, 1); i++)
 133         {
 134           printf (",\n\t\t");
 135           gen_exp (XVECEXP (x, 1, i), subroutine_type, used);
 136         }
 137       printf (")");
 138       return;
 139
 140     case MATCH_OPERATOR:
 141       printf ("gen_rtx_fmt_");
 142       for (i = 0; i < XVECLEN (x, 2); i++)
 143         printf ("e");
 144       printf (" (GET_CODE (operand%d)", XINT (x, 0));
 145       printf (", %smode", GET_MODE_NAME (GET_MODE (x)));
 146       for (i = 0; i < XVECLEN (x, 2); i++)
 147         {
 148           printf (",\n\t\t");
 149           gen_exp (XVECEXP (x, 2, i), subroutine_type, used);
 150         }
 151       printf (")");
 152       return;
 153
 154     case MATCH_PARALLEL:
 155     case MATCH_PAR_DUP:
 156       printf ("operand%d", XINT (x, 0));
 157       return;
 158
 159     case MATCH_SCRATCH:
 160       gen_rtx_scratch (x, subroutine_type);
 161       return;
 162
 163     case PC:
 164       printf ("pc_rtx");
 165       return;
 166     case RETURN:
 167       printf ("ret_rtx");
 168       return;
 169     case SIMPLE_RETURN:
 170       printf ("simple_return_rtx");
 171       return;
 172     case CLOBBER:
 173       if (REG_P (XEXP (x, 0)))
 174         {
 175           printf ("gen_hard_reg_clobber (%smode, %i)", GET_MODE_NAME (GET_MODE (XEXP (x, 0))),
 176                                                      REGNO (XEXP (x, 0)));
 177           return;
 178         }
 179       break;
 180
 181     case CC0:
 182       printf ("cc0_rtx");
 183       return;
 184
 185     case CONST_INT:
 186       if (INTVAL (x) == 0)
 187         printf ("const0_rtx");
 188       else if (INTVAL (x) == 1)
 189         printf ("const1_rtx");
 190       else if (INTVAL (x) == -1)
 191         printf ("constm1_rtx");
 192       else if (-MAX_SAVED_CONST_INT <= INTVAL (x)
 193           && INTVAL (x) <= MAX_SAVED_CONST_INT)
 194         printf ("const_int_rtx[MAX_SAVED_CONST_INT + (%d)]",
 195                 (int) INTVAL (x));
 196       else if (INTVAL (x) == STORE_FLAG_VALUE)
 197         printf ("const_true_rtx");
 198       else
 199         {
 200           printf ("GEN_INT (");
 201           printf (HOST_WIDE_INT_PRINT_DEC_C, INTVAL (x));
 202           printf (")");
 203         }
 204       return;
 205
 206     case CONST_DOUBLE:
 207     case CONST_FIXED:
 208     case CONST_WIDE_INT:
 209       /* These shouldn't be written in MD files.  Instead, the appropriate
 210          routines in varasm.c should be called.  */
 211       gcc_unreachable ();
 212
 213     default:
 214       break;
 215     }
 216
 217   printf ("gen_rtx_");
 218   print_code (code);
 219   printf (" (");
 220   if (!always_void_p (code))
 221     {
 222       printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
 223       sep = ",\n\t";
 224     }
 225
 226   fmt = GET_RTX_FORMAT (code);
 227   len = GET_RTX_LENGTH (code);
 228   for (i = 0; i < len; i++)
 229     {
 230       if (fmt[i] == '0')
 231         break;
 232       fputs (sep, stdout);
 233       switch (fmt[i])
 234         {
 235         case 'e': case 'u':
 236           gen_exp (XEXP (x, i), subroutine_type, used);
 237           break;
 238
 239         case 'i':
 240           printf ("%u", XINT (x, i));
 241           break;
 242
 243         case 'r':
 244           printf ("%u", REGNO (x));
 245           break;
 246
 247         case 's':
 248           printf ("\"%s\"", XSTR (x, i));
 249           break;
 250
 251         case 'E':
 252           {
 253             int j;
 254             printf ("gen_rtvec (%d", XVECLEN (x, i));
 255             for (j = 0; j < XVECLEN (x, i); j++)
