gcc/genemit.c

   1 /* Generate code from machine description to emit insns as rtl.
   2    Copyright (C) 1987-2013 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
  98   if (x == 0)
  99     {
 100       printf ("NULL_RTX");
 101       return;
 102     }
 103
 104   code = GET_CODE (x);
 105
 106   switch (code)
 107     {
 108     case MATCH_OPERAND:
 109     case MATCH_DUP:
 110       if (used)
 111         {
 112           if (used[XINT (x, 0)])
 113             {
 114               printf ("copy_rtx (operand%d)", XINT (x, 0));
 115               return;
 116             }
 117           used[XINT (x, 0)] = 1;
 118         }
 119       printf ("operand%d", XINT (x, 0));
 120       return;
 121
 122     case MATCH_OP_DUP:
 123       printf ("gen_rtx_fmt_");
 124       for (i = 0; i < XVECLEN (x, 1); i++)
 125         printf ("e");
 126       printf (" (GET_CODE (operand%d), ", XINT (x, 0));
 127       if (GET_MODE (x) == VOIDmode)
 128         printf ("GET_MODE (operand%d)", XINT (x, 0));
 129       else
 130         printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
 131       for (i = 0; i < XVECLEN (x, 1); i++)
 132         {
 133           printf (",\n\t\t");
 134           gen_exp (XVECEXP (x, 1, i), subroutine_type, used);
 135         }
 136       printf (")");
 137       return;
 138
 139     case MATCH_OPERATOR:
 140       printf ("gen_rtx_fmt_");
 141       for (i = 0; i < XVECLEN (x, 2); i++)
 142         printf ("e");
 143       printf (" (GET_CODE (operand%d)", XINT (x, 0));
 144       printf (", %smode", GET_MODE_NAME (GET_MODE (x)));
 145       for (i = 0; i < XVECLEN (x, 2); i++)
 146         {
 147           printf (",\n\t\t");
 148           gen_exp (XVECEXP (x, 2, i), subroutine_type, used);
 149         }
 150       printf (")");
 151       return;
 152
 153     case MATCH_PARALLEL:
 154     case MATCH_PAR_DUP:
 155       printf ("operand%d", XINT (x, 0));
 156       return;
 157
 158     case MATCH_SCRATCH:
 159       gen_rtx_scratch (x, subroutine_type);
 160       return;
 161
 162     case PC:
 163       printf ("pc_rtx");
 164       return;
 165     case RETURN:
 166       printf ("ret_rtx");
 167       return;
 168     case SIMPLE_RETURN:
 169       printf ("simple_return_rtx");
 170       return;
 171     case CLOBBER:
 172       if (REG_P (XEXP (x, 0)))
 173         {
 174           printf ("gen_hard_reg_clobber (%smode, %i)", GET_MODE_NAME (GET_MODE (XEXP (x, 0))),
 175                                                      REGNO (XEXP (x, 0)));
 176           return;
 177         }
 178       break;
 179
 180     case CC0:
 181       printf ("cc0_rtx");
 182       return;
 183
 184     case CONST_INT:
 185       if (INTVAL (x) == 0)
 186         printf ("const0_rtx");
 187       else if (INTVAL (x) == 1)
 188         printf ("const1_rtx");
 189       else if (INTVAL (x) == -1)
 190         printf ("constm1_rtx");
 191       else if (-MAX_SAVED_CONST_INT <= INTVAL (x)
 192           && INTVAL (x) <= MAX_SAVED_CONST_INT)
 193         printf ("const_int_rtx[MAX_SAVED_CONST_INT + (%d)]",
 194                 (int) INTVAL (x));
 195       else if (INTVAL (x) == STORE_FLAG_VALUE)
 196         printf ("const_true_rtx");
 197       else
 198         {
 199           printf ("GEN_INT (");
 200           printf (HOST_WIDE_INT_PRINT_DEC_C, INTVAL (x));
 201           printf (")");
 202         }
 203       return;
 204
 205     case CONST_DOUBLE:
 206     case CONST_FIXED:
 207       /* These shouldn't be written in MD files.  Instead, the appropriate
 208          routines in varasm.c should be called.  */
 209       gcc_unreachable ();
 210
 211     default:
 212       break;
 213     }
 214
 215   printf ("gen_rtx_");
 216   print_code (code);
 217   printf (" (%smode", GET_MODE_NAME (GET_MODE (x)));
 218
 219   fmt = GET_RTX_FORMAT (code);
