gcc/genemit.c

   1 /* Generate code from machine description to emit insns as rtl.
   2    Copyright (C) 1987, 88, 91, 94, 95, 97, 98, 1999 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21
  22 #include "hconfig.h"
  23 #include "system.h"
  24 #include "rtl.h"
  25 #include "obstack.h"
  26 #include "errors.h"
  27
  28 static struct obstack obstack;
  29 struct obstack *rtl_obstack = &obstack;
  30
  31 #define obstack_chunk_alloc xmalloc
  32 #define obstack_chunk_free free
  33
  34 static int max_opno;
  35 static int max_dup_opno;
  36 static int max_scratch_opno;
  37 static int register_constraints;
  38 static int insn_code_number;
  39 static int insn_index_number;
  40
  41 /* Data structure for recording the patterns of insns that have CLOBBERs.
  42    We use this to output a function that adds these CLOBBERs to a
  43    previously-allocated PARALLEL expression.  */
  44
  45 struct clobber_pat
  46 {
  47   struct clobber_ent *insns;
  48   rtx pattern;
  49   int first_clobber;
  50   struct clobber_pat *next;
  51 } *clobber_list;
  52
  53 /* Records one insn that uses the clobber list.  */
  54
  55 struct clobber_ent
  56 {
  57   int code_number;              /* Counts only insns.  */
  58   struct clobber_ent *next;
  59 };
  60
  61 static void max_operand_1               PROTO((rtx));
  62 static int max_operand_vec              PROTO((rtx, int));
  63 static void print_code                  PROTO((RTX_CODE));
  64 static void gen_exp                     PROTO((rtx, enum rtx_code));
  65 static void gen_insn                    PROTO((rtx));
  66 static void gen_expand                  PROTO((rtx));
  67 static void gen_split                   PROTO((rtx));
  68 static void output_add_clobbers         PROTO((void));
  69 static void gen_rtx_scratch             PROTO((rtx, enum rtx_code));
  70 static void output_peephole2_scratches  PROTO((rtx));
  71
  72 \f
  73 static void
  74 max_operand_1 (x)
  75      rtx x;
  76 {
  77   register RTX_CODE code;
  78   register int i;
  79   register int len;
  80   register const char *fmt;
  81
  82   if (x == 0)
  83     return;
  84
  85   code = GET_CODE (x);
  86
  87   if (code == MATCH_OPERAND && XSTR (x, 2) != 0 && *XSTR (x, 2) != '\0')
  88     register_constraints = 1;
  89   if (code == MATCH_SCRATCH && XSTR (x, 1) != 0 && *XSTR (x, 1) != '\0')
  90     register_constraints = 1;
  91   if (code == MATCH_OPERAND || code == MATCH_OPERATOR
  92       || code == MATCH_PARALLEL)
  93     max_opno = MAX (max_opno, XINT (x, 0));
  94   if (code == MATCH_DUP || code == MATCH_OP_DUP || code == MATCH_PAR_DUP)
  95     max_dup_opno = MAX (max_dup_opno, XINT (x, 0));
  96   if (code == MATCH_SCRATCH)
  97     max_scratch_opno = MAX (max_scratch_opno, XINT (x, 0));
  98
  99   fmt = GET_RTX_FORMAT (code);
 100   len = GET_RTX_LENGTH (code);
 101   for (i = 0; i < len; i++)
 102     {
 103       if (fmt[i] == 'e' || fmt[i] == 'u')
 104         max_operand_1 (XEXP (x, i));
 105       else if (fmt[i] == 'E')
 106         {
 107           int j;
 108           for (j = 0; j < XVECLEN (x, i); j++)
 109             max_operand_1 (XVECEXP (x, i, j));
 110         }
 111     }
 112 }
 113
 114 static int
 115 max_operand_vec (insn, arg)
 116      rtx insn;
 117      int arg;
 118 {
 119   register int len = XVECLEN (insn, arg);
 120   register int i;
 121
 122   max_opno = -1;
 123   max_dup_opno = -1;
 124   max_scratch_opno = -1;
 125
 126   for (i = 0; i < len; i++)
 127     max_operand_1 (XVECEXP (insn, arg, i));
 128
 129   return max_opno + 1;
 130 }
 131 \f
 132 static void
 133 print_code (code)
 134      RTX_CODE code;
 135 {
 136   register const char *p1;
 137   for (p1 = GET_RTX_NAME (code); *p1; p1++)
 138     putchar (TOUPPER(*p1));
 139 }
 140
 141 static void
 142 gen_rtx_scratch (x, subroutine_type)
 143      rtx x;
 144      enum rtx_code subroutine_type;
 145 {
 146   if (subroutine_type == DEFINE_PEEPHOLE2)
