src/bytecode.c

   1 /* Execution of byte code produced by bytecomp.el.
   2    Copyright (C) 1985-1988, 1993, 2000-2011 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 3 of the License, or
   9 (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  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 <setjmp.h>
  37 #include "lisp.h"
  38 #include "buffer.h"
  39 #include "character.h"
  40 #include "syntax.h"
  41 #include "window.h"
  42
  43 #ifdef CHECK_FRAME_FONT
  44 #include "frame.h"
  45 #include "xterm.h"
  46 #endif
  47
  48 /*
  49  * define BYTE_CODE_SAFE to enable some minor sanity checking (useful for
  50  * debugging the byte compiler...)
  51  *
  52  * define BYTE_CODE_METER to enable generation of a byte-op usage histogram.
  53  */
  54 /* #define BYTE_CODE_SAFE */
  55 /* #define BYTE_CODE_METER */
  56
  57 \f
  58 #ifdef BYTE_CODE_METER
  59
  60 Lisp_Object Qbyte_code_meter;
  61 #define METER_2(code1, code2) \
  62   XFASTINT (XVECTOR (XVECTOR (Vbyte_code_meter)->contents[(code1)]) \
  63             ->contents[(code2)])
  64
  65 #define METER_1(code) METER_2 (0, (code))
  66
  67 #define METER_CODE(last_code, this_code)                                \
  68 {                                                                       \
  69   if (byte_metering_on)                                                 \
  70     {                                                                   \
  71       if (METER_1 (this_code) < MOST_POSITIVE_FIXNUM)                   \
  72         METER_1 (this_code)++;                                          \
  73       if (last_code                                                     \
  74           && METER_2 (last_code, this_code) < MOST_POSITIVE_FIXNUM)     \
  75         METER_2 (last_code, this_code)++;                               \
  76     }                                                                   \
  77 }
  78
  79 #endif /* 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 #ifdef BYTE_CODE_SAFE
 146 #define Bscan_buffer 0153 /* No longer generated as of v18 */
 147 #endif
 148 #define Beolp 0154
 149 #define Beobp 0155
 150 #define Bbolp 0156
 151 #define Bbobp 0157
 152 #define Bcurrent_buffer 0160
 153 #define Bset_buffer 0161
 154 #define Bsave_current_buffer_1 0162 /* Replacing Bsave_current_buffer.  */
 155 #if 0
 156 #define Bread_char 0162 /* No longer generated as of v19 */
 157 #endif
 158 #ifdef BYTE_CODE_SAFE
 159 #define Bset_mark 0163 /* this loser is no longer generated as of v18 */
 160 #endif
 161 #define Binteractive_p 0164 /* Needed since interactive-p takes unevalled args */
 162
 163 #define Bforward_char 0165
 164 #define Bforward_word 0166
 165 #define Bskip_chars_forward 0167
 166 #define Bskip_chars_backward 0170
 167 #define Bforward_line 0171
 168 #define Bchar_syntax 0172
 169 #define Bbuffer_substring 0173
 170 #define Bdelete_region 0174
 171 #define Bnarrow_to_region 0175
 172 #define Bwiden 0176
 173 #define Bend_of_line 0177
 174
 175 #define Bconstant2 0201
 176 #define Bgoto 0202
 177 #define Bgotoifnil 0203
 178 #define Bgotoifnonnil 0204
 179 #define Bgotoifnilelsepop 0205
 180 #define Bgotoifnonnilelsepop 0206
 181 #define Breturn 0207
 182 #define Bdiscard 0210
 183 #define Bdup 0211
 184
 185 #define Bsave_excursion 0212
 186 #define Bsave_window_excursion 0213
 187 #define Bsave_restriction 0214
 188 #define Bcatch 0215
 189
 190 #define Bunwind_protect 0216
 191 #define Bcondition_case 0217
 192 #define Btemp_output_buffer_setup 0220
 193 #define Btemp_output_buffer_show 0221
 194
 195 #define Bunbind_all 0222
 196
 197 #define Bset_marker 0223
 198 #define Bmatch_beginning 0224
 199 #define Bmatch_end 0225
 200 #define Bupcase 0226
 201 #define Bdowncase 0227
 202
 203 #define Bstringeqlsign 0230
 204 #define Bstringlss 0231
 205 #define Bequal 0232
 206 #define Bnthcdr 0233
 207 #define Belt 0234
 208 #define Bmember 0235
 209 #define Bassq 0236
 210 #define Bnreverse 0237
 211 #define Bsetcar 0240
 212 #define Bsetcdr 0241
 213 #define Bcar_safe 0242
 214 #define Bcdr_safe 0243
 215 #define Bnconc 0244
 216 #define Bquo 0245
 217 #define Brem 0246
 218 #define Bnumberp 0247
 219 #define Bintegerp 0250
 220
 221 #define BRgoto 0252
 222 #define BRgotoifnil 0253
 223 #define BRgotoifnonnil 0254
 224 #define BRgotoifnilelsepop 0255
 225 #define BRgotoifnonnilelsepop 0256
 226
 227 #define BlistN 0257
 228 #define BconcatN 0260
 229 #define BinsertN 0261
 230
 231 #define Bconstant 0300
 232
 233 /* Whether to maintain a `top' and `bottom' field in the stack frame.  */
 234 #define BYTE_MAINTAIN_TOP (BYTE_CODE_SAFE || BYTE_MARK_STACK)
 235 \f
 236 /* Structure describing a value stack used during byte-code execution
 237    in Fbyte_code.  */
 238
 239 struct byte_stack
 240 {
 241   /* Program counter.  This points into the byte_string below
 242      and is relocated when that string is relocated.  */
 243   const unsigned char *pc;
 244
 245   /* Top and bottom of stack.  The bottom points to an area of memory
 246      allocated with alloca in Fbyte_code.  */
 247 #if BYTE_MAINTAIN_TOP
 248   Lisp_Object *top, *bottom;
 249 #endif
 250
 251   /* The string containing the byte-code, and its current address.
 252      Storing this here protects it from GC because mark_byte_stack
 253      marks it.  */
 254   Lisp_Object byte_string;
 255   const unsigned char *byte_string_start;
 256
 257   /* The vector of constants used during byte-code execution.  Storing
 258      this here protects it from GC because mark_byte_stack marks it.  */
 259   Lisp_Object constants;
 260
 261   /* Next entry in byte_stack_list.  */
 262   struct byte_stack *next;
 263 };
 264
 265 /* A list of currently active byte-code execution value stacks.
