src/bytecode.c

   1 /* Execution of byte code produced by bytecomp.el.
   2    Copyright (C) 1985, 1986, 1987, 1988, 1993 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs 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 Emacs 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 Emacs; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20 hacked on by jwz@lucid.com 17-jun-91
  21   o  added a compile-time switch to turn on simple sanity checking;
  22   o  put back the obsolete byte-codes for error-detection;
  23   o  added a new instruction, unbind_all, which I will use for
  24      tail-recursion elimination;
  25   o  made temp_output_buffer_show be called with the right number
  26      of args;
  27   o  made the new bytecodes be called with args in the right order;
  28   o  added metering support.
  29
  30 by Hallvard:
  31   o  added relative jump instructions;
  32   o  all conditionals now only do QUIT if they jump.
  33  */
  34
  35 #include <config.h>
  36 #include "lisp.h"
  37 #include "buffer.h"
  38 #include "syntax.h"
  39
  40 /*
  41  * define BYTE_CODE_SAFE to enable some minor sanity checking (useful for
  42  * debugging the byte compiler...)
  43  *
  44  * define BYTE_CODE_METER to enable generation of a byte-op usage histogram.
  45  */
  46 /* #define BYTE_CODE_SAFE */
  47 /* #define BYTE_CODE_METER */
  48
  49 \f
  50 #ifdef BYTE_CODE_METER
  51
  52 Lisp_Object Vbyte_code_meter, Qbyte_code_meter;
  53 int byte_metering_on;
  54
  55 #define METER_2(code1, code2) \
  56   XFASTINT (XVECTOR (XVECTOR (Vbyte_code_meter)->contents[(code1)]) \
  57             ->contents[(code2)])
  58
  59 #define METER_1(code) METER_2 (0, (code))
  60
  61 #define METER_CODE(last_code, this_code)                        \
  62 {                                                               \
  63   if (byte_metering_on)                                         \
  64     {                                                           \
  65       if (METER_1 (this_code) != ((1<<VALBITS)-1))              \
  66         METER_1 (this_code)++;                                  \
  67       if (last_code                                             \
  68           && METER_2 (last_code, this_code) != ((1<<VALBITS)-1))\
  69         METER_2 (last_code, this_code)++;                       \
  70     }                                                           \
  71 }
  72
  73 #else /* no BYTE_CODE_METER */
  74
  75 #define METER_CODE(last_code, this_code)
  76
  77 #endif /* no BYTE_CODE_METER */
  78 \f
  79
  80 Lisp_Object Qbytecode;
  81
  82 /*  Byte codes: */
  83
  84 #define Bvarref 010
  85 #define Bvarset 020
  86 #define Bvarbind 030
  87 #define Bcall 040
  88 #define Bunbind 050
  89
  90 #define Bnth 070
  91 #define Bsymbolp 071
  92 #define Bconsp 072
  93 #define Bstringp 073
  94 #define Blistp 074
  95 #define Beq 075
  96 #define Bmemq 076
  97 #define Bnot 077
  98 #define Bcar 0100
  99 #define Bcdr 0101
 100 #define Bcons 0102
 101 #define Blist1 0103
 102 #define Blist2 0104
 103 #define Blist3 0105
 104 #define Blist4 0106
 105 #define Blength 0107
 106 #define Baref 0110
 107 #define Baset 0111
 108 #define Bsymbol_value 0112
 109 #define Bsymbol_function 0113
 110 #define Bset 0114
 111 #define Bfset 0115
 112 #define Bget 0116
 113 #define Bsubstring 0117
 114 #define Bconcat2 0120
 115 #define Bconcat3 0121
 116 #define Bconcat4 0122
 117 #define Bsub1 0123
 118 #define Badd1 0124
 119 #define Beqlsign 0125
 120 #define Bgtr 0126
 121 #define Blss 0127
 122 #define Bleq 0130
 123 #define Bgeq 0131
 124 #define Bdiff 0132
 125 #define Bnegate 0133
 126 #define Bplus 0134