 220   len = GET_RTX_LENGTH (code);
 221   for (i = 0; i < len; i++)
 222     {
 223       if (fmt[i] == '0')
 224         break;
 225       printf (",\n\t");
 226       switch (fmt[i])
 227         {
 228         case 'e': case 'u':
 229           gen_exp (XEXP (x, i), subroutine_type, used);
 230           break;
 231
 232         case 'i':
 233           printf ("%u", XINT (x, i));
 234           break;
 235
 236         case 's':
 237           printf ("\"%s\"", XSTR (x, i));
 238           break;
 239
 240         case 'E':
 241           {
 242             int j;
 243             printf ("gen_rtvec (%d", XVECLEN (x, i));
 244             for (j = 0; j < XVECLEN (x, i); j++)
 245               {
 246                 printf (",\n\t\t");
 247                 gen_exp (XVECEXP (x, i, j), subroutine_type, used);
 248               }
 249             printf (")");
 250             break;
 251           }
 252
 253         default:
 254           gcc_unreachable ();
 255         }
 256     }
 257   printf (")");
 258 }
 259 \f
 260 /* Generate the `gen_...' function for a DEFINE_INSN.  */
 261
 262 static void
 263 gen_insn (rtx insn, int lineno)
 264 {
 265   struct pattern_stats stats;
 266   int i;
 267
 268   /* See if the pattern for this insn ends with a group of CLOBBERs of (hard)
 269      registers or MATCH_SCRATCHes.  If so, store away the information for
 270      later.  */
 271
 272   if (XVEC (insn, 1))
 273     {
 274       int has_hard_reg = 0;
 275
 276       for (i = XVECLEN (insn, 1) - 1; i > 0; i--)
 277         {
 278           if (GET_CODE (XVECEXP (insn, 1, i)) != CLOBBER)
 279             break;
 280
 281           if (REG_P (XEXP (XVECEXP (insn, 1, i), 0)))
 282             has_hard_reg = 1;
 283           else if (GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != MATCH_SCRATCH)
 284             break;
 285         }
 286
 287       if (i != XVECLEN (insn, 1) - 1)
 288         {
 289           struct clobber_pat *p;
 290           struct clobber_ent *link = XNEW (struct clobber_ent);
 291           int j;
 292
 293           link->code_number = insn_code_number;
 294
 295           /* See if any previous CLOBBER_LIST entry is the same as this
 296              one.  */
 297
 298           for (p = clobber_list; p; p = p->next)
 299             {
 300               if (p->first_clobber != i + 1
 301                   || XVECLEN (p->pattern, 1) != XVECLEN (insn, 1))
 302                 continue;
 303
 304               for (j = i + 1; j < XVECLEN (insn, 1); j++)
 305                 {
 306                   rtx old_rtx = XEXP (XVECEXP (p->pattern, 1, j), 0);
 307                   rtx new_rtx = XEXP (XVECEXP (insn, 1, j), 0);
 308
 309                   /* OLD and NEW_INSN are the same if both are to be a SCRATCH
 310                      of the same mode,
 311                      or if both are registers of the same mode and number.  */
 312                   if (! (GET_MODE (old_rtx) == GET_MODE (new_rtx)
 313                          && ((GET_CODE (old_rtx) == MATCH_SCRATCH
 314                               && GET_CODE (new_rtx) == MATCH_SCRATCH)
 315                              || (REG_P (old_rtx) && REG_P (new_rtx)
 316                                  && REGNO (old_rtx) == REGNO (new_rtx)))))
 317                     break;
 318                 }
 319
 320               if (j == XVECLEN (insn, 1))
 321                 break;
 322             }
 323
 324           if (p == 0)
 325             {
 326               p = XNEW (struct clobber_pat);
 327
 328               p->insns = 0;
 329               p->pattern = insn;
 330               p->first_clobber = i + 1;
 331               p->next = clobber_list;
 332               p->has_hard_reg = has_hard_reg;
 333               clobber_list = p;
 334             }
 335
 336           link->next = p->insns;