 256               {
 257                 printf (",\n\t\t");
 258                 gen_exp (XVECEXP (x, i, j), subroutine_type, used);
 259               }
 260             printf (")");
 261             break;
 262           }
 263
 264         default:
 265           gcc_unreachable ();
 266         }
 267       sep = ",\n\t";
 268     }
 269   printf (")");
 270 }
 271 \f
 272 /* Generate the `gen_...' function for a DEFINE_INSN.  */
 273
 274 static void
 275 gen_insn (rtx insn, int lineno)
 276 {
 277   struct pattern_stats stats;
 278   int i;
 279
 280   /* See if the pattern for this insn ends with a group of CLOBBERs of (hard)
 281      registers or MATCH_SCRATCHes.  If so, store away the information for
 282      later.  */
 283
 284   if (XVEC (insn, 1))
 285     {
 286       int has_hard_reg = 0;
 287
 288       for (i = XVECLEN (insn, 1) - 1; i > 0; i--)
 289         {
 290           if (GET_CODE (XVECEXP (insn, 1, i)) != CLOBBER)
 291             break;
 292
 293           if (REG_P (XEXP (XVECEXP (insn, 1, i), 0)))
 294             has_hard_reg = 1;
 295           else if (GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != MATCH_SCRATCH)
 296             break;
 297         }
 298
 299       if (i != XVECLEN (insn, 1) - 1)
 300         {
 301           struct clobber_pat *p;
 302           struct clobber_ent *link = XNEW (struct clobber_ent);
 303           int j;
 304
 305           link->code_number = insn_code_number;
 306
 307           /* See if any previous CLOBBER_LIST entry is the same as this
 308              one.  */
 309
 310           for (p = clobber_list; p; p = p->next)
 311             {
 312               if (p->first_clobber != i + 1
 313                   || XVECLEN (p->pattern, 1) != XVECLEN (insn, 1))
 314                 continue;
 315
 316               for (j = i + 1; j < XVECLEN (insn, 1); j++)
 317                 {
 318                   rtx old_rtx = XEXP (XVECEXP (p->pattern, 1, j), 0);
 319                   rtx new_rtx = XEXP (XVECEXP (insn, 1, j), 0);
 320
 321                   /* OLD and NEW_INSN are the same if both are to be a SCRATCH
 322                      of the same mode,
 323                      or if both are registers of the same mode and number.  */
 324                   if (! (GET_MODE (old_rtx) == GET_MODE (new_rtx)
 325                          && ((GET_CODE (old_rtx) == MATCH_SCRATCH
 326                               && GET_CODE (new_rtx) == MATCH_SCRATCH)
 327                              || (REG_P (old_rtx) && REG_P (new_rtx)
 328                                  && REGNO (old_rtx) == REGNO (new_rtx)))))
 329                     break;
 330                 }
 331
 332               if (j == XVECLEN (insn, 1))
 333                 break;
 334             }
 335
 336           if (p == 0)
 337             {
 338               p = XNEW (struct clobber_pat);
 339
 340               p->insns = 0;
 341               p->pattern = insn;
 342               p->first_clobber = i + 1;
 343               p->next = clobber_list;
 344               p->has_hard_reg = has_hard_reg;
 345               clobber_list = p;
 346             }
 347
 348           link->next = p->insns;
 349           p->insns = link;
 350         }
 351     }
 352
 353   /* Don't mention instructions whose names are the null string
 354      or begin with '*'.  They are in the machine description just
 355      to be recognized.  */
 356   if (XSTR (insn, 0)[0] == 0 || XSTR (insn, 0)[0] == '*')
 357     return;
 358
 359   printf ("/* %s:%d */\n", read_md_filename, lineno);
 360