 127 #define Bmax 0135
 128 #define Bmin 0136
 129 #define Bmult 0137
 130
 131 #define Bpoint 0140
 132 #define Bmark 0141 /* no longer generated as of v18 */
 133 #define Bgoto_char 0142
 134 #define Binsert 0143
 135 #define Bpoint_max 0144
 136 #define Bpoint_min 0145
 137 #define Bchar_after 0146
 138 #define Bfollowing_char 0147
 139 #define Bpreceding_char 0150
 140 #define Bcurrent_column 0151
 141 #define Bindent_to 0152
 142 #define Bscan_buffer 0153 /* No longer generated as of v18 */
 143 #define Beolp 0154
 144 #define Beobp 0155
 145 #define Bbolp 0156
 146 #define Bbobp 0157
 147 #define Bcurrent_buffer 0160
 148 #define Bset_buffer 0161
 149 #define Bread_char 0162 /* No longer generated as of v19 */
 150 #define Bset_mark 0163 /* this loser is no longer generated as of v18 */
 151 #define Binteractive_p 0164 /* Needed since interactive-p takes unevalled args */
 152
 153 #define Bforward_char 0165
 154 #define Bforward_word 0166
 155 #define Bskip_chars_forward 0167
 156 #define Bskip_chars_backward 0170
 157 #define Bforward_line 0171
 158 #define Bchar_syntax 0172
 159 #define Bbuffer_substring 0173
 160 #define Bdelete_region 0174
 161 #define Bnarrow_to_region 0175
 162 #define Bwiden 0176
 163 #define Bend_of_line 0177
 164
 165 #define Bconstant2 0201
 166 #define Bgoto 0202
 167 #define Bgotoifnil 0203
 168 #define Bgotoifnonnil 0204
 169 #define Bgotoifnilelsepop 0205
 170 #define Bgotoifnonnilelsepop 0206
 171 #define Breturn 0207
 172 #define Bdiscard 0210
 173 #define Bdup 0211
 174
 175 #define Bsave_excursion 0212
 176 #define Bsave_window_excursion 0213
 177 #define Bsave_restriction 0214
 178 #define Bcatch 0215
 179
 180 #define Bunwind_protect 0216
 181 #define Bcondition_case 0217
 182 #define Btemp_output_buffer_setup 0220
 183 #define Btemp_output_buffer_show 0221
 184
 185 #define Bunbind_all 0222
 186
 187 #define Bset_marker 0223
 188 #define Bmatch_beginning 0224
 189 #define Bmatch_end 0225
 190 #define Bupcase 0226
 191 #define Bdowncase 0227
 192
 193 #define Bstringeqlsign 0230
 194 #define Bstringlss 0231
 195 #define Bequal 0232
 196 #define Bnthcdr 0233
 197 #define Belt 0234
 198 #define Bmember 0235
 199 #define Bassq 0236
 200 #define Bnreverse 0237
 201 #define Bsetcar 0240
 202 #define Bsetcdr 0241
 203 #define Bcar_safe 0242
 204 #define Bcdr_safe 0243
 205 #define Bnconc 0244
 206 #define Bquo 0245
 207 #define Brem 0246
 208 #define Bnumberp 0247
 209 #define Bintegerp 0250
 210
 211 #define BRgoto 0252
 212 #define BRgotoifnil 0253
 213 #define BRgotoifnonnil 0254
 214 #define BRgotoifnilelsepop 0255
 215 #define BRgotoifnonnilelsepop 0256
 216
 217 #define BlistN 0257
 218 #define BconcatN 0260
 219 #define BinsertN 0261
 220
 221 #define Bconstant 0300
 222 #define CONSTANTLIM 0100
 223 \f
 224 /* Fetch the next byte from the bytecode stream */
 225
 226 #define FETCH *pc++
 227
 228 /* Fetch two bytes from the bytecode stream
 229  and make a 16-bit number out of them */
 230
 231 #define FETCH2 (op = FETCH, op + (FETCH << 8))
 232
 233 /* Push x onto the execution stack. */
 234
 235 /* This used to be #define PUSH(x) (*++stackp = (x))
 236    This oddity is necessary because Alliant can't be bothered to
 237    compile the preincrement operator properly, as of 4/91.  -JimB  */
 238 #define PUSH(x) (stackp++, *stackp = (x))
 239
 240 /* Pop a value off the execution stack.  */
 241
 242 #define POP (*stackp--)
 243
 244 /* Discard n values from the execution stack.  */
 245
 246 #define DISCARD(n) (stackp -= (n))
 247
 248 /* Get the value which is at the top of the execution stack, but don't pop it. */
 249
 250 #define TOP (*stackp)
