gcc/genemit.c

   1 /* Generate code from machine description to emit insns as rtl.
   2    Copyright (C) 1987, 1988, 1991, 1994, 1995, 1997, 1998, 1999, 2000, 2001,
   3    2003, 2004, 2005, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21
  22 #include "bconfig.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "rtl.h"
  27 #include "errors.h"
  28 #include "read-md.h"
  29 #include "gensupport.h"
  30
  31
  32 static int insn_code_number;
  33 static int insn_index_number;
  34
  35 /* Data structure for recording the patterns of insns that have CLOBBERs.
  36    We use this to output a function that adds these CLOBBERs to a
  37    previously-allocated PARALLEL expression.  */
  38
  39 struct clobber_pat
  40 {
  41   struct clobber_ent *insns;
  42   rtx pattern;
  43   int first_clobber;
  44   struct clobber_pat *next;
  45   int has_hard_reg;
  46 } *clobber_list;
  47
  48 /* Records one insn that uses the clobber list.  */
  49
  50 struct clobber_ent
  51 {
  52   int code_number;              /* Counts only insns.  */
  53   struct clobber_ent *next;
  54 };
  55
  56 static void print_code                  (RTX_CODE);
  57 static void gen_exp                     (rtx, enum rtx_code, char *);
  58 static void gen_insn                    (rtx, int);
  59 static void gen_expand                  (rtx);
  60 static void gen_split                   (rtx);
  61 static void output_add_clobbers         (void);
  62 static void output_added_clobbers_hard_reg_p (void);
  63 static void gen_rtx_scratch             (rtx, enum rtx_code);
  64 static void output_peephole2_scratches  (rtx);
  65
  66 \f
  67 static void
  68 print_code (RTX_CODE code)
  69 {
  70   const char *p1;
  71   for (p1 = GET_RTX_NAME (code); *p1; p1++)
  72     putchar (TOUPPER(*p1));
  73 }
  74
  75 static void
  76 gen_rtx_scratch (rtx x, enum rtx_code subroutine_type)
  77 {
  78   if (subroutine_type == DEFINE_PEEPHOLE2)
  79     {
  80       printf ("operand%d", XINT (x, 0));
  81     }
  82   else
  83     {
  84       printf ("gen_rtx_SCRATCH (%smode)", GET_MODE_NAME (GET_MODE (x)));
  85     }
  86 }
  87
  88 /* Print a C expression to construct an RTX just like X,
  89    substituting any operand references appearing within.  */
  90
  91 static void
  92 gen_exp (rtx x, enum rtx_code subroutine_type, char *used)
  93 {
  94   RTX_CODE code;
  95   int i;
  96   int len;
  97   const char *fmt;
  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       /* These shouldn't be written in MD files.  Instead, the appropriate
 209          routines in varasm.c should be called.  */
 210       gcc_unreachable ();
 211
 212     default:
 213       break;
 214     }
 215
 216   printf ("gen_rtx_");
 217   print_code (code);
 218   printf (" (%smode", GET_MODE_NAME (GET_MODE (x)));
 219
 220   fmt = GET_RTX_FORMAT (code);
 221   len = GET_RTX_LENGTH (code);
 222   for (i = 0; i < len; i++)
 223     {
 224       if (fmt[i] == '0')
 225         break;
 226       printf (",\n\t");
 227       switch (fmt[i])
 228         {
 229         case 'e': case 'u':
 230           gen_exp (XEXP (x, i), subroutine_type, used);
 231           break;
 232
 233         case 'i':
 234           printf ("%u", XINT (x, i));
 235           break;
 236
 237         case 's':
 238           printf ("\"%s\"", XSTR (x, i));
 239           break;
 240
 241         case 'E':
 242           {
 243             int j;
 244             printf ("gen_rtvec (%d", XVECLEN (x, i));
 245             for (j = 0; j < XVECLEN (x, i); j++)
 246               {