 361   /* Find out how many operands this function has.  */
 362   get_pattern_stats (&stats, XVEC (insn, 1));
 363   if (stats.max_dup_opno > stats.max_opno)
 364     fatal ("match_dup operand number has no match_operand");
 365
 366   /* Output the function name and argument declarations.  */
 367   printf ("rtx\ngen_%s (", XSTR (insn, 0));
 368   if (stats.num_generator_args)
 369     for (i = 0; i < stats.num_generator_args; i++)
 370       if (i)
 371         printf (",\n\trtx operand%d ATTRIBUTE_UNUSED", i);
 372       else
 373         printf ("rtx operand%d ATTRIBUTE_UNUSED", i);
 374   else
 375     printf ("void");
 376   printf (")\n");
 377   printf ("{\n");
 378
 379   /* Output code to construct and return the rtl for the instruction body.  */
 380
 381   if (XVECLEN (insn, 1) == 1)
 382     {
 383       printf ("  return ");
 384       gen_exp (XVECEXP (insn, 1, 0), DEFINE_INSN, NULL);
 385       printf (";\n}\n\n");
 386     }
 387   else
 388     {
 389       char *used = XCNEWVEC (char, stats.num_generator_args);
 390
 391       printf ("  return gen_rtx_PARALLEL (VOIDmode, gen_rtvec (%d",
 392               XVECLEN (insn, 1));
 393
 394       for (i = 0; i < XVECLEN (insn, 1); i++)
 395         {
 396           printf (",\n\t\t");
 397           gen_exp (XVECEXP (insn, 1, i), DEFINE_INSN, used);
 398         }
 399       printf ("));\n}\n\n");
 400       XDELETEVEC (used);
 401     }
 402 }
 403 \f
 404 /* Generate the `gen_...' function for a DEFINE_EXPAND.  */
 405
 406 static void
 407 gen_expand (rtx expand)
 408 {
 409   struct pattern_stats stats;
 410   int i;
 411   char *used;
 412
 413   if (strlen (XSTR (expand, 0)) == 0)
 414     fatal ("define_expand lacks a name");
 415   if (XVEC (expand, 1) == 0)
 416     fatal ("define_expand for %s lacks a pattern", XSTR (expand, 0));
 417
 418   /* Find out how many operands this function has.  */
 419   get_pattern_stats (&stats, XVEC (expand, 1));
 420
 421   /* Output the function name and argument declarations.  */
 422   printf ("rtx\ngen_%s (", XSTR (expand, 0));
 423   if (stats.num_generator_args)
 424     for (i = 0; i < stats.num_generator_args; i++)
 425       if (i)
 426         printf (",\n\trtx operand%d", i);
 427       else
 428         printf ("rtx operand%d", i);
 429   else
 430     printf ("void");
 431   printf (")\n");
 432   printf ("{\n");
 433
 434   /* If we don't have any C code to write, only one insn is being written,
 435      and no MATCH_DUPs are present, we can just return the desired insn
 436      like we do for a DEFINE_INSN.  This saves memory.  */
 437   if ((XSTR (expand, 3) == 0 || *XSTR (expand, 3) == '\0')
 438       && stats.max_opno >= stats.max_dup_opno
 439       && XVECLEN (expand, 1) == 1)
 440     {
 441       printf ("  return ");
 442       gen_exp (XVECEXP (expand, 1, 0), DEFINE_EXPAND, NULL);
 443       printf (";\n}\n\n");
 444       return;
 445     }
 446
 447   /* For each operand referred to only with MATCH_DUPs,
 448      make a local variable.  */
 449   for (i = stats.num_generator_args; i <= stats.max_dup_opno; i++)
 450     printf ("  rtx operand%d;\n", i);
 451   for (; i <= stats.max_scratch_opno; i++)
 452     printf ("  rtx operand%d ATTRIBUTE_UNUSED;\n", i);
 453   printf ("  rtx_insn *_val = 0;\n");
 454   printf ("  start_sequence ();\n");
 455
 456   /* The fourth operand of DEFINE_EXPAND is some code to be executed
 457      before the actual construction.
 458      This code expects to refer to `operands'
 459      just as the output-code in a DEFINE_INSN does,
 460      but here `operands' is an automatic array.
