src/bytecode.c

   1 /* Execution of byte code produced by bytecomp.el.
   2    Copyright (C) 1985, 1986, 1987, 1988, 1993, 2000 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, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.
  20
  21 hacked on by jwz@lucid.com 17-jun-91
  22   o  added a compile-time switch to turn on simple sanity checking;
  23   o  put back the obsolete byte-codes for error-detection;
  24   o  added a new instruction, unbind_all, which I will use for
  25      tail-recursion elimination;
  26   o  made temp_output_buffer_show be called with the right number
  27      of args;
  28   o  made the new bytecodes be called with args in the right order;
  29   o  added metering support.
  30
  31 by Hallvard:
  32   o  added relative jump instructions;
  33   o  all conditionals now only do QUIT if they jump.
  34  */
  35
  36 #include <config.h>
  37 #include "lisp.h"
  38 #include "buffer.h"
  39 #include "charset.h"
  40 #include "syntax.h"
  41
  42 /*
  43  * define BYTE_CODE_SAFE to enable some minor sanity checking (useful for
  44  * debugging the byte compiler...)
  45  *
  46  * define BYTE_CODE_METER to enable generation of a byte-op usage histogram.
  47  */
  48 /* #define BYTE_CODE_SAFE */
  49 /* #define BYTE_CODE_METER */
  50
  51 \f
  52 #ifdef BYTE_CODE_METER
  53
  54 Lisp_Object Vbyte_code_meter, Qbyte_code_meter;
  55 int byte_metering_on;
  56
  57 #define METER_2(code1, code2) \
  58   XFASTINT (XVECTOR (XVECTOR (Vbyte_code_meter)->contents[(code1)]) \
  59             ->contents[(code2)])
  60
  61 #define METER_1(code) METER_2 (0, (code))
  62
  63 #define METER_CODE(last_code, this_code)                        \
  64 {                                                               \
  65   if (byte_metering_on)                                         \
  66     {                                                           \
  67       if (METER_1 (this_code) != ((1<<VALBITS)-1))              \
  68         METER_1 (this_code)++;                                  \
  69       if (last_code                                             \
  70           && METER_2 (last_code, this_code) != ((1<<VALBITS)-1))\
  71         METER_2 (last_code, this_code)++;                       \
  72     }                                                           \
  73 }
  74
  75 #else /* no BYTE_CODE_METER */
  76
  77 #define METER_CODE(last_code, this_code)
  78
  79 #endif /* no BYTE_CODE_METER */
  80 \f
  81
  82 Lisp_Object Qbytecode;
  83
  84 /*  Byte codes: */
  85
  86 #define Bvarref 010
  87 #define Bvarset 020
  88 #define Bvarbind 030
  89 #define Bcall 040
  90 #define Bunbind 050
  91
  92 #define Bnth 070
  93 #define Bsymbolp 071
  94 #define Bconsp 072
  95 #define Bstringp 073
  96 #define Blistp 074
  97 #define Beq 075
  98 #define Bmemq 076
  99 #define Bnot 077
 100 #define Bcar 0100
 101 #define Bcdr 0101
 102 #define Bcons 0102
 103 #define Blist1 0103
 104 #define Blist2 0104
 105 #define Blist3 0105
 106 #define Blist4 0106
 107 #define Blength 0107
 108 #define Baref 0110
 109 #define Baset 0111
 110 #define Bsymbol_value 0112
 111 #define Bsymbol_function 0113
 112 #define Bset 0114
 113 #define Bfset 0115
 114 #define Bget 0116
 115 #define Bsubstring 0117
 116 #define Bconcat2 0120
 117 #define Bconcat3 0121
 118 #define Bconcat4 0122
 119 #define Bsub1 0123
 120 #define Badd1 0124
 121 #define Beqlsign 0125
 122 #define Bgtr 0126
 123 #define Blss 0127
 124 #define Bleq 0130
 125 #define Bgeq 0131
 126 #define Bdiff 0132
 127 #define Bnegate 0133
 128 #define Bplus 0134
 129 #define Bmax 0135
 130 #define Bmin 0136
 131 #define Bmult 0137
 132
 133 #define Bpoint 0140
 134 /* Was Bmark in v17.  */
 135 #define Bsave_current_buffer 0141
 136 #define Bgoto_char 0142
 137 #define Binsert 0143
 138 #define Bpoint_max 0144
 139 #define Bpoint_min 0145
 140 #define Bchar_after 0146
 141 #define Bfollowing_char 0147
 142 #define Bpreceding_char 0150
 143 #define Bcurrent_column 0151
 144 #define Bindent_to 0152
 145 #define Bscan_buffer 0153 /* No longer generated as of v18 */
 146 #define Beolp 0154
 147 #define Beobp 0155
 148 #define Bbolp 0156
 149 #define Bbobp 0157
 150 #define Bcurrent_buffer 0160
 151 #define Bset_buffer 0161
 152 #define Bsave_current_buffer_1 0162 /* Replacing Bsave_current_buffer.  */
 153 #define Bread_char 0162 /* No longer generated as of v19 */
 154 #define Bset_mark 0163 /* this loser is no longer generated as of v18 */
 155 #define Binteractive_p 0164 /* Needed since interactive-p takes unevalled args */
 156
 157 #define Bforward_char 0165
 158 #define Bforward_word 0166
 159 #define Bskip_chars_forward 0167
 160 #define Bskip_chars_backward 0170
 161 #define Bforward_line 0171
 162 #define Bchar_syntax 0172
 163 #define Bbuffer_substring 0173
 164 #define Bdelete_region 0174
 165 #define Bnarrow_to_region 0175
 166 #define Bwiden 0176
 167 #define Bend_of_line 0177
 168
 169 #define Bconstant2 0201
 170 #define Bgoto 0202
 171 #define Bgotoifnil 0203
 172 #define Bgotoifnonnil 0204
 173 #define Bgotoifnilelsepop 0205
 174 #define Bgotoifnonnilelsepop 0206
 175 #define Breturn 0207
 176 #define Bdiscard 0210
 177 #define Bdup 0211
 178
 179 #define Bsave_excursion 0212
 180 #define Bsave_window_excursion 0213
 181 #define Bsave_restriction 0214
 182 #define Bcatch 0215
 183
 184 #define Bunwind_protect 0216
 185 #define Bcondition_case 0217
 186 #define Btemp_output_buffer_setup 0220
 187 #define Btemp_output_buffer_show 0221
 188
 189 #define Bunbind_all 0222
 190
 191 #define Bset_marker 0223
 192 #define Bmatch_beginning 0224
 193 #define Bmatch_end 0225
 194 #define Bupcase 0226
 195 #define Bdowncase 0227
 196
 197 #define Bstringeqlsign 0230
 198 #define Bstringlss 0231
 199 #define Bequal 0232
 200 #define Bnthcdr 0233
 201 #define Belt 0234
 202 #define Bmember 0235
 203 #define Bassq 0236
 204 #define Bnreverse 0237
 205 #define Bsetcar 0240
 206 #define Bsetcdr 0241
 207 #define Bcar_safe 0242
 208 #define Bcdr_safe 0243
 209 #define Bnconc 0244
 210 #define Bquo 0245
 211 #define Brem 0246
 212 #define Bnumberp 0247
 213 #define Bintegerp 0250
 214
 215 #define BRgoto 0252
 216 #define BRgotoifnil 0253
 217 #define BRgotoifnonnil 0254
 218 #define BRgotoifnilelsepop 0255
 219 #define BRgotoifnonnilelsepop 0256
 220
 221 #define BlistN 0257
 222 #define BconcatN 0260
 223 #define BinsertN 0261
 224
 225 #define Bconstant 0300
 226 #define CONSTANTLIM 0100
 227
 228 \f
 229 /* Structure describing a value stack used during byte-code execution
 230    in Fbyte_code.  */
 231
 232 struct byte_stack
 233 {
 234   /* Program counter.  This points into the byte_string below
 235      and is relocated when that string is relocated.  */
 236   unsigned char *pc;
 237
 238   /* Top and bottom of stack.  The bottom points to an area of memory
 239      allocated with alloca in Fbyte_code.  */
 240   Lisp_Object *top, *bottom;
 241
 242   /* The string containing the byte-code, and its current address.