 247                 printf (",\n\t\t");
 248                 gen_exp (XVECEXP (x, i, j), subroutine_type, used);
 249               }
 250             printf (")");
 251             break;
 252           }
 253
 254         default:
 255           gcc_unreachable ();
 256         }
 257     }
 258   printf (")");
 259 }
 260 \f
 261 /* Generate the `gen_...' function for a DEFINE_INSN.  */
 262
 263 static void
 264 gen_insn (rtx insn, int lineno)
 265 {
 266   struct pattern_stats stats;
 267   int i;
 268
 269   /* See if the pattern for this insn ends with a group of CLOBBERs of (hard)
 270      registers or MATCH_SCRATCHes.  If so, store away the information for
 271      later.  */
 272
 273   if (XVEC (insn, 1))
 274     {
 275       int has_hard_reg = 0;
 276
 277       for (i = XVECLEN (insn, 1) - 1; i > 0; i--)
 278         {
 279           if (GET_CODE (XVECEXP (insn, 1, i)) != CLOBBER)
 280             break;
 281
 282           if (REG_P (XEXP (XVECEXP (insn, 1, i), 0)))
 283             has_hard_reg = 1;
 284           else if (GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != MATCH_SCRATCH)
 285             break;
 286         }
 287
 288       if (i != XVECLEN (insn, 1) - 1)
 289         {
 290           struct clobber_pat *p;
 291           struct clobber_ent *link = XNEW (struct clobber_ent);
 292           int j;
 293
 294           link->code_number = insn_code_number;
 295
 296           /* See if any previous CLOBBER_LIST entry is the same as this
 297              one.  */
 298
 299           for (p = clobber_list; p; p = p->next)
 300             {
 301               if (p->first_clobber != i + 1
 302                   || XVECLEN (p->pattern, 1) != XVECLEN (insn, 1))
 303                 continue;
 304
 305               for (j = i + 1; j < XVECLEN (insn, 1); j++)
 306                 {
 307                   rtx old_rtx = XEXP (XVECEXP (p->pattern, 1, j), 0);
 308                   rtx new_rtx = XEXP (XVECEXP (insn, 1, j), 0);
 309
 310                   /* OLD and NEW_INSN are the same if both are to be a SCRATCH
 311                      of the same mode,
 312                      or if both are registers of the same mode and number.  */
 313                   if (! (GET_MODE (old_rtx) == GET_MODE (new_rtx)
 314                          && ((GET_CODE (old_rtx) == MATCH_SCRATCH
 315                               && GET_CODE (new_rtx) == MATCH_SCRATCH)
 316                              || (REG_P (old_rtx) && REG_P (new_rtx)
 317                                  && REGNO (old_rtx) == REGNO (new_rtx)))))
 318                     break;
 319                 }
 320
 321               if (j == XVECLEN (insn, 1))
 322                 break;
 323             }
 324
 325           if (p == 0)
 326             {
 327               p = XNEW (struct clobber_pat);
 328
 329               p->insns = 0;
 330               p->pattern = insn;
 331               p->first_clobber = i + 1;
 332               p->next = clobber_list;
 333               p->has_hard_reg = has_hard_reg;
 334               clobber_list = p;
 335             }
 336
 337           link->next = p->insns;
 338           p->insns = link;
 339         }
 340     }
 341
 342   /* Don't mention instructions whose names are the null string
 343      or begin with '*'.  They are in the machine description just
 344      to be recognized.  */
 345   if (XSTR (insn, 0)[0] == 0 || XSTR (insn, 0)[0] == '*')
 346     return;
 347
 348   printf ("/* %s:%d */\n", read_md_filename, lineno);
 349
 350   /* Find out how many operands this function has.  */