 337           p->insns = link;
 338         }
 339     }
 340
 341   /* Don't mention instructions whose names are the null string
 342      or begin with '*'.  They are in the machine description just
 343      to be recognized.  */
 344   if (XSTR (insn, 0)[0] == 0 || XSTR (insn, 0)[0] == '*')
 345     return;
 346
 347   printf ("/* %s:%d */\n", read_md_filename, lineno);
 348
 349   /* Find out how many operands this function has.  */
 350   get_pattern_stats (&stats, XVEC (insn, 1));
 351   if (stats.max_dup_opno > stats.max_opno)
 352     fatal ("match_dup operand number has no match_operand");
 353
 354   /* Output the function name and argument declarations.  */
 355   printf ("rtx\ngen_%s (", XSTR (insn, 0));
 356   if (stats.num_generator_args)
 357     for (i = 0; i < stats.num_generator_args; i++)
 358       if (i)
 359         printf (",\n\trtx operand%d ATTRIBUTE_UNUSED", i);
 360       else
 361         printf ("rtx operand%d ATTRIBUTE_UNUSED", i);
 362   else
 363     printf ("void");
 364   printf (")\n");
 365   printf ("{\n");
 366
 367   /* Output code to construct and return the rtl for the instruction body.  */
 368
 369   if (XVECLEN (insn, 1) == 1)
 370     {
 371       printf ("  return ");
 372       gen_exp (XVECEXP (insn, 1, 0), DEFINE_INSN, NULL);
 373       printf (";\n}\n\n");
 374     }
 375   else
 376     {
 377       char *used = XCNEWVEC (char, stats.num_generator_args);
 378
 379       printf ("  return gen_rtx_PARALLEL (VOIDmode, gen_rtvec (%d",
 380               XVECLEN (insn, 1));
 381
 382       for (i = 0; i < XVECLEN (insn, 1); i++)
 383         {
 384           printf (",\n\t\t");
 385           gen_exp (XVECEXP (insn, 1, i), DEFINE_INSN, used);
 386         }
 387       printf ("));\n}\n\n");
 388       XDELETEVEC (used);
 389     }
 390 }
 391 \f
 392 /* Generate the `gen_...' function for a DEFINE_EXPAND.  */
 393
 394 static void
 395 gen_expand (rtx expand)
 396 {
 397   struct pattern_stats stats;
 398   int i;
 399   char *used;
 400
 401   if (strlen (XSTR (expand, 0)) == 0)
 402     fatal ("define_expand lacks a name");
 403   if (XVEC (expand, 1) == 0)
 404     fatal ("define_expand for %s lacks a pattern", XSTR (expand, 0));
 405
 406   /* Find out how many operands this function has.  */
 407   get_pattern_stats (&stats, XVEC (expand, 1));
 408
 409   /* Output the function name and argument declarations.  */
 410   printf ("rtx\ngen_%s (", XSTR (expand, 0));
 411   if (stats.num_generator_args)
 412     for (i = 0; i < stats.num_generator_args; i++)
 413       if (i)
 414         printf (",\n\trtx operand%d", i);
 415       else
 416         printf ("rtx operand%d", i);
 417   else
 418     printf ("void");
 419   printf (")\n");
 420   printf ("{\n");
 421
 422   /* If we don't have any C code to write, only one insn is being written,
 423      and no MATCH_DUPs are present, we can just return the desired insn
 424      like we do for a DEFINE_INSN.  This saves memory.  */
 425   if ((XSTR (expand, 3) == 0 || *XSTR (expand, 3) == '\0')
 426       && stats.max_opno >= stats.max_dup_opno
 427       && XVECLEN (expand, 1) == 1)
 428     {
 429       printf ("  return ");
 430       gen_exp (XVECEXP (expand, 1, 0), DEFINE_EXPAND, NULL);
 431       printf (";\n}\n\n");
 432       return;
 433     }
 434
 435   /* For each operand referred to only with MATCH_DUPs,
 436      make a local variable.  */
 437   for (i = stats.num_generator_args; i <= stats.max_dup_opno; i++)
 438     printf ("  rtx operand%d;\n", i);
 439   for (; i <= stats.max_scratch_opno; i++)
 440     printf ("  rtx operand%d ATTRIBUTE_UNUSED;\n", i);
 441   printf ("  rtx _val = 0;\n");
 442   printf ("  start_sequence ();\n");
 443
 444   /* The fourth operand of DEFINE_EXPAND is some code to be executed
 445      before the actual construction.