 243      Storing this here protects it from GC because mark_byte_stack
 244      marks it.  */
 245   Lisp_Object byte_string;
 246   unsigned char *byte_string_start;
 247
 248   /* The vector of constants used during byte-code execution.  Storing
 249      this here protects it from GC because mark_byte_stack marks it.  */
 250   Lisp_Object constants;
 251
 252   /* Next entry in byte_stack_list.  */
 253   struct byte_stack *next;
 254 };
 255
 256 /* A list of currently active byte-code execution value stacks.
 257    Fbyte_code adds an entry to the head of this list before it starts
 258    processing byte-code, and it removed the entry again when it is
 259    done.  Signalling an error truncates the list analoguous to
 260    gcprolist.  */
 261
 262 struct byte_stack *byte_stack_list;
 263
 264 \f
 265 /* Mark objects on byte_stack_list.  Called during GC.  */
 266
 267 void
 268 mark_byte_stack ()
 269 {
 270   struct byte_stack *stack;
 271   Lisp_Object *obj;
 272
 273   for (stack = byte_stack_list; stack; stack = stack->next)
 274     {
 275       /* If STACK->top is null here, this means there's an opcode in
 276          Fbyte_code that wasn't expected to GC, but did.  To find out
 277          which opcode this is, record the value of `stack', and walk
 278          up the stack in a debugger, stopping in frames of Fbyte_code.
 279          The culprit is found in the frame of Fbyte_code where the
 280          address of its local variable `stack' is equal to the
 281          recorded value of `stack' here.  */
 282       if (!stack->top)
 283         abort ();
 284
 285       for (obj = stack->bottom; obj <= stack->top; ++obj)
 286         if (!XMARKBIT (*obj))
 287           {
 288             mark_object (obj);
 289             XMARK (*obj);
 290           }
 291
 292       if (!XMARKBIT (stack->byte_string))
 293         {
 294           mark_object (&stack->byte_string);
 295           XMARK (stack->byte_string);
 296         }
 297
 298       if (!XMARKBIT (stack->constants))
 299         {
 300           mark_object (&stack->constants);
 301           XMARK (stack->constants);
 302         }
 303     }
 304 }
 305
 306
 307 /* Unmark objects in the stacks on byte_stack_list.  Relocate program
 308    counters.  Called when GC has completed.  */
 309
 310 void
 311 unmark_byte_stack ()
 312 {
 313   struct byte_stack *stack;
 314   Lisp_Object *obj;
 315
 316   for (stack = byte_stack_list; stack; stack = stack->next)
 317     {
 318       for (obj = stack->bottom; obj <= stack->top; ++obj)
 319         XUNMARK (*obj);
 320
 321       XUNMARK (stack->byte_string);
 322       XUNMARK (stack->constants);
 323
 324       if (stack->byte_string_start != XSTRING (stack->byte_string)->data)
 325         {
 326           int offset = stack->pc - stack->byte_string_start;
 327           stack->byte_string_start = XSTRING (stack->byte_string)->data;
 328           stack->pc = stack->byte_string_start + offset;
 329         }
 330     }
 331 }
 332
 333 \f
 334 /* Fetch the next byte from the bytecode stream */
 335
 336 #define FETCH *stack.pc++
 337
 338 /* Fetch two bytes from the bytecode stream and make a 16-bit number
 339    out of them */
 340
 341 #define FETCH2 (op = FETCH, op + (FETCH << 8))
 342
 343 /* Push x onto the execution stack.  This used to be #define PUSH(x)
 344    (*++stackp = (x)) This oddity is necessary because Alliant can't be
 345    bothered to compile the preincrement operator properly, as of 4/91.
 346    -JimB */
 347
 348 #define PUSH(x) (top++, *top = (x))
 349
 350 /* Pop a value off the execution stack.  */
 351
 352 #define POP (*top--)
 353
 354 /* Discard n values from the execution stack.  */
 355
 356 #define DISCARD(n) (top -= (n))
 357
 358 /* Get the value which is at the top of the execution stack, but don't
 359    pop it. */
 360
 361 #define TOP (*top)
 362
 363 /* Actions that must be performed before and after calling a function
 364    that might GC.  */
 365
 366 #define BEFORE_POTENTIAL_GC()   stack.top = top
 367 #define AFTER_POTENTIAL_GC()    stack.top = NULL
 368
 369 /* Garbage collect if we have consed enough since the last time.
 370    We do this at every branch, to avoid loops that never GC.  */
 371
 372 #define MAYBE_GC()                              \
 373   if (consing_since_gc > gc_cons_threshold)     \
 374     {                                           \
 375       BEFORE_POTENTIAL_GC ();                   \
 376       Fgarbage_collect ();                      \
 377       AFTER_POTENTIAL_GC ();                    \
 378     }                                           \
 379   else
 380
 381 /* Check for jumping out of range.  */
 382
 383 #ifdef BYTE_CODE_SAFE
 384
 385 #define CHECK_RANGE(ARG) \
 386   if (ARG >= bytestr_length) abort ()
 387
 388 #else /* not BYTE_CODE_SAFE */
 389
 390 #define CHECK_RANGE(ARG)