 266    Fbyte_code adds an entry to the head of this list before it starts
 267    processing byte-code, and it removed the entry again when it is
 268    done.  Signalling an error truncates the list analoguous to
 269    gcprolist.  */
 270
 271 struct byte_stack *byte_stack_list;
 272
 273 \f
 274 /* Mark objects on byte_stack_list.  Called during GC.  */
 275
 276 #if BYTE_MARK_STACK
 277 void
 278 mark_byte_stack (void)
 279 {
 280   struct byte_stack *stack;
 281   Lisp_Object *obj;
 282
 283   for (stack = byte_stack_list; stack; stack = stack->next)
 284     {
 285       /* If STACK->top is null here, this means there's an opcode in
 286          Fbyte_code that wasn't expected to GC, but did.  To find out
 287          which opcode this is, record the value of `stack', and walk
 288          up the stack in a debugger, stopping in frames of Fbyte_code.
 289          The culprit is found in the frame of Fbyte_code where the
 290          address of its local variable `stack' is equal to the
 291          recorded value of `stack' here.  */
 292       eassert (stack->top);
 293
 294       for (obj = stack->bottom; obj <= stack->top; ++obj)
 295         mark_object (*obj);
 296
 297       mark_object (stack->byte_string);
 298       mark_object (stack->constants);
 299     }
 300 }
 301 #endif
 302
 303 /* Unmark objects in the stacks on byte_stack_list.  Relocate program
 304    counters.  Called when GC has completed.  */
 305
 306 void
 307 unmark_byte_stack (void)
 308 {
 309   struct byte_stack *stack;
 310
 311   for (stack = byte_stack_list; stack; stack = stack->next)
 312     {
 313       if (stack->byte_string_start != SDATA (stack->byte_string))
 314         {
 315           int offset = stack->pc - stack->byte_string_start;
 316           stack->byte_string_start = SDATA (stack->byte_string);
 317           stack->pc = stack->byte_string_start + offset;
 318         }
 319     }
 320 }
 321
 322 \f
 323 /* Fetch the next byte from the bytecode stream */
 324
 325 #define FETCH *stack.pc++
 326
 327 /* Fetch two bytes from the bytecode stream and make a 16-bit number
 328    out of them */
 329
 330 #define FETCH2 (op = FETCH, op + (FETCH << 8))
 331
 332 /* Push x onto the execution stack.  This used to be #define PUSH(x)
 333    (*++stackp = (x)) This oddity is necessary because Alliant can't be
 334    bothered to compile the preincrement operator properly, as of 4/91.
 335    -JimB */
 336
 337 #define PUSH(x) (top++, *top = (x))
 338
 339 /* Pop a value off the execution stack.  */
 340
 341 #define POP (*top--)
 342
 343 /* Discard n values from the execution stack.  */
 344
 345 #define DISCARD(n) (top -= (n))
 346
 347 /* Get the value which is at the top of the execution stack, but don't
 348    pop it. */
 349
 350 #define TOP (*top)
 351
 352 /* Actions that must be performed before and after calling a function
 353    that might GC.  */
 354
 355 #if !BYTE_MAINTAIN_TOP
 356 #define BEFORE_POTENTIAL_GC()   ((void)0)
 357 #define AFTER_POTENTIAL_GC()    ((void)0)
 358 #else
 359 #define BEFORE_POTENTIAL_GC()   stack.top = top
 360 #define AFTER_POTENTIAL_GC()    stack.top = NULL
 361 #endif
 362
 363 /* Garbage collect if we have consed enough since the last time.
 364    We do this at every branch, to avoid loops that never GC.  */
 365
 366 #define MAYBE_GC()                                      \
 367  do {                                                   \
 368   if (consing_since_gc > gc_cons_threshold              \
 369       && consing_since_gc > gc_relative_threshold)      \
 370     {                                                   \
 371       BEFORE_POTENTIAL_GC ();                           \
 372       Fgarbage_collect ();                              \
 373       AFTER_POTENTIAL_GC ();                            \
 374     }                                                   \
 375  } while (0)
 376
 377 /* Check for jumping out of range.  */
 378
 379 #ifdef BYTE_CODE_SAFE
 380
 381 #define CHECK_RANGE(ARG) \
 382   if (ARG >= bytestr_length) abort ()
 383
 384 #else /* not BYTE_CODE_SAFE */
 385
 386 #define CHECK_RANGE(ARG)
 387
 388 #endif /* not BYTE_CODE_SAFE */
 389
 390 /* A version of the QUIT macro which makes sure that the stack top is
 391    set before signaling `quit'.  */
 392
 393 #define BYTE_CODE_QUIT                                  \
 394   do {                                                  \
 395     if (!NILP (Vquit_flag) && NILP (Vinhibit_quit))     \
 396       {                                                 \
 397         Lisp_Object flag = Vquit_flag;                  \
 398         Vquit_flag = Qnil;                              \
 399         BEFORE_POTENTIAL_GC ();                         \
 400         if (EQ (Vthrow_on_input, flag))                 \
 401           Fthrow (Vthrow_on_input, Qt);                 \
 402         Fsignal (Qquit, Qnil);                          \
 403         AFTER_POTENTIAL_GC ();                          \
 404       }                                                 \
 405     ELSE_PENDING_SIGNALS                                \
 406   } while (0)
 407
 408
 409 DEFUN ("byte-code", Fbyte_code, Sbyte_code, 3, 3, 0,
 410        doc: /* Function used internally in byte-compiled code.
 411 The first argument, BYTESTR, is a string of byte code;
 412 the second, VECTOR, a vector of constants;
 413 the third, MAXDEPTH, the maximum stack depth used in this function.
