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 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
  35 char **insn_name_ptr = 0;
  36
  37 static int max_opno;
  38 static int max_dup_opno;
  39 static int max_scratch_opno;
  40 static int register_constraints;
  41 static int insn_code_number;
  42 static int insn_index_number;
  43
  44 /* Data structure for recording the patterns of insns that have CLOBBERs.
  45    We use this to output a function that adds these CLOBBERs to a
  46    previously-allocated PARALLEL expression.  */
  47
  48 struct clobber_pat
  49 {
  50   struct clobber_ent *insns;
  51   rtx pattern;
  52   int first_clobber;
  53   struct clobber_pat *next;
  54 } *clobber_list;
  55
  56 /* Records one insn that uses the clobber list.  */
  57
  58 struct clobber_ent
  59 {
  60   int code_number;              /* Counts only insns.  */
  61   struct clobber_ent *next;
  62 };
  63
  64 static void max_operand_1               PROTO((rtx));
  65 static int max_operand_vec              PROTO((rtx, int));
  66 static void print_code                  PROTO((RTX_CODE));
  67 static void gen_exp                     PROTO((rtx, enum rtx_code));
  68 static void gen_insn                    PROTO((rtx));
  69 static void gen_expand                  PROTO((rtx));
  70 static void gen_split                   PROTO((rtx));
  71 static void output_add_clobbers         PROTO((void));
  72 static void gen_rtx_scratch             PROTO((rtx, enum rtx_code));
  73 static void output_peephole2_scratches  PROTO((rtx));
  74
  75 \f
  76 static void
  77 max_operand_1 (x)
  78      rtx x;
  79 {
  80   register RTX_CODE code;
  81   register int i;
  82   register int len;
  83   register const char *fmt;
  84
  85   if (x == 0)
  86     return;
  87
  88   code = GET_CODE (x);
  89
  90   if (code == MATCH_OPERAND && XSTR (x, 2) != 0 && *XSTR (x, 2) != '\0')
  91     register_constraints = 1;
  92   if (code == MATCH_SCRATCH && XSTR (x, 1) != 0 && *XSTR (x, 1) != '\0')
  93     register_constraints = 1;
  94   if (code == MATCH_OPERAND || code == MATCH_OPERATOR
  95       || code == MATCH_PARALLEL)
  96     max_opno = MAX (max_opno, XINT (x, 0));
  97   if (code == MATCH_DUP || code == MATCH_OP_DUP || code == MATCH_PAR_DUP)
  98     max_dup_opno = MAX (max_dup_opno, XINT (x, 0));
  99   if (code == MATCH_SCRATCH)
 100     max_scratch_opno = MAX (max_scratch_opno, XINT (x, 0));
 101
 102   fmt = GET_RTX_FORMAT (code);
 103   len = GET_RTX_LENGTH (code);
 104   for (i = 0; i < len; i++)
 105     {
 106       if (fmt[i] == 'e' || fmt[i] == 'u')
 107         max_operand_1 (XEXP (x, i));
 108       else if (fmt[i] == 'E')
 109         {
 110           int j;
 111           for (j = 0; j < XVECLEN (x, i); j++)
 112             max_operand_1 (XVECEXP (x, i, j));
 113         }
 114     }
 115 }
 116
 117 static int
 118 max_operand_vec (insn, arg)
 119      rtx insn;
 120      int arg;
 121 {
 122   register int len = XVECLEN (insn, arg);
 123   register int i;
 124
 125   max_opno = -1;
 126   max_dup_opno = -1;
 127   max_scratch_opno = -1;
 128
 129   for (i = 0; i < len; i++)
 130     max_operand_1 (XVECEXP (insn, arg, i));
 131
 132   return max_opno + 1;
 133 }
 134 \f
 135 static void
 136 print_code (code)
 137      RTX_CODE code;
 138 {
 139   register const char *p1;
 140   for (p1 = GET_RTX_NAME (code); *p1; p1++)
 141     {
 142       if (ISLOWER(*p1))
 143         putchar (toupper(*p1));
 144       else
 145         putchar (*p1);