 391
 392 #endif /* not BYTE_CODE_SAFE */
 393
 394
 395 DEFUN ("byte-code", Fbyte_code, Sbyte_code, 3, 3, 0,
 396   "Function used internally in byte-compiled code.\n\
 397 The first argument, BYTESTR, is a string of byte code;\n\
 398 the second, VECTOR, a vector of constants;\n\
 399 the third, MAXDEPTH, the maximum stack depth used in this function.\n\
 400 If the third argument is incorrect, Emacs may crash.")
 401   (bytestr, vector, maxdepth)
 402      Lisp_Object bytestr, vector, maxdepth;
 403 {
 404   int count = specpdl_ptr - specpdl;
 405 #ifdef BYTE_CODE_METER
 406   int this_op = 0;
 407   int prev_op;
 408 #endif
 409   int op;
 410   /* Lisp_Object v1, v2; */
 411   Lisp_Object *vectorp;
 412 #ifdef BYTE_CODE_SAFE
 413   int const_length = XVECTOR (vector)->size;
 414   Lisp_Object *stacke;
 415 #endif
 416   int bytestr_length;
 417   struct byte_stack stack;
 418   Lisp_Object *top;
 419   Lisp_Object result;
 420
 421   CHECK_STRING (bytestr, 0);
 422   if (!VECTORP (vector))
 423     vector = wrong_type_argument (Qvectorp, vector);
 424   CHECK_NUMBER (maxdepth, 2);
 425
 426   if (STRING_MULTIBYTE (bytestr))
 427     /* BYTESTR must have been produced by Emacs 20.2 or the earlier
 428        because they produced a raw 8-bit string for byte-code and now
 429        such a byte-code string is loaded as multibyte while raw 8-bit
 430        characters converted to multibyte form.  Thus, now we must
 431        convert them back to the original unibyte form.  */
 432     bytestr = Fstring_as_unibyte (bytestr);
 433
 434   bytestr_length = STRING_BYTES (XSTRING (bytestr));
 435   vectorp = XVECTOR (vector)->contents;
 436
 437   stack.byte_string = bytestr;
 438   stack.pc = stack.byte_string_start = XSTRING (bytestr)->data;
 439   stack.constants = vector;
 440   stack.bottom = (Lisp_Object *) alloca (XFASTINT (maxdepth)
 441                                          * sizeof (Lisp_Object));
 442   top = stack.bottom - 1;
 443   stack.top = NULL;
 444   stack.next = byte_stack_list;
 445   byte_stack_list = &stack;
 446
 447 #ifdef BYTE_CODE_SAFE
 448   stacke = stack.bottom - 1 + XFASTINT (maxdepth);
 449 #endif
 450
 451   while (1)
 452     {
 453 #ifdef BYTE_CODE_SAFE
 454       if (top > stacke)
 455         abort ();
 456       else if (top < stack.bottom - 1)
 457         abort ();
 458 #endif
 459
 460 #ifdef BYTE_CODE_METER
 461       prev_op = this_op;
 462       this_op = op = FETCH;
 463       METER_CODE (prev_op, op);
 464 #else
 465       op = FETCH;
 466 #endif
 467
 468       switch (op)
 469         {
 470         case Bvarref + 7:
 471           op = FETCH2;
 472           goto varref;
 473
 474         case Bvarref:
 475         case Bvarref + 1:
 476         case Bvarref + 2:
 477         case Bvarref + 3:
 478         case Bvarref + 4:
 479         case Bvarref + 5:
 480           op = op - Bvarref;
 481           goto varref;
 482
 483         /* This seems to be the most frequently executed byte-code
 484            among the Bvarref's, so avoid a goto here.  */
 485         case Bvarref+6:
 486           op = FETCH;
 487         varref:
 488           {
 489             Lisp_Object v1, v2;
 490
 491             v1 = vectorp[op];
 492             if (SYMBOLP (v1))
 493               {
 494                 v2 = XSYMBOL (v1)->value;
 495                 if (MISCP (v2) || EQ (v2, Qunbound))
 496                   {
 497                     BEFORE_POTENTIAL_GC ();
 498                     v2 = Fsymbol_value (v1);
 499                     AFTER_POTENTIAL_GC ();
 500                   }
 501               }
 502             else
 503               {
 504                 BEFORE_POTENTIAL_GC ();
 505                 v2 = Fsymbol_value (v1);
 506                 AFTER_POTENTIAL_GC ();
 507               }
 508             PUSH (v2);
 509             break;
 510           }
 511
 512         case Bgotoifnil:
 513           MAYBE_GC ();
 514           op = FETCH2;
 515           if (NILP (POP))
 516             {
 517               QUIT;
 518               CHECK_RANGE (op);
 519               stack.pc = stack.byte_string_start + op;
 520             }
 521           break;
 522
 523         case Bcar:
 524           {
 525             Lisp_Object v1;
 526             v1 = TOP;
 527             if (CONSP (v1))
 528               TOP = XCAR (v1);
 529             else if (NILP (v1))
 530               TOP = Qnil;
 531             else
 532               {
 533                 BEFORE_POTENTIAL_GC ();
 534                 Fcar (wrong_type_argument (Qlistp, v1));
 535                 AFTER_POTENTIAL_GC ();
 536               }
 537             break;
 538           }
 539
 540         case Beq:
 541           {
 542             Lisp_Object v1;
 543             v1 = POP;
 544             TOP = EQ (v1, TOP) ? Qt : Qnil;
 545             break;
 546           }
 547
 548         case Bmemq:
 549           {
 550             Lisp_Object v1;
 551             BEFORE_POTENTIAL_GC ();
 552             v1 = POP;
 553             TOP = Fmemq (TOP, v1);
 554             AFTER_POTENTIAL_GC ();
 555             break;
 556           }
 557
 558         case Bcdr:
 559           {
 560             Lisp_Object v1;
 561             v1 = TOP;
 562             if (CONSP (v1))
 563               TOP = XCDR (v1);
 564             else if (NILP (v1))
 565               TOP = Qnil;
 566             else
 567               {
 568                 BEFORE_POTENTIAL_GC ();
 569                 Fcdr (wrong_type_argument (Qlistp, v1));
 570                 AFTER_POTENTIAL_GC ();
 571               }
 572             break;
 573           }
 574
 575         case Bvarset:
 576         case Bvarset+1:
 577         case Bvarset+2:
 578         case Bvarset+3:
 579         case Bvarset+4:
 580         case Bvarset+5:
 581           op -= Bvarset;
 582           goto varset;
 583
 584         case Bvarset+7:
 585           op = FETCH2;
 586           goto varset;
 587
 588         case Bvarset+6:
 589           op = FETCH;
 590         varset:
 591           {
 592             Lisp_Object sym, val;
 593
 594             sym = vectorp[op];
 595             val = TOP;
 596
 597             /* Inline the most common case.  */
 598             if (SYMBOLP (sym)
 599                 && !EQ (val, Qunbound)
 600                 && !MISCP (XSYMBOL (sym)->value)
 601                 /* I think this should either be checked in the byte
 602                    compiler, or there should be a flag indicating that
 603                    a symbol might be constant in Lisp_Symbol, instead