 147     {
 148       printf ("operand%d", XINT (x, 0));
 149     }
 150   else
 151     {
 152       printf ("gen_rtx_SCRATCH (%smode)", GET_MODE_NAME (GET_MODE (x)));
 153     }
 154 }
 155
 156 /* Print a C expression to construct an RTX just like X,
 157    substituting any operand references appearing within.  */
 158
 159 static void
 160 gen_exp (x, subroutine_type)
 161      rtx x;
 162      enum rtx_code subroutine_type;
 163 {
 164   register RTX_CODE code;
 165   register int i;
 166   register int len;
 167   register const char *fmt;
 168
 169   if (x == 0)
 170     {
 171       printf ("NULL_RTX");
 172       return;
 173     }
 174
 175   code = GET_CODE (x);
 176
 177   switch (code)
 178     {
 179     case MATCH_OPERAND:
 180     case MATCH_DUP:
 181       printf ("operand%d", XINT (x, 0));
 182       return;
 183
 184     case MATCH_OP_DUP:
 185       printf ("gen_rtx (GET_CODE (operand%d), ", XINT (x, 0));
 186       if (GET_MODE (x) == VOIDmode)
 187         printf ("GET_MODE (operand%d)", XINT (x, 0));
 188       else
 189         printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
 190       for (i = 0; i < XVECLEN (x, 1); i++)
 191         {
 192           printf (",\n\t\t");
 193           gen_exp (XVECEXP (x, 1, i), subroutine_type);
 194         }
 195       printf (")");
 196       return;
 197
 198     case MATCH_OPERATOR:
 199       printf ("gen_rtx (GET_CODE (operand%d)", XINT (x, 0));
 200       printf (", %smode", GET_MODE_NAME (GET_MODE (x)));
 201       for (i = 0; i < XVECLEN (x, 2); i++)
 202         {
 203           printf (",\n\t\t");
 204           gen_exp (XVECEXP (x, 2, i), subroutine_type);
 205         }
 206       printf (")");
 207       return;
 208
 209     case MATCH_PARALLEL:
 210     case MATCH_PAR_DUP:
 211       printf ("operand%d", XINT (x, 0));
 212       return;
 213
 214     case MATCH_SCRATCH:
 215       gen_rtx_scratch (x, subroutine_type);
 216       return;
 217
 218     case ADDRESS:
 219       fatal ("ADDRESS expression code used in named instruction pattern");
 220
 221     case PC:
 222       printf ("pc_rtx");
 223       return;
 224
 225     case CC0:
 226       printf ("cc0_rtx");
 227       return;
 228
 229     case CONST_INT:
 230       if (INTVAL (x) == 0)
 231         printf ("const0_rtx");
 232       else if (INTVAL (x) == 1)
 233         printf ("const1_rtx");
 234       else if (INTVAL (x) == -1)
 235         printf ("constm1_rtx");
 236       else if (INTVAL (x) == STORE_FLAG_VALUE)
 237         printf ("const_true_rtx");
 238       else
 239         {
 240           printf ("GEN_INT (");
 241           printf (HOST_WIDE_INT_PRINT_DEC, INTVAL (x));
 242           printf (")");
 243         }
 244       return;
 245
 246     case CONST_DOUBLE:
 247       /* These shouldn't be written in MD files.  Instead, the appropriate
 248          routines in varasm.c should be called.  */
 249       abort ();
 250
 251     default:
 252       break;
 253     }
 254
 255   printf ("gen_rtx_");
 256   print_code (code);
 257   printf (" (%smode", GET_MODE_NAME (GET_MODE (x)));
 258
 259   fmt = GET_RTX_FORMAT (code);
 260   len = GET_RTX_LENGTH (code);
 261   for (i = 0; i < len; i++)
 262     {
 263       if (fmt[i] == '0')
 264         break;
 265       printf (",\n\t");
 266       if (fmt[i] == 'e' || fmt[i] == 'u')
 267         gen_exp (XEXP (x, i), subroutine_type);
 268       else if (fmt[i] == 'i')
 269         printf ("%u", XINT (x, i));
 270       else if (fmt[i] == 's')
 271         printf ("\"%s\"", XSTR (x, i));
 272       else if (fmt[i] == 'E')
 273         {
 274           int j;
 275           printf ("gen_rtvec (%d", XVECLEN (x, i));
 276           for (j = 0; j < XVECLEN (x, i); j++)
 277             {
 278               printf (",\n\t\t");
 279               gen_exp (XVECEXP (x, i, j), subroutine_type);
 280             }
 281           printf (")");
 282         }
 283       else