 146     }
 147 }
 148
 149 static void
 150 gen_rtx_scratch (x, subroutine_type)
 151      rtx x;
 152      enum rtx_code subroutine_type;
 153 {
 154   if (subroutine_type == DEFINE_PEEPHOLE2)
 155     {
 156       printf ("operand%d", XINT (x, 0));
 157     }
 158   else
 159     {
 160       printf ("gen_rtx_SCRATCH (%smode)", GET_MODE_NAME (GET_MODE (x)));
 161     }
 162 }
 163
 164 /* Print a C expression to construct an RTX just like X,
 165    substituting any operand references appearing within.  */
 166
 167 static void
 168 gen_exp (x, subroutine_type)
 169      rtx x;
 170      enum rtx_code subroutine_type;
 171 {
 172   register RTX_CODE code;
 173   register int i;
 174   register int len;
 175   register const char *fmt;
 176
 177   if (x == 0)
 178     {
 179       printf ("NULL_RTX");
 180       return;
 181     }
 182
 183   code = GET_CODE (x);
 184
 185   switch (code)
 186     {
 187     case MATCH_OPERAND:
 188     case MATCH_DUP:
 189       printf ("operand%d", XINT (x, 0));
 190       return;
 191
 192     case MATCH_OP_DUP:
 193       printf ("gen_rtx (GET_CODE (operand%d), ", XINT (x, 0));
 194       if (GET_MODE (x) == VOIDmode)
 195         printf ("GET_MODE (operand%d)", XINT (x, 0));
 196       else
 197         printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
 198       for (i = 0; i < XVECLEN (x, 1); i++)
 199         {
 200           printf (",\n\t\t");
 201           gen_exp (XVECEXP (x, 1, i), subroutine_type);
 202         }
 203       printf (")");
 204       return;
 205
 206     case MATCH_OPERATOR:
 207       printf ("gen_rtx (GET_CODE (operand%d)", XINT (x, 0));
 208       printf (", %smode", GET_MODE_NAME (GET_MODE (x)));
 209       for (i = 0; i < XVECLEN (x, 2); i++)
 210         {
 211           printf (",\n\t\t");
 212           gen_exp (XVECEXP (x, 2, i), subroutine_type);
 213         }
 214       printf (")");
 215       return;
 216
 217     case MATCH_PARALLEL:
 218     case MATCH_PAR_DUP:
 219       printf ("operand%d", XINT (x, 0));
 220       return;
 221
 222     case MATCH_SCRATCH:
 223       gen_rtx_scratch (x, subroutine_type);
 224       return;
 225
 226     case ADDRESS:
 227       fatal ("ADDRESS expression code used in named instruction pattern");
 228
 229     case PC:
 230       printf ("pc_rtx");
 231       return;
 232
 233     case CC0:
 234       printf ("cc0_rtx");
 235       return;
 236
 237     case CONST_INT:
 238       if (INTVAL (x) == 0)
 239         printf ("const0_rtx");
 240       else if (INTVAL (x) == 1)
 241         printf ("const1_rtx");
 242       else if (INTVAL (x) == -1)
 243         printf ("constm1_rtx");
 244       else if (INTVAL (x) == STORE_FLAG_VALUE)
 245         printf ("const_true_rtx");
 246       else
 247         {
 248           printf ("GEN_INT (");
 249           printf (HOST_WIDE_INT_PRINT_DEC, INTVAL (x));
 250           printf (")");
 251         }
 252       return;
 253
 254     case CONST_DOUBLE:
 255       /* These shouldn't be written in MD files.  Instead, the appropriate
 256          routines in varasm.c should be called.  */
 257       abort ();
 258
 259     default:
 260       break;
 261     }
 262
 263   printf ("gen_rtx_");
 264   print_code (code);
 265   printf (" (%smode", GET_MODE_NAME (GET_MODE (x)));
 266
 267   fmt = GET_RTX_FORMAT (code);
 268   len = GET_RTX_LENGTH (code);
 269   for (i = 0; i < len; i++)
 270     {
 271       if (fmt[i] == '0')
 272         break;
 273       printf (",\n\t");