 604                    of checking this here over and over again. --gerd.  */
 605                 && !EQ (sym, Qnil)
 606                 && !EQ (sym, Qt)
 607                 && !(XSYMBOL (sym)->name->data[0] == ':'
 608                      && EQ (XSYMBOL (sym)->obarray, initial_obarray)
 609                      && !EQ (val, sym)))
 610               XSYMBOL (sym)->value = val;
 611             else
 612               {
 613                 BEFORE_POTENTIAL_GC ();
 614                 set_internal (sym, val, current_buffer, 0);
 615                 AFTER_POTENTIAL_GC ();
 616               }
 617           }
 618           POP;
 619           break;
 620
 621         case Bdup:
 622           {
 623             Lisp_Object v1;
 624             v1 = TOP;
 625             PUSH (v1);
 626             break;
 627           }
 628
 629         /* ------------------ */
 630
 631         case Bvarbind+6:
 632           op = FETCH;
 633           goto varbind;
 634
 635         case Bvarbind+7:
 636           op = FETCH2;
 637           goto varbind;
 638
 639         case Bvarbind:
 640         case Bvarbind+1:
 641         case Bvarbind+2:
 642         case Bvarbind+3:
 643         case Bvarbind+4:
 644         case Bvarbind+5:
 645           op -= Bvarbind;
 646         varbind:
 647           specbind (vectorp[op], POP);
 648           break;
 649
 650         case Bcall+6:
 651           op = FETCH;
 652           goto docall;
 653
 654         case Bcall+7:
 655           op = FETCH2;
 656           goto docall;
 657
 658         case Bcall:
 659         case Bcall+1:
 660         case Bcall+2:
 661         case Bcall+3:
 662         case Bcall+4:
 663         case Bcall+5:
 664           op -= Bcall;
 665         docall:
 666           {
 667             BEFORE_POTENTIAL_GC ();
 668             DISCARD (op);
 669 #ifdef BYTE_CODE_METER
 670             if (byte_metering_on && SYMBOLP (TOP))
 671               {
 672                 Lisp_Object v1, v2;
 673
 674                 v1 = TOP;
 675                 v2 = Fget (v1, Qbyte_code_meter);
 676                 if (INTEGERP (v2)
 677                     && XINT (v2) != ((1<<VALBITS)-1))
 678                   {
 679                     XSETINT (v2, XINT (v2) + 1);
 680                     Fput (v1, Qbyte_code_meter, v2);
 681                   }
 682               }
 683 #endif
 684             TOP = Ffuncall (op + 1, &TOP);
 685             AFTER_POTENTIAL_GC ();
 686             break;
 687           }
 688
 689         case Bunbind+6:
 690           op = FETCH;
 691           goto dounbind;
 692
 693         case Bunbind+7:
 694           op = FETCH2;
 695           goto dounbind;
 696
 697         case Bunbind:
 698         case Bunbind+1:
 699         case Bunbind+2:
 700         case Bunbind+3:
 701         case Bunbind+4:
 702         case Bunbind+5:
 703           op -= Bunbind;
 704         dounbind:
 705           BEFORE_POTENTIAL_GC ();
 706           unbind_to (specpdl_ptr - specpdl - op, Qnil);
 707           AFTER_POTENTIAL_GC ();
 708           break;
 709
 710         case Bunbind_all:
 711           /* To unbind back to the beginning of this frame.  Not used yet,
 712              but will be needed for tail-recursion elimination.  */
 713           BEFORE_POTENTIAL_GC ();
 714           unbind_to (count, Qnil);
 715           AFTER_POTENTIAL_GC ();
 716           break;
 717
 718         case Bgoto:
 719           MAYBE_GC ();
 720           QUIT;
 721           op = FETCH2;    /* pc = FETCH2 loses since FETCH2 contains pc++ */
 722           CHECK_RANGE (op);
 723           stack.pc = stack.byte_string_start + op;
 724           break;
 725
 726         case Bgotoifnonnil:
 727           MAYBE_GC ();
 728           op = FETCH2;
 729           if (!NILP (POP))
 730             {
 731               QUIT;
 732               CHECK_RANGE (op);
 733               stack.pc = stack.byte_string_start + op;
 734             }
 735           break;
 736
 737         case Bgotoifnilelsepop:
 738           MAYBE_GC ();
 739           op = FETCH2;
 740           if (NILP (TOP))
 741             {
 742               QUIT;
 743               CHECK_RANGE (op);
 744               stack.pc = stack.byte_string_start + op;
 745             }
 746           else DISCARD (1);
 747           break;
 748
 749         case Bgotoifnonnilelsepop:
 750           MAYBE_GC ();
 751           op = FETCH2;
 752           if (!NILP (TOP))
 753             {
 754               QUIT;
 755               CHECK_RANGE (op);
 756               stack.pc = stack.byte_string_start + op;
 757             }
 758           else DISCARD (1);
 759           break;
 760
 761         case BRgoto:
 762           MAYBE_GC ();
 763           QUIT;
 764           stack.pc += (int) *stack.pc - 127;
 765           break;
 766
 767         case BRgotoifnil:
 768           MAYBE_GC ();
 769           if (NILP (POP))
 770             {
 771               QUIT;
 772               stack.pc += (int) *stack.pc - 128;
 773             }
 774           stack.pc++;
 775           break;
 776
 777         case BRgotoifnonnil:
 778           MAYBE_GC ();
 779           if (!NILP (POP))
 780             {
 781               QUIT;
 782               stack.pc += (int) *stack.pc - 128;
 783             }
 784           stack.pc++;
 785           break;
 786
 787         case BRgotoifnilelsepop:
 788           MAYBE_GC ();
 789           op = *stack.pc++;
 790           if (NILP (TOP))
 791             {
 792               QUIT;
 793               stack.pc += op - 128;
 794             }
 795           else DISCARD (1);
 796           break;
 797
 798         case BRgotoifnonnilelsepop:
 799           MAYBE_GC ();
 800           op = *stack.pc++;
 801           if (!NILP (TOP))
 802             {
 803               QUIT;
 804               stack.pc += op - 128;
 805             }
 806           else DISCARD (1);
 807           break;
 808
 809         case Breturn:
 810           result = POP;
 811           goto exit;
 812
 813         case Bdiscard:
 814           DISCARD (1);
 815           break;
 816
 817         case Bconstant2:
 818           PUSH (vectorp[FETCH2]);
 819           break;
 820
 821         case Bsave_excursion:
 822           record_unwind_protect (save_excursion_restore,
 823                                  save_excursion_save ());
 824           break;
 825
 826         case Bsave_current_buffer:
 827         case Bsave_current_buffer_1:
 828           record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
 829           break;
 830
 831         case Bsave_window_excursion:
 832           BEFORE_POTENTIAL_GC ();
 833           TOP = Fsave_window_excursion (TOP);
 834           AFTER_POTENTIAL_GC ();
 835           break;
 836
 837         case Bsave_restriction:
 838           record_unwind_protect (save_restriction_restore,
 839                                  save_restriction_save ());
 840           break;
 841
 842         case Bcatch:
 843           {
 844             Lisp_Object v1;
 845             BEFORE_POTENTIAL_GC ();
 846             v1 = POP;
 847             TOP = internal_catch (TOP, Feval, v1);
 848             AFTER_POTENTIAL_GC ();
 849             break;
 850           }
 851
 852         case Bunwind_protect:
 853           record_unwind_protect (0, POP);
 854           (specpdl_ptr - 1)->symbol = Qnil;
 855           break;
 856
 857         case Bcondition_case:
 858           {
 859             Lisp_Object v1;
 860             v1 = POP;
 861             v1 = Fcons (POP, v1);
 862             BEFORE_POTENTIAL_GC ();
 863             TOP = Fcondition_case (Fcons (TOP, v1));
 864             AFTER_POTENTIAL_GC ();
 865             break;
 866           }
 867
 868         case Btemp_output_buffer_setup:
 869           BEFORE_POTENTIAL_GC ();
 870           temp_output_buffer_setup (XSTRING (TOP)->data);
 871           AFTER_POTENTIAL_GC ();
 872           TOP = Vstandard_output;
 873           break;
 874
 875         case Btemp_output_buffer_show:
 876           {
 877             Lisp_Object v1;
 878             BEFORE_POTENTIAL_GC ();
 879             v1 = POP;
 880             temp_output_buffer_show (TOP);
 881             TOP = v1;
 882             /* pop binding of standard-output */
 883             unbind_to (specpdl_ptr - specpdl - 1, Qnil);
 884             AFTER_POTENTIAL_GC ();
 885             break;
 886           }
 887
 888         case Bnth:
 889           {
 890             Lisp_Object v1, v2;
 891             BEFORE_POTENTIAL_GC ();
 892             v1 = POP;
 893             v2 = TOP;
 894             CHECK_NUMBER (v2, 0);
 895             AFTER_POTENTIAL_GC ();
 896             op = XINT (v2);
 897             immediate_quit = 1;
 898             while (--op >= 0)
 899               {
 900                 if (CONSP (v1))
 901                   v1 = XCDR (v1);
 902                 else if (!NILP (v1))
 903                   {
 904                     immediate_quit = 0;
 905                     BEFORE_POTENTIAL_GC ();
 906                     v1 = wrong_type_argument (Qlistp, v1);
 907                     AFTER_POTENTIAL_GC ();
 908                     immediate_quit = 1;
 909                     op++;
 910                   }
 911               }
 912             immediate_quit = 0;
 913             if (CONSP (v1))
 914               TOP = XCAR (v1);
 915             else if (NILP (v1))
 916               TOP = Qnil;
 917             else
 918               {
 919                 BEFORE_POTENTIAL_GC ();
 920                 Fcar (wrong_type_argument (Qlistp, v1));
 921                 AFTER_POTENTIAL_GC ();
 922               }
 923             break;
 924           }
 925
 926         case Bsymbolp:
 927           TOP = SYMBOLP (TOP) ? Qt : Qnil;
 928           break;
 929
 930         case Bconsp:
 931           TOP = CONSP (TOP) ? Qt : Qnil;
 932           break;
 933
 934         case Bstringp:
 935           TOP = STRINGP (TOP) ? Qt : Qnil;
 936           break;
 937
 938         case Blistp:
 939           TOP = CONSP (TOP) || NILP (TOP) ? Qt : Qnil;
 940           break;
 941
 942         case Bnot:
 943           TOP = NILP (TOP) ? Qt : Qnil;
 944           break;
 945
 946         case Bcons:
 947           {
 948             Lisp_Object v1;
 949             v1 = POP;
 950             TOP = Fcons (TOP, v1);
 951             break;
 952           }
 953
 954         case Blist1:
 955           TOP = Fcons (TOP, Qnil);
 956           break;
 957
 958         case Blist2:
 959           {
 960             Lisp_Object v1;
 961             v1 = POP;
 962             TOP = Fcons (TOP, Fcons (v1, Qnil));
 963             break;
 964           }
 965
 966         case Blist3:
 967           DISCARD (2);
 968           TOP = Flist (3, &TOP);
 969           break;
 970
 971         case Blist4:
 972           DISCARD (3);
 973           TOP = Flist (4, &TOP);
 974           break;
 975
 976         case BlistN:
 977           op = FETCH;
 978           DISCARD (op - 1);
 979           TOP = Flist (op, &TOP);
 980           break;
 981
 982         case Blength:
 983           BEFORE_POTENTIAL_GC ();
 984           TOP = Flength (TOP);
 985           AFTER_POTENTIAL_GC ();
 986           break;
 987
 988         case Baref:
 989           {
 990             Lisp_Object v1;
 991             BEFORE_POTENTIAL_GC ();
 992             v1 = POP;
 993             TOP = Faref (TOP, v1);
 994             AFTER_POTENTIAL_GC ();
 995             break;
 996           }
 997
 998         case Baset:
 999           {
1000             Lisp_Object v1, v2;
1001             BEFORE_POTENTIAL_GC ();
1002             v2 = POP; v1 = POP;
1003             TOP = Faset (TOP, v1, v2);
1004             AFTER_POTENTIAL_GC ();
1005             break;
1006           }
1007
1008         case Bsymbol_value:
1009           BEFORE_POTENTIAL_GC ();
1010           TOP = Fsymbol_value (TOP);
1011           AFTER_POTENTIAL_GC ();
1012           break;
1013
1014         case Bsymbol_function:
1015           BEFORE_POTENTIAL_GC ();
1016           TOP = Fsymbol_function (TOP);
1017           AFTER_POTENTIAL_GC ();
1018           break;
1019
1020         case Bset:
1021           {
1022             Lisp_Object v1;
1023             BEFORE_POTENTIAL_GC ();
1024             v1 = POP;
1025             TOP = Fset (TOP, v1);
1026             AFTER_POTENTIAL_GC ();
1027             break;
1028           }
1029
1030         case Bfset:
1031           {
1032             Lisp_Object v1;
1033             BEFORE_POTENTIAL_GC ();
1034             v1 = POP;
1035             TOP = Ffset (TOP, v1);
1036             AFTER_POTENTIAL_GC ();
1037             break;
1038           }
1039
1040         case Bget:
1041           {
1042             Lisp_Object v1;
1043             BEFORE_POTENTIAL_GC ();
1044             v1 = POP;
1045             TOP = Fget (TOP, v1);
1046             AFTER_POTENTIAL_GC ();
1047             break;
1048           }
1049
1050         case Bsubstring:
1051           {
1052             Lisp_Object v1, v2;
1053             BEFORE_POTENTIAL_GC ();
1054             v2 = POP; v1 = POP;
1055             TOP = Fsubstring (TOP, v1, v2);