 351   get_pattern_stats (&stats, XVEC (insn, 1));
 352   if (stats.max_dup_opno > stats.max_opno)
 353     fatal ("match_dup operand number has no match_operand");
 354
 355   /* Output the function name and argument declarations.  */
 356   printf ("rtx\ngen_%s (", XSTR (insn, 0));
 357   if (stats.num_generator_args)
 358     for (i = 0; i < stats.num_generator_args; i++)
 359       if (i)
 360         printf (",\n\trtx operand%d ATTRIBUTE_UNUSED", i);
 361       else
 362         printf ("rtx operand%d ATTRIBUTE_UNUSED", i);
 363   else
 364     printf ("void");
 365   printf (")\n");
 366   printf ("{\n");
 367
 368   /* Output code to construct and return the rtl for the instruction body.  */
 369
 370   if (XVECLEN (insn, 1) == 1)
 371     {
 372       printf ("  return ");
 373       gen_exp (XVECEXP (insn, 1, 0), DEFINE_INSN, NULL);
 374       printf (";\n}\n\n");
 375     }
 376   else
 377     {
 378       char *used = XCNEWVEC (char, stats.num_generator_args);
 379
 380       printf ("  return gen_rtx_PARALLEL (VOIDmode, gen_rtvec (%d",
 381               XVECLEN (insn, 1));
 382
 383       for (i = 0; i < XVECLEN (insn, 1); i++)
 384         {
 385           printf (",\n\t\t");
 386           gen_exp (XVECEXP (insn, 1, i), DEFINE_INSN, used);
 387         }
 388       printf ("));\n}\n\n");
 389       XDELETEVEC (used);
 390     }
 391 }
 392 \f
 393 /* Generate the `gen_...' function for a DEFINE_EXPAND.  */
 394
 395 static void
 396 gen_expand (rtx expand)
 397 {
 398   struct pattern_stats stats;
 399   int i;
 400   char *used;
 401
 402   if (strlen (XSTR (expand, 0)) == 0)
 403     fatal ("define_expand lacks a name");
 404   if (XVEC (expand, 1) == 0)
 405     fatal ("define_expand for %s lacks a pattern", XSTR (expand, 0));
 406
 407   /* Find out how many operands this function has.  */
 408   get_pattern_stats (&stats, XVEC (expand, 1));
 409
 410   /* Output the function name and argument declarations.  */
 411   printf ("rtx\ngen_%s (", XSTR (expand, 0));
 412   if (stats.num_generator_args)
 413     for (i = 0; i < stats.num_generator_args; i++)
 414       if (i)
 415         printf (",\n\trtx operand%d", i);
 416       else
 417         printf ("rtx operand%d", i);
 418   else
 419     printf ("void");
 420   printf (")\n");
 421   printf ("{\n");
 422
 423   /* If we don't have any C code to write, only one insn is being written,
 424      and no MATCH_DUPs are present, we can just return the desired insn
 425      like we do for a DEFINE_INSN.  This saves memory.  */
 426   if ((XSTR (expand, 3) == 0 || *XSTR (expand, 3) == '\0')
 427       && stats.max_opno >= stats.max_dup_opno
 428       && XVECLEN (expand, 1) == 1)
 429     {
 430       printf ("  return ");
 431       gen_exp (XVECEXP (expand, 1, 0), DEFINE_EXPAND, NULL);
 432       printf (";\n}\n\n");
 433       return;
 434     }
 435
 436   /* For each operand referred to only with MATCH_DUPs,
 437      make a local variable.  */
 438   for (i = stats.num_generator_args; i <= stats.max_dup_opno; i++)
 439     printf ("  rtx operand%d;\n", i);
 440   for (; i <= stats.max_scratch_opno; i++)
 441     printf ("  rtx operand%d ATTRIBUTE_UNUSED;\n", i);
 442   printf ("  rtx _val = 0;\n");
 443   printf ("  start_sequence ();\n");
 444
 445   /* The fourth operand of DEFINE_EXPAND is some code to be executed
 446      before the actual construction.
 447      This code expects to refer to `operands'
 448      just as the output-code in a DEFINE_INSN does,
 449      but here `operands' is an automatic array.