 284         abort ();
 285     }
 286   printf (")");
 287 }
 288 \f
 289 /* Generate the `gen_...' function for a DEFINE_INSN.  */
 290
 291 static void
 292 gen_insn (insn)
 293      rtx insn;
 294 {
 295   int operands;
 296   register int i;
 297
 298   /* See if the pattern for this insn ends with a group of CLOBBERs of (hard)
 299      registers or MATCH_SCRATCHes.  If so, store away the information for
 300      later.  */
 301
 302   if (XVEC (insn, 1))
 303     {
 304       for (i = XVECLEN (insn, 1) - 1; i > 0; i--)
 305         if (GET_CODE (XVECEXP (insn, 1, i)) != CLOBBER
 306             || (GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != REG
 307                 && GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != MATCH_SCRATCH))
 308           break;
 309
 310       if (i != XVECLEN (insn, 1) - 1)
 311         {
 312           register struct clobber_pat *p;
 313           register struct clobber_ent *link
 314             = (struct clobber_ent *) xmalloc (sizeof (struct clobber_ent));
 315           register int j;
 316
 317           link->code_number = insn_code_number;
 318
 319           /* See if any previous CLOBBER_LIST entry is the same as this
 320              one.  */
 321
 322           for (p = clobber_list; p; p = p->next)
 323             {
 324               if (p->first_clobber != i + 1
 325                   || XVECLEN (p->pattern, 1) != XVECLEN (insn, 1))
 326                 continue;
 327
 328               for (j = i + 1; j < XVECLEN (insn, 1); j++)
 329                 {
 330                   rtx old = XEXP (XVECEXP (p->pattern, 1, j), 0);
 331                   rtx new = XEXP (XVECEXP (insn, 1, j), 0);
 332
 333                   /* OLD and NEW are the same if both are to be a SCRATCH
 334                      of the same mode,
 335                      or if both are registers of the same mode and number.  */
 336                   if (! (GET_MODE (old) == GET_MODE (new)
 337                          && ((GET_CODE (old) == MATCH_SCRATCH
 338                               && GET_CODE (new) == MATCH_SCRATCH)
 339                              || (GET_CODE (old) == REG && GET_CODE (new) == REG
 340                                  && REGNO (old) == REGNO (new)))))
 341                     break;
 342                 }
 343
 344               if (j == XVECLEN (insn, 1))
 345                 break;
 346             }
 347
 348           if (p == 0)
 349             {
 350               p = (struct clobber_pat *) xmalloc (sizeof (struct clobber_pat));
 351
 352               p->insns = 0;
 353               p->pattern = insn;
 354               p->first_clobber = i + 1;
 355               p->next = clobber_list;
 356               clobber_list = p;
 357             }
 358
 359           link->next = p->insns;
 360           p->insns = link;
 361         }
 362     }
 363
 364   /* Don't mention instructions whose names are the null string
 365      or begin with '*'.  They are in the machine description just
 366      to be recognized.  */
 367   if (XSTR (insn, 0)[0] == 0 || XSTR (insn, 0)[0] == '*')
 368     return;
 369
 370   /* Find out how many operands this function has,
 371      and also whether any of them have register constraints.  */
 372   register_constraints = 0;
 373   operands = max_operand_vec (insn, 1);
 374   if (max_dup_opno >= operands)
 375     fatal ("match_dup operand number has no match_operand");
 376
 377   /* Output the function name and argument declarations.  */
 378   printf ("rtx\ngen_%s (", XSTR (insn, 0));
 379   for (i = 0; i < operands; i++)
 380     printf (i ? ", operand%d" : "operand%d", i);
 381   printf (")\n");
 382   for (i = 0; i < operands; i++)
 383     printf ("     rtx operand%d;\n", i);
 384   printf ("{\n");
 385
 386   /* Output code to construct and return the rtl for the instruction body */
 387
 388   if (XVECLEN (insn, 1) == 1)
 389     {
 390       printf ("  return ");
