gcc/bc-emit.c

   1 /* Output bytecodes for GNU C-compiler.
   2    Copyright (C) 1993, 1994, 1996 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 "config.h"
  23 #ifdef __STDC__
  24 #include <stdarg.h>
  25 #else
  26 #include <varargs.h>
  27 #endif
  28 #include "machmode.h"
  29 #include "rtl.h"
  30 #include "real.h"
  31 #include "obstack.h"
  32 #include "bytecode.h"
  33 #ifdef __GNUC__
  34 #include "bytetypes.h"
  35 #endif
  36 #include "bc-emit.h"
  37 #include "bc-opcode.h"
  38 #include "bc-typecd.h"
  39 #include "bi-run.h"
  40
  41 #include <stdio.h>
  42
  43 extern char *xmalloc (), *xrealloc ();
  44
  45 extern struct obstack *rtl_obstack;
  46
  47 /* Indexed by mode class, gives the narrowest mode for each class.  */
  48
  49 extern enum machine_mode class_narrowest_mode[(int) MAX_MODE_CLASS];
  50
  51 /* Commonly used modes.  */
  52 /* Mode whose width is BITS_PER_UNIT */
  53 extern enum machine_mode byte_mode;
  54
  55 /* Mode whose width is BITS_PER_WORD */
  56 extern enum machine_mode word_mode;
  57
  58 /* Vector indexed by opcode giving info about the args for each opcode. */
  59 static struct arityvec arityvec[] = {
  60 #include "bc-arity.h"
  61 };
  62
  63 /* How to print a symbol name for the assembler.  */
  64 static void
  65 prsym (file, s)
  66      FILE *file;
  67      char *s;
  68 {
  69   if (*s == '*')
  70     fprintf (file, "%s", s + 1);
  71   else
  72
  73 #ifdef NAMES_HAVE_UNDERSCORES
  74     fprintf (file, "_%s", s);
  75 #else
  76     fprintf (file, "%s", s);
  77 #endif
  78
  79 }
  80
  81 /* Maintain a bucket hash table for symbol names. */
  82
  83 #define HASH_BITS 32
  84 #define HASH_SIZE 509
  85
  86 static struct bc_sym *hashtab[HASH_SIZE];
  87
  88 static unsigned int
  89 hash (name)
  90      char *name;
  91 {
  92   unsigned int hash = 0;
  93
  94   while (*name)
  95     {
  96       hash = hash << 3 | hash >> HASH_BITS - 3;
  97       hash += *name++;
  98     }
  99
 100   return hash % HASH_SIZE;
 101 }
 102
 103
 104 /* Look up the named symbol, creating it if it doesn't exist. */
 105 struct bc_sym *
 106 sym_lookup (name)
 107      char *name;
 108 {
 109   int i;
 110   struct bc_sym *s;
 111
 112   i = hash (name);
 113   for (s = hashtab[i]; s; s = s->next)
 114     if (!strcmp (s->name, name))
 115       return s;
 116
 117   s = (struct bc_sym *) xmalloc (sizeof (struct bc_sym));
 118   s->name = xmalloc (strlen (name) + 1);
 119   strcpy (s->name, name);
 120   s->defined = s->global = s->common = 0;
 121   s->val = 0;
 122   s->next = hashtab[i];
 123   hashtab[i] = s;
 124   return s;
 125 }
 126
 127
 128 /* Write out .globl and common symbols to the named file.  */
 129 static void
 130 bc_sym_write (file)
 131      FILE *file;
 132 {
 133   int i;
 134   struct bc_sym *s;
 135
 136   for (i = 0; i < HASH_SIZE; ++i)
 137     for (s = hashtab[i]; s; s = s->next)
 138       {
 139         if (s->global)
 140           {
 141             fprintf (file, "\n\t.globl ");
 142             prsym (file, s->name);
 143             putc ('\n', file);
 144             if (s->common)
 145               {
 146                 fprintf (file, "\n\t.comm ");
 147                 prsym (file, s->name);
 148                 fprintf (file, ", %lu\n", s->val);
 149               }
 150           }
 151         else if (s->common)
 152           {
 153             fprintf (file, "\n\t.lcomm ");
 154             prsym (file, s->name);
 155             fprintf (file, ", %lu\n", s->val);
 156           }
 157       }
 158 }
 159
 160 \f
 161
 162
 163 /* Create and initialize a new segment. */
 164 static struct bc_seg *