 461      So copy the operand values there before executing it.  */
 462   if (XSTR (expand, 3) && *XSTR (expand, 3))
 463     {
 464       printf ("  {\n");
 465       if (stats.num_operand_vars > 0)
 466         printf ("    rtx operands[%d];\n", stats.num_operand_vars);
 467
 468       /* Output code to copy the arguments into `operands'.  */
 469       for (i = 0; i < stats.num_generator_args; i++)
 470         printf ("    operands[%d] = operand%d;\n", i, i);
 471
 472       /* Output the special code to be executed before the sequence
 473          is generated.  */
 474       print_md_ptr_loc (XSTR (expand, 3));
 475       printf ("%s\n", XSTR (expand, 3));
 476
 477       /* Output code to copy the arguments back out of `operands'
 478          (unless we aren't going to use them at all).  */
 479       if (XVEC (expand, 1) != 0)
 480         {
 481           for (i = 0; i < stats.num_operand_vars; i++)
 482             {
 483               printf ("    operand%d = operands[%d];\n", i, i);
 484               printf ("    (void) operand%d;\n", i);
 485             }
 486         }
 487       printf ("  }\n");
 488     }
 489
 490   /* Output code to construct the rtl for the instruction bodies.
 491      Use emit_insn to add them to the sequence being accumulated.
 492      But don't do this if the user's code has set `no_more' nonzero.  */
 493
 494   used = XCNEWVEC (char, stats.num_operand_vars);
 495
 496   for (i = 0; i < XVECLEN (expand, 1); i++)
 497     {
 498       rtx next = XVECEXP (expand, 1, i);
 499       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
 500           || (GET_CODE (next) == PARALLEL
 501               && ((GET_CODE (XVECEXP (next, 0, 0)) == SET
 502                    && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
 503                   || ANY_RETURN_P (XVECEXP (next, 0, 0))))
 504           || ANY_RETURN_P (next))
 505         printf ("  emit_jump_insn (");
 506       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
 507                || GET_CODE (next) == CALL
 508                || (GET_CODE (next) == PARALLEL
 509                    && GET_CODE (XVECEXP (next, 0, 0)) == SET
 510                    && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
 511                || (GET_CODE (next) == PARALLEL
 512                    && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
 513         printf ("  emit_call_insn (");
 514       else if (LABEL_P (next))
 515         printf ("  emit_label (");
 516       else if (GET_CODE (next) == MATCH_OPERAND
 517                || GET_CODE (next) == MATCH_DUP
 518                || GET_CODE (next) == MATCH_OPERATOR
 519                || GET_CODE (next) == MATCH_OP_DUP
 520                || GET_CODE (next) == MATCH_PARALLEL
 521                || GET_CODE (next) == MATCH_PAR_DUP
 522                || GET_CODE (next) == PARALLEL)
 523         printf ("  emit (");
 524       else
 525         printf ("  emit_insn (");
 526       gen_exp (next, DEFINE_EXPAND, used);
 527       printf (");\n");
 528       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
 529           && GET_CODE (SET_SRC (next)) == LABEL_REF)
 530         printf ("  emit_barrier ();");
 531     }
 532
 533   XDELETEVEC (used);
 534
 535   /* Call `get_insns' to extract the list of all the
 536      insns emitted within this gen_... function.  */
 537
 538   printf ("  _val = get_insns ();\n");
 539   printf ("  end_sequence ();\n");
 540   printf ("  return _val;\n}\n\n");
 541 }
 542
 543 /* Like gen_expand, but generates insns resulting from splitting SPLIT.  */
 544
 545 static void
 546 gen_split (rtx split)
 547 {
 548   struct pattern_stats stats;
 549   int i;
 550   const char *const name =
 551     ((GET_CODE (split) == DEFINE_PEEPHOLE2) ? "peephole2" : "split");
 552   const char *unused;
 553   char *used;
 554
 555   if (XVEC (split, 0) == 0)
 556     fatal ("define_%s (definition %d) lacks a pattern", name,
 557            insn_index_number);
 558   else if (XVEC (split, 2) == 0)