 251
 252 DEFUN ("byte-code", Fbyte_code, Sbyte_code, 3, 3, 0,
 253   "Function used internally in byte-compiled code.\n\
 254 The first argument is a string of byte code; the second, a vector of constants;\n\
 255 the third, the maximum stack depth used in this function.\n\
 256 If the third argument is incorrect, Emacs may crash.")
 257   (bytestr, vector, maxdepth)
 258      Lisp_Object bytestr, vector, maxdepth;
 259 {
 260   struct gcpro gcpro1, gcpro2, gcpro3;
 261   int count = specpdl_ptr - specpdl;
 262 #ifdef BYTE_CODE_METER
 263   int this_op = 0;
 264   int prev_op;
 265 #endif
 266   register int op;
 267   unsigned char *pc;
 268   Lisp_Object *stack;
 269   register Lisp_Object *stackp;
 270   Lisp_Object *stacke;
 271   register Lisp_Object v1, v2;
 272   register Lisp_Object *vectorp = XVECTOR (vector)->contents;
 273 #ifdef BYTE_CODE_SAFE
 274   register int const_length = XVECTOR (vector)->size;
 275 #endif
 276   /* Copy of BYTESTR, saved so we can tell if BYTESTR was relocated.  */
 277   Lisp_Object string_saved;
 278   /* Cached address of beginning of string,
 279      valid if BYTESTR equals STRING_SAVED.  */
 280   register unsigned char *strbeg;
 281
 282   CHECK_STRING (bytestr, 0);
 283   if (!VECTORP (vector))
 284     vector = wrong_type_argument (Qvectorp, vector);
 285   CHECK_NUMBER (maxdepth, 2);
 286
 287   stackp = (Lisp_Object *) alloca (XFASTINT (maxdepth) * sizeof (Lisp_Object));
 288   bzero (stackp, XFASTINT (maxdepth) * sizeof (Lisp_Object));
 289   GCPRO3 (bytestr, vector, *stackp);
 290   gcpro3.nvars = XFASTINT (maxdepth);
 291
 292   --stackp;
 293   stack = stackp;
 294   stacke = stackp + XFASTINT (maxdepth);
 295
 296   /* Initialize the saved pc-pointer for fetching from the string.  */
 297   string_saved = bytestr;
 298   pc = XSTRING (string_saved)->data;
 299
 300   while (1)
 301     {
 302 #ifdef BYTE_CODE_SAFE
 303       if (stackp > stacke)
 304         error ("Byte code stack overflow (byte compiler bug), pc %d, depth %d",
 305                pc - XSTRING (string_saved)->data, stacke - stackp);
 306       if (stackp < stack)
 307         error ("Byte code stack underflow (byte compiler bug), pc %d",
 308                pc - XSTRING (string_saved)->data);
 309 #endif
 310
 311       if (! EQ (string_saved, bytestr))
 312         {
 313           pc = pc - XSTRING (string_saved)->data + XSTRING (bytestr)->data;
 314           string_saved = bytestr;
 315         }
 316
 317 #ifdef BYTE_CODE_METER
 318       prev_op = this_op;
 319       this_op = op = FETCH;
 320       METER_CODE (prev_op, op);
 321       switch (op)
 322 #else
 323       switch (op = FETCH)
 324 #endif
 325         {
 326         case Bvarref+6:
 327           op = FETCH;
 328           goto varref;
 329
 330         case Bvarref+7:
 331           op = FETCH2;
 332           goto varref;
 333
 334         case Bvarref: case Bvarref+1: case Bvarref+2: case Bvarref+3:
 335         case Bvarref+4: case Bvarref+5:
 336           op = op - Bvarref;
 337         varref:
 338           v1 = vectorp[op];
 339           if (!SYMBOLP (v1))
 340             v2 = Fsymbol_value (v1);
 341           else
 342             {
 343               v2 = XSYMBOL (v1)->value;
 344               if (MISCP (v2) || EQ (v2, Qunbound))
 345                 v2 = Fsymbol_value (v1);
 346             }
 347           PUSH (v2);
 348           break;
 349
 350         case Bvarset+6:
 351           op = FETCH;
 352           goto varset;
 353
 354         case Bvarset+7:
 355           op = FETCH2;
 356           goto varset;
 357
 358         case Bvarset: case Bvarset+1: case Bvarset+2: case Bvarset+3:
 359         case Bvarset+4: case Bvarset+5:
 360           op -= Bvarset;
 361         varset:
 362           Fset (vectorp[op], POP);
 363           break;
 364
 365         case Bvarbind+6:
 366           op = FETCH;
 367           goto varbind;
 368
 369         case Bvarbind+7:
 370           op = FETCH2;
 371           goto varbind;
 372
 373         case Bvarbind: case Bvarbind+1: case Bvarbind+2: case Bvarbind+3:
 374         case Bvarbind+4: case Bvarbind+5:
 375           op -= Bvarbind;
 376         varbind:
 377           specbind (vectorp[op], POP);
 378           break;
 379
 380         case Bcall+6:
 381           op = FETCH;
 382           goto docall;
 383
 384         case Bcall+7:
 385           op = FETCH2;
 386           goto docall;
 387
 388         case Bcall: case Bcall+1: case Bcall+2: case Bcall+3:
 389         case Bcall+4: case Bcall+5:
 390           op -= Bcall;
 391         docall:
 392           DISCARD (op);
 393 #ifdef BYTE_CODE_METER
 394           if (byte_metering_on && SYMBOLP (TOP))
 395             {
 396               v1 = TOP;
 397               v2 = Fget (v1, Qbyte_code_meter);
 398               if (INTEGERP (v2)
 399                   && XINT (v2) != ((1<<VALBITS)-1))
 400                 {
 401                   XSETINT (v2, XINT (v2) + 1);
 402                   Fput (v1, Qbyte_code_meter, v2);
 403                 }
 404             }
 405 #endif
 406           TOP = Ffuncall (op + 1, &TOP);
 407           break;
 408
 409         case Bunbind+6:
 410           op = FETCH;
 411           goto dounbind;
 412
 413         case Bunbind+7:
 414           op = FETCH2;
 415           goto dounbind;
 416
 417         case Bunbind: case Bunbind+1: case Bunbind+2: case Bunbind+3:
 418         case Bunbind+4: case Bunbind+5:
 419           op -= Bunbind;
 420         dounbind:
 421           unbind_to (specpdl_ptr - specpdl - op, Qnil);
 422           break;
 423
 424         case Bunbind_all:
 425           /* To unbind back to the beginning of this frame.  Not used yet,
 426              but will be needed for tail-recursion elimination.  */
 427           unbind_to (count, Qnil);
 428           break;
 429
 430         case Bgoto:
 431           QUIT;
 432           op = FETCH2;    /* pc = FETCH2 loses since FETCH2 contains pc++ */
 433           pc = XSTRING (string_saved)->data + op;
 434           break;
 435
 436         case Bgotoifnil:
 437           op = FETCH2;
 438           if (NILP (POP))
 439             {
 440               QUIT;
 441               pc = XSTRING (string_saved)->data + op;
 442             }
 443           break;
 444
 445         case Bgotoifnonnil:
 446           op = FETCH2;
 447           if (!NILP (POP))
 448             {
 449               QUIT;
 450               pc = XSTRING (string_saved)->data + op;
 451             }
 452           break;
 453
 454         case Bgotoifnilelsepop:
 455           op = FETCH2;
 456           if (NILP (TOP))
 457             {
 458               QUIT;
 459               pc = XSTRING (string_saved)->data + op;
 460             }
 461           else DISCARD (1);
 462           break;
 463
 464         case Bgotoifnonnilelsepop:
 465           op = FETCH2;
 466           if (!NILP (TOP))
 467             {
 468               QUIT;
 469               pc = XSTRING (string_saved)->data + op;
 470             }
 471           else DISCARD (1);
 472           break;
 473
 474         case BRgoto:
 475           QUIT;
 476           pc += *pc - 127;
 477           break;
 478
 479         case BRgotoifnil:
 480           if (NILP (POP))
 481             {
 482               QUIT;
 483               pc += *pc - 128;
 484             }
 485           pc++;
 486           break;
 487
 488         case BRgotoifnonnil:
 489           if (!NILP (POP))
 490             {
 491               QUIT;
 492               pc += *pc - 128;
 493             }
 494           pc++;
 495           break;
 496
 497         case BRgotoifnilelsepop:
 498           op = *pc++;
 499           if (NILP (TOP))
 500             {
 501               QUIT;
 502               pc += op - 128;
 503             }
 504           else DISCARD (1);
 505           break;
 506
 507         case BRgotoifnonnilelsepop:
 508           op = *pc++;
 509           if (!NILP (TOP))
 510             {
 511               QUIT;
 512               pc += op - 128;
 513             }
 514           else DISCARD (1);
 515           break;
 516
 517         case Breturn:
 518           v1 = POP;
 519           goto exit;
 520
 521         case Bdiscard:
 522           DISCARD (1);
 523           break;
 524
 525         case Bdup:
 526           v1 = TOP;
 527           PUSH (v1);