 165 seg_create ()
 166 {
 167   struct bc_seg *result;
 168
 169   result = (struct bc_seg *) xmalloc (sizeof (struct bc_seg));
 170   result->alloc = 256;
 171   result->data = xmalloc (result->alloc);
 172   result->size = 0;
 173   result->syms = 0;
 174   result->relocs = 0;
 175   return result;
 176 }
 177
 178
 179 /* Advance the segment index to the next alignment boundary. */
 180 static void
 181 seg_align (seg, log)
 182      struct bc_seg *seg;
 183      int log;
 184 {
 185   unsigned int oldsize = seg->size;
 186
 187   seg->size = seg->size + (1 << log) - 1 & ~((1 << log) - 1);
 188   if (seg->size > seg->alloc)
 189     {
 190       while (seg->size > seg->alloc)
 191         seg->alloc *= 2;
 192       seg->data = xrealloc (seg->data, seg->alloc);
 193     }
 194   bzero (seg->data + oldsize, seg->size - oldsize);
 195 }
 196
 197
 198 /* Append the given data to the given segment. */
 199 static void
 200 seg_data (seg, data, size)
 201      struct bc_seg *seg;
 202      char *data;
 203      unsigned int size;
 204 {
 205   if (seg->size + size > seg->alloc)
 206     {
 207       while (seg->size + size > seg->alloc)
 208         seg->alloc *= 2;
 209       seg->data = xrealloc (seg->data, seg->alloc);
 210     }
 211
 212   bcopy (data, seg->data + seg->size, size);
 213   seg->size += size;
 214 }
 215
 216
 217 /* Append a zero-filled skip to the given segment.  */
 218 static void
 219 seg_skip (seg, size)
 220      struct bc_seg *seg;
 221      unsigned int size;
 222 {
 223   if (seg->size + size > seg->alloc)
 224     {
 225       while (seg->size + size > seg->alloc)
 226         seg->alloc *= 2;
 227       seg->data = xrealloc (seg->data, seg->alloc);
 228     }
 229
 230   memset (seg->data + seg->size, 0, size);
 231   seg->size += size;
 232 }
 233
 234
 235 /* Define the given name as the current offset in the given segment.  It
 236    is an error if the name is already defined.  Return 0 or 1 indicating
 237    failure or success respectively. */
 238 static int
 239 seg_defsym (seg, name)
 240      struct bc_seg *seg;
 241      char *name;
 242 {
 243   struct bc_sym *sym;
 244   struct bc_segsym *segsym;
 245
 246   sym = sym_lookup (name);
 247   if (sym->defined)
 248     return 0;
 249
 250   sym->defined = 1;
 251   sym->val = seg->size;
 252   segsym = (struct bc_segsym *) xmalloc (sizeof (struct bc_segsym));
 253   segsym->sym = sym;
 254   segsym->next = seg->syms;
 255   seg->syms = segsym;
 256   return 1;
 257 }
 258
 259
 260 /* Generate in seg's data a reference to the given sym, adjusted by
 261    the given offset. */
 262 static void
 263 seg_refsym (seg, name, offset)
 264      struct bc_seg *seg;
 265      char *name;
 266      int offset;
 267 {
 268   struct bc_sym *sym;
 269   struct bc_segreloc *segreloc;
 270
 271   sym = sym_lookup (name);
 272   segreloc = (struct bc_segreloc *) xmalloc (sizeof (struct bc_segreloc));
 273   segreloc->offset = seg->size;
 274   segreloc->sym = sym;
 275   segreloc->next = seg->relocs;
 276   seg->relocs = segreloc;
 277   seg_data (seg, (char *) &offset, sizeof offset);
 278 }
 279
 280
 281 /* Concatenate the contents of given segments into the first argument. */
 282 static void
 283 seg_concat (result, seg)
 284      struct bc_seg *result, *seg;
 285 {
 286   unsigned int fix;
 287   struct bc_segsym *segsym;
 288   struct bc_segreloc *segreloc;
 289
 290   seg_align (result, MACHINE_SEG_ALIGN);
 291   fix = result->size;
 292   seg_data (result, seg->data, seg->size);
 293   free (seg->data);
 294
 295   /* Go through the symbols and relocs of SEG, adjusting their offsets
 296      for their new location in RESULT. */