 391       gen_exp (XVECEXP (insn, 1, 0), DEFINE_INSN);
 392       printf (";\n}\n\n");
 393     }
 394   else
 395     {
 396       printf ("  return gen_rtx_PARALLEL (VOIDmode, gen_rtvec (%d",
 397               XVECLEN (insn, 1));
 398
 399       for (i = 0; i < XVECLEN (insn, 1); i++)
 400         {
 401           printf (",\n\t\t");
 402           gen_exp (XVECEXP (insn, 1, i), DEFINE_INSN);
 403         }
 404       printf ("));\n}\n\n");
 405     }
 406 }
 407 \f
 408 /* Generate the `gen_...' function for a DEFINE_EXPAND.  */
 409
 410 static void
 411 gen_expand (expand)
 412      rtx expand;
 413 {
 414   int operands;
 415   register int i;
 416
 417   if (strlen (XSTR (expand, 0)) == 0)
 418     fatal ("define_expand lacks a name");
 419   if (XVEC (expand, 1) == 0)
 420     fatal ("define_expand for %s lacks a pattern", XSTR (expand, 0));
 421
 422   /* Find out how many operands this function has,
 423      and also whether any of them have register constraints.  */
 424   register_constraints = 0;
 425
 426   operands = max_operand_vec (expand, 1);
 427
 428   /* Output the function name and argument declarations.  */
 429   printf ("rtx\ngen_%s (", XSTR (expand, 0));
 430   for (i = 0; i < operands; i++)
 431     printf (i ? ", operand%d" : "operand%d", i);
 432   printf (")\n");
 433   for (i = 0; i < operands; i++)
 434     printf ("     rtx operand%d;\n", i);
 435   printf ("{\n");
 436
 437   /* If we don't have any C code to write, only one insn is being written,
 438      and no MATCH_DUPs are present, we can just return the desired insn
 439      like we do for a DEFINE_INSN.  This saves memory.  */
 440   if ((XSTR (expand, 3) == 0 || *XSTR (expand, 3) == '\0')
 441       && operands > max_dup_opno
 442       && XVECLEN (expand, 1) == 1)
 443     {
 444       printf ("  return ");
 445       gen_exp (XVECEXP (expand, 1, 0), DEFINE_EXPAND);
 446       printf (";\n}\n\n");
 447       return;
 448     }
 449
 450   /* For each operand referred to only with MATCH_DUPs,
 451      make a local variable.  */
 452   for (i = operands; i <= max_dup_opno; i++)
 453     printf ("  rtx operand%d;\n", i);
 454   for (; i <= max_scratch_opno; i++)
 455     printf ("  rtx operand%d;\n", i);
 456   printf ("  rtx _val = 0;\n");
 457   printf ("  start_sequence ();\n");
 458
 459   /* The fourth operand of DEFINE_EXPAND is some code to be executed
 460      before the actual construction.
 461      This code expects to refer to `operands'
 462      just as the output-code in a DEFINE_INSN does,
 463      but here `operands' is an automatic array.
 464      So copy the operand values there before executing it.  */
 465   if (XSTR (expand, 3) && *XSTR (expand, 3))
 466     {
 467       printf ("  {\n");
 468       if (operands > 0 || max_dup_opno >= 0 || max_scratch_opno >= 0)
 469         printf ("    rtx operands[%d];\n",
 470             MAX (operands, MAX (max_scratch_opno, max_dup_opno) + 1));
 471       /* Output code to copy the arguments into `operands'.  */
 472       for (i = 0; i < operands; i++)
 473         printf ("    operands[%d] = operand%d;\n", i, i);
 474
 475       /* Output the special code to be executed before the sequence
 476          is generated.  */
 477       printf ("%s\n", XSTR (expand, 3));
 478
 479       /* Output code to copy the arguments back out of `operands'
 480          (unless we aren't going to use them at all).  */
 481       if (XVEC (expand, 1) != 0)
 482         {
 483           for (i = 0; i < operands; i++)
 484             printf ("    operand%d = operands[%d];\n", i, i);
 485           for (; i <= max_dup_opno; i++)
 486             printf ("    operand%d = operands[%d];\n", i, i);
 487           for (; i <= max_scratch_opno; i++)
 488             printf ("    operand%d = operands[%d];\n", i, i);
 489         }
 490       printf ("  }\n");
 491     }
 492
 493   /* Output code to construct the rtl for the instruction bodies.