 528           break;
 529
 530         case Bconstant2:
 531           PUSH (vectorp[FETCH2]);
 532           break;
 533
 534         case Bsave_excursion:
 535           record_unwind_protect (save_excursion_restore, save_excursion_save ());
 536           break;
 537
 538         case Bsave_window_excursion:
 539           TOP = Fsave_window_excursion (TOP);
 540           break;
 541
 542         case Bsave_restriction:
 543           record_unwind_protect (save_restriction_restore, save_restriction_save ());
 544           break;
 545
 546         case Bcatch:
 547           v1 = POP;
 548           TOP = internal_catch (TOP, Feval, v1);
 549           break;
 550
 551         case Bunwind_protect:
 552           record_unwind_protect (0, POP);
 553           (specpdl_ptr - 1)->symbol = Qnil;
 554           break;
 555
 556         case Bcondition_case:
 557           v1 = POP;
 558           v1 = Fcons (POP, v1);
 559           TOP = Fcondition_case (Fcons (TOP, v1));
 560           break;
 561
 562         case Btemp_output_buffer_setup:
 563           temp_output_buffer_setup (XSTRING (TOP)->data);
 564           TOP = Vstandard_output;
 565           break;
 566
 567         case Btemp_output_buffer_show:
 568           v1 = POP;
 569           temp_output_buffer_show (TOP);
 570           TOP = v1;
 571           /* pop binding of standard-output */
 572           unbind_to (specpdl_ptr - specpdl - 1, Qnil);
 573           break;
 574
 575         case Bnth:
 576           v1 = POP;
 577           v2 = TOP;
 578         nth_entry:
 579           CHECK_NUMBER (v2, 0);
 580           op = XINT (v2);
 581           immediate_quit = 1;
 582           while (--op >= 0)
 583             {
 584               if (CONSP (v1))
 585                 v1 = XCONS (v1)->cdr;
 586               else if (!NILP (v1))
 587                 {
 588                   immediate_quit = 0;
 589                   v1 = wrong_type_argument (Qlistp, v1);
 590                   immediate_quit = 1;
 591                   op++;
 592                 }
 593             }
 594           immediate_quit = 0;
 595           goto docar;
 596
 597         case Bsymbolp:
 598           TOP = SYMBOLP (TOP) ? Qt : Qnil;
 599           break;
 600
 601         case Bconsp:
 602           TOP = CONSP (TOP) ? Qt : Qnil;
 603           break;
 604
 605         case Bstringp:
 606           TOP = STRINGP (TOP) ? Qt : Qnil;
 607           break;
 608
 609         case Blistp:
 610           TOP = CONSP (TOP) || NILP (TOP) ? Qt : Qnil;
 611           break;
 612
 613         case Beq:
 614           v1 = POP;
 615           TOP = EQ (v1, TOP) ? Qt : Qnil;
 616           break;
 617
 618         case Bmemq:
 619           v1 = POP;
 620           TOP = Fmemq (TOP, v1);
 621           break;
 622
 623         case Bnot:
 624           TOP = NILP (TOP) ? Qt : Qnil;
 625           break;
 626
 627         case Bcar:
 628           v1 = TOP;
 629         docar:
 630           if (CONSP (v1)) TOP = XCONS (v1)->car;
 631           else if (NILP (v1)) TOP = Qnil;
 632           else Fcar (wrong_type_argument (Qlistp, v1));
 633           break;
 634
 635         case Bcdr:
 636           v1 = TOP;
 637           if (CONSP (v1)) TOP = XCONS (v1)->cdr;
 638           else if (NILP (v1)) TOP = Qnil;
 639           else Fcdr (wrong_type_argument (Qlistp, v1));
 640           break;
 641
 642         case Bcons:
 643           v1 = POP;
 644           TOP = Fcons (TOP, v1);
 645           break;
 646
 647         case Blist1:
 648           TOP = Fcons (TOP, Qnil);
 649           break;
 650
 651         case Blist2:
 652           v1 = POP;
 653           TOP = Fcons (TOP, Fcons (v1, Qnil));
 654           break;
 655
 656         case Blist3:
 657           DISCARD (2);
 658           TOP = Flist (3, &TOP);
 659           break;
 660
 661         case Blist4:
 662           DISCARD (3);
 663           TOP = Flist (4, &TOP);
 664           break;
 665
 666         case BlistN:
 667           op = FETCH;
 668           DISCARD (op - 1);
 669           TOP = Flist (op, &TOP);
 670           break;
 671
 672         case Blength:
 673           TOP = Flength (TOP);
 674           break;