 274       if (fmt[i] == 'e' || fmt[i] == 'u')
 275         gen_exp (XEXP (x, i), subroutine_type);
 276       else if (fmt[i] == 'i')
 277         printf ("%u", XINT (x, i));
 278       else if (fmt[i] == 's')
 279         printf ("\"%s\"", XSTR (x, i));
 280       else if (fmt[i] == 'E')
 281         {
 282           int j;
 283           printf ("gen_rtvec (%d", XVECLEN (x, i));
 284           for (j = 0; j < XVECLEN (x, i); j++)
 285             {
 286               printf (",\n\t\t");
 287               gen_exp (XVECEXP (x, i, j), subroutine_type);
 288             }
 289           printf (")");
 290         }
 291       else
 292         abort ();
 293     }
 294   printf (")");
 295 }
 296 \f
 297 /* Generate the `gen_...' function for a DEFINE_INSN.  */
 298
 299 static void
 300 gen_insn (insn)
 301      rtx insn;
 302 {
 303   int operands;
 304   register int i;
 305
 306   /* See if the pattern for this insn ends with a group of CLOBBERs of (hard)
 307      registers or MATCH_SCRATCHes.  If so, store away the information for
 308      later.  */
 309
 310   if (XVEC (insn, 1))
 311     {
 312       for (i = XVECLEN (insn, 1) - 1; i > 0; i--)
 313         if (GET_CODE (XVECEXP (insn, 1, i)) != CLOBBER
 314             || (GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != REG
 315                 && GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != MATCH_SCRATCH))
 316           break;
 317
 318       if (i != XVECLEN (insn, 1) - 1)
 319         {
 320           register struct clobber_pat *p;
 321           register struct clobber_ent *link
 322             = (struct clobber_ent *) xmalloc (sizeof (struct clobber_ent));
 323           register int j;
 324
 325           link->code_number = insn_code_number;
 326
 327           /* See if any previous CLOBBER_LIST entry is the same as this
 328              one.  */
 329
 330           for (p = clobber_list; p; p = p->next)
 331             {
 332               if (p->first_clobber != i + 1
 333                   || XVECLEN (p->pattern, 1) != XVECLEN (insn, 1))
 334                 continue;
 335
 336               for (j = i + 1; j < XVECLEN (insn, 1); j++)
 337                 {
 338                   rtx old = XEXP (XVECEXP (p->pattern, 1, j), 0);
 339                   rtx new = XEXP (XVECEXP (insn, 1, j), 0);
 340
 341                   /* OLD and NEW are the same if both are to be a SCRATCH
 342                      of the same mode,
 343                      or if both are registers of the same mode and number.  */
 344                   if (! (GET_MODE (old) == GET_MODE (new)
 345                          && ((GET_CODE (old) == MATCH_SCRATCH
 346                               && GET_CODE (new) == MATCH_SCRATCH)
 347                              || (GET_CODE (old) == REG && GET_CODE (new) == REG
 348                                  && REGNO (old) == REGNO (new)))))
 349                     break;
 350                 }
 351
 352               if (j == XVECLEN (insn, 1))
 353                 break;
 354             }
 355
 356           if (p == 0)
 357             {
 358               p = (struct clobber_pat *) xmalloc (sizeof (struct clobber_pat));
 359
 360               p->insns = 0;
 361               p->pattern = insn;
 362               p->first_clobber = i + 1;
 363               p->next = clobber_list;
 364               clobber_list = p;
 365             }
 366
 367           link->next = p->insns;
 368           p->insns = link;
 369         }
 370     }
 371