 494      Use emit_insn to add them to the sequence being accumulated.
 495      But don't do this if the user's code has set `no_more' nonzero.  */
 496
 497   for (i = 0; i < XVECLEN (expand, 1); i++)
 498     {
 499       rtx next = XVECEXP (expand, 1, i);
 500       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
 501           || (GET_CODE (next) == PARALLEL
 502               && GET_CODE (XVECEXP (next, 0, 0)) == SET
 503               && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
 504           || GET_CODE (next) == RETURN)
 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 (GET_CODE (next) == CODE_LABEL)
 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);
 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   /* Call `gen_sequence' to make a SEQUENCE out of all the
 534      insns emitted within this gen_... function.  */
 535
 536   printf ("  _val = gen_sequence ();\n");
 537   printf ("  end_sequence ();\n");
 538   printf ("  return _val;\n}\n\n");
 539 }
 540
 541 /* Like gen_expand, but generates a SEQUENCE.  */
 542
 543 static void
 544 gen_split (split)
 545      rtx split;
 546 {
 547   register int i;
 548   int operands;
 549   const char *name = "split";
 550
 551   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 552     name = "peephole2";
 553
 554   if (XVEC (split, 0) == 0)
 555     fatal ("define_%s (definition %d) lacks a pattern", name,
 556            insn_index_number);
 557   else if (XVEC (split, 2) == 0)
 558     fatal ("define_%s (definition %d) lacks a replacement pattern", name,
 559            insn_index_number);
 560
 561   /* Find out how many operands this function has.  */
 562
 563   max_operand_vec (split, 2);
 564   operands = MAX (max_opno, MAX (max_dup_opno, max_scratch_opno)) + 1;
 565
 566   /* Output the prototype, function name and argument declarations.  */
 567   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 568     {
 569       printf ("extern rtx gen_%s_%d PROTO ((rtx, rtx *));\n",
 570               name, insn_code_number);
 571       printf ("rtx\ngen_%s_%d (curr_insn, operands)\n\
 572      rtx curr_insn ATTRIBUTE_UNUSED;\n\
 573      rtx *operands;\n",
 574               name, insn_code_number);
 575     }
 576   else
 577     {
 578       printf ("extern rtx gen_split_%d PROTO ((rtx *));\n", insn_code_number);
 579       printf ("rtx\ngen_%s_%d (operands)\n     rtx *operands;\n", name,
 580               insn_code_number);
 581     }
 582   printf ("{\n");
 583
 584   /* Declare all local variables.  */
 585   for (i = 0; i < operands; i++)
 586     printf ("  rtx operand%d;\n", i);
 587   printf ("  rtx _val = 0;\n");
 588
 589   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 590     output_peephole2_scratches (split);
 591
 592   printf ("  start_sequence ();\n");
 593
 594   /* The fourth operand of DEFINE_SPLIT is some code to be executed
 595      before the actual construction.  */
 596
 597   if (XSTR (split, 3))
 598     printf ("%s\n", XSTR (split, 3));
 599
 600   /* Output code to copy the arguments back out of `operands'  */
 601   for (i = 0; i < operands; i++)
 602     printf ("  operand%d = operands[%d];\n", i, i);
 603
 604   /* Output code to construct the rtl for the instruction bodies.