 450      So copy the operand values there before executing it.  */
 451   if (XSTR (expand, 3) && *XSTR (expand, 3))
 452     {
 453       printf ("  {\n");
 454       if (stats.num_operand_vars > 0)
 455         printf ("    rtx operands[%d];\n", stats.num_operand_vars);
 456
 457       /* Output code to copy the arguments into `operands'.  */
 458       for (i = 0; i < stats.num_generator_args; i++)
 459         printf ("    operands[%d] = operand%d;\n", i, i);
 460
 461       /* Output the special code to be executed before the sequence
 462          is generated.  */
 463       print_md_ptr_loc (XSTR (expand, 3));
 464       printf ("%s\n", XSTR (expand, 3));
 465
 466       /* Output code to copy the arguments back out of `operands'
 467          (unless we aren't going to use them at all).  */
 468       if (XVEC (expand, 1) != 0)
 469         {
 470           for (i = 0; i < stats.num_operand_vars; i++)
 471             {
 472               printf ("    operand%d = operands[%d];\n", i, i);
 473               printf ("    (void) operand%d;\n", i);
 474             }
 475         }
 476       printf ("  }\n");
 477     }
 478
 479   /* Output code to construct the rtl for the instruction bodies.
 480      Use emit_insn to add them to the sequence being accumulated.
 481      But don't do this if the user's code has set `no_more' nonzero.  */
 482
 483   used = XCNEWVEC (char, stats.num_operand_vars);
 484
 485   for (i = 0; i < XVECLEN (expand, 1); i++)
 486     {
 487       rtx next = XVECEXP (expand, 1, i);
 488       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
 489           || (GET_CODE (next) == PARALLEL
 490               && ((GET_CODE (XVECEXP (next, 0, 0)) == SET
 491                    && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
 492                   || ANY_RETURN_P (XVECEXP (next, 0, 0))))
 493           || ANY_RETURN_P (next))
 494         printf ("  emit_jump_insn (");
 495       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
 496                || GET_CODE (next) == CALL
 497                || (GET_CODE (next) == PARALLEL
 498                    && GET_CODE (XVECEXP (next, 0, 0)) == SET
 499                    && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
 500                || (GET_CODE (next) == PARALLEL
 501                    && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
 502         printf ("  emit_call_insn (");
 503       else if (LABEL_P (next))
 504         printf ("  emit_label (");
 505       else if (GET_CODE (next) == MATCH_OPERAND
 506                || GET_CODE (next) == MATCH_DUP
 507                || GET_CODE (next) == MATCH_OPERATOR
 508                || GET_CODE (next) == MATCH_OP_DUP
 509                || GET_CODE (next) == MATCH_PARALLEL
 510                || GET_CODE (next) == MATCH_PAR_DUP
 511                || GET_CODE (next) == PARALLEL)
 512         printf ("  emit (");
 513       else
 514         printf ("  emit_insn (");
 515       gen_exp (next, DEFINE_EXPAND, used);
 516       printf (");\n");
 517       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
 518           && GET_CODE (SET_SRC (next)) == LABEL_REF)
 519         printf ("  emit_barrier ();");
 520     }
 521
 522   XDELETEVEC (used);
 523
 524   /* Call `get_insns' to extract the list of all the
 525      insns emitted within this gen_... function.  */
 526
 527   printf ("  _val = get_insns ();\n");
 528   printf ("  end_sequence ();\n");
 529   printf ("  return _val;\n}\n\n");
 530 }
 531
 532 /* Like gen_expand, but generates insns resulting from splitting SPLIT.  */
 533
 534 static void
 535 gen_split (rtx split)
 536 {
 537   struct pattern_stats stats;
 538   int i;
 539   const char *const name =
 540     ((GET_CODE (split) == DEFINE_PEEPHOLE2) ? "peephole2" : "split");
 541   const char *unused;