 414 If the third argument is incorrect, Emacs may crash.  */)
 415   (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth)
 416 {
 417   int count = SPECPDL_INDEX ();
 418 #ifdef BYTE_CODE_METER
 419   int this_op = 0;
 420   int prev_op;
 421 #endif
 422   int op;
 423   /* Lisp_Object v1, v2; */
 424   Lisp_Object *vectorp;
 425 #ifdef BYTE_CODE_SAFE
 426   int const_length = XVECTOR (vector)->size;
 427   Lisp_Object *stacke;
 428 #endif
 429   int bytestr_length;
 430   struct byte_stack stack;
 431   Lisp_Object *top;
 432   Lisp_Object result;
 433
 434 #if 0 /* CHECK_FRAME_FONT */
 435  {
 436    struct frame *f = SELECTED_FRAME ();
 437    if (FRAME_X_P (f)
 438        && FRAME_FONT (f)->direction != 0
 439        && FRAME_FONT (f)->direction != 1)
 440      abort ();
 441  }
 442 #endif
 443
 444   CHECK_STRING (bytestr);
 445   CHECK_VECTOR (vector);
 446   CHECK_NUMBER (maxdepth);
 447
 448   if (STRING_MULTIBYTE (bytestr))
 449     /* BYTESTR must have been produced by Emacs 20.2 or the earlier
 450        because they produced a raw 8-bit string for byte-code and now
 451        such a byte-code string is loaded as multibyte while raw 8-bit
 452        characters converted to multibyte form.  Thus, now we must
 453        convert them back to the originally intended unibyte form.  */
 454     bytestr = Fstring_as_unibyte (bytestr);
 455
 456   bytestr_length = SBYTES (bytestr);
 457   vectorp = XVECTOR (vector)->contents;
 458
 459   stack.byte_string = bytestr;
 460   stack.pc = stack.byte_string_start = SDATA (bytestr);
 461   stack.constants = vector;
 462   top = (Lisp_Object *) alloca (XFASTINT (maxdepth)
 463                                          * sizeof (Lisp_Object));
 464 #if BYTE_MAINTAIN_TOP
 465   stack.bottom = top;
 466   stack.top = NULL;
 467 #endif
 468   top -= 1;
 469   stack.next = byte_stack_list;
 470   byte_stack_list = &stack;
 471
 472 #ifdef BYTE_CODE_SAFE
 473   stacke = stack.bottom - 1 + XFASTINT (maxdepth);
 474 #endif
 475
 476   while (1)
 477     {
 478 #ifdef BYTE_CODE_SAFE
 479       if (top > stacke)
 480         abort ();
 481       else if (top < stack.bottom - 1)
 482         abort ();
 483 #endif
 484
 485 #ifdef BYTE_CODE_METER
 486       prev_op = this_op;
 487       this_op = op = FETCH;
 488       METER_CODE (prev_op, op);
 489 #else
 490       op = FETCH;
 491 #endif
 492
 493       switch (op)
 494         {
 495         case Bvarref + 7:
 496           op = FETCH2;
 497           goto varref;
 498
 499         case Bvarref:
 500         case Bvarref + 1:
 501         case Bvarref + 2:
 502         case Bvarref + 3:
 503         case Bvarref + 4:
 504         case Bvarref + 5:
 505           op = op - Bvarref;
 506           goto varref;
 507
 508         /* This seems to be the most frequently executed byte-code
 509            among the Bvarref's, so avoid a goto here.  */
 510         case Bvarref+6:
 511           op = FETCH;
 512         varref:
 513           {
 514             Lisp_Object v1, v2;
 515
 516             v1 = vectorp[op];
 517             if (SYMBOLP (v1))
 518               {
 519                 if (XSYMBOL (v1)->redirect != SYMBOL_PLAINVAL
 520                     || (v2 = SYMBOL_VAL (XSYMBOL (v1)),
 521                         EQ (v2, Qunbound)))
 522                   {
 523                     BEFORE_POTENTIAL_GC ();
 524                     v2 = Fsymbol_value (v1);
 525                     AFTER_POTENTIAL_GC ();
 526                   }
 527               }
 528             else
 529               {
 530                 BEFORE_POTENTIAL_GC ();
 531                 v2 = Fsymbol_value (v1);
 532                 AFTER_POTENTIAL_GC ();
 533               }
 534             PUSH (v2);
 535             break;
 536           }
 537
 538         case Bgotoifnil:
 539           {
 540             Lisp_Object v1;
 541             MAYBE_GC ();
 542             op = FETCH2;
 543             v1 = POP;
 544             if (NILP (v1))
 545               {
 546                 BYTE_CODE_QUIT;
 547                 CHECK_RANGE (op);
 548                 stack.pc = stack.byte_string_start + op;
 549               }
 550             break;
 551           }
 552
 553         case Bcar:
 554           {
 555             Lisp_Object v1;
 556             v1 = TOP;
 557             TOP = CAR (v1);
 558             break;
 559           }
 560
 561         case Beq:
 562           {
 563             Lisp_Object v1;
 564             v1 = POP;
 565             TOP = EQ (v1, TOP) ? Qt : Qnil;
 566             break;
 567           }
 568
 569         case Bmemq:
 570           {
 571             Lisp_Object v1;
 572             BEFORE_POTENTIAL_GC ();
 573             v1 = POP;
 574             TOP = Fmemq (TOP, v1);
 575             AFTER_POTENTIAL_GC ();
 576             break;
 577           }
 578
 579         case Bcdr:
 580           {
 581             Lisp_Object v1;
 582             v1 = TOP;
 583             TOP = CDR (v1);
 584             break;
 585           }
 586
 587         case Bvarset:
 588         case Bvarset+1:
 589         case Bvarset+2:
 590         case Bvarset+3:
 591         case Bvarset+4:
 592         case Bvarset+5:
 593           op -= Bvarset;
 594           goto varset;
 595
 596         case Bvarset+7:
 597           op = FETCH2;
 598           goto varset;
 599
 600         case Bvarset+6:
 601           op = FETCH;
 602         varset:
 603           {
 604             Lisp_Object sym, val;
 605
 606             sym = vectorp[op];
 607             val = TOP;
 608
 609             /* Inline the most common case.  */
 610             if (SYMBOLP (sym)
 611                 && !EQ (val, Qunbound)
 612                 && !XSYMBOL (sym)->redirect
 613                 && !SYMBOL_CONSTANT_P (sym))
 614               XSYMBOL (sym)->val.value = val;
 615             else
 616               {
 617                 BEFORE_POTENTIAL_GC ();
 618                 set_internal (sym, val, Qnil, 0);
 619                 AFTER_POTENTIAL_GC ();
 620               }
 621           }
 622           (void) POP;
 623           break;
 624
 625         case Bdup:
 626           {
 627             Lisp_Object v1;
 628             v1 = TOP;
 629             PUSH (v1);
 630             break;
 631           }
 632