 559     fatal ("define_%s (definition %d) lacks a replacement pattern", name,
 560            insn_index_number);
 561
 562   /* Find out how many operands this function has.  */
 563
 564   get_pattern_stats (&stats, XVEC (split, 2));
 565   unused = (stats.num_operand_vars == 0 ? " ATTRIBUTE_UNUSED" : "");
 566   used = XCNEWVEC (char, stats.num_operand_vars);
 567
 568   /* Output the prototype, function name and argument declarations.  */
 569   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 570     {
 571       printf ("extern rtx_insn *gen_%s_%d (rtx_insn *, rtx *);\n",
 572               name, insn_code_number);
 573       printf ("rtx_insn *\ngen_%s_%d (rtx_insn *curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
 574               name, insn_code_number, unused);
 575     }
 576   else
 577     {
 578       printf ("extern rtx_insn *gen_split_%d (rtx_insn *, rtx *);\n",
 579               insn_code_number);
 580       printf ("rtx_insn *\ngen_split_%d "
 581               "(rtx_insn *curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
 582               insn_code_number, unused);
 583     }
 584   printf ("{\n");
 585
 586   /* Declare all local variables.  */
 587   for (i = 0; i < stats.num_operand_vars; i++)
 588     printf ("  rtx operand%d;\n", i);
 589   printf ("  rtx_insn *_val = NULL;\n");
 590
 591   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 592     output_peephole2_scratches (split);
 593
 594   printf ("  if (dump_file)\n");
 595   printf ("    fprintf (dump_file, \"Splitting with gen_%s_%d\\n\");\n",
 596           name, insn_code_number);
 597
 598   printf ("  start_sequence ();\n");
 599
 600   /* The fourth operand of DEFINE_SPLIT is some code to be executed
 601      before the actual construction.  */
 602
 603   if (XSTR (split, 3))
 604     {
 605       print_md_ptr_loc (XSTR (split, 3));
 606       printf ("%s\n", XSTR (split, 3));
 607     }
 608
 609   /* Output code to copy the arguments back out of `operands'  */
 610   for (i = 0; i < stats.num_operand_vars; i++)
 611     {
 612       printf ("  operand%d = operands[%d];\n", i, i);
 613       printf ("  (void) operand%d;\n", i);
 614     }
 615
 616   /* Output code to construct the rtl for the instruction bodies.
 617      Use emit_insn to add them to the sequence being accumulated.
 618      But don't do this if the user's code has set `no_more' nonzero.  */
 619
 620   for (i = 0; i < XVECLEN (split, 2); i++)
 621     {
 622       rtx next = XVECEXP (split, 2, i);
 623       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
 624           || (GET_CODE (next) == PARALLEL
 625               && GET_CODE (XVECEXP (next, 0, 0)) == SET
 626               && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
 627           || ANY_RETURN_P (next))
 628         printf ("  emit_jump_insn (");
 629       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
 630                || GET_CODE (next) == CALL
 631                || (GET_CODE (next) == PARALLEL
 632                    && GET_CODE (XVECEXP (next, 0, 0)) == SET
 633                    && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
 634                || (GET_CODE (next) == PARALLEL
 635                    && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
 636         printf ("  emit_call_insn (");
 637       else if (LABEL_P (next))
 638         printf ("  emit_label (");
 639       else if (GET_CODE (next) == MATCH_OPERAND
 640                || GET_CODE (next) == MATCH_OPERATOR
 641                || GET_CODE (next) == MATCH_PARALLEL
 642                || GET_CODE (next) == MATCH_OP_DUP
 643                || GET_CODE (next) == MATCH_DUP
 644                || GET_CODE (next) == PARALLEL)
 645         printf ("  emit (");
 646       else
 647         printf ("  emit_insn (");
 648       gen_exp (next, GET_CODE (split), used);
 649       printf (");\n");
 650       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
 651           && GET_CODE (SET_SRC (next)) == LABEL_REF)
 652         printf ("  emit_barrier ();");
 653     }
 654