 297   if (seg->syms)
 298     {
 299       segsym = seg->syms;
 300       do
 301         segsym->sym->val += fix;
 302       while (segsym->next && (segsym = segsym->next));
 303       segsym->next = result->syms;
 304       result->syms = seg->syms;
 305     }
 306   if (seg->relocs)
 307     {
 308       segreloc = seg->relocs;
 309       do
 310         segreloc->offset += fix;
 311       while (segreloc->next && (segreloc = segreloc->next));
 312       segreloc->next = result->relocs;
 313       result->relocs = seg->relocs;
 314     }
 315
 316   free ((char *) seg);
 317 }
 318
 319 /* Write a segment to a file.  */
 320 static void
 321 bc_seg_write (seg, file)
 322      struct bc_seg *seg;
 323      FILE *file;
 324 {
 325   struct bc_segsym *segsym, *nsegsym, *psegsym;
 326   struct bc_segreloc *segreloc, *nsegreloc, *psegreloc;
 327   int i, offset, flag;
 328
 329   /* Reverse the list of symbols.  */
 330   for (psegsym = 0, segsym = seg->syms; segsym; segsym = nsegsym)
 331     {
 332       nsegsym = segsym->next;
 333       segsym->next = psegsym;
 334       psegsym = segsym;
 335     }
 336   seg->syms = psegsym;
 337
 338   /* Reverse the list of relocs.  */
 339   for (psegreloc = 0, segreloc = seg->relocs; segreloc; segreloc = nsegreloc)
 340     {
 341       nsegreloc = segreloc->next;
 342       segreloc->next = psegreloc;
 343       psegreloc = segreloc;
 344     }
 345   seg->relocs = psegreloc;
 346
 347   /* Output each byte of the segment.  */
 348   for (i = 0, segsym = seg->syms, segreloc = seg->relocs; i < seg->size; ++i)
 349     {
 350       while (segsym && segsym->sym->val == i)
 351         {
 352           if (i % 8 != 0)
 353             putc ('\n', file);
 354
 355           BC_WRITE_SEGSYM (segsym, file);
 356           segsym = segsym->next;
 357           flag = 1;
 358         }
 359       if (segreloc && segreloc->offset == i)
 360         {
 361           if (i % 8 != 0)
 362             putc ('\n', file);
 363
 364           bcopy (seg->data + i, (char *) &offset, sizeof (int));
 365           i += sizeof (int) - 1;
 366
 367           BC_WRITE_RELOC_ENTRY (segreloc, file, offset);
 368           segreloc = segreloc->next;
 369           flag = 1;
 370         }
 371       else
 372         {
 373           if (i % 8 == 0 || flag)
 374             BC_START_BYTECODE_LINE (file);
 375
 376           BC_WRITE_BYTECODE (i % 8 == 0 || flag ? ' ' : ',',
 377                              seg->data[i] & 0xFF,
 378                              file);
 379           flag = 0;
 380           if (i % 8 == 7)
 381             putc ('\n', file);
 382         }
 383     }
 384
 385   /* Paranoia check--we should have visited all syms and relocs during
 386      the output pass.  */
 387
 388   if (segsym || segreloc)
 389     abort ();
 390 }
 391
 392 \f
 393
 394 /* Text and data segments of the object file in making. */
 395 static struct bc_seg *bc_text_seg;
 396 static struct bc_seg *bc_data_seg;
 397
 398 /* Called before anything else in this module. */
 399 void
 400 bc_initialize ()
 401 {
 402   int min_class_size[(int) MAX_MODE_CLASS];
 403   enum machine_mode mode;
 404   int i;
 405
 406   bc_init_mode_to_code_map ();
 407
 408   bc_text_seg = seg_create ();
 409   bc_data_seg = seg_create ();
 410
 411   dconst0 = REAL_VALUE_ATOF ("0", DFmode);
 412   dconst1 = REAL_VALUE_ATOF ("1", DFmode);
 413   dconst2 = REAL_VALUE_ATOF ("2", DFmode);
 414   dconstm1 = REAL_VALUE_ATOF ("-1", DFmode);
 415
 416   /* Find the narrowest mode for each class and compute the word and byte
 417      modes.  */
 418
 419   for (i = 0; i < (int) MAX_MODE_CLASS; i++)