 446      This code expects to refer to `operands'
 447      just as the output-code in a DEFINE_INSN does,
 448      but here `operands' is an automatic array.
 449      So copy the operand values there before executing it.  */
 450   if (XSTR (expand, 3) && *XSTR (expand, 3))
 451     {
 452       printf ("  {\n");
 453       if (stats.num_operand_vars > 0)
 454         printf ("    rtx operands[%d];\n", stats.num_operand_vars);
 455
 456       /* Output code to copy the arguments into `operands'.  */
 457       for (i = 0; i < stats.num_generator_args; i++)
 458         printf ("    operands[%d] = operand%d;\n", i, i);
 459
 460       /* Output the special code to be executed before the sequence
 461          is generated.  */
 462       print_md_ptr_loc (XSTR (expand, 3));
 463       printf ("%s\n", XSTR (expand, 3));
 464
 465       /* Output code to copy the arguments back out of `operands'
 466          (unless we aren't going to use them at all).  */
 467       if (XVEC (expand, 1) != 0)
 468         {
 469           for (i = 0; i < stats.num_operand_vars; i++)
 470             {
 471               printf ("    operand%d = operands[%d];\n", i, i);
 472               printf ("    (void) operand%d;\n", i);
 473             }
 474         }
 475       printf ("  }\n");
 476     }
 477
 478   /* Output code to construct the rtl for the instruction bodies.
 479      Use emit_insn to add them to the sequence being accumulated.
 480      But don't do this if the user's code has set `no_more' nonzero.  */
 481
 482   used = XCNEWVEC (char, stats.num_operand_vars);
 483
 484   for (i = 0; i < XVECLEN (expand, 1); i++)
 485     {
 486       rtx next = XVECEXP (expand, 1, i);
 487       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
 488           || (GET_CODE (next) == PARALLEL
 489               && ((GET_CODE (XVECEXP (next, 0, 0)) == SET
 490                    && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
 491                   || ANY_RETURN_P (XVECEXP (next, 0, 0))))
 492           || ANY_RETURN_P (next))
 493         printf ("  emit_jump_insn (");
 494       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
 495                || GET_CODE (next) == CALL
 496                || (GET_CODE (next) == PARALLEL
 497                    && GET_CODE (XVECEXP (next, 0, 0)) == SET
 498                    && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
 499                || (GET_CODE (next) == PARALLEL
 500                    && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
 501         printf ("  emit_call_insn (");
 502       else if (LABEL_P (next))
 503         printf ("  emit_label (");
 504       else if (GET_CODE (next) == MATCH_OPERAND
 505                || GET_CODE (next) == MATCH_DUP
 506                || GET_CODE (next) == MATCH_OPERATOR
 507                || GET_CODE (next) == MATCH_OP_DUP
 508                || GET_CODE (next) == MATCH_PARALLEL
 509                || GET_CODE (next) == MATCH_PAR_DUP
 510                || GET_CODE (next) == PARALLEL)
 511         printf ("  emit (");
 512       else
 513         printf ("  emit_insn (");
 514       gen_exp (next, DEFINE_EXPAND, used);
 515       printf (");\n");
 516       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
 517           && GET_CODE (SET_SRC (next)) == LABEL_REF)
 518         printf ("  emit_barrier ();");
 519     }
 520
 521   XDELETEVEC (used);
 522
 523   /* Call `get_insns' to extract the list of all the
 524      insns emitted within this gen_... function.  */
 525
 526   printf ("  _val = get_insns ();\n");
 527   printf ("  end_sequence ();\n");
 528   printf ("  return _val;\n}\n\n");
 529 }
 530
 531 /* Like gen_expand, but generates insns resulting from splitting SPLIT.  */
 532
 533 static void
 534 gen_split (rtx split)
 535 {
 536   struct pattern_stats stats;
 537   int i;