1056             AFTER_POTENTIAL_GC ();
1057             break;
1058           }
1059
1060         case Bconcat2:
1061           BEFORE_POTENTIAL_GC ();
1062           DISCARD (1);
1063           TOP = Fconcat (2, &TOP);
1064           AFTER_POTENTIAL_GC ();
1065           break;
1066
1067         case Bconcat3:
1068           BEFORE_POTENTIAL_GC ();
1069           DISCARD (2);
1070           TOP = Fconcat (3, &TOP);
1071           AFTER_POTENTIAL_GC ();
1072           break;
1073
1074         case Bconcat4:
1075           BEFORE_POTENTIAL_GC ();
1076           DISCARD (3);
1077           TOP = Fconcat (4, &TOP);
1078           AFTER_POTENTIAL_GC ();
1079           break;
1080
1081         case BconcatN:
1082           op = FETCH;
1083           BEFORE_POTENTIAL_GC ();
1084           DISCARD (op - 1);
1085           TOP = Fconcat (op, &TOP);
1086           AFTER_POTENTIAL_GC ();
1087           break;
1088
1089         case Bsub1:
1090           {
1091             Lisp_Object v1;
1092             v1 = TOP;
1093             if (INTEGERP (v1))
1094               {
1095                 XSETINT (v1, XINT (v1) - 1);
1096                 TOP = v1;
1097               }
1098             else
1099               TOP = Fsub1 (v1);
1100             break;
1101           }
1102
1103         case Badd1:
1104           {
1105             Lisp_Object v1;
1106             v1 = TOP;
1107             if (INTEGERP (v1))
1108               {
1109                 XSETINT (v1, XINT (v1) + 1);
1110                 TOP = v1;
1111               }
1112             else
1113               {
1114                 BEFORE_POTENTIAL_GC ();
1115                 TOP = Fadd1 (v1);
1116                 AFTER_POTENTIAL_GC ();
1117               }
1118             break;
1119           }
1120
1121         case Beqlsign:
1122           {
1123             Lisp_Object v1, v2;
1124             BEFORE_POTENTIAL_GC ();
1125             v2 = POP; v1 = TOP;
1126             CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (v1, 0);
1127             CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (v2, 0);
1128             AFTER_POTENTIAL_GC ();
1129             if (FLOATP (v1) || FLOATP (v2))
1130               {
1131                 double f1, f2;
1132
1133                 f1 = (FLOATP (v1) ? XFLOAT_DATA (v1) : XINT (v1));
1134                 f2 = (FLOATP (v2) ? XFLOAT_DATA (v2) : XINT (v2));
1135                 TOP = (f1 == f2 ? Qt : Qnil);
1136               }
1137             else
1138               TOP = (XINT (v1) == XINT (v2) ? Qt : Qnil);
1139             break;
1140           }
1141
1142         case Bgtr:
1143           {
1144             Lisp_Object v1;
1145             BEFORE_POTENTIAL_GC ();
1146             v1 = POP;
1147             TOP = Fgtr (TOP, v1);
1148             AFTER_POTENTIAL_GC ();
1149             break;
1150           }
1151
1152         case Blss:
1153           {
1154             Lisp_Object v1;
1155             BEFORE_POTENTIAL_GC ();
1156             v1 = POP;
1157             TOP = Flss (TOP, v1);
1158             AFTER_POTENTIAL_GC ();
1159             break;
1160           }
1161
1162         case Bleq:
1163           {
1164             Lisp_Object v1;
1165             BEFORE_POTENTIAL_GC ();
1166             v1 = POP;
1167             TOP = Fleq (TOP, v1);
1168             AFTER_POTENTIAL_GC ();
1169             break;
1170           }
1171
1172         case Bgeq:
1173           {
1174             Lisp_Object v1;
1175             v1 = POP;
1176             TOP = Fgeq (TOP, v1);
1177             break;
1178           }
1179
1180         case Bdiff:
1181           BEFORE_POTENTIAL_GC ();
1182           DISCARD (1);
1183           TOP = Fminus (2, &TOP);
1184           AFTER_POTENTIAL_GC ();
1185           break;
1186
1187         case Bnegate:
1188           {
1189             Lisp_Object v1;
1190             v1 = TOP;
1191             if (INTEGERP (v1))
1192               {
1193                 XSETINT (v1, - XINT (v1));
1194                 TOP = v1;
1195               }
1196             else
1197               {
1198                 BEFORE_POTENTIAL_GC ();
1199                 TOP = Fminus (1, &TOP);
1200                 AFTER_POTENTIAL_GC ();
1201               }
1202             break;
1203           }
1204
1205         case Bplus:
1206           BEFORE_POTENTIAL_GC ();
1207           DISCARD (1);
1208           TOP = Fplus (2, &TOP);
1209           AFTER_POTENTIAL_GC ();
1210           break;
1211
1212         case Bmax:
1213           BEFORE_POTENTIAL_GC ();
1214           DISCARD (1);
1215           TOP = Fmax (2, &TOP);
1216           AFTER_POTENTIAL_GC ();
1217           break;
1218
1219         case Bmin:
1220           BEFORE_POTENTIAL_GC ();
1221           DISCARD (1);
1222           TOP = Fmin (2, &TOP);
1223           AFTER_POTENTIAL_GC ();
1224           break;
1225
1226         case Bmult:
1227           BEFORE_POTENTIAL_GC ();
1228           DISCARD (1);
1229           TOP = Ftimes (2, &TOP);
1230           AFTER_POTENTIAL_GC ();
1231           break;
1232
1233         case Bquo:
1234           BEFORE_POTENTIAL_GC ();
1235           DISCARD (1);
1236           TOP = Fquo (2, &TOP);
1237           AFTER_POTENTIAL_GC ();
1238           break;
1239
1240         case Brem:
1241           {
1242             Lisp_Object v1;
1243             BEFORE_POTENTIAL_GC ();
1244             v1 = POP;
1245             TOP = Frem (TOP, v1);
1246             AFTER_POTENTIAL_GC ();
1247             break;
1248           }
1249
1250         case Bpoint:
1251           {
1252             Lisp_Object v1;
1253             XSETFASTINT (v1, PT);
1254             PUSH (v1);
1255             break;
1256           }
1257
1258         case Bgoto_char:
1259           BEFORE_POTENTIAL_GC ();
1260           TOP = Fgoto_char (TOP);
1261           AFTER_POTENTIAL_GC ();
1262           break;
1263
1264         case Binsert:
1265           BEFORE_POTENTIAL_GC ();
1266           TOP = Finsert (1, &TOP);
1267           AFTER_POTENTIAL_GC ();
1268           break;
1269
1270         case BinsertN:
1271           op = FETCH;
1272           BEFORE_POTENTIAL_GC ();
1273           DISCARD (op - 1);
1274           TOP = Finsert (op, &TOP);
1275           AFTER_POTENTIAL_GC ();
1276           break;
1277
1278         case Bpoint_max:
1279           {
1280             Lisp_Object v1;
1281             XSETFASTINT (v1, ZV);
1282             PUSH (v1);
1283             break;
1284           }
1285
1286         case Bpoint_min:
1287           {
1288             Lisp_Object v1;
1289             XSETFASTINT (v1, BEGV);