 372   /* Don't mention instructions whose names are the null string
 373      or begin with '*'.  They are in the machine description just
 374      to be recognized.  */
 375   if (XSTR (insn, 0)[0] == 0 || XSTR (insn, 0)[0] == '*')
 376     return;
 377
 378   /* Find out how many operands this function has,
 379      and also whether any of them have register constraints.  */
 380   register_constraints = 0;
 381   operands = max_operand_vec (insn, 1);
 382   if (max_dup_opno >= operands)
 383     fatal ("match_dup operand number has no match_operand");
 384
 385   /* Output the function name and argument declarations.  */
 386   printf ("rtx\ngen_%s (", XSTR (insn, 0));
 387   for (i = 0; i < operands; i++)
 388     printf (i ? ", operand%d" : "operand%d", i);
 389   printf (")\n");
 390   for (i = 0; i < operands; i++)
 391     printf ("     rtx operand%d;\n", i);
 392   printf ("{\n");
 393
 394   /* Output code to construct and return the rtl for the instruction body */
 395
 396   if (XVECLEN (insn, 1) == 1)
 397     {
 398       printf ("  return ");
 399       gen_exp (XVECEXP (insn, 1, 0), DEFINE_INSN);
 400       printf (";\n}\n\n");
 401     }
 402   else
 403     {
 404       printf ("  return gen_rtx_PARALLEL (VOIDmode, gen_rtvec (%d",
 405               XVECLEN (insn, 1));
 406
 407       for (i = 0; i < XVECLEN (insn, 1); i++)
 408         {
 409           printf (",\n\t\t");
 410           gen_exp (XVECEXP (insn, 1, i), DEFINE_INSN);
 411         }
 412       printf ("));\n}\n\n");
 413     }
 414 }
 415 \f
 416 /* Generate the `gen_...' function for a DEFINE_EXPAND.  */
 417
 418 static void
 419 gen_expand (expand)
 420      rtx expand;
 421 {
 422   int operands;
 423   register int i;
 424
 425   if (strlen (XSTR (expand, 0)) == 0)
 426     fatal ("define_expand lacks a name");
 427   if (XVEC (expand, 1) == 0)
 428     fatal ("define_expand for %s lacks a pattern", XSTR (expand, 0));
 429
 430   /* Find out how many operands this function has,
 431      and also whether any of them have register constraints.  */
 432   register_constraints = 0;
 433
 434   operands = max_operand_vec (expand, 1);
 435
 436   /* Output the function name and argument declarations.  */
 437   printf ("rtx\ngen_%s (", XSTR (expand, 0));
 438   for (i = 0; i < operands; i++)
 439     printf (i ? ", operand%d" : "operand%d", i);
 440   printf (")\n");
 441   for (i = 0; i < operands; i++)
 442     printf ("     rtx operand%d;\n", i);
 443   printf ("{\n");
 444
 445   /* If we don't have any C code to write, only one insn is being written,
 446      and no MATCH_DUPs are present, we can just return the desired insn
 447      like we do for a DEFINE_INSN.  This saves memory.  */
 448   if ((XSTR (expand, 3) == 0 || *XSTR (expand, 3) == '\0')
 449       && operands > max_dup_opno
 450       && XVECLEN (expand, 1) == 1)
 451     {
 452       printf ("  return ");
 453       gen_exp (XVECEXP (expand, 1, 0), DEFINE_EXPAND);
 454       printf (";\n}\n\n");
 455       return;
 456     }
 457
 458   /* For each operand referred to only with MATCH_DUPs,
 459      make a local variable.  */
 460   for (i = operands; i <= max_dup_opno; i++)
 461     printf ("  rtx operand%d;\n", i);
 462   for (; i <= max_scratch_opno; i++)
 463     printf ("  rtx operand%d;\n", i);
 464   printf ("  rtx _val = 0;\n");
 465   printf ("  start_sequence ();\n");
 466
 467   /* The fourth operand of DEFINE_EXPAND is some code to be executed
 468      before the actual construction.