 675
 676         case Baref:
 677           v1 = POP;
 678           TOP = Faref (TOP, v1);
 679           break;
 680
 681         case Baset:
 682           v2 = POP; v1 = POP;
 683           TOP = Faset (TOP, v1, v2);
 684           break;
 685
 686         case Bsymbol_value:
 687           TOP = Fsymbol_value (TOP);
 688           break;
 689
 690         case Bsymbol_function:
 691           TOP = Fsymbol_function (TOP);
 692           break;
 693
 694         case Bset:
 695           v1 = POP;
 696           TOP = Fset (TOP, v1);
 697           break;
 698
 699         case Bfset:
 700           v1 = POP;
 701           TOP = Ffset (TOP, v1);
 702           break;
 703
 704         case Bget:
 705           v1 = POP;
 706           TOP = Fget (TOP, v1);
 707           break;
 708
 709         case Bsubstring:
 710           v2 = POP; v1 = POP;
 711           TOP = Fsubstring (TOP, v1, v2);
 712           break;
 713
 714         case Bconcat2:
 715           DISCARD (1);
 716           TOP = Fconcat (2, &TOP);
 717           break;
 718
 719         case Bconcat3:
 720           DISCARD (2);
 721           TOP = Fconcat (3, &TOP);
 722           break;
 723
 724         case Bconcat4:
 725           DISCARD (3);
 726           TOP = Fconcat (4, &TOP);
 727           break;
 728
 729         case BconcatN:
 730           op = FETCH;
 731           DISCARD (op - 1);
 732           TOP = Fconcat (op, &TOP);
 733           break;
 734
 735         case Bsub1:
 736           v1 = TOP;
 737           if (INTEGERP (v1))
 738             {
 739               XSETINT (v1, XINT (v1) - 1);
 740               TOP = v1;
 741             }
 742           else
 743             TOP = Fsub1 (v1);
 744           break;
 745
 746         case Badd1:
 747           v1 = TOP;
 748           if (INTEGERP (v1))
 749             {
 750               XSETINT (v1, XINT (v1) + 1);
 751               TOP = v1;
 752             }
 753           else
 754             TOP = Fadd1 (v1);
 755           break;
 756
 757         case Beqlsign:
 758           v2 = POP; v1 = TOP;
 759           CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (v1, 0);
 760           CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (v2, 0);
 761           TOP = (XFLOATINT (v1) == XFLOATINT (v2)) ? Qt : Qnil;
 762           break;
 763
 764         case Bgtr:
 765           v1 = POP;
 766           TOP = Fgtr (TOP, v1);
 767           break;
 768
 769         case Blss:
 770           v1 = POP;
 771           TOP = Flss (TOP, v1);
 772           break;
 773
 774         case Bleq:
 775           v1 = POP;
 776           TOP = Fleq (TOP, v1);
 777           break;
 778
 779         case Bgeq:
 780           v1 = POP;
 781           TOP = Fgeq (TOP, v1);
 782           break;
 783
 784         case Bdiff:
 785           DISCARD (1);
 786           TOP = Fminus (2, &TOP);
 787           break;
 788
 789         case Bnegate:
 790           v1 = TOP;
 791           if (INTEGERP (v1))
 792             {
 793               XSETINT (v1, - XINT (v1));
 794               TOP = v1;
 795             }
 796           else
 797             TOP = Fminus (1, &TOP);
 798           break;
 799
 800         case Bplus:
 801           DISCARD (1);
 802           TOP = Fplus (2, &TOP);
 803           break;
 804
 805         case Bmax:
 806           DISCARD (1);
 807           TOP = Fmax (2, &TOP);
 808           break;
 809
 810         case Bmin:
 811           DISCARD (1);
 812           TOP = Fmin (2, &TOP);
 813           break;
 814
 815         case Bmult:
 816           DISCARD (1);
 817           TOP = Ftimes (2, &TOP);
 818           break;
 819
 820         case Bquo:
 821           DISCARD (1);
 822           TOP = Fquo (2, &TOP);
 823           break;
 824
 825         case Brem:
 826           v1 = POP;
 827           TOP = Frem (TOP, v1);
 828           break;
 829
 830         case Bpoint:
 831           XSETFASTINT (v1, point);
 832           PUSH (v1);
 833           break;
 834
 835         case Bgoto_char:
 836           TOP = Fgoto_char (TOP);
 837           break;
 838
 839         case Binsert:
 840           TOP = Finsert (1, &TOP);