 655   /* Call `get_insns' to make a list of all the
 656      insns emitted within this gen_... function.  */
 657
 658   printf ("  _val = get_insns ();\n");
 659   printf ("  end_sequence ();\n");
 660   printf ("  return _val;\n}\n\n");
 661
 662   free (used);
 663 }
 664 \f
 665 /* Write a function, `add_clobbers', that is given a PARALLEL of sufficient
 666    size for the insn and an INSN_CODE, and inserts the required CLOBBERs at
 667    the end of the vector.  */
 668
 669 static void
 670 output_add_clobbers (void)
 671 {
 672   struct clobber_pat *clobber;
 673   struct clobber_ent *ent;
 674   int i;
 675
 676   printf ("\n\nvoid\nadd_clobbers (rtx pattern ATTRIBUTE_UNUSED, int insn_code_number)\n");
 677   printf ("{\n");
 678   printf ("  switch (insn_code_number)\n");
 679   printf ("    {\n");
 680
 681   for (clobber = clobber_list; clobber; clobber = clobber->next)
 682     {
 683       for (ent = clobber->insns; ent; ent = ent->next)
 684         printf ("    case %d:\n", ent->code_number);
 685
 686       for (i = clobber->first_clobber; i < XVECLEN (clobber->pattern, 1); i++)
 687         {
 688           printf ("      XVECEXP (pattern, 0, %d) = ", i);
 689           gen_exp (XVECEXP (clobber->pattern, 1, i),
 690                    GET_CODE (clobber->pattern), NULL);
 691           printf (";\n");
 692         }
 693
 694       printf ("      break;\n\n");
 695     }
 696
 697   printf ("    default:\n");
 698   printf ("      gcc_unreachable ();\n");
 699   printf ("    }\n");
 700   printf ("}\n");
 701 }
 702 \f
 703 /* Write a function, `added_clobbers_hard_reg_p' that is given an insn_code
 704    number that will have clobbers added (as indicated by `recog') and returns
 705    1 if those include a clobber of a hard reg or 0 if all of them just clobber
 706    SCRATCH.  */
 707
 708 static void
 709 output_added_clobbers_hard_reg_p (void)
 710 {
 711   struct clobber_pat *clobber;
 712   struct clobber_ent *ent;
 713   int clobber_p, used;
 714
 715   printf ("\n\nint\nadded_clobbers_hard_reg_p (int insn_code_number)\n");
 716   printf ("{\n");
 717   printf ("  switch (insn_code_number)\n");
 718   printf ("    {\n");
 719
 720   for (clobber_p = 0; clobber_p <= 1; clobber_p++)
 721     {
 722       used = 0;
 723       for (clobber = clobber_list; clobber; clobber = clobber->next)
 724         if (clobber->has_hard_reg == clobber_p)
 725           for (ent = clobber->insns; ent; ent = ent->next)
 726             {
 727               printf ("    case %d:\n", ent->code_number);
 728               used++;
 729             }
 730
 731       if (used)
 732         printf ("      return %d;\n\n", clobber_p);
 733     }
 734
 735   printf ("    default:\n");
 736   printf ("      gcc_unreachable ();\n");
 737   printf ("    }\n");
 738   printf ("}\n");
 739 }
 740 \f
 741 /* Generate code to invoke find_free_register () as needed for the
 742    scratch registers used by the peephole2 pattern in SPLIT.  */
 743
 744 static void
 745 output_peephole2_scratches (rtx split)
 746 {
 747   int i;
 748   int insn_nr = 0;
 749   bool first = true;
 750
 751   for (i = 0; i < XVECLEN (split, 0); i++)
 752     {
 753       rtx elt = XVECEXP (split, 0, i);
 754       if (GET_CODE (elt) == MATCH_SCRATCH)
 755         {
 756           int last_insn_nr = insn_nr;
 757           int cur_insn_nr = insn_nr;
 758           int j;
 759           for (j = i + 1; j < XVECLEN (split, 0); j++)
 760             if (GET_CODE (XVECEXP (split, 0, j)) == MATCH_DUP)
 761               {
 762                 if (XINT (XVECEXP (split, 0, j), 0) == XINT (elt, 0))
 763                   last_insn_nr = cur_insn_nr;
 764               }
 765             else if (GET_CODE (XVECEXP (split, 0, j)) != MATCH_SCRATCH)
 766               cur_insn_nr++;
 767
 768           if (first)
 769             {
 770               printf ("  HARD_REG_SET _regs_allocated;\n");
 771               printf ("  CLEAR_HARD_REG_SET (_regs_allocated);\n");
 772               first = false;
 773             }
 774