 542   char *used;
 543
 544   if (XVEC (split, 0) == 0)
 545     fatal ("define_%s (definition %d) lacks a pattern", name,
 546            insn_index_number);
 547   else if (XVEC (split, 2) == 0)
 548     fatal ("define_%s (definition %d) lacks a replacement pattern", name,
 549            insn_index_number);
 550
 551   /* Find out how many operands this function has.  */
 552
 553   get_pattern_stats (&stats, XVEC (split, 2));
 554   unused = (stats.num_operand_vars == 0 ? " ATTRIBUTE_UNUSED" : "");
 555   used = XCNEWVEC (char, stats.num_operand_vars);
 556
 557   /* Output the prototype, function name and argument declarations.  */
 558   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 559     {
 560       printf ("extern rtx gen_%s_%d (rtx, rtx *);\n",
 561               name, insn_code_number);
 562       printf ("rtx\ngen_%s_%d (rtx curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
 563               name, insn_code_number, unused);
 564     }
 565   else
 566     {
 567       printf ("extern rtx gen_split_%d (rtx, rtx *);\n", insn_code_number);
 568       printf ("rtx\ngen_split_%d (rtx curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
 569               insn_code_number, unused);
 570     }
 571   printf ("{\n");
 572
 573   /* Declare all local variables.  */
 574   for (i = 0; i < stats.num_operand_vars; i++)
 575     printf ("  rtx operand%d;\n", i);
 576   printf ("  rtx _val = 0;\n");
 577
 578   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 579     output_peephole2_scratches (split);
 580
 581   printf ("  start_sequence ();\n");
 582
 583   /* The fourth operand of DEFINE_SPLIT is some code to be executed
 584      before the actual construction.  */
 585
 586   if (XSTR (split, 3))
 587     {
 588       print_md_ptr_loc (XSTR (split, 3));
 589       printf ("%s\n", XSTR (split, 3));
 590     }
 591
 592   /* Output code to copy the arguments back out of `operands'  */
 593   for (i = 0; i < stats.num_operand_vars; i++)
 594     {
 595       printf ("  operand%d = operands[%d];\n", i, i);
 596       printf ("  (void) operand%d;\n", i);
 597     }
 598
 599   /* Output code to construct the rtl for the instruction bodies.
 600      Use emit_insn to add them to the sequence being accumulated.
 601      But don't do this if the user's code has set `no_more' nonzero.  */
 602
 603   for (i = 0; i < XVECLEN (split, 2); i++)
 604     {
 605       rtx next = XVECEXP (split, 2, i);
 606       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
 607           || (GET_CODE (next) == PARALLEL
 608               && GET_CODE (XVECEXP (next, 0, 0)) == SET
 609               && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
 610           || ANY_RETURN_P (next))
 611         printf ("  emit_jump_insn (");
 612       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
 613                || GET_CODE (next) == CALL
 614                || (GET_CODE (next) == PARALLEL
 615                    && GET_CODE (XVECEXP (next, 0, 0)) == SET
 616                    && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
 617                || (GET_CODE (next) == PARALLEL
 618                    && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
 619         printf ("  emit_call_insn (");
 620       else if (LABEL_P (next))
 621         printf ("  emit_label (");
 622       else if (GET_CODE (next) == MATCH_OPERAND
 623                || GET_CODE (next) == MATCH_OPERATOR
 624                || GET_CODE (next) == MATCH_PARALLEL
 625                || GET_CODE (next) == MATCH_OP_DUP
 626                || GET_CODE (next) == MATCH_DUP
 627                || GET_CODE (next) == PARALLEL)
 628         printf ("  emit (");
 629       else
 630         printf ("  emit_insn (");
 631       gen_exp (next, GET_CODE (split), used);