 633         /* ------------------ */
 634
 635         case Bvarbind+6:
 636           op = FETCH;
 637           goto varbind;
 638
 639         case Bvarbind+7:
 640           op = FETCH2;
 641           goto varbind;
 642
 643         case Bvarbind:
 644         case Bvarbind+1:
 645         case Bvarbind+2:
 646         case Bvarbind+3:
 647         case Bvarbind+4:
 648         case Bvarbind+5:
 649           op -= Bvarbind;
 650         varbind:
 651           /* Specbind can signal and thus GC.  */
 652           BEFORE_POTENTIAL_GC ();
 653           specbind (vectorp[op], POP);
 654           AFTER_POTENTIAL_GC ();
 655           break;
 656
 657         case Bcall+6:
 658           op = FETCH;
 659           goto docall;
 660
 661         case Bcall+7:
 662           op = FETCH2;
 663           goto docall;
 664
 665         case Bcall:
 666         case Bcall+1:
 667         case Bcall+2:
 668         case Bcall+3:
 669         case Bcall+4:
 670         case Bcall+5:
 671           op -= Bcall;
 672         docall:
 673           {
 674             BEFORE_POTENTIAL_GC ();
 675             DISCARD (op);
 676 #ifdef BYTE_CODE_METER
 677             if (byte_metering_on && SYMBOLP (TOP))
 678               {
 679                 Lisp_Object v1, v2;
 680
 681                 v1 = TOP;
 682                 v2 = Fget (v1, Qbyte_code_meter);
 683                 if (INTEGERP (v2)
 684                     && XINT (v2) < MOST_POSITIVE_FIXNUM)
 685                   {
 686                     XSETINT (v2, XINT (v2) + 1);
 687                     Fput (v1, Qbyte_code_meter, v2);
 688                   }
 689               }
 690 #endif
 691             TOP = Ffuncall (op + 1, &TOP);
 692             AFTER_POTENTIAL_GC ();
 693             break;
 694           }
 695
 696         case Bunbind+6:
 697           op = FETCH;
 698           goto dounbind;
 699
 700         case Bunbind+7:
 701           op = FETCH2;
 702           goto dounbind;
 703
 704         case Bunbind:
 705         case Bunbind+1:
 706         case Bunbind+2:
 707         case Bunbind+3:
 708         case Bunbind+4:
 709         case Bunbind+5:
 710           op -= Bunbind;
 711         dounbind:
 712           BEFORE_POTENTIAL_GC ();
 713           unbind_to (SPECPDL_INDEX () - op, Qnil);
 714           AFTER_POTENTIAL_GC ();
 715           break;
 716
 717         case Bunbind_all:
 718           /* To unbind back to the beginning of this frame.  Not used yet,
 719              but will be needed for tail-recursion elimination.  */
 720           BEFORE_POTENTIAL_GC ();
 721           unbind_to (count, Qnil);
 722           AFTER_POTENTIAL_GC ();
 723           break;
 724
 725         case Bgoto:
 726           MAYBE_GC ();
 727           BYTE_CODE_QUIT;
 728           op = FETCH2;    /* pc = FETCH2 loses since FETCH2 contains pc++ */
 729           CHECK_RANGE (op);
 730           stack.pc = stack.byte_string_start + op;
 731           break;
 732
 733         case Bgotoifnonnil:
 734           {
 735             Lisp_Object v1;
 736             MAYBE_GC ();
 737             op = FETCH2;
 738             v1 = POP;
 739             if (!NILP (v1))
 740               {
 741                 BYTE_CODE_QUIT;
 742                 CHECK_RANGE (op);
 743                 stack.pc = stack.byte_string_start + op;
 744               }
 745             break;
 746           }
 747
 748         case Bgotoifnilelsepop:
 749           MAYBE_GC ();
 750           op = FETCH2;
 751           if (NILP (TOP))
 752             {
 753               BYTE_CODE_QUIT;
 754               CHECK_RANGE (op);
 755               stack.pc = stack.byte_string_start + op;
 756             }
 757           else DISCARD (1);
 758           break;
 759
 760         case Bgotoifnonnilelsepop:
 761           MAYBE_GC ();
 762           op = FETCH2;
 763           if (!NILP (TOP))
 764             {
 765               BYTE_CODE_QUIT;
 766               CHECK_RANGE (op);
 767               stack.pc = stack.byte_string_start + op;
 768             }
 769           else DISCARD (1);
 770           break;
 771
 772         case BRgoto:
 773           MAYBE_GC ();
 774           BYTE_CODE_QUIT;
 775           stack.pc += (int) *stack.pc - 127;
 776           break;
 777
 778         case BRgotoifnil:
 779           {
 780             Lisp_Object v1;
 781             MAYBE_GC ();
 782             v1 = POP;
 783             if (NILP (v1))
 784               {
 785                 BYTE_CODE_QUIT;
 786                 stack.pc += (int) *stack.pc - 128;
 787               }
 788             stack.pc++;
 789             break;
 790           }
 791
 792         case BRgotoifnonnil:
 793           {
 794             Lisp_Object v1;
 795             MAYBE_GC ();
 796             v1 = POP;
 797             if (!NILP (v1))
 798               {
 799                 BYTE_CODE_QUIT;
 800                 stack.pc += (int) *stack.pc - 128;
 801               }
 802             stack.pc++;
 803             break;
 804           }
 805
 806         case BRgotoifnilelsepop:
 807           MAYBE_GC ();
 808           op = *stack.pc++;
 809           if (NILP (TOP))
 810             {
 811               BYTE_CODE_QUIT;
 812               stack.pc += op - 128;
 813             }
 814           else DISCARD (1);
 815           break;
 816
 817         case BRgotoifnonnilelsepop:
 818           MAYBE_GC ();
 819           op = *stack.pc++;
 820           if (!NILP (TOP))
 821             {
 822               BYTE_CODE_QUIT;
 823               stack.pc += op - 128;
 824             }
 825           else DISCARD (1);
 826           break;
 827
 828         case Breturn:
 829           result = POP;
 830           goto exit;
 831
 832         case Bdiscard:
 833           DISCARD (1);
 834           break;
 835
 836         case Bconstant2:
 837           PUSH (vectorp[FETCH2]);
 838           break;
 839
 840         case Bsave_excursion:
 841           record_unwind_protect (save_excursion_restore,
 842                                  save_excursion_save ());
 843           break;
 844
 845         case Bsave_current_buffer:
 846         case Bsave_current_buffer_1:
 847           record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
 848           break;
 849