 775           printf ("  if ((operands[%d] = peep2_find_free_register (%d, %d, \"%s\", %smode, &_regs_allocated)) == NULL_RTX)\n\
 776     return NULL;\n",
 777                   XINT (elt, 0),
 778                   insn_nr, last_insn_nr,
 779                   XSTR (elt, 1),
 780                   GET_MODE_NAME (GET_MODE (elt)));
 781
 782         }
 783       else if (GET_CODE (elt) != MATCH_DUP)
 784         insn_nr++;
 785     }
 786 }
 787
 788 int
 789 main (int argc, char **argv)
 790 {
 791   rtx desc;
 792
 793   progname = "genemit";
 794
 795   if (!init_rtx_reader_args (argc, argv))
 796     return (FATAL_EXIT_CODE);
 797
 798   /* Assign sequential codes to all entries in the machine description
 799      in parallel with the tables in insn-output.c.  */
 800
 801   insn_code_number = 0;
 802   insn_index_number = 0;
 803
 804   printf ("/* Generated automatically by the program `genemit'\n\
 805 from the machine description file `md'.  */\n\n");
 806
 807   printf ("#include \"config.h\"\n");
 808   printf ("#include \"system.h\"\n");
 809   printf ("#include \"coretypes.h\"\n");
 810   printf ("#include \"tm.h\"\n");
 811   printf ("#include \"input.h\"\n");
 812   printf ("#include \"alias.h\"\n");
 813   printf ("#include \"symtab.h\"\n");
 814   printf ("#include \"tree.h\"\n");
 815   printf ("#include \"varasm.h\"\n");
 816   printf ("#include \"stor-layout.h\"\n");
 817   printf ("#include \"calls.h\"\n");
 818   printf ("#include \"rtl.h\"\n");
 819   printf ("#include \"tm_p.h\"\n");
 820   printf ("#include \"hard-reg-set.h\"\n");
 821   printf ("#include \"function.h\"\n");
 822   printf ("#include \"flags.h\"\n");
 823   printf ("#include \"insn-config.h\"\n");
 824   printf ("#include \"expmed.h\"\n");
 825   printf ("#include \"dojump.h\"\n");
 826   printf ("#include \"explow.h\"\n");
 827   printf ("#include \"emit-rtl.h\"\n");
 828   printf ("#include \"stmt.h\"\n");
 829   printf ("#include \"expr.h\"\n");
 830   printf ("#include \"insn-codes.h\"\n");
 831   printf ("#include \"optabs.h\"\n");
 832   printf ("#include \"dfp.h\"\n");
 833   printf ("#include \"output.h\"\n");
 834   printf ("#include \"recog.h\"\n");
 835   printf ("#include \"predict.h\"\n");
 836   printf ("#include \"basic-block.h\"\n");
 837   printf ("#include \"resource.h\"\n");
 838   printf ("#include \"reload.h\"\n");
 839   printf ("#include \"diagnostic-core.h\"\n");
 840   printf ("#include \"regs.h\"\n");
 841   printf ("#include \"tm-constrs.h\"\n");
 842   printf ("#include \"ggc.h\"\n");
 843   printf ("#include \"basic-block.h\"\n");
 844   printf ("#include \"dumpfile.h\"\n");
 845   printf ("#include \"target.h\"\n\n");
 846   printf ("#define FAIL return (end_sequence (), _val)\n");
 847   printf ("#define DONE return (_val = get_insns (), end_sequence (), _val)\n\n");
 848
 849   /* Read the machine description.  */
 850
 851   while (1)
 852     {
 853       int line_no;
 854
 855       desc = read_md_rtx (&line_no, &insn_code_number);
 856       if (desc == NULL)
 857         break;
 858
 859       switch (GET_CODE (desc))
 860         {
 861         case DEFINE_INSN:
 862           gen_insn (desc, line_no);
 863           break;
 864
 865         case DEFINE_EXPAND:
 866           printf ("/* %s:%d */\n", read_md_filename, line_no);
 867           gen_expand (desc);
 868           break;
 869
 870         case DEFINE_SPLIT:
 871           printf ("/* %s:%d */\n", read_md_filename, line_no);
 872           gen_split (desc);
 873           break;
 874
 875         case DEFINE_PEEPHOLE2:
 876           printf ("/* %s:%d */\n", read_md_filename, line_no);
 877           gen_split (desc);
 878           break;
 879
 880         default:
 881           break;
 882         }
 883       ++insn_index_number;
 884     }
 885
 886   /* Write out the routines to add CLOBBERs to a pattern and say whether they
 887      clobber a hard reg.  */
 888   output_add_clobbers ();
 889   output_added_clobbers_hard_reg_p ();
 890
 891   fflush (stdout);
 892   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 893 }