 538   const char *const name =
 539     ((GET_CODE (split) == DEFINE_PEEPHOLE2) ? "peephole2" : "split");
 540   const char *unused;
 541   char *used;
 542
 543   if (XVEC (split, 0) == 0)
 544     fatal ("define_%s (definition %d) lacks a pattern", name,
 545            insn_index_number);
 546   else if (XVEC (split, 2) == 0)
 547     fatal ("define_%s (definition %d) lacks a replacement pattern", name,
 548            insn_index_number);
 549
 550   /* Find out how many operands this function has.  */
 551
 552   get_pattern_stats (&stats, XVEC (split, 2));
 553   unused = (stats.num_operand_vars == 0 ? " ATTRIBUTE_UNUSED" : "");
 554   used = XCNEWVEC (char, stats.num_operand_vars);
 555
 556   /* Output the prototype, function name and argument declarations.  */
 557   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 558     {
 559       printf ("extern rtx gen_%s_%d (rtx, rtx *);\n",
 560               name, insn_code_number);
 561       printf ("rtx\ngen_%s_%d (rtx curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
 562               name, insn_code_number, unused);
 563     }
 564   else
 565     {
 566       printf ("extern rtx gen_split_%d (rtx, rtx *);\n", insn_code_number);
 567       printf ("rtx\ngen_split_%d (rtx curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
 568               insn_code_number, unused);
 569     }
 570   printf ("{\n");
 571
 572   /* Declare all local variables.  */
 573   for (i = 0; i < stats.num_operand_vars; i++)
 574     printf ("  rtx operand%d;\n", i);
 575   printf ("  rtx _val = 0;\n");
 576
 577   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 578     output_peephole2_scratches (split);
 579
 580   printf ("  start_sequence ();\n");
 581
 582   /* The fourth operand of DEFINE_SPLIT is some code to be executed
 583      before the actual construction.  */
 584
 585   if (XSTR (split, 3))
 586     {
 587       print_md_ptr_loc (XSTR (split, 3));
 588       printf ("%s\n", XSTR (split, 3));
 589     }
 590
 591   /* Output code to copy the arguments back out of `operands'  */
 592   for (i = 0; i < stats.num_operand_vars; i++)
 593     {
 594       printf ("  operand%d = operands[%d];\n", i, i);
 595       printf ("  (void) operand%d;\n", i);
 596     }
 597
 598   /* Output code to construct the rtl for the instruction bodies.
 599      Use emit_insn to add them to the sequence being accumulated.
 600      But don't do this if the user's code has set `no_more' nonzero.  */
 601
 602   for (i = 0; i < XVECLEN (split, 2); i++)
 603     {
 604       rtx next = XVECEXP (split, 2, i);
 605       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
 606           || (GET_CODE (next) == PARALLEL
 607               && GET_CODE (XVECEXP (next, 0, 0)) == SET
 608               && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
 609           || ANY_RETURN_P (next))
 610         printf ("  emit_jump_insn (");
 611       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
 612                || GET_CODE (next) == CALL
 613                || (GET_CODE (next) == PARALLEL
 614                    && GET_CODE (XVECEXP (next, 0, 0)) == SET
 615                    && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
 616                || (GET_CODE (next) == PARALLEL
 617                    && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
 618         printf ("  emit_call_insn (");
 619       else if (LABEL_P (next))
 620         printf ("  emit_label (");
 621       else if (GET_CODE (next) == MATCH_OPERAND
 622                || GET_CODE (next) == MATCH_OPERATOR
 623                || GET_CODE (next) == MATCH_PARALLEL
 624                || GET_CODE (next) == MATCH_OP_DUP
 625                || GET_CODE (next) == MATCH_DUP
 626                || GET_CODE (next) == PARALLEL)
 627         printf ("  emit (");
 628       else