 850         case Bsave_window_excursion:
 851           BEFORE_POTENTIAL_GC ();
 852           TOP = Fsave_window_excursion (TOP);
 853           AFTER_POTENTIAL_GC ();
 854           break;
 855
 856         case Bsave_restriction:
 857           record_unwind_protect (save_restriction_restore,
 858                                  save_restriction_save ());
 859           break;
 860
 861         case Bcatch:
 862           {
 863             Lisp_Object v1;
 864             BEFORE_POTENTIAL_GC ();
 865             v1 = POP;
 866             TOP = internal_catch (TOP, Feval, v1);
 867             AFTER_POTENTIAL_GC ();
 868             break;
 869           }
 870
 871         case Bunwind_protect:
 872           record_unwind_protect (Fprogn, POP);
 873           break;
 874
 875         case Bcondition_case:
 876           {
 877             Lisp_Object handlers, body;
 878             handlers = POP;
 879             body = POP;
 880             BEFORE_POTENTIAL_GC ();
 881             TOP = internal_lisp_condition_case (TOP, body, handlers);
 882             AFTER_POTENTIAL_GC ();
 883             break;
 884           }
 885
 886         case Btemp_output_buffer_setup:
 887           BEFORE_POTENTIAL_GC ();
 888           CHECK_STRING (TOP);
 889           temp_output_buffer_setup (SSDATA (TOP));
 890           AFTER_POTENTIAL_GC ();
 891           TOP = Vstandard_output;
 892           break;
 893
 894         case Btemp_output_buffer_show:
 895           {
 896             Lisp_Object v1;
 897             BEFORE_POTENTIAL_GC ();
 898             v1 = POP;
 899             temp_output_buffer_show (TOP);
 900             TOP = v1;
 901             /* pop binding of standard-output */
 902             unbind_to (SPECPDL_INDEX () - 1, Qnil);
 903             AFTER_POTENTIAL_GC ();
 904             break;
 905           }
 906
 907         case Bnth:
 908           {
 909             Lisp_Object v1, v2;
 910             BEFORE_POTENTIAL_GC ();
 911             v1 = POP;
 912             v2 = TOP;
 913             CHECK_NUMBER (v2);
 914             AFTER_POTENTIAL_GC ();
 915             op = XINT (v2);
 916             immediate_quit = 1;
 917             while (--op >= 0 && CONSP (v1))
 918               v1 = XCDR (v1);
 919             immediate_quit = 0;
 920             TOP = CAR (v1);
 921             break;
 922           }
 923
 924         case Bsymbolp:
 925           TOP = SYMBOLP (TOP) ? Qt : Qnil;
 926           break;
 927
 928         case Bconsp:
 929           TOP = CONSP (TOP) ? Qt : Qnil;
 930           break;
 931
 932         case Bstringp:
 933           TOP = STRINGP (TOP) ? Qt : Qnil;
 934           break;
 935
 936         case Blistp:
 937           TOP = CONSP (TOP) || NILP (TOP) ? Qt : Qnil;
 938           break;
 939
 940         case Bnot:
 941           TOP = NILP (TOP) ? Qt : Qnil;
 942           break;
 943
 944         case Bcons:
 945           {
 946             Lisp_Object v1;
 947             v1 = POP;
 948             TOP = Fcons (TOP, v1);
 949             break;
 950           }
 951
 952         case Blist1:
 953           TOP = Fcons (TOP, Qnil);
 954           break;
 955
 956         case Blist2:
 957           {
 958             Lisp_Object v1;
 959             v1 = POP;
 960             TOP = Fcons (TOP, Fcons (v1, Qnil));
 961             break;
 962           }
 963
 964         case Blist3:
 965           DISCARD (2);
 966           TOP = Flist (3, &TOP);
 967           break;
 968
 969         case Blist4:
 970           DISCARD (3);
 971           TOP = Flist (4, &TOP);
 972           break;
 973
 974         case BlistN:
 975           op = FETCH;
 976           DISCARD (op - 1);
 977           TOP = Flist (op, &TOP);
 978           break;
 979
 980         case Blength:
 981           BEFORE_POTENTIAL_GC ();
 982           TOP = Flength (TOP);
 983           AFTER_POTENTIAL_GC ();
 984           break;
 985
 986         case Baref:
 987           {
 988             Lisp_Object v1;
 989             BEFORE_POTENTIAL_GC ();
 990             v1 = POP;
 991             TOP = Faref (TOP, v1);
 992             AFTER_POTENTIAL_GC ();
 993             break;
 994           }
 995
 996         case Baset:
 997           {
 998             Lisp_Object v1, v2;
 999             BEFORE_POTENTIAL_GC ();
1000             v2 = POP; v1 = POP;
1001             TOP = Faset (TOP, v1, v2);
1002             AFTER_POTENTIAL_GC ();
1003             break;
1004           }
1005
1006         case Bsymbol_value:
1007           BEFORE_POTENTIAL_GC ();
1008           TOP = Fsymbol_value (TOP);
1009           AFTER_POTENTIAL_GC ();
1010           break;
1011
1012         case Bsymbol_function:
1013           BEFORE_POTENTIAL_GC ();
1014           TOP = Fsymbol_function (TOP);
1015           AFTER_POTENTIAL_GC ();
1016           break;
1017
1018         case Bset:
1019           {
1020             Lisp_Object v1;
1021             BEFORE_POTENTIAL_GC ();
1022             v1 = POP;
1023             TOP = Fset (TOP, v1);
1024             AFTER_POTENTIAL_GC ();
1025             break;
1026           }
1027
1028         case Bfset:
1029           {
1030             Lisp_Object v1;
1031             BEFORE_POTENTIAL_GC ();
1032             v1 = POP;
1033             TOP = Ffset (TOP, v1);
1034             AFTER_POTENTIAL_GC ();
1035             break;
1036           }
1037
1038         case Bget:
1039           {
1040             Lisp_Object v1;
1041             BEFORE_POTENTIAL_GC ();
1042             v1 = POP;
1043             TOP = Fget (TOP, v1);
1044             AFTER_POTENTIAL_GC ();
1045             break;
1046           }
1047
1048         case Bsubstring:
1049           {
1050             Lisp_Object v1, v2;
1051             BEFORE_POTENTIAL_GC ();
1052             v2 = POP; v1 = POP;
1053             TOP = Fsubstring (TOP, v1, v2);
1054             AFTER_POTENTIAL_GC ();
1055             break;
1056           }
1057
1058         case Bconcat2:
1059           BEFORE_POTENTIAL_GC ();
1060           DISCARD (1);
1061           TOP = Fconcat (2, &TOP);
1062           AFTER_POTENTIAL_GC ();
1063           break;
1064
1065         case Bconcat3:
1066           BEFORE_POTENTIAL_GC ();
1067           DISCARD (2);
1068           TOP = Fconcat (3, &TOP);
1069           AFTER_POTENTIAL_GC ();