 420     min_class_size[i] = 1000;
 421
 422   for (mode = VOIDmode; (int) mode < (int) MAX_MACHINE_MODE;
 423        mode = (enum machine_mode) ((int) mode + 1))
 424     {
 425       if (GET_MODE_SIZE (mode) < min_class_size[(int) GET_MODE_CLASS (mode)])
 426         {
 427           class_narrowest_mode[(int) GET_MODE_CLASS (mode)] = mode;
 428           min_class_size[(int) GET_MODE_CLASS (mode)] = GET_MODE_SIZE (mode);
 429         }
 430       if (GET_MODE_CLASS (mode) == MODE_INT
 431           && GET_MODE_BITSIZE (mode) == BITS_PER_UNIT)
 432         byte_mode = mode;
 433
 434       if (GET_MODE_CLASS (mode) == MODE_INT
 435           && GET_MODE_BITSIZE (mode) == BITS_PER_WORD)
 436         word_mode = mode;
 437     }
 438 }
 439
 440
 441 /* External addresses referenced in a function.  Rather than trying to
 442    work relocatable address directly into bytecoded functions (which would
 443    require us to provide hairy location info and possibly obey alignment
 444    rules imposed by the architecture) we build an auxiliary table of
 445    pointer constants, and encode just offsets into this table into the
 446    actual bytecode. */
 447 static struct bc_seg *ptrconsts;
 448
 449 /* Trampoline code for the function entry.  */
 450 struct bc_seg *trampoline;
 451
 452 /* Actual byte code of the function. */
 453 struct bc_seg *bytecode;
 454
 455 /* List of labels defined in the function. */
 456 struct bc_label *labels;
 457
 458 /* List of label references in the function. */
 459 struct bc_labelref *labelrefs;
 460
 461
 462 /* Add symbol to pointer table.  Return offset into table where
 463    pointer was stored.  The offset usually goes into the bytecode
 464    stream as a constP literal. */
 465 int
 466 bc_define_pointer (p)
 467      char *p;
 468 {
 469   int offset = ptrconsts->size;
 470
 471   seg_refsym (ptrconsts, p, 0);
 472   return offset;
 473 }
 474
 475
 476 /* Begin a bytecoded function.  */
 477 int
 478 bc_begin_function (name)
 479     char *name;
 480 {
 481   ptrconsts = seg_create ();
 482   trampoline = seg_create ();
 483   bytecode = seg_create ();
 484   return seg_defsym (trampoline, name);
 485 }
 486
 487
 488 /* Force alignment in inline bytecode.  */
 489 void
 490 bc_align_bytecode (align)
 491     int align;
 492 {
 493   seg_align (bytecode, align);
 494 }
 495
 496
 497 /* Emit data inline into bytecode.  */
 498 void
 499 bc_emit_bytecode_const (data, size)
 500      char *data;
 501      unsigned int size;
 502 {
 503   if (bytecode)
 504     seg_data (bytecode, data, size);
 505 }
 506
 507
 508 /* Create a new "bytecode label", to have its value defined later.
 509    Bytecode labels have nothing to do with the object file symbol table,
 510    and are purely local to a given bytecoded function. */
 511 struct bc_label *
 512 bc_get_bytecode_label ()
 513 {
 514   struct bc_label *result;
 515
 516   result = (struct bc_label *) xmalloc (sizeof (struct bc_label));
 517   result->defined = 0;
 518   result->next = labels;
 519   result->uid = 0;
 520   labels = result;
 521   return result;
 522 }
 523
 524
 525 /* Define the given label with the current location counter. */
 526 int
 527 bc_emit_bytecode_labeldef (label)
 528      struct bc_label *label;
 529 {
 530   extern int bc_new_uid ();
 531
 532   if (!label || label->defined)
 533     return 0;
 534
 535   label->offset = bytecode->size;
 536   label->defined = 1;
 537   label->uid = bc_new_uid ();
 538
 539 #ifdef DEBUG_PRINT_CODE
 540   fprintf (stderr, "$%lx:\n", label);
 541 #endif
 542
 543   return 1;
 544 }
 545
 546
 547 /* Generate a location-relative reference to the given bytecode label.