 629         printf ("  emit_insn (");
 630       gen_exp (next, GET_CODE (split), used);
 631       printf (");\n");
 632       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
 633           && GET_CODE (SET_SRC (next)) == LABEL_REF)
 634         printf ("  emit_barrier ();");
 635     }
 636
 637   /* Call `get_insns' to make a list of all the
 638      insns emitted within this gen_... function.  */
 639
 640   printf ("  _val = get_insns ();\n");
 641   printf ("  end_sequence ();\n");
 642   printf ("  return _val;\n}\n\n");
 643
 644   free (used);
 645 }
 646 \f
 647 /* Write a function, `add_clobbers', that is given a PARALLEL of sufficient
 648    size for the insn and an INSN_CODE, and inserts the required CLOBBERs at
 649    the end of the vector.  */
 650
 651 static void
 652 output_add_clobbers (void)
 653 {
 654   struct clobber_pat *clobber;
 655   struct clobber_ent *ent;
 656   int i;
 657
 658   printf ("\n\nvoid\nadd_clobbers (rtx pattern ATTRIBUTE_UNUSED, int insn_code_number)\n");
 659   printf ("{\n");
 660   printf ("  switch (insn_code_number)\n");
 661   printf ("    {\n");
 662
 663   for (clobber = clobber_list; clobber; clobber = clobber->next)
 664     {
 665       for (ent = clobber->insns; ent; ent = ent->next)
 666         printf ("    case %d:\n", ent->code_number);
 667
 668       for (i = clobber->first_clobber; i < XVECLEN (clobber->pattern, 1); i++)
 669         {
 670           printf ("      XVECEXP (pattern, 0, %d) = ", i);
 671           gen_exp (XVECEXP (clobber->pattern, 1, i),
 672                    GET_CODE (clobber->pattern), NULL);
 673           printf (";\n");
 674         }
 675
 676       printf ("      break;\n\n");
 677     }
 678
 679   printf ("    default:\n");
 680   printf ("      gcc_unreachable ();\n");
 681   printf ("    }\n");
 682   printf ("}\n");
 683 }
 684 \f
 685 /* Write a function, `added_clobbers_hard_reg_p' that is given an insn_code
 686    number that will have clobbers added (as indicated by `recog') and returns
 687    1 if those include a clobber of a hard reg or 0 if all of them just clobber
 688    SCRATCH.  */
 689
 690 static void
 691 output_added_clobbers_hard_reg_p (void)
 692 {
 693   struct clobber_pat *clobber;
 694   struct clobber_ent *ent;
 695   int clobber_p, used;
 696
 697   printf ("\n\nint\nadded_clobbers_hard_reg_p (int insn_code_number)\n");
 698   printf ("{\n");
 699   printf ("  switch (insn_code_number)\n");
 700   printf ("    {\n");
 701
 702   for (clobber_p = 0; clobber_p <= 1; clobber_p++)
 703     {
 704       used = 0;
 705       for (clobber = clobber_list; clobber; clobber = clobber->next)
 706         if (clobber->has_hard_reg == clobber_p)
 707           for (ent = clobber->insns; ent; ent = ent->next)
 708             {
 709               printf ("    case %d:\n", ent->code_number);
 710               used++;
 711             }
 712
 713       if (used)
 714         printf ("      return %d;\n\n", clobber_p);
 715     }
 716
 717   printf ("    default:\n");
 718   printf ("      gcc_unreachable ();\n");
 719   printf ("    }\n");
 720   printf ("}\n");
 721 }
 722 \f
 723 /* Generate code to invoke find_free_register () as needed for the
 724    scratch registers used by the peephole2 pattern in SPLIT.  */
 725
 726 static void
 727 output_peephole2_scratches (rtx split)
 728 {
 729   int i;
 730   int insn_nr = 0;
 731   bool first = true;
 732
 733   for (i = 0; i < XVECLEN (split, 0); i++)
 734     {
 735       rtx elt = XVECEXP (split, 0, i);
 736       if (GET_CODE (elt) == MATCH_SCRATCH)
 737         {
 738           int last_insn_nr = insn_nr;
 739           int cur_insn_nr = insn_nr;
 740           int j;
 741           for (j = i + 1; j < XVECLEN (split, 0); j++)
 742             if (GET_CODE (XVECEXP (split, 0, j)) == MATCH_DUP)
 743               {