1070           break;
1071
1072         case Bconcat4:
1073           BEFORE_POTENTIAL_GC ();
1074           DISCARD (3);
1075           TOP = Fconcat (4, &TOP);
1076           AFTER_POTENTIAL_GC ();
1077           break;
1078
1079         case BconcatN:
1080           op = FETCH;
1081           BEFORE_POTENTIAL_GC ();
1082           DISCARD (op - 1);
1083           TOP = Fconcat (op, &TOP);
1084           AFTER_POTENTIAL_GC ();
1085           break;
1086
1087         case Bsub1:
1088           {
1089             Lisp_Object v1;
1090             v1 = TOP;
1091             if (INTEGERP (v1))
1092               {
1093                 XSETINT (v1, XINT (v1) - 1);
1094                 TOP = v1;
1095               }
1096             else
1097               {
1098                 BEFORE_POTENTIAL_GC ();
1099                 TOP = Fsub1 (v1);
1100                 AFTER_POTENTIAL_GC ();
1101               }
1102             break;
1103           }
1104
1105         case Badd1:
1106           {
1107             Lisp_Object v1;
1108             v1 = TOP;
1109             if (INTEGERP (v1))
1110               {
1111                 XSETINT (v1, XINT (v1) + 1);
1112                 TOP = v1;
1113               }
1114             else
1115               {
1116                 BEFORE_POTENTIAL_GC ();
1117                 TOP = Fadd1 (v1);
1118                 AFTER_POTENTIAL_GC ();
1119               }
1120             break;
1121           }
1122
1123         case Beqlsign:
1124           {
1125             Lisp_Object v1, v2;
1126             BEFORE_POTENTIAL_GC ();
1127             v2 = POP; v1 = TOP;
1128             CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (v1);
1129             CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (v2);
1130             AFTER_POTENTIAL_GC ();
1131             if (FLOATP (v1) || FLOATP (v2))
1132               {
1133                 double f1, f2;
1134
1135                 f1 = (FLOATP (v1) ? XFLOAT_DATA (v1) : XINT (v1));
1136                 f2 = (FLOATP (v2) ? XFLOAT_DATA (v2) : XINT (v2));
1137                 TOP = (f1 == f2 ? Qt : Qnil);
1138               }
1139             else
1140               TOP = (XINT (v1) == XINT (v2) ? Qt : Qnil);
1141             break;
1142           }
1143
1144         case Bgtr:
1145           {
1146             Lisp_Object v1;
1147             BEFORE_POTENTIAL_GC ();
1148             v1 = POP;
1149             TOP = Fgtr (TOP, v1);
1150             AFTER_POTENTIAL_GC ();
1151             break;
1152           }
1153
1154         case Blss:
1155           {
1156             Lisp_Object v1;
1157             BEFORE_POTENTIAL_GC ();
1158             v1 = POP;
1159             TOP = Flss (TOP, v1);
1160             AFTER_POTENTIAL_GC ();
1161             break;
1162           }
1163
1164         case Bleq:
1165           {
1166             Lisp_Object v1;
1167             BEFORE_POTENTIAL_GC ();
1168             v1 = POP;
1169             TOP = Fleq (TOP, v1);
1170             AFTER_POTENTIAL_GC ();
1171             break;
1172           }
1173
1174         case Bgeq:
1175           {
1176             Lisp_Object v1;
1177             BEFORE_POTENTIAL_GC ();
1178             v1 = POP;
1179             TOP = Fgeq (TOP, v1);
1180             AFTER_POTENTIAL_GC ();
1181             break;
1182           }
1183
1184         case Bdiff:
1185           BEFORE_POTENTIAL_GC ();
1186           DISCARD (1);
1187           TOP = Fminus (2, &TOP);
1188           AFTER_POTENTIAL_GC ();
1189           break;
1190
1191         case Bnegate:
1192           {
1193             Lisp_Object v1;
1194             v1 = TOP;
1195             if (INTEGERP (v1))
1196               {
1197                 XSETINT (v1, - XINT (v1));
1198                 TOP = v1;
1199               }
1200             else
1201               {
1202                 BEFORE_POTENTIAL_GC ();
1203                 TOP = Fminus (1, &TOP);
1204                 AFTER_POTENTIAL_GC ();
1205               }
1206             break;
1207           }
1208
1209         case Bplus:
1210           BEFORE_POTENTIAL_GC ();
1211           DISCARD (1);
1212           TOP = Fplus (2, &TOP);
1213           AFTER_POTENTIAL_GC ();
1214           break;
1215
1216         case Bmax:
1217           BEFORE_POTENTIAL_GC ();
1218           DISCARD (1);
1219           TOP = Fmax (2, &TOP);
1220           AFTER_POTENTIAL_GC ();
1221           break;
1222
1223         case Bmin:
1224           BEFORE_POTENTIAL_GC ();
1225           DISCARD (1);
1226           TOP = Fmin (2, &TOP);
1227           AFTER_POTENTIAL_GC ();
1228           break;
1229
1230         case Bmult:
1231           BEFORE_POTENTIAL_GC ();
1232           DISCARD (1);
1233           TOP = Ftimes (2, &TOP);
1234           AFTER_POTENTIAL_GC ();
1235           break;
1236
1237         case Bquo:
1238           BEFORE_POTENTIAL_GC ();
1239           DISCARD (1);
1240           TOP = Fquo (2, &TOP);
1241           AFTER_POTENTIAL_GC ();
1242           break;
1243
1244         case Brem:
1245           {
1246             Lisp_Object v1;
1247             BEFORE_POTENTIAL_GC ();
1248             v1 = POP;
1249             TOP = Frem (TOP, v1);
1250             AFTER_POTENTIAL_GC ();
1251             break;
1252           }
1253
1254         case Bpoint:
1255           {
1256             Lisp_Object v1;
1257             XSETFASTINT (v1, PT);
1258             PUSH (v1);
1259             break;
1260           }
1261
1262         case Bgoto_char:
1263           BEFORE_POTENTIAL_GC ();
1264           TOP = Fgoto_char (TOP);
1265           AFTER_POTENTIAL_GC ();
1266           break;
1267
1268         case Binsert:
1269           BEFORE_POTENTIAL_GC ();
1270           TOP = Finsert (1, &TOP);
1271           AFTER_POTENTIAL_GC ();
1272           break;
1273
1274         case BinsertN:
1275           op = FETCH;
1276           BEFORE_POTENTIAL_GC ();
1277           DISCARD (op - 1);
1278           TOP = Finsert (op, &TOP);
1279           AFTER_POTENTIAL_GC ();
1280           break;
1281
1282         case Bpoint_max:
1283           {
1284             Lisp_Object v1;
1285             XSETFASTINT (v1, ZV);
1286             PUSH (v1);
1287             break;
1288           }
1289
1290         case Bpoint_min:
1291           {