 469      This code expects to refer to `operands'
 470      just as the output-code in a DEFINE_INSN does,
 471      but here `operands' is an automatic array.
 472      So copy the operand values there before executing it.  */
 473   if (XSTR (expand, 3) && *XSTR (expand, 3))
 474     {
 475       printf ("  {\n");
 476       if (operands > 0 || max_dup_opno >= 0 || max_scratch_opno >= 0)
 477         printf ("    rtx operands[%d];\n",
 478             MAX (operands, MAX (max_scratch_opno, max_dup_opno) + 1));
 479       /* Output code to copy the arguments into `operands'.  */
 480       for (i = 0; i < operands; i++)
 481         printf ("    operands[%d] = operand%d;\n", i, i);
 482
 483       /* Output the special code to be executed before the sequence
 484          is generated.  */
 485       printf ("%s\n", XSTR (expand, 3));
 486
 487       /* Output code to copy the arguments back out of `operands'
 488          (unless we aren't going to use them at all).  */
 489       if (XVEC (expand, 1) != 0)
 490         {
 491           for (i = 0; i < operands; i++)
 492             printf ("    operand%d = operands[%d];\n", i, i);
 493           for (; i <= max_dup_opno; i++)
 494             printf ("    operand%d = operands[%d];\n", i, i);
 495           for (; i <= max_scratch_opno; i++)
 496             printf ("    operand%d = operands[%d];\n", i, i);
 497         }
 498       printf ("  }\n");
 499     }
 500
 501   /* Output code to construct the rtl for the instruction bodies.
 502      Use emit_insn to add them to the sequence being accumulated.
 503      But don't do this if the user's code has set `no_more' nonzero.  */
 504
 505   for (i = 0; i < XVECLEN (expand, 1); i++)
 506     {
 507       rtx next = XVECEXP (expand, 1, i);
 508       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
 509           || (GET_CODE (next) == PARALLEL
 510               && GET_CODE (XVECEXP (next, 0, 0)) == SET
 511               && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
 512           || GET_CODE (next) == RETURN)
 513         printf ("  emit_jump_insn (");
 514       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
 515                || GET_CODE (next) == CALL
 516                || (GET_CODE (next) == PARALLEL
 517                    && GET_CODE (XVECEXP (next, 0, 0)) == SET
 518                    && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
 519                || (GET_CODE (next) == PARALLEL
 520                    && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
 521         printf ("  emit_call_insn (");
 522       else if (GET_CODE (next) == CODE_LABEL)
 523         printf ("  emit_label (");
 524       else if (GET_CODE (next) == MATCH_OPERAND
 525                || GET_CODE (next) == MATCH_DUP
 526                || GET_CODE (next) == MATCH_OPERATOR
 527                || GET_CODE (next) == MATCH_OP_DUP
 528                || GET_CODE (next) == MATCH_PARALLEL
 529                || GET_CODE (next) == MATCH_PAR_DUP
 530                || GET_CODE (next) == PARALLEL)
 531         printf ("  emit (");
 532       else
 533         printf ("  emit_insn (");
 534       gen_exp (next, DEFINE_EXPAND);
 535       printf (");\n");
 536       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
 537           && GET_CODE (SET_SRC (next)) == LABEL_REF)
 538         printf ("  emit_barrier ();");
 539     }
 540
 541   /* Call `gen_sequence' to make a SEQUENCE out of all the
 542      insns emitted within this gen_... function.  */
 543
 544   printf ("  _val = gen_sequence ();\n");
 545   printf ("  end_sequence ();\n");
 546   printf ("  return _val;\n}\n\n");