 605      Use emit_insn to add them to the sequence being accumulated.
 606      But don't do this if the user's code has set `no_more' nonzero.  */
 607
 608   for (i = 0; i < XVECLEN (split, 2); i++)
 609     {
 610       rtx next = XVECEXP (split, 2, i);
 611       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
 612           || (GET_CODE (next) == PARALLEL
 613               && GET_CODE (XVECEXP (next, 0, 0)) == SET
 614               && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
 615           || GET_CODE (next) == RETURN)
 616         printf ("  emit_jump_insn (");
 617       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
 618                || GET_CODE (next) == CALL
 619                || (GET_CODE (next) == PARALLEL
 620                    && GET_CODE (XVECEXP (next, 0, 0)) == SET
 621                    && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
 622                || (GET_CODE (next) == PARALLEL
 623                    && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
 624         printf ("  emit_call_insn (");
 625       else if (GET_CODE (next) == CODE_LABEL)
 626         printf ("  emit_label (");
 627       else if (GET_CODE (next) == MATCH_OPERAND
 628                || GET_CODE (next) == MATCH_OPERATOR
 629                || GET_CODE (next) == MATCH_PARALLEL
 630                || GET_CODE (next) == MATCH_OP_DUP
 631                || GET_CODE (next) == MATCH_DUP
 632                || GET_CODE (next) == PARALLEL)
 633         printf ("  emit (");
 634       else
 635         printf ("  emit_insn (");
 636       gen_exp (next, GET_CODE (split));
 637       printf (");\n");
 638       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
 639           && GET_CODE (SET_SRC (next)) == LABEL_REF)
 640         printf ("  emit_barrier ();");
 641     }
 642
 643   /* Call `gen_sequence' to make a SEQUENCE out of all the
 644      insns emitted within this gen_... function.  */
 645
 646   printf ("  _val = gen_sequence ();\n");
 647   printf ("  end_sequence ();\n");
 648   printf ("  return _val;\n}\n\n");
 649 }
 650 \f
 651 /* Write a function, `add_clobbers', that is given a PARALLEL of sufficient
 652    size for the insn and an INSN_CODE, and inserts the required CLOBBERs at
 653    the end of the vector.  */
 654
 655 static void
 656 output_add_clobbers ()
 657 {
 658   struct clobber_pat *clobber;
 659   struct clobber_ent *ent;
 660   int i;
 661
 662   printf ("\n\nvoid\nadd_clobbers (pattern, insn_code_number)\n");
 663   printf ("     rtx pattern;\n     int insn_code_number;\n");
 664   printf ("{\n");
 665   printf ("  switch (insn_code_number)\n");
 666   printf ("    {\n");
 667
 668   for (clobber = clobber_list; clobber; clobber = clobber->next)
 669     {
 670       for (ent = clobber->insns; ent; ent = ent->next)
 671         printf ("    case %d:\n", ent->code_number);
 672
 673       for (i = clobber->first_clobber; i < XVECLEN (clobber->pattern, 1); i++)
 674         {
 675           printf ("      XVECEXP (pattern, 0, %d) = ", i);
 676           gen_exp (XVECEXP (clobber->pattern, 1, i),
 677                    GET_CODE (clobber->pattern));
 678           printf (";\n");
 679         }
 680
 681       printf ("      break;\n\n");
 682     }
 683
 684   printf ("    default:\n");
 685   printf ("      abort ();\n");
 686   printf ("    }\n");
 687   printf ("}\n");
 688 }
 689 \f
 690 /* Generate code to invoke find_free_register () as needed for the
 691    scratch registers used by the peephole2 pattern in SPLIT. */
 692
 693 static void
 694 output_peephole2_scratches (split)
 695      rtx split;
 696 {
 697   int i;
 698   int insn_nr = 0;
 699
 700   printf ("  rtx first_insn ATTRIBUTE_UNUSED;\n");
 701   printf ("  rtx last_insn ATTRIBUTE_UNUSED;\n");
 702   printf ("  HARD_REG_SET _regs_allocated;\n");
 703
 704   printf ("  CLEAR_HARD_REG_SET (_regs_allocated);\n");
 705
 706   for (i = 0; i < XVECLEN (split, 0); i++)
 707     {
 708       rtx elt = XVECEXP (split, 0, i);
 709       if (GET_CODE (elt) == MATCH_SCRATCH)
 710         {
 711           int last_insn_nr = insn_nr;
 712           int cur_insn_nr = insn_nr;
 713           int j;
 714           for (j = i + 1; j < XVECLEN (split, 0); j++)
 715             if (GET_CODE (XVECEXP (split, 0, j)) == MATCH_DUP)
 716               {
 717                 if (XINT (XVECEXP (split, 0, j), 0) == XINT (elt, 0))
 718                   last_insn_nr = cur_insn_nr;