1290             PUSH (v1);
1291             break;
1292           }
1293
1294         case Bchar_after:
1295           BEFORE_POTENTIAL_GC ();
1296           TOP = Fchar_after (TOP);
1297           AFTER_POTENTIAL_GC ();
1298           break;
1299
1300         case Bfollowing_char:
1301           {
1302             Lisp_Object v1;
1303             BEFORE_POTENTIAL_GC ();
1304             v1 = Ffollowing_char ();
1305             AFTER_POTENTIAL_GC ();
1306             PUSH (v1);
1307             break;
1308           }
1309
1310         case Bpreceding_char:
1311           {
1312             Lisp_Object v1;
1313             BEFORE_POTENTIAL_GC ();
1314             v1 = Fprevious_char ();
1315             AFTER_POTENTIAL_GC ();
1316             PUSH (v1);
1317             break;
1318           }
1319
1320         case Bcurrent_column:
1321           {
1322             Lisp_Object v1;
1323             XSETFASTINT (v1, current_column ());
1324             PUSH (v1);
1325             break;
1326           }
1327
1328         case Bindent_to:
1329           BEFORE_POTENTIAL_GC ();
1330           TOP = Findent_to (TOP, Qnil);
1331           AFTER_POTENTIAL_GC ();
1332           break;
1333
1334         case Beolp:
1335           PUSH (Feolp ());
1336           break;
1337
1338         case Beobp:
1339           PUSH (Feobp ());
1340           break;
1341
1342         case Bbolp:
1343           PUSH (Fbolp ());
1344           break;
1345
1346         case Bbobp:
1347           PUSH (Fbobp ());
1348           break;
1349
1350         case Bcurrent_buffer:
1351           PUSH (Fcurrent_buffer ());
1352           break;
1353
1354         case Bset_buffer:
1355           BEFORE_POTENTIAL_GC ();
1356           TOP = Fset_buffer (TOP);
1357           AFTER_POTENTIAL_GC ();
1358           break;
1359
1360         case Binteractive_p:
1361           PUSH (Finteractive_p ());
1362           break;
1363
1364         case Bforward_char:
1365           BEFORE_POTENTIAL_GC ();
1366           TOP = Fforward_char (TOP);
1367           AFTER_POTENTIAL_GC ();
1368           break;
1369
1370         case Bforward_word:
1371           BEFORE_POTENTIAL_GC ();
1372           TOP = Fforward_word (TOP);
1373           AFTER_POTENTIAL_GC ();
1374           break;
1375
1376         case Bskip_chars_forward:
1377           {
1378             Lisp_Object v1;
1379             BEFORE_POTENTIAL_GC ();
1380             v1 = POP;
1381             TOP = Fskip_chars_forward (TOP, v1);
1382             AFTER_POTENTIAL_GC ();
1383             break;
1384           }
1385
1386         case Bskip_chars_backward:
1387           {
1388             Lisp_Object v1;
1389             BEFORE_POTENTIAL_GC ();
1390             v1 = POP;
1391             TOP = Fskip_chars_backward (TOP, v1);
1392             AFTER_POTENTIAL_GC ();
1393             break;
1394           }
1395
1396         case Bforward_line:
1397           BEFORE_POTENTIAL_GC ();
1398           TOP = Fforward_line (TOP);
1399           AFTER_POTENTIAL_GC ();
1400           break;
1401
1402         case Bchar_syntax:
1403           BEFORE_POTENTIAL_GC ();
1404           CHECK_NUMBER (TOP, 0);
1405           AFTER_POTENTIAL_GC ();
1406           XSETFASTINT (TOP, syntax_code_spec[(int) SYNTAX (XINT (TOP))]);
1407           break;
1408
1409         case Bbuffer_substring:
1410           {
1411             Lisp_Object v1;
1412             BEFORE_POTENTIAL_GC ();
1413             v1 = POP;
1414             TOP = Fbuffer_substring (TOP, v1);
1415             AFTER_POTENTIAL_GC ();
1416             break;
1417           }
1418
1419         case Bdelete_region:
1420           {
1421             Lisp_Object v1;
1422             BEFORE_POTENTIAL_GC ();
1423             v1 = POP;
1424             TOP = Fdelete_region (TOP, v1);
1425             AFTER_POTENTIAL_GC ();
1426             break;
1427           }
1428
1429         case Bnarrow_to_region:
1430           {
1431             Lisp_Object v1;
1432             BEFORE_POTENTIAL_GC ();
1433             v1 = POP;
1434             TOP = Fnarrow_to_region (TOP, v1);
1435             AFTER_POTENTIAL_GC ();
1436             break;
1437           }
1438
1439         case Bwiden:
1440           BEFORE_POTENTIAL_GC ();
1441           PUSH (Fwiden ());
1442           AFTER_POTENTIAL_GC ();
1443           break;
1444
1445         case Bend_of_line:
1446           BEFORE_POTENTIAL_GC ();
1447           TOP = Fend_of_line (TOP);
1448           AFTER_POTENTIAL_GC ();
1449           break;
1450
1451         case Bset_marker:
1452           {
1453             Lisp_Object v1, v2;
1454             BEFORE_POTENTIAL_GC ();
1455             v1 = POP;
1456             v2 = POP;
1457             TOP = Fset_marker (TOP, v2, v1);
1458             AFTER_POTENTIAL_GC ();
1459             break;
1460           }
1461
1462         case Bmatch_beginning:
1463           BEFORE_POTENTIAL_GC ();
1464           TOP = Fmatch_beginning (TOP);
1465           AFTER_POTENTIAL_GC ();
1466           break;
1467
1468         case Bmatch_end:
1469           BEFORE_POTENTIAL_GC ();
1470           TOP = Fmatch_end (TOP);
1471           AFTER_POTENTIAL_GC ();
1472           break;
1473
1474         case Bupcase:
1475           BEFORE_POTENTIAL_GC ();
1476           TOP = Fupcase (TOP);
1477           AFTER_POTENTIAL_GC ();
1478           break;
1479
1480         case Bdowncase:
1481           BEFORE_POTENTIAL_GC ();
1482           TOP = Fdowncase (TOP);
1483           AFTER_POTENTIAL_GC ();
1484         break;
1485
1486         case Bstringeqlsign:
1487           {
1488             Lisp_Object v1;
1489             BEFORE_POTENTIAL_GC ();
1490             v1 = POP;
1491             TOP = Fstring_equal (TOP, v1);
1492             AFTER_POTENTIAL_GC ();
1493             break;
1494           }
1495
1496         case Bstringlss:
1497           {
1498             Lisp_Object v1;
1499             BEFORE_POTENTIAL_GC ();
1500             v1 = POP;
1501             TOP = Fstring_lessp (TOP, v1);
1502             AFTER_POTENTIAL_GC ();
1503             break;
1504           }
1505
1506         case Bequal:
1507           {
1508             Lisp_Object v1;
1509             v1 = POP;
1510             TOP = Fequal (TOP, v1);
1511             break;
1512           }
1513
1514         case Bnthcdr:
1515           {
1516             Lisp_Object v1;
1517             BEFORE_POTENTIAL_GC ();
1518             v1 = POP;
1519             TOP = Fnthcdr (TOP, v1);
1520             AFTER_POTENTIAL_GC ();
1521             break;
1522           }
1523
1524         case Belt:
1525           {