 548    It need not be defined yet; label references will be backpatched later. */
 549 void
 550 bc_emit_bytecode_labelref (label)
 551      struct bc_label *label;
 552 {
 553   struct bc_labelref *labelref;
 554   static int zero;
 555
 556   labelref = (struct bc_labelref *) xmalloc (sizeof (struct bc_labelref));
 557   labelref->label = label;
 558   labelref->offset = bytecode->size;
 559   labelref->next = labelrefs;
 560   labelrefs = labelref;
 561
 562 #ifdef DEBUG_PRINT_CODE
 563   fprintf (stderr, " $%lx", label);
 564 #endif
 565
 566   seg_data (bytecode, (char *) &zero, sizeof zero);
 567 }
 568
 569
 570 /* Emit a reference to an external address; generate the reference in the
 571    ptrconst area, and emit an offset in the bytecode. */
 572 void
 573 bc_emit_code_labelref (name, offset)
 574      char *name;
 575      int offset;
 576 {
 577   int ptroff;
 578
 579   ptroff = ptrconsts->size / sizeof (char *);
 580   seg_data (bytecode, (char *) &ptroff, sizeof ptroff);
 581   seg_refsym (ptrconsts, name, offset);
 582
 583 #ifdef DEBUG_PRINT_CODE
 584   fprintf (stderr, " [external <%x> %s]", ptroff, name);
 585 #endif
 586 }
 587
 588
 589 /* Backpatch label references in the byte code, and concatenate the bytecode
 590    and pointer constant segments to the cumulative text for the object file.
 591    Return a label name for the pointer constants region.  */
 592 char *
 593 bc_end_function ()
 594 {
 595   int addr;
 596   struct bc_label *label, *next;
 597   struct bc_labelref *ref, *nextref;
 598   char ptrconsts_label[20];
 599   static int nlab;
 600
 601   /* Backpatch bytecode label references. */
 602   for (ref = labelrefs; ref; ref = ref->next)
 603     if (ref->label->defined)
 604       {
 605         addr = ref->label->offset;
 606         bcopy ((char *) &addr, bytecode->data + ref->offset, sizeof addr);
 607       }
 608
 609   /* Free the chains of labelrefs and labeldefs. */
 610   for (ref = labelrefs; ref; ref = nextref)
 611     {
 612       nextref = ref->next;
 613       free ((char *) ref);
 614     }
 615
 616   for (label = labels; label; label = next)
 617     {
 618       next = label->next;
 619       free ((char *) label);
 620     }
 621
 622   seg_concat (trampoline, bytecode);
 623   seg_align (trampoline, MACHINE_SEG_ALIGN);
 624   sprintf (ptrconsts_label, "*LP%d", nlab++);
 625   seg_defsym (trampoline, ptrconsts_label);
 626   seg_concat (trampoline, ptrconsts);
 627   seg_concat (bc_text_seg, trampoline);
 628
 629   labels = 0;
 630   labelrefs = 0;
 631   trampoline = 0;
 632   bytecode = 0;
 633   ptrconsts = 0;
 634
 635   return sym_lookup (ptrconsts_label)->name;
 636 }
 637
 638 /* Force alignment in const data. */
 639 void
 640 bc_align_const (align)
 641      int align;
 642 {
 643   seg_align (bc_text_seg, align);
 644 }
 645
 646 /* Emit const data. */
 647 void
 648 bc_emit_const (data, size)
 649      char *data;
 650      unsigned int size;
 651 {
 652   seg_data (bc_text_seg, data, size);
 653 }
 654
 655 /* Emit a zero-filled constant skip. */
 656 void
 657 bc_emit_const_skip (size)
 658      unsigned int size;
 659 {
 660   seg_skip (bc_text_seg, size);
 661 }
 662
 663 /* Emit a label definition in const data. */
 664 int
 665 bc_emit_const_labeldef (name)