 719               }
 720             else if (GET_CODE (XVECEXP (split, 0, j)) != MATCH_SCRATCH)
 721               cur_insn_nr++;
 722           printf ("  first_insn = recog_next_insn (curr_insn, %d);\n", insn_nr);
 723           if (last_insn_nr > insn_nr)
 724             printf ("  last_insn = recog_next_insn (curr_insn, %d);\n",
 725                     last_insn_nr - 1);
 726           else
 727             printf ("  last_insn = 0;\n");
 728           printf ("  if ((operands[%d] = find_free_register (first_insn, last_insn, \"%s\", %smode, &_regs_allocated)) == NULL_RTX)\n\
 729     return NULL;\n",
 730                   XINT (elt, 0),
 731                   XSTR (elt, 1),
 732                   GET_MODE_NAME (GET_MODE (elt)));
 733
 734         }
 735       else if (GET_CODE (elt) != MATCH_DUP)
 736         insn_nr++;
 737     }
 738 }
 739 \f
 740 PTR
 741 xmalloc (size)
 742   size_t size;
 743 {
 744   register PTR val = (PTR) malloc (size);
 745
 746   if (val == 0)
 747     fatal ("virtual memory exhausted");
 748
 749   return val;
 750 }
 751
 752 PTR
 753 xrealloc (old, size)
 754   PTR old;
 755   size_t size;
 756 {
 757   register PTR ptr;
 758   if (old)
 759     ptr = (PTR) realloc (old, size);
 760   else
 761     ptr = (PTR) malloc (size);
 762   if (!ptr)
 763     fatal ("virtual memory exhausted");
 764   return ptr;
 765 }
 766
 767 extern int main PROTO ((int, char **));
 768
 769 int
 770 main (argc, argv)
 771      int argc;
 772      char **argv;
 773 {
 774   rtx desc;
 775   FILE *infile;
 776   register int c;
 777
 778   progname = "genemit";
 779   obstack_init (rtl_obstack);
 780
 781   if (argc <= 1)
 782     fatal ("No input file name.");
 783
 784   infile = fopen (argv[1], "r");
 785   if (infile == 0)
 786     {
 787       perror (argv[1]);
 788       return (FATAL_EXIT_CODE);
 789     }
 790   read_rtx_filename = argv[1];
 791
 792   /* Assign sequential codes to all entries in the machine description
 793      in parallel with the tables in insn-output.c.  */
 794
 795   insn_code_number = 0;
 796   insn_index_number = 0;
 797
 798   printf ("/* Generated automatically by the program `genemit'\n\
 799 from the machine description file `md'.  */\n\n");
 800
 801   printf ("#include \"config.h\"\n");
 802   printf ("#include \"system.h\"\n");
 803   printf ("#include \"rtl.h\"\n");
 804   printf ("#include \"tm_p.h\"\n");
 805   printf ("#include \"function.h\"\n");
 806   printf ("#include \"expr.h\"\n");
 807   printf ("#include \"real.h\"\n");
 808   printf ("#include \"flags.h\"\n");
 809   printf ("#include \"output.h\"\n");
 810   printf ("#include \"insn-config.h\"\n");
 811   printf ("#include \"insn-flags.h\"\n");
 812   printf ("#include \"insn-codes.h\"\n");
 813   printf ("#include \"recog.h\"\n");
 814   printf ("#include \"hard-reg-set.h\"\n");
 815   printf ("#include \"resource.h\"\n");
 816   printf ("#include \"reload.h\"\n\n");
 817   printf ("#define FAIL return (end_sequence (), _val)\n");
 818   printf ("#define DONE return (_val = gen_sequence (), end_sequence (), _val)\n");
 819
 820   /* Read the machine description.  */
 821
 822   while (1)
 823     {
 824       c = read_skip_spaces (infile);
 825       if (c == EOF)
 826         break;
 827       ungetc (c, infile);
 828
 829       desc = read_rtx (infile);
 830
 831       if (GET_CODE (desc) == DEFINE_INSN)
 832         {
 833           gen_insn (desc);
 834           ++insn_code_number;
 835         }
 836       if (GET_CODE (desc) == DEFINE_EXPAND)
 837         {
 838           gen_expand (desc);
 839           ++insn_code_number;
 840         }
 841       if (GET_CODE (desc) == DEFINE_SPLIT)
 842         {
 843           gen_split (desc);
 844           ++insn_code_number;
 845         }
 846       if (GET_CODE (desc) == DEFINE_PEEPHOLE2)
 847         {
 848           gen_split (desc);
 849           ++insn_code_number;
 850         }
 851       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 852         {
 853           ++insn_code_number;
 854         }
 855       ++insn_index_number;
 856     }
 857
 858   /* Write out the routine to add CLOBBERs to a pattern.  */
 859   output_add_clobbers ();
 860
 861   fflush (stdout);
 862   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 863 }
 864
 865 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
 866 const char *
 867 get_insn_name (code)
 868      int code ATTRIBUTE_UNUSED;
 869 {
 870   return NULL;
 871 }