 547 }
 548
 549 /* Like gen_expand, but generates a SEQUENCE.  */
 550
 551 static void
 552 gen_split (split)
 553      rtx split;
 554 {
 555   register int i;
 556   int operands;
 557   char *name = "split";
 558
 559   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 560     name = "peephole2";
 561
 562   if (XVEC (split, 0) == 0)
 563     fatal ("define_%s (definition %d) lacks a pattern", name,
 564            insn_index_number);
 565   else if (XVEC (split, 2) == 0)
 566     fatal ("define_%s (definition %d) lacks a replacement pattern", name,
 567            insn_index_number);
 568
 569   /* Find out how many operands this function has.  */
 570
 571   max_operand_vec (split, 2);
 572   operands = MAX (max_opno, MAX (max_dup_opno, max_scratch_opno)) + 1;
 573
 574   /* Output the prototype, function name and argument declarations.  */
 575   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 576     {
 577       printf ("extern rtx gen_%s_%d PROTO ((rtx, rtx *));\n",
 578               name, insn_code_number);
 579       printf ("rtx\ngen_%s_%d (curr_insn, operands)\n\
 580      rtx curr_insn ATTRIBUTE_UNUSED;\n\
 581      rtx *operands;\n",
 582               name, insn_code_number);
 583     }
 584   else
 585     {
 586       printf ("extern rtx gen_split_%d PROTO ((rtx *));\n", insn_code_number);
 587       printf ("rtx\ngen_%s_%d (operands)\n     rtx *operands;\n", name,
 588               insn_code_number);
 589     }
 590   printf ("{\n");
 591
 592   /* Declare all local variables.  */
 593   for (i = 0; i < operands; i++)
 594     printf ("  rtx operand%d;\n", i);
 595   printf ("  rtx _val = 0;\n");
 596
 597   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
 598     output_peephole2_scratches (split);
 599
 600   printf ("  start_sequence ();\n");
 601
 602   /* The fourth operand of DEFINE_SPLIT is some code to be executed
 603      before the actual construction.  */
 604
 605   if (XSTR (split, 3))
 606     printf ("%s\n", XSTR (split, 3));
 607
 608   /* Output code to copy the arguments back out of `operands'  */
 609   for (i = 0; i < operands; i++)
 610     printf ("  operand%d = operands[%d];\n", i, i);
 611
 612   /* Output code to construct the rtl for the instruction bodies.
 613      Use emit_insn to add them to the sequence being accumulated.
 614      But don't do this if the user's code has set `no_more' nonzero.  */
 615
 616   for (i = 0; i < XVECLEN (split, 2); i++)
 617     {
 618       rtx next = XVECEXP (split, 2, i);
 619       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
 620           || (GET_CODE (next) == PARALLEL
 621               && GET_CODE (XVECEXP (next, 0, 0)) == SET
 622               && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
 623           || GET_CODE (next) == RETURN)
 624         printf ("  emit_jump_insn (");
 625       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
 626                || GET_CODE (next) == CALL
 627                || (GET_CODE (next) == PARALLEL
 628                    && GET_CODE (XVECEXP (next, 0, 0)) == SET
 629                    && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
 630                || (GET_CODE (next) == PARALLEL
 631                    && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
 632         printf ("  emit_call_insn (");
 633       else if (GET_CODE (next) == CODE_LABEL)
 634         printf ("  emit_label (");
 635       else if (GET_CODE (next) == MATCH_OPERAND
 636                || GET_CODE (next) == MATCH_OPERATOR
 637                || GET_CODE (next) == MATCH_PARALLEL
 638                || GET_CODE (next) == MATCH_OP_DUP