1526             Lisp_Object v1, v2;
1527             if (CONSP (TOP))
1528               {
1529                 /* Exchange args and then do nth.  */
1530                 BEFORE_POTENTIAL_GC ();
1531                 v2 = POP;
1532                 v1 = TOP;
1533                 CHECK_NUMBER (v2, 0);
1534                 AFTER_POTENTIAL_GC ();
1535                 op = XINT (v2);
1536                 immediate_quit = 1;
1537                 while (--op >= 0)
1538                   {
1539                     if (CONSP (v1))
1540                       v1 = XCDR (v1);
1541                     else if (!NILP (v1))
1542                       {
1543                         immediate_quit = 0;
1544                         BEFORE_POTENTIAL_GC ();
1545                         v1 = wrong_type_argument (Qlistp, v1);
1546                         AFTER_POTENTIAL_GC ();
1547                         immediate_quit = 1;
1548                         op++;
1549                       }
1550                   }
1551                 immediate_quit = 0;
1552                 if (CONSP (v1))
1553                   TOP = XCAR (v1);
1554                 else if (NILP (v1))
1555                   TOP = Qnil;
1556                 else
1557                   {
1558                     BEFORE_POTENTIAL_GC ();
1559                     Fcar (wrong_type_argument (Qlistp, v1));
1560                     AFTER_POTENTIAL_GC ();
1561                   }
1562               }
1563             else
1564               {
1565                 BEFORE_POTENTIAL_GC ();
1566                 v1 = POP;
1567                 TOP = Felt (TOP, v1);
1568                 AFTER_POTENTIAL_GC ();
1569               }
1570             break;
1571           }
1572
1573         case Bmember:
1574           {
1575             Lisp_Object v1;
1576             BEFORE_POTENTIAL_GC ();
1577             v1 = POP;
1578             TOP = Fmember (TOP, v1);
1579             AFTER_POTENTIAL_GC ();
1580             break;
1581           }
1582
1583         case Bassq:
1584           {
1585             Lisp_Object v1;
1586             BEFORE_POTENTIAL_GC ();
1587             v1 = POP;
1588             TOP = Fassq (TOP, v1);
1589             AFTER_POTENTIAL_GC ();
1590             break;
1591           }
1592
1593         case Bnreverse:
1594           BEFORE_POTENTIAL_GC ();
1595           TOP = Fnreverse (TOP);
1596           AFTER_POTENTIAL_GC ();
1597           break;
1598
1599         case Bsetcar:
1600           {
1601             Lisp_Object v1;
1602             BEFORE_POTENTIAL_GC ();
1603             v1 = POP;
1604             TOP = Fsetcar (TOP, v1);
1605             AFTER_POTENTIAL_GC ();
1606             break;
1607           }
1608
1609         case Bsetcdr:
1610           {
1611             Lisp_Object v1;
1612             BEFORE_POTENTIAL_GC ();
1613             v1 = POP;
1614             TOP = Fsetcdr (TOP, v1);
1615             AFTER_POTENTIAL_GC ();
1616             break;
1617           }
1618
1619         case Bcar_safe:
1620           {
1621             Lisp_Object v1;
1622             v1 = TOP;
1623             if (CONSP (v1))
1624               TOP = XCAR (v1);
1625             else
1626               TOP = Qnil;
1627             break;
1628           }
1629
1630         case Bcdr_safe:
1631           {
1632             Lisp_Object v1;
1633             v1 = TOP;
1634             if (CONSP (v1))
1635               TOP = XCDR (v1);
1636             else
1637               TOP = Qnil;
1638             break;
1639           }
1640
1641         case Bnconc:
1642           BEFORE_POTENTIAL_GC ();
1643           DISCARD (1);
1644           TOP = Fnconc (2, &TOP);
1645           AFTER_POTENTIAL_GC ();
1646           break;
1647
1648         case Bnumberp:
1649           TOP = (NUMBERP (TOP) ? Qt : Qnil);
1650           break;
1651
1652         case Bintegerp:
1653           TOP = INTEGERP (TOP) ? Qt : Qnil;
1654           break;
1655
1656 #ifdef BYTE_CODE_SAFE
1657         case Bset_mark:
1658           BEFORE_POTENTIAL_GC ();
1659           error ("set-mark is an obsolete bytecode");
1660           AFTER_POTENTIAL_GC ();
1661           break;
1662         case Bscan_buffer:
1663           BEFORE_POTENTIAL_GC ();
1664           error ("scan-buffer is an obsolete bytecode");
1665           AFTER_POTENTIAL_GC ();
1666           break;
1667 #endif
1668
1669         case 0:
1670           abort ();
1671
1672         case 255:
1673         default:
1674 #ifdef BYTE_CODE_SAFE
1675           if (op < Bconstant)
1676             {
1677               abort ();
1678             }
1679           if ((op -= Bconstant) >= const_length)
1680             {
1681               abort ();
1682             }
1683           PUSH (vectorp[op]);
1684 #else
1685           PUSH (vectorp[op - Bconstant]);
1686 #endif
1687         }
1688     }
1689
1690  exit:
1691
1692   byte_stack_list = byte_stack_list->next;
1693
1694   /* Binds and unbinds are supposed to be compiled balanced.  */
1695   if (specpdl_ptr - specpdl != count)
1696 #ifdef BYTE_CODE_SAFE
1697     error ("binding stack not balanced (serious byte compiler bug)");
1698 #else
1699     abort ();
1700 #endif
1701
1702   return result;
1703 }
1704
1705 void
1706 syms_of_bytecode ()
1707 {
1708   Qbytecode = intern ("byte-code");
1709   staticpro (&Qbytecode);
1710
1711   defsubr (&Sbyte_code);
1712
1713 #ifdef BYTE_CODE_METER
1714
1715   DEFVAR_LISP ("byte-code-meter", &Vbyte_code_meter,
1716    "A vector of vectors which holds a histogram of byte-code usage.\n\
1717 (aref (aref byte-code-meter 0) CODE) indicates how many times the byte\n\
1718 opcode CODE has been executed.\n\
1719 (aref (aref byte-code-meter CODE1) CODE2), where CODE1 is not 0,\n\
1720 indicates how many times the byte opcodes CODE1 and CODE2 have been\n\
1721 executed in succession.");
1722   DEFVAR_BOOL ("byte-metering-on", &byte_metering_on,
1723    "If non-nil, keep profiling information on byte code usage.\n\
1724 The variable byte-code-meter indicates how often each byte opcode is used.\n\
1725 If a symbol has a property named `byte-code-meter' whose value is an\n\
1726 integer, it is incremented each time that symbol's function is called.");
1727
1728   byte_metering_on = 0;
1729   Vbyte_code_meter = Fmake_vector (make_number (256), make_number (0));
1730   Qbyte_code_meter = intern ("byte-code-meter");
1731   staticpro (&Qbyte_code_meter);
1732   {
1733     int i = 256;
1734     while (i--)
1735       XVECTOR (Vbyte_code_meter)->contents[i] =
1736         Fmake_vector (make_number (256), make_number (0));
1737   }
1738 #endif
1739 }