1292             Lisp_Object v1;
1293             XSETFASTINT (v1, BEGV);
1294             PUSH (v1);
1295             break;
1296           }
1297
1298         case Bchar_after:
1299           BEFORE_POTENTIAL_GC ();
1300           TOP = Fchar_after (TOP);
1301           AFTER_POTENTIAL_GC ();
1302           break;
1303
1304         case Bfollowing_char:
1305           {
1306             Lisp_Object v1;
1307             BEFORE_POTENTIAL_GC ();
1308             v1 = Ffollowing_char ();
1309             AFTER_POTENTIAL_GC ();
1310             PUSH (v1);
1311             break;
1312           }
1313
1314         case Bpreceding_char:
1315           {
1316             Lisp_Object v1;
1317             BEFORE_POTENTIAL_GC ();
1318             v1 = Fprevious_char ();
1319             AFTER_POTENTIAL_GC ();
1320             PUSH (v1);
1321             break;
1322           }
1323
1324         case Bcurrent_column:
1325           {
1326             Lisp_Object v1;
1327             BEFORE_POTENTIAL_GC ();
1328             XSETFASTINT (v1, current_column ());
1329             AFTER_POTENTIAL_GC ();
1330             PUSH (v1);
1331             break;
1332           }
1333
1334         case Bindent_to:
1335           BEFORE_POTENTIAL_GC ();
1336           TOP = Findent_to (TOP, Qnil);
1337           AFTER_POTENTIAL_GC ();
1338           break;
1339
1340         case Beolp:
1341           PUSH (Feolp ());
1342           break;
1343
1344         case Beobp:
1345           PUSH (Feobp ());
1346           break;
1347
1348         case Bbolp:
1349           PUSH (Fbolp ());
1350           break;
1351
1352         case Bbobp:
1353           PUSH (Fbobp ());
1354           break;
1355
1356         case Bcurrent_buffer:
1357           PUSH (Fcurrent_buffer ());
1358           break;
1359
1360         case Bset_buffer:
1361           BEFORE_POTENTIAL_GC ();
1362           TOP = Fset_buffer (TOP);
1363           AFTER_POTENTIAL_GC ();
1364           break;
1365
1366         case Binteractive_p:
1367           PUSH (Finteractive_p ());
1368           break;
1369
1370         case Bforward_char:
1371           BEFORE_POTENTIAL_GC ();
1372           TOP = Fforward_char (TOP);
1373           AFTER_POTENTIAL_GC ();
1374           break;
1375
1376         case Bforward_word:
1377           BEFORE_POTENTIAL_GC ();
1378           TOP = Fforward_word (TOP);
1379           AFTER_POTENTIAL_GC ();
1380           break;
1381
1382         case Bskip_chars_forward:
1383           {
1384             Lisp_Object v1;
1385             BEFORE_POTENTIAL_GC ();
1386             v1 = POP;
1387             TOP = Fskip_chars_forward (TOP, v1);
1388             AFTER_POTENTIAL_GC ();
1389             break;
1390           }
1391
1392         case Bskip_chars_backward:
1393           {
1394             Lisp_Object v1;
1395             BEFORE_POTENTIAL_GC ();
1396             v1 = POP;
1397             TOP = Fskip_chars_backward (TOP, v1);
1398             AFTER_POTENTIAL_GC ();
1399             break;
1400           }
1401
1402         case Bforward_line:
1403           BEFORE_POTENTIAL_GC ();
1404           TOP = Fforward_line (TOP);
1405           AFTER_POTENTIAL_GC ();
1406           break;
1407
1408         case Bchar_syntax:
1409           {
1410             int c;
1411
1412             BEFORE_POTENTIAL_GC ();
1413             CHECK_CHARACTER (TOP);
1414             AFTER_POTENTIAL_GC ();
1415             c = XFASTINT (TOP);
1416             if (NILP (BVAR (current_buffer, enable_multibyte_characters)))
1417               MAKE_CHAR_MULTIBYTE (c);
1418             XSETFASTINT (TOP, syntax_code_spec[(int) SYNTAX (c)]);
1419           }
1420           break;
1421
1422         case Bbuffer_substring:
1423           {
1424             Lisp_Object v1;
1425             BEFORE_POTENTIAL_GC ();
1426             v1 = POP;
1427             TOP = Fbuffer_substring (TOP, v1);
1428             AFTER_POTENTIAL_GC ();
1429             break;
1430           }
1431
1432         case Bdelete_region:
1433           {
1434             Lisp_Object v1;
1435             BEFORE_POTENTIAL_GC ();
1436             v1 = POP;
1437             TOP = Fdelete_region (TOP, v1);
1438             AFTER_POTENTIAL_GC ();
1439             break;
1440           }
1441
1442         case Bnarrow_to_region:
1443           {
1444             Lisp_Object v1;
1445             BEFORE_POTENTIAL_GC ();
1446             v1 = POP;
1447             TOP = Fnarrow_to_region (TOP, v1);
1448             AFTER_POTENTIAL_GC ();
1449             break;
1450           }
1451
1452         case Bwiden:
1453           BEFORE_POTENTIAL_GC ();
1454           PUSH (Fwiden ());
1455           AFTER_POTENTIAL_GC ();
1456           break;
1457
1458         case Bend_of_line:
1459           BEFORE_POTENTIAL_GC ();
1460           TOP = Fend_of_line (TOP);
1461           AFTER_POTENTIAL_GC ();
1462           break;
1463
1464         case Bset_marker:
1465           {
1466             Lisp_Object v1, v2;
1467             BEFORE_POTENTIAL_GC ();
1468             v1 = POP;
1469             v2 = POP;
1470             TOP = Fset_marker (TOP, v2, v1);
1471             AFTER_POTENTIAL_GC ();
1472             break;
1473           }
1474
1475         case Bmatch_beginning:
1476           BEFORE_POTENTIAL_GC ();
1477           TOP = Fmatch_beginning (TOP);
1478           AFTER_POTENTIAL_GC ();
1479           break;
1480
1481         case Bmatch_end:
1482           BEFORE_POTENTIAL_GC ();
1483           TOP = Fmatch_end (TOP);
1484           AFTER_POTENTIAL_GC ();
1485           break;
1486
1487         case Bupcase:
1488           BEFORE_POTENTIAL_GC ();
1489           TOP = Fupcase (TOP);
1490           AFTER_POTENTIAL_GC ();
1491           break;
1492
1493         case Bdowncase:
1494           BEFORE_POTENTIAL_GC ();
1495           TOP = Fdowncase (TOP);
1496           AFTER_POTENTIAL_GC ();
1497         break;
1498
1499         case Bstringeqlsign:
1500           {
1501             Lisp_Object v1;
1502             BEFORE_POTENTIAL_GC ();
1503             v1 = POP;
1504             TOP = Fstring_equal (TOP, v1);
1505             AFTER_POTENTIAL_GC ();
1506             break;
1507           }
1508
1509         case Bstringlss:
1510           {
1511             Lisp_Object v1;
1512             BEFORE_POTENTIAL_GC ();