 666      char *name;
 667 {
 668   return seg_defsym (bc_text_seg, name);
 669 }
 670
 671 /* Emit a label reference in const data. */
 672 void
 673 bc_emit_const_labelref (name, offset)
 674      char *name;
 675      int offset;
 676 {
 677   seg_refsym (bc_text_seg, name, offset);
 678 }
 679
 680 /* Force alignment in data. */
 681 void
 682 bc_align_data (align)
 683      int align;
 684 {
 685   seg_align (bc_data_seg, align);
 686 }
 687
 688 /* Emit data. */
 689 void
 690 bc_emit_data (data, size)
 691      char *data;
 692      unsigned int size;
 693 {
 694   seg_data (bc_data_seg, data, size);
 695 }
 696
 697 /* Emit a zero-filled data skip.  */
 698 void
 699 bc_emit_data_skip (size)
 700      unsigned int size;
 701 {
 702   seg_skip (bc_data_seg, size);
 703 }
 704
 705 /* Emit label definition in data. */
 706 int
 707 bc_emit_data_labeldef (name)
 708      char *name;
 709 {
 710   return seg_defsym (bc_data_seg, name);
 711 }
 712
 713 /* Emit label reference in data. */
 714 void
 715 bc_emit_data_labelref (name, offset)
 716      char *name;
 717      int offset;
 718 {
 719   seg_refsym (bc_data_seg, name, offset);
 720 }
 721
 722 /* Emit a common block of the given name and size.  Note that
 723    when the .o file is actually written non-global "common"
 724    blocks will have to be turned into space in the data section.  */
 725 int
 726 bc_emit_common (name, size)
 727      char *name;
 728      unsigned int size;
 729 {
 730   struct bc_sym *sym;
 731
 732   sym = sym_lookup (name);
 733   if (sym->defined)
 734     return 0;
 735
 736   sym->defined = 1;
 737   sym->common = 1;
 738   sym->val = size;
 739   return 1;
 740 }
 741
 742 /* Globalize the given label. */
 743 void
 744 bc_globalize_label (name)
 745      char *name;
 746 {
 747   struct bc_sym *sym;
 748
 749   sym = sym_lookup (name);
 750   sym->global = 1;
 751 }
 752
 753 static enum { in_text, in_data } section = in_text;
 754
 755 void
 756 bc_text ()
 757 {
 758   section = in_text;
 759 }
 760
 761 void
 762 bc_data ()
 763 {
 764   section = in_data;
 765 }
 766
 767 void
 768 bc_align (align)
 769      int align;
 770 {
 771   if (section == in_text)
 772     bc_align_const (align);
 773   else
 774     bc_align_data (align);
 775 }
 776
 777 void
 778 bc_emit (data, size)
 779      char *data;
 780      unsigned int size;
 781 {
 782   if (section == in_text)
 783     bc_emit_const (data, size);
 784   else
 785     bc_emit_data (data, size);
 786 }
 787
 788 void
 789 bc_emit_skip (size)
 790      unsigned int size;
 791 {
 792   if (section == in_text)
 793     bc_emit_const_skip (size);
 794   else
 795     bc_emit_data_skip (size);
 796 }
 797
 798 int
 799 bc_emit_labeldef (name)
 800      char *name;
 801 {
 802   if (section == in_text)
 803     return bc_emit_const_labeldef (name);
 804   else
 805     return bc_emit_data_labeldef (name);
 806 }
 807
 808 void
 809 bc_emit_labelref (name, offset)
 810      char *name;
 811      int offset;
 812 {
 813   if (section == in_text)
 814     bc_emit_const_labelref (name, offset);
 815   else
 816     bc_emit_data_labelref (name, offset);
 817 }
 818
 819 void
 820 bc_write_file (file)
 821      FILE *file;
 822 {
 823   BC_WRITE_FILE (file);
 824 }
 825
 826
 827 /* Allocate a new bytecode rtx.