 639                || GET_CODE (next) == MATCH_DUP
 640                || GET_CODE (next) == PARALLEL)
 641         printf ("  emit (");
 642       else
 643         printf ("  emit_insn (");
 644       gen_exp (next, GET_CODE (split));
 645       printf (");\n");
 646       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
 647           && GET_CODE (SET_SRC (next)) == LABEL_REF)
 648         printf ("  emit_barrier ();");
 649     }
 650
 651   /* Call `gen_sequence' to make a SEQUENCE out of all the
 652      insns emitted within this gen_... function.  */
 653
 654   printf ("  _val = gen_sequence ();\n");
 655   printf ("  end_sequence ();\n");
 656   printf ("  return _val;\n}\n\n");
 657 }
 658 \f
 659 /* Write a function, `add_clobbers', that is given a PARALLEL of sufficient
 660    size for the insn and an INSN_CODE, and inserts the required CLOBBERs at
 661    the end of the vector.  */
 662
 663 static void
 664 output_add_clobbers ()
 665 {
 666   struct clobber_pat *clobber;
 667   struct clobber_ent *ent;
 668   int i;
 669
 670   printf ("\n\nvoid\nadd_clobbers (pattern, insn_code_number)\n");
 671   printf ("     rtx pattern;\n     int insn_code_number;\n");
 672   printf ("{\n");
 673   printf ("  switch (insn_code_number)\n");
 674   printf ("    {\n");
 675
 676   for (clobber = clobber_list; clobber; clobber = clobber->next)
 677     {
 678       for (ent = clobber->insns; ent; ent = ent->next)
 679         printf ("    case %d:\n", ent->code_number);
 680
 681       for (i = clobber->first_clobber; i < XVECLEN (clobber->pattern, 1); i++)
 682         {
 683           printf ("      XVECEXP (pattern, 0, %d) = ", i);
 684           gen_exp (XVECEXP (clobber->pattern, 1, i),
 685                    GET_CODE (clobber->pattern));
 686           printf (";\n");
 687         }
 688
 689       printf ("      break;\n\n");
 690     }
 691
 692   printf ("    default:\n");
 693   printf ("      abort ();\n");
 694   printf ("    }\n");
 695   printf ("}\n");
 696 }
 697 \f
 698 /* Generate code to invoke find_free_register () as needed for the
 699    scratch registers used by the peephole2 pattern in SPLIT. */
 700
 701 static void
 702 output_peephole2_scratches (split)
 703      rtx split;
 704 {
 705   int i;
 706   int insn_nr = 0;
 707
 708   printf ("  rtx first_insn ATTRIBUTE_UNUSED;\n");
 709   printf ("  rtx last_insn ATTRIBUTE_UNUSED;\n");
 710   printf ("  HARD_REG_SET _regs_allocated;\n");
 711
 712   printf ("  CLEAR_HARD_REG_SET (_regs_allocated);\n");
 713
 714   for (i = 0; i < XVECLEN (split, 0); i++)
 715     {
 716       rtx elt = XVECEXP (split, 0, i);
 717       if (GET_CODE (elt) == MATCH_SCRATCH)
 718         {
 719           int last_insn_nr = insn_nr;
 720           int cur_insn_nr = insn_nr;
 721           int j;
 722           for (j = i + 1; j < XVECLEN (split, 0); j++)
 723             if (GET_CODE (XVECEXP (split, 0, j)) == MATCH_DUP)
 724               {
 725                 if (XINT (XVECEXP (split, 0, j), 0) == XINT (elt, 0))
 726                   last_insn_nr = cur_insn_nr;
 727               }
 728             else if (GET_CODE (XVECEXP (split, 0, j)) != MATCH_SCRATCH)
 729               cur_insn_nr++;
 730           printf ("  first_insn = recog_next_insn (curr_insn, %d);\n", insn_nr);
 731           if (last_insn_nr > insn_nr)
 732             printf ("  last_insn = recog_next_insn (curr_insn, %d);\n",
 733                     last_insn_nr - 1);
 734           else
 735             printf ("  last_insn = 0;\n");
 736           printf ("  if ((operands[%d] = find_free_register (first_insn, last_insn, \"%s\", %smode, &_regs_allocated)) == NULL_RTX)\n\