 841           break;
 842
 843         case BinsertN:
 844           op = FETCH;
 845           DISCARD (op - 1);
 846           TOP = Finsert (op, &TOP);
 847           break;
 848
 849         case Bpoint_max:
 850           XSETFASTINT (v1, ZV);
 851           PUSH (v1);
 852           break;
 853
 854         case Bpoint_min:
 855           XSETFASTINT (v1, BEGV);
 856           PUSH (v1);
 857           break;
 858
 859         case Bchar_after:
 860           TOP = Fchar_after (TOP);
 861           break;
 862
 863         case Bfollowing_char:
 864           XSETFASTINT (v1, PT == ZV ? 0 : FETCH_CHAR (point));
 865           PUSH (v1);
 866           break;
 867
 868         case Bpreceding_char:
 869           XSETFASTINT (v1, point <= BEGV ? 0 : FETCH_CHAR (point - 1));
 870           PUSH (v1);
 871           break;
 872
 873         case Bcurrent_column:
 874           XSETFASTINT (v1, current_column ());
 875           PUSH (v1);
 876           break;
 877
 878         case Bindent_to:
 879           TOP = Findent_to (TOP, Qnil);
 880           break;
 881
 882         case Beolp:
 883           PUSH (Feolp ());
 884           break;
 885
 886         case Beobp:
 887           PUSH (Feobp ());
 888           break;
 889
 890         case Bbolp:
 891           PUSH (Fbolp ());
 892           break;
 893
 894         case Bbobp:
 895           PUSH (Fbobp ());
 896           break;
 897
 898         case Bcurrent_buffer:
 899           PUSH (Fcurrent_buffer ());
 900           break;
 901
 902         case Bset_buffer:
 903           TOP = Fset_buffer (TOP);
 904           break;
 905
 906         case Bread_char:
 907           PUSH (Fread_char ());
 908           QUIT;
 909           break;
 910
 911         case Binteractive_p:
 912           PUSH (Finteractive_p ());
 913           break;
 914
 915         case Bforward_char:
 916           TOP = Fforward_char (TOP);
 917           break;
 918
 919         case Bforward_word:
 920           TOP = Fforward_word (TOP);
 921           break;
 922
 923         case Bskip_chars_forward:
 924           v1 = POP;
 925           TOP = Fskip_chars_forward (TOP, v1);
 926           break;
 927
 928         case Bskip_chars_backward:
 929           v1 = POP;
 930           TOP = Fskip_chars_backward (TOP, v1);
 931           break;
 932
 933         case Bforward_line:
 934           TOP = Fforward_line (TOP);
 935           break;
 936
 937         case Bchar_syntax:
 938           CHECK_NUMBER (TOP, 0);
 939           XSETFASTINT (TOP,
 940                        syntax_code_spec[(int) SYNTAX (0xFF & XINT (TOP))]);
 941           break;
 942
 943         case Bbuffer_substring:
 944           v1 = POP;
 945           TOP = Fbuffer_substring (TOP, v1);
 946           break;
 947
 948         case Bdelete_region:
 949           v1 = POP;
 950           TOP = Fdelete_region (TOP, v1);
 951           break;
 952
 953         case Bnarrow_to_region:
 954           v1 = POP;
 955           TOP = Fnarrow_to_region (TOP, v1);
 956           break;
 957
 958         case Bwiden:
 959           PUSH (Fwiden ());
 960           break;
 961
 962         case Bend_of_line:
 963           TOP = Fend_of_line (TOP);
 964           break;
 965
 966         case Bset_marker:
 967           v1 = POP;
 968           v2 = POP;
 969           TOP = Fset_marker (TOP, v2, v1);
 970           break;
 971
 972         case Bmatch_beginning:
 973           TOP = Fmatch_beginning (TOP);
 974           break;
 975
 976         case Bmatch_end:
 977           TOP = Fmatch_end (TOP);
 978           break;
 979
 980         case Bupcase:
 981           TOP = Fupcase (TOP);
 982           break;
 983
 984         case Bdowncase:
 985           TOP = Fdowncase (TOP);
 986         break;
 987
 988         case Bstringeqlsign:
 989           v1 = POP;
 990           TOP = Fstring_equal (TOP, v1);
 991           break;
 992
 993         case Bstringlss:
 994           v1 = POP;
 995           TOP = Fstring_lessp (TOP, v1);
 996           break;
 997
 998         case Bequal:
 999           v1 = POP;
1000           TOP = Fequal (TOP, v1);
1001           break;
1002
1003         case Bnthcdr:
1004           v1 = POP;