1513             v1 = POP;
1514             TOP = Fstring_lessp (TOP, v1);
1515             AFTER_POTENTIAL_GC ();
1516             break;
1517           }
1518
1519         case Bequal:
1520           {
1521             Lisp_Object v1;
1522             v1 = POP;
1523             TOP = Fequal (TOP, v1);
1524             break;
1525           }
1526
1527         case Bnthcdr:
1528           {
1529             Lisp_Object v1;
1530             BEFORE_POTENTIAL_GC ();
1531             v1 = POP;
1532             TOP = Fnthcdr (TOP, v1);
1533             AFTER_POTENTIAL_GC ();
1534             break;
1535           }
1536
1537         case Belt:
1538           {
1539             Lisp_Object v1, v2;
1540             if (CONSP (TOP))
1541               {
1542                 /* Exchange args and then do nth.  */
1543                 BEFORE_POTENTIAL_GC ();
1544                 v2 = POP;
1545                 v1 = TOP;
1546                 CHECK_NUMBER (v2);
1547                 AFTER_POTENTIAL_GC ();
1548                 op = XINT (v2);
1549                 immediate_quit = 1;
1550                 while (--op >= 0 && CONSP (v1))
1551                   v1 = XCDR (v1);
1552                 immediate_quit = 0;
1553                 TOP = CAR (v1);
1554               }
1555             else
1556               {
1557                 BEFORE_POTENTIAL_GC ();
1558                 v1 = POP;
1559                 TOP = Felt (TOP, v1);
1560                 AFTER_POTENTIAL_GC ();
1561               }
1562             break;
1563           }
1564
1565         case Bmember:
1566           {
1567             Lisp_Object v1;
1568             BEFORE_POTENTIAL_GC ();
1569             v1 = POP;
1570             TOP = Fmember (TOP, v1);
1571             AFTER_POTENTIAL_GC ();
1572             break;
1573           }
1574
1575         case Bassq:
1576           {
1577             Lisp_Object v1;
1578             BEFORE_POTENTIAL_GC ();
1579             v1 = POP;
1580             TOP = Fassq (TOP, v1);
1581             AFTER_POTENTIAL_GC ();
1582             break;
1583           }
1584
1585         case Bnreverse:
1586           BEFORE_POTENTIAL_GC ();
1587           TOP = Fnreverse (TOP);
1588           AFTER_POTENTIAL_GC ();
1589           break;
1590
1591         case Bsetcar:
1592           {
1593             Lisp_Object v1;
1594             BEFORE_POTENTIAL_GC ();
1595             v1 = POP;
1596             TOP = Fsetcar (TOP, v1);
1597             AFTER_POTENTIAL_GC ();
1598             break;
1599           }
1600
1601         case Bsetcdr:
1602           {
1603             Lisp_Object v1;
1604             BEFORE_POTENTIAL_GC ();
1605             v1 = POP;
1606             TOP = Fsetcdr (TOP, v1);
1607             AFTER_POTENTIAL_GC ();
1608             break;
1609           }
1610
1611         case Bcar_safe:
1612           {
1613             Lisp_Object v1;
1614             v1 = TOP;
1615             TOP = CAR_SAFE (v1);
1616             break;
1617           }
1618
1619         case Bcdr_safe:
1620           {
1621             Lisp_Object v1;
1622             v1 = TOP;
1623             TOP = CDR_SAFE (v1);
1624             break;
1625           }
1626
1627         case Bnconc:
1628           BEFORE_POTENTIAL_GC ();
1629           DISCARD (1);
1630           TOP = Fnconc (2, &TOP);
1631           AFTER_POTENTIAL_GC ();
1632           break;
1633
1634         case Bnumberp:
1635           TOP = (NUMBERP (TOP) ? Qt : Qnil);
1636           break;
1637
1638         case Bintegerp:
1639           TOP = INTEGERP (TOP) ? Qt : Qnil;
1640           break;
1641
1642 #ifdef BYTE_CODE_SAFE
1643         case Bset_mark:
1644           BEFORE_POTENTIAL_GC ();
1645           error ("set-mark is an obsolete bytecode");
1646           AFTER_POTENTIAL_GC ();
1647           break;
1648         case Bscan_buffer:
1649           BEFORE_POTENTIAL_GC ();
1650           error ("scan-buffer is an obsolete bytecode");
1651           AFTER_POTENTIAL_GC ();
1652           break;
1653 #endif
1654
1655         case 0:
1656           abort ();
1657
1658         case 255:
1659         default:
1660 #ifdef BYTE_CODE_SAFE
1661           if (op < Bconstant)
1662             {
1663               abort ();
1664             }
1665           if ((op -= Bconstant) >= const_length)
1666             {
1667               abort ();
1668             }
1669           PUSH (vectorp[op]);
1670 #else
1671           PUSH (vectorp[op - Bconstant]);
1672 #endif
1673         }
1674     }
1675
1676  exit:
1677
1678   byte_stack_list = byte_stack_list->next;
1679
1680   /* Binds and unbinds are supposed to be compiled balanced.  */
1681   if (SPECPDL_INDEX () != count)
1682 #ifdef BYTE_CODE_SAFE
1683     error ("binding stack not balanced (serious byte compiler bug)");
1684 #else
1685     abort ();
1686 #endif
1687
1688   return result;
1689 }
1690
1691 void
1692 syms_of_bytecode (void)
1693 {
1694   Qbytecode = intern_c_string ("byte-code");
1695   staticpro (&Qbytecode);
1696
1697   defsubr (&Sbyte_code);
1698
1699 #ifdef BYTE_CODE_METER
1700
1701   DEFVAR_LISP ("byte-code-meter", Vbyte_code_meter,
1702                doc: /* A vector of vectors which holds a histogram of byte-code usage.
1703 \(aref (aref byte-code-meter 0) CODE) indicates how many times the byte
1704 opcode CODE has been executed.
1705 \(aref (aref byte-code-meter CODE1) CODE2), where CODE1 is not 0,
1706 indicates how many times the byte opcodes CODE1 and CODE2 have been
1707 executed in succession.  */);
1708
1709   DEFVAR_BOOL ("byte-metering-on", byte_metering_on,
1710                doc: /* If non-nil, keep profiling information on byte code usage.
1711 The variable byte-code-meter indicates how often each byte opcode is used.
1712 If a symbol has a property named `byte-code-meter' whose value is an
1713 integer, it is incremented each time that symbol's function is called.  */);
1714
1715   byte_metering_on = 0;
1716   Vbyte_code_meter = Fmake_vector (make_number (256), make_number (0));
1717   Qbyte_code_meter = intern_c_string ("byte-code-meter");
1718   staticpro (&Qbyte_code_meter);
1719   {
1720     int i = 256;
1721     while (i--)
1722       XVECTOR (Vbyte_code_meter)->contents[i] =
1723         Fmake_vector (make_number (256), make_number (0));
1724   }
1725 #endif
1726 }