 632       printf (");\n");
 633       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
 634           && GET_CODE (SET_SRC (next)) == LABEL_REF)
 635         printf ("  emit_barrier ();");
 636     }
 637
 638   /* Call `get_insns' to make a list of all the
 639      insns emitted within this gen_... function.  */
 640
 641   printf ("  _val = get_insns ();\n");
 642   printf ("  end_sequence ();\n");
 643   printf ("  return _val;\n}\n\n");
 644
 645   free (used);
 646 }
 647 \f
 648 /* Write a function, `add_clobbers', that is given a PARALLEL of sufficient
 649    size for the insn and an INSN_CODE, and inserts the required CLOBBERs at
 650    the end of the vector.  */
 651
 652 static void
 653 output_add_clobbers (void)
 654 {
 655   struct clobber_pat *clobber;
 656   struct clobber_ent *ent;
 657   int i;
 658
 659   printf ("\n\nvoid\nadd_clobbers (rtx pattern ATTRIBUTE_UNUSED, int insn_code_number)\n");
 660   printf ("{\n");
 661   printf ("  switch (insn_code_number)\n");
 662   printf ("    {\n");
 663
 664   for (clobber = clobber_list; clobber; clobber = clobber->next)
 665     {
 666       for (ent = clobber->insns; ent; ent = ent->next)
 667         printf ("    case %d:\n", ent->code_number);
 668
 669       for (i = clobber->first_clobber; i < XVECLEN (clobber->pattern, 1); i++)
 670         {
 671           printf ("      XVECEXP (pattern, 0, %d) = ", i);
 672           gen_exp (XVECEXP (clobber->pattern, 1, i),
 673                    GET_CODE (clobber->pattern), NULL);
 674           printf (";\n");
 675         }
 676
 677       printf ("      break;\n\n");
 678     }
 679
 680   printf ("    default:\n");
 681   printf ("      gcc_unreachable ();\n");
 682   printf ("    }\n");
 683   printf ("}\n");
 684 }
 685 \f
 686 /* Write a function, `added_clobbers_hard_reg_p' that is given an insn_code
 687    number that will have clobbers added (as indicated by `recog') and returns
 688    1 if those include a clobber of a hard reg or 0 if all of them just clobber
 689    SCRATCH.  */
 690
 691 static void
 692 output_added_clobbers_hard_reg_p (void)
 693 {
 694   struct clobber_pat *clobber;
 695   struct clobber_ent *ent;
 696   int clobber_p, used;
 697
 698   printf ("\n\nint\nadded_clobbers_hard_reg_p (int insn_code_number)\n");
 699   printf ("{\n");
 700   printf ("  switch (insn_code_number)\n");
 701   printf ("    {\n");
 702
 703   for (clobber_p = 0; clobber_p <= 1; clobber_p++)
 704     {
 705       used = 0;
 706       for (clobber = clobber_list; clobber; clobber = clobber->next)
 707         if (clobber->has_hard_reg == clobber_p)
 708           for (ent = clobber->insns; ent; ent = ent->next)
 709             {
 710               printf ("    case %d:\n", ent->code_number);
 711               used++;
 712             }
 713
 714       if (used)
 715         printf ("      return %d;\n\n", clobber_p);
 716     }
 717
 718   printf ("    default:\n");
 719   printf ("      gcc_unreachable ();\n");
 720   printf ("    }\n");
 721   printf ("}\n");
 722 }
 723 \f
 724 /* Generate code to invoke find_free_register () as needed for the
 725    scratch registers used by the peephole2 pattern in SPLIT.  */
 726
 727 static void
 728 output_peephole2_scratches (rtx split)
 729 {
 730   int i;
 731   int insn_nr = 0;
 732   bool first = true;
 733
 734   for (i = 0; i < XVECLEN (split, 0); i++)
 735     {
 736       rtx elt = XVECEXP (split, 0, i);
 737       if (GET_CODE (elt) == MATCH_SCRATCH)
 738         {
 739           int last_insn_nr = insn_nr;
 740           int cur_insn_nr = insn_nr;
 741           int j;
 742           for (j = i + 1; j < XVECLEN (split, 0); j++)
 743             if (GET_CODE (XVECEXP (split, 0, j)) == MATCH_DUP)
 744               {
 745                 if (XINT (XVECEXP (split, 0, j), 0) == XINT (elt, 0))