 744                 if (XINT (XVECEXP (split, 0, j), 0) == XINT (elt, 0))
 745                   last_insn_nr = cur_insn_nr;
 746               }
 747             else if (GET_CODE (XVECEXP (split, 0, j)) != MATCH_SCRATCH)
 748               cur_insn_nr++;
 749
 750           if (first)
 751             {
 752               printf ("  HARD_REG_SET _regs_allocated;\n");
 753               printf ("  CLEAR_HARD_REG_SET (_regs_allocated);\n");
 754               first = false;
 755             }
 756
 757           printf ("  if ((operands[%d] = peep2_find_free_register (%d, %d, \"%s\", %smode, &_regs_allocated)) == NULL_RTX)\n\
 758     return NULL;\n",
 759                   XINT (elt, 0),
 760                   insn_nr, last_insn_nr,
 761                   XSTR (elt, 1),
 762                   GET_MODE_NAME (GET_MODE (elt)));
 763
 764         }
 765       else if (GET_CODE (elt) != MATCH_DUP)
 766         insn_nr++;
 767     }
 768 }
 769
 770 int
 771 main (int argc, char **argv)
 772 {
 773   rtx desc;
 774
 775   progname = "genemit";
 776
 777   if (!init_rtx_reader_args (argc, argv))
 778     return (FATAL_EXIT_CODE);
 779
 780   /* Assign sequential codes to all entries in the machine description
 781      in parallel with the tables in insn-output.c.  */
 782
 783   insn_code_number = 0;
 784   insn_index_number = 0;
 785
 786   printf ("/* Generated automatically by the program `genemit'\n\
 787 from the machine description file `md'.  */\n\n");
 788
 789   printf ("#include \"config.h\"\n");
 790   printf ("#include \"system.h\"\n");
 791   printf ("#include \"coretypes.h\"\n");
 792   printf ("#include \"tm.h\"\n");
 793   printf ("#include \"rtl.h\"\n");
 794   printf ("#include \"tm_p.h\"\n");
 795   printf ("#include \"function.h\"\n");
 796   printf ("#include \"expr.h\"\n");
 797   printf ("#include \"optabs.h\"\n");
 798   printf ("#include \"dfp.h\"\n");
 799   printf ("#include \"flags.h\"\n");
 800   printf ("#include \"output.h\"\n");
 801   printf ("#include \"insn-config.h\"\n");
 802   printf ("#include \"hard-reg-set.h\"\n");
 803   printf ("#include \"recog.h\"\n");
 804   printf ("#include \"resource.h\"\n");
 805   printf ("#include \"reload.h\"\n");
 806   printf ("#include \"diagnostic-core.h\"\n");
 807   printf ("#include \"regs.h\"\n");
 808   printf ("#include \"tm-constrs.h\"\n");
 809   printf ("#include \"ggc.h\"\n");
 810   printf ("#include \"basic-block.h\"\n");
 811   printf ("#include \"target.h\"\n\n");
 812   printf ("#define FAIL return (end_sequence (), _val)\n");
 813   printf ("#define DONE return (_val = get_insns (), end_sequence (), _val)\n\n");
 814
 815   /* Read the machine description.  */
 816
 817   while (1)
 818     {
 819       int line_no;
 820
 821       desc = read_md_rtx (&line_no, &insn_code_number);
 822       if (desc == NULL)
 823         break;
 824
 825       switch (GET_CODE (desc))
 826         {
 827         case DEFINE_INSN:
 828           gen_insn (desc, line_no);
 829           break;
 830
 831         case DEFINE_EXPAND:
 832           printf ("/* %s:%d */\n", read_md_filename, line_no);
 833           gen_expand (desc);
 834           break;
 835
 836         case DEFINE_SPLIT:
 837           printf ("/* %s:%d */\n", read_md_filename, line_no);
 838           gen_split (desc);
 839           break;
 840
 841         case DEFINE_PEEPHOLE2:
 842           printf ("/* %s:%d */\n", read_md_filename, line_no);
 843           gen_split (desc);
 844           break;
 845
 846         default:
 847           break;
 848         }
 849       ++insn_index_number;
 850     }
 851
 852   /* Write out the routines to add CLOBBERs to a pattern and say whether they
 853      clobber a hard reg.  */
 854   output_add_clobbers ();
 855   output_added_clobbers_hard_reg_p ();
 856
 857   fflush (stdout);
 858   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 859 }