1005           TOP = Fnthcdr (TOP, v1);
1006           break;
1007
1008         case Belt:
1009           if (CONSP (TOP))
1010             {
1011               /* Exchange args and then do nth.  */
1012               v2 = POP;
1013               v1 = TOP;
1014               goto nth_entry;
1015             }
1016           v1 = POP;
1017           TOP = Felt (TOP, v1);
1018           break;
1019
1020         case Bmember:
1021           v1 = POP;
1022           TOP = Fmember (TOP, v1);
1023           break;
1024
1025         case Bassq:
1026           v1 = POP;
1027           TOP = Fassq (TOP, v1);
1028           break;
1029
1030         case Bnreverse:
1031           TOP = Fnreverse (TOP);
1032           break;
1033
1034         case Bsetcar:
1035           v1 = POP;
1036           TOP = Fsetcar (TOP, v1);
1037           break;
1038
1039         case Bsetcdr:
1040           v1 = POP;
1041           TOP = Fsetcdr (TOP, v1);
1042           break;
1043
1044         case Bcar_safe:
1045           v1 = TOP;
1046           if (CONSP (v1))
1047             TOP = XCONS (v1)->car;
1048           else
1049             TOP = Qnil;
1050           break;
1051
1052         case Bcdr_safe:
1053           v1 = TOP;
1054           if (CONSP (v1))
1055             TOP = XCONS (v1)->cdr;
1056           else
1057             TOP = Qnil;
1058           break;
1059
1060         case Bnconc:
1061           DISCARD (1);
1062           TOP = Fnconc (2, &TOP);
1063           break;
1064
1065         case Bnumberp:
1066           TOP = (NUMBERP (TOP) ? Qt : Qnil);
1067           break;
1068
1069         case Bintegerp:
1070           TOP = INTEGERP (TOP) ? Qt : Qnil;
1071           break;
1072
1073 #ifdef BYTE_CODE_SAFE
1074         case Bset_mark:
1075           error ("set-mark is an obsolete bytecode");
1076           break;
1077         case Bscan_buffer:
1078           error ("scan-buffer is an obsolete bytecode");
1079           break;
1080         case Bmark:
1081           error ("mark is an obsolete bytecode");
1082           break;
1083 #endif
1084
1085         default:
1086 #ifdef BYTE_CODE_SAFE
1087           if (op < Bconstant)
1088             error ("unknown bytecode %d (byte compiler bug)", op);
1089           if ((op -= Bconstant) >= const_length)
1090             error ("no constant number %d (byte compiler bug)", op);
1091           PUSH (vectorp[op]);
1092 #else
1093           PUSH (vectorp[op - Bconstant]);
1094 #endif
1095         }
1096     }
1097
1098  exit:
1099   UNGCPRO;
1100   /* Binds and unbinds are supposed to be compiled balanced.  */
1101   if (specpdl_ptr - specpdl != count)
1102 #ifdef BYTE_CODE_SAFE
1103     error ("binding stack not balanced (serious byte compiler bug)");
1104 #else
1105     abort ();
1106 #endif
1107   return v1;
1108 }
1109
1110 syms_of_bytecode ()
1111 {
1112   Qbytecode = intern ("byte-code");
1113   staticpro (&Qbytecode);
1114
1115   defsubr (&Sbyte_code);
1116
1117 #ifdef BYTE_CODE_METER
1118
1119   DEFVAR_LISP ("byte-code-meter", &Vbyte_code_meter,
1120    "A vector of vectors which holds a histogram of byte-code usage.\n\
1121 (aref (aref byte-code-meter 0) CODE) indicates how many times the byte\n\
1122 opcode CODE has been executed.\n\
1123 (aref (aref byte-code-meter CODE1) CODE2), where CODE1 is not 0,\n\
1124 indicates how many times the byte opcodes CODE1 and CODE2 have been\n\
1125 executed in succession.");
1126   DEFVAR_BOOL ("byte-metering-on", &byte_metering_on,
1127    "If non-nil, keep profiling information on byte code usage.\n\
1128 The variable byte-code-meter indicates how often each byte opcode is used.\n\
1129 If a symbol has a property named `byte-code-meter' whose value is an\n\
1130 integer, it is incremented each time that symbol's function is called.");
1131
1132   byte_metering_on = 0;
1133   Vbyte_code_meter = Fmake_vector (make_number (256), make_number (0));
1134   Qbyte_code_meter = intern ("byte-code-meter");
1135   staticpro (&Qbyte_code_meter);
1136   {
1137     int i = 256;
1138     while (i--)
1139       XVECTOR (Vbyte_code_meter)->contents[i] =
1140         Fmake_vector (make_number (256), make_number (0));
1141   }
1142 #endif
1143 }