 746                   last_insn_nr = cur_insn_nr;
 747               }
 748             else if (GET_CODE (XVECEXP (split, 0, j)) != MATCH_SCRATCH)
 749               cur_insn_nr++;
 750
 751           if (first)
 752             {
 753               printf ("  HARD_REG_SET _regs_allocated;\n");
 754               printf ("  CLEAR_HARD_REG_SET (_regs_allocated);\n");
 755               first = false;
 756             }
 757
 758           printf ("  if ((operands[%d] = peep2_find_free_register (%d, %d, \"%s\", %smode, &_regs_allocated)) == NULL_RTX)\n\
 759     return NULL;\n",
 760                   XINT (elt, 0),
 761                   insn_nr, last_insn_nr,
 762                   XSTR (elt, 1),
 763                   GET_MODE_NAME (GET_MODE (elt)));
 764
 765         }
 766       else if (GET_CODE (elt) != MATCH_DUP)
 767         insn_nr++;
 768     }
 769 }
 770
 771 int
 772 main (int argc, char **argv)
 773 {
 774   rtx desc;
 775
 776   progname = "genemit";
 777
 778   if (!init_rtx_reader_args (argc, argv))
 779     return (FATAL_EXIT_CODE);
 780
 781   /* Assign sequential codes to all entries in the machine description
 782      in parallel with the tables in insn-output.c.  */
 783
 784   insn_code_number = 0;
 785   insn_index_number = 0;
 786
 787   printf ("/* Generated automatically by the program `genemit'\n\
 788 from the machine description file `md'.  */\n\n");
 789
 790   printf ("#include \"config.h\"\n");
 791   printf ("#include \"system.h\"\n");
 792   printf ("#include \"coretypes.h\"\n");
 793   printf ("#include \"tm.h\"\n");
 794   printf ("#include \"rtl.h\"\n");
 795   printf ("#include \"tm_p.h\"\n");
 796   printf ("#include \"function.h\"\n");
 797   printf ("#include \"expr.h\"\n");
 798   printf ("#include \"optabs.h\"\n");
 799   printf ("#include \"dfp.h\"\n");
 800   printf ("#include \"flags.h\"\n");
 801   printf ("#include \"output.h\"\n");
 802   printf ("#include \"insn-config.h\"\n");
 803   printf ("#include \"hard-reg-set.h\"\n");
 804   printf ("#include \"recog.h\"\n");
 805   printf ("#include \"resource.h\"\n");
 806   printf ("#include \"reload.h\"\n");
 807   printf ("#include \"diagnostic-core.h\"\n");
 808   printf ("#include \"regs.h\"\n");
 809   printf ("#include \"tm-constrs.h\"\n");
 810   printf ("#include \"ggc.h\"\n");
 811   printf ("#include \"basic-block.h\"\n");
 812   printf ("#include \"target.h\"\n\n");
 813   printf ("#define FAIL return (end_sequence (), _val)\n");
 814   printf ("#define DONE return (_val = get_insns (), end_sequence (), _val)\n\n");
 815
 816   /* Read the machine description.  */
 817
 818   while (1)
 819     {
 820       int line_no;
 821
 822       desc = read_md_rtx (&line_no, &insn_code_number);
 823       if (desc == NULL)
 824         break;
 825
 826       switch (GET_CODE (desc))
 827         {
 828         case DEFINE_INSN:
 829           gen_insn (desc, line_no);
 830           break;
 831
 832         case DEFINE_EXPAND:
 833           printf ("/* %s:%d */\n", read_md_filename, line_no);
 834           gen_expand (desc);
 835           break;
 836
 837         case DEFINE_SPLIT:
 838           printf ("/* %s:%d */\n", read_md_filename, line_no);
 839           gen_split (desc);
 840           break;
 841
 842         case DEFINE_PEEPHOLE2:
 843           printf ("/* %s:%d */\n", read_md_filename, line_no);
 844           gen_split (desc);
 845           break;
 846
 847         default:
 848           break;
 849         }
 850       ++insn_index_number;
 851     }
 852
 853   /* Write out the routines to add CLOBBERs to a pattern and say whether they
 854      clobber a hard reg.  */
 855   output_add_clobbers ();
 856   output_added_clobbers_hard_reg_p ();
 857
 858   fflush (stdout);
 859   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 860 }