 828    If you supply a null BC_LABEL, we generate one.  */
 829
 830 rtx
 831 bc_gen_rtx (label, offset, bc_label)
 832      char *label;
 833      int offset;
 834      struct bc_label *bc_label;
 835 {
 836   rtx r;
 837
 838   if (bc_label == 0)
 839     bc_label = (struct bc_label *) xmalloc (sizeof (struct bc_label));
 840
 841   r = gen_rtx (CODE_LABEL, VOIDmode, label, bc_label);
 842   bc_label->offset = offset;
 843
 844   return r;
 845 }
 846
 847
 848 /* Print bytecode rtx */
 849 void
 850 bc_print_rtl (fp, r)
 851      FILE *fp;
 852      rtx r;
 853 {
 854 #if 0 /* This needs to get fixed to really work again.  */
 855   /* BC_WRITE_RTL has a definition
 856      that doesn't even make sense for this use.  */
 857   BC_WRITE_RTL (r, fp);
 858 #endif
 859 }
 860
 861
 862 /* Emit a bytecode, keeping a running tally of the stack depth.  */
 863 void
 864 bc_emit_bytecode (bytecode)
 865      enum bytecode_opcode bytecode;
 866 {
 867   char byte;
 868   static int prev_lineno = -1;
 869
 870   byte = (char) bytecode;
 871
 872 #ifdef BCDEBUG_PRINT_CODE
 873   if (lineno != prev_lineno)
 874     {
 875       fprintf (stderr, "<line %d>\n", lineno);
 876       prev_lineno = lineno;
 877     }
 878
 879   fputs (opcode_name[(unsigned int) bytecode], stderr);
 880 #endif
 881
 882   /* Due to errors we are often requested to output bytecodes that
 883      will cause an interpreter stack undeflow when executed.  Instead of
 884      dumping core on such occasions, we omit the bytecode.  Erroneous code
 885      should not be executed, regardless.  This makes life much easier, since
 886      we don't have to deceive ourselves about the known stack depth. */
 887
 888   bc_emit_bytecode_const (&byte, 1);
 889
 890   if ((stack_depth -= arityvec[(int) bytecode].ninputs) >= 0)
 891     {
 892       if ((stack_depth += arityvec[(int) bytecode].noutputs) > max_stack_depth)
 893         max_stack_depth = stack_depth;
 894     }
 895
 896 #ifdef VALIDATE_STACK_FOR_BC
 897   VALIDATE_STACK_FOR_BC ();
 898 #endif
 899 }
 900
 901
 902 #ifdef BCDEBUG_PRINT_CODE
 903 #define PRLIT(TYPE, PTR)  fprintf (stderr, " [%x]", *(TYPE *) PTR)
 904 #else
 905 #define PRLIT(X,Y)
 906 #endif
 907
 908 /* Emit a complete bytecode instruction, expecting the correct number
 909    of literal values in the call.  First argument is the instruction, the
 910    remaining arguments are literals of size HOST_WIDE_INT or smaller. */
 911 void
 912 bc_emit_instruction VPROTO((enum bytecode_opcode opcode, ...))
 913 {
 914 #ifndef __STDC__
 915   enum bytecode_opcode opcode;
 916 #endif
 917   va_list arguments;
 918   int nliteral, instruction;
 919
 920   VA_START (arguments, opcode);
 921
 922 #ifndef __STDC__
 923   opcode = va_arg (arguments, enum bytecode_opcode);
 924 #endif
 925
 926   /* Emit instruction bytecode */
 927   bc_emit_bytecode (opcode);
 928   instruction = (int) opcode;
 929
 930   /* Loop literals and emit as bytecode constants */
 931   for (nliteral = 0; nliteral < arityvec[instruction].nliterals; nliteral++)
 932     {
 933       switch (arityvec[instruction].literals[nliteral])
 934         {
 935 /* This conditional is a kludge, but it's necessary
 936    because TYPE might be long long.  */
 937 #ifdef __GNUC__
 938           /* Expand definitions into case statements */
 939 #define DEFTYPECODE(CODE, NAME, MODE, TYPE)                             \
 940         case CODE:                                                      \
 941           {                                                             \
 942             TYPE temp = va_arg (arguments, TYPE);                       \
 943             bc_emit_bytecode_const ((void *) &temp, sizeof temp);       \
 944             PRLIT (TYPE, &temp); }                                      \
 945           break;
 946
 947 #include "bc-typecd.def"
 948
 949 #undef DEFTYPECODE
 950 #endif /* __GNUC__ */
 951
 952         default:
 953           abort ();
 954         }
 955     }
 956
 957   va_end (arguments);
 958
 959 #ifdef BCDEBUG_PRINT_CODE
 960   fputc ('\n', stderr);
 961 #endif
 962 }
 963 \f
 964 /* Emit the machine-code interface trampoline at the beginning of a byte
 965    coded function.  The argument is a label name of the interpreter
 966    bytecode callinfo structure; the return value is a label name for
 967    the beginning of the actual bytecode.  */
 968 char *
 969 bc_emit_trampoline (callinfo)
 970      char *callinfo;
 971 {
 972   char mylab[20];
 973   static int n;
 974
 975   sprintf (mylab, "*LB%d", n++);
 976
 977   BC_EMIT_TRAMPOLINE (trampoline, callinfo);
 978
 979   seg_defsym (bytecode, mylab);
 980   return sym_lookup (mylab)->name;
 981 }