 737     return NULL;\n",
 738                   XINT (elt, 0),
 739                   XSTR (elt, 1),
 740                   GET_MODE_NAME (GET_MODE (elt)));
 741
 742         }
 743       else if (GET_CODE (elt) != MATCH_DUP)
 744         insn_nr++;
 745     }
 746 }
 747 \f
 748 PTR
 749 xmalloc (size)
 750   size_t size;
 751 {
 752   register PTR val = (PTR) malloc (size);
 753
 754   if (val == 0)
 755     fatal ("virtual memory exhausted");
 756
 757   return val;
 758 }
 759
 760 PTR
 761 xrealloc (old, size)
 762   PTR old;
 763   size_t size;
 764 {
 765   register PTR ptr;
 766   if (old)
 767     ptr = (PTR) realloc (old, size);
 768   else
 769     ptr = (PTR) malloc (size);
 770   if (!ptr)
 771     fatal ("virtual memory exhausted");
 772   return ptr;
 773 }
 774
 775 int
 776 main (argc, argv)
 777      int argc;
 778      char **argv;
 779 {
 780   rtx desc;
 781   FILE *infile;
 782   register int c;
 783
 784   progname = "genemit";
 785   obstack_init (rtl_obstack);
 786
 787   if (argc <= 1)
 788     fatal ("No input file name.");
 789
 790   infile = fopen (argv[1], "r");
 791   if (infile == 0)
 792     {
 793       perror (argv[1]);
 794       exit (FATAL_EXIT_CODE);
 795     }
 796
 797   /* Assign sequential codes to all entries in the machine description
 798      in parallel with the tables in insn-output.c.  */
 799
 800   insn_code_number = 0;
 801   insn_index_number = 0;
 802
 803   printf ("/* Generated automatically by the program `genemit'\n\
 804 from the machine description file `md'.  */\n\n");
 805
 806   printf ("#include \"config.h\"\n");
 807   printf ("#include \"system.h\"\n");
 808   printf ("#include \"rtl.h\"\n");
 809   printf ("#include \"function.h\"\n");
 810   printf ("#include \"expr.h\"\n");
 811   printf ("#include \"real.h\"\n");
 812   printf ("#include \"flags.h\"\n");
 813   printf ("#include \"output.h\"\n");
 814   printf ("#include \"insn-config.h\"\n");
 815   printf ("#include \"insn-flags.h\"\n");
 816   printf ("#include \"insn-codes.h\"\n");
 817   printf ("#include \"recog.h\"\n");
 818   printf ("#include \"hard-reg-set.h\"\n");
 819   printf ("#include \"resource.h\"\n");
 820   printf ("#include \"reload.h\"\n\n");
 821   printf ("#define FAIL return (end_sequence (), _val)\n");
 822   printf ("#define DONE return (_val = gen_sequence (), end_sequence (), _val)\n");
 823
 824   /* Read the machine description.  */
 825
 826   while (1)
 827     {
 828       c = read_skip_spaces (infile);
 829       if (c == EOF)
 830         break;
 831       ungetc (c, infile);
 832
 833       desc = read_rtx (infile);
 834
 835       if (GET_CODE (desc) == DEFINE_INSN)
 836         {
 837           gen_insn (desc);
 838           ++insn_code_number;
 839         }
 840       if (GET_CODE (desc) == DEFINE_EXPAND)
 841         {
 842           gen_expand (desc);
 843           ++insn_code_number;
 844         }
 845       if (GET_CODE (desc) == DEFINE_SPLIT)
 846         {
 847           gen_split (desc);
 848           ++insn_code_number;
 849         }
 850       if (GET_CODE (desc) == DEFINE_PEEPHOLE2)
 851         {
 852           gen_split (desc);
 853           ++insn_code_number;
 854         }
 855       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 856         {
 857           ++insn_code_number;
 858         }
 859       ++insn_index_number;
 860     }
 861
 862   /* Write out the routine to add CLOBBERs to a pattern.  */
 863   output_add_clobbers ();
 864
 865   fflush (stdout);
 866   exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 867   /* NOTREACHED */
 868   return 0;
 869 }