rpm  4.5
lcode.c
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1 /*
2 ** $Id: lcode.c,v 1.1 2004/03/16 21:58:30 niemeyer Exp $
3 ** Code generator for Lua
4 ** See Copyright Notice in lua.h
5 */
6 
7 
8 #include <stdlib.h>
9 
10 #define lcode_c
11 
12 #include "lua.h"
13 
14 #include "lcode.h"
15 #include "ldebug.h"
16 #include "ldo.h"
17 #include "llex.h"
18 #include "lmem.h"
19 #include "lobject.h"
20 #include "lopcodes.h"
21 #include "lparser.h"
22 #include "ltable.h"
23 
24 
25 #define hasjumps(e) ((e)->t != (e)->f)
26 
27 
28 void luaK_nil (FuncState *fs, int from, int n) {
29  Instruction *previous;
30  if (fs->pc > fs->lasttarget && /* no jumps to current position? */
31  GET_OPCODE(*(previous = &fs->f->code[fs->pc-1])) == OP_LOADNIL) {
32  int pfrom = GETARG_A(*previous);
33  int pto = GETARG_B(*previous);
34  if (pfrom <= from && from <= pto+1) { /* can connect both? */
35  if (from+n-1 > pto)
36  SETARG_B(*previous, from+n-1);
37  return;
38  }
39  }
40  luaK_codeABC(fs, OP_LOADNIL, from, from+n-1, 0); /* else no optimization */
41 }
42 
43 
44 int luaK_jump (FuncState *fs) {
45  int jpc = fs->jpc; /* save list of jumps to here */
46  int j;
47  fs->jpc = NO_JUMP;
48  j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
49  luaK_concat(fs, &j, jpc); /* keep them on hold */
50  return j;
51 }
52 
53 
54 static int luaK_condjump (FuncState *fs, OpCode op, int A, int B, int C)
55  /*@modifies fs @*/
56 {
57  luaK_codeABC(fs, op, A, B, C);
58  return luaK_jump(fs);
59 }
60 
61 
62 static void luaK_fixjump (FuncState *fs, int pc, int dest)
63  /*@modifies fs @*/
64 {
65  Instruction *jmp = &fs->f->code[pc];
66  int offset = dest-(pc+1);
67  lua_assert(dest != NO_JUMP);
68  if (abs(offset) > MAXARG_sBx)
69  luaX_syntaxerror(fs->ls, "control structure too long");
70  SETARG_sBx(*jmp, offset);
71 }
72 
73 
74 /*
75 ** returns current `pc' and marks it as a jump target (to avoid wrong
76 ** optimizations with consecutive instructions not in the same basic block).
77 */
79  fs->lasttarget = fs->pc;
80  return fs->pc;
81 }
82 
83 
84 static int luaK_getjump (FuncState *fs, int pc)
85  /*@*/
86 {
87  int offset = GETARG_sBx(fs->f->code[pc]);
88  if (offset == NO_JUMP) /* point to itself represents end of list */
89  return NO_JUMP; /* end of list */
90  else
91  return (pc+1)+offset; /* turn offset into absolute position */
92 }
93 
94 
95 static Instruction *getjumpcontrol (FuncState *fs, int pc)
96  /*@*/
97 {
98  Instruction *pi = &fs->f->code[pc];
99  if (pc >= 1 && testOpMode(GET_OPCODE(*(pi-1)), OpModeT))
100  return pi-1;
101  else
102  return pi;
103 }
104 
105 
106 /*
107 ** check whether list has any jump that do not produce a value
108 ** (or produce an inverted value)
109 */
110 static int need_value (FuncState *fs, int list, int cond)
111  /*@*/
112 {
113  for (; list != NO_JUMP; list = luaK_getjump(fs, list)) {
114  Instruction i = *getjumpcontrol(fs, list);
115  if (GET_OPCODE(i) != OP_TEST || GETARG_C(i) != cond) return 1;
116  }
117  return 0; /* not found */
118 }
119 
120 
121 static void patchtestreg (Instruction *i, int reg)
122  /*@modifies *i @*/
123 {
124  if (reg == NO_REG) reg = GETARG_B(*i);
125  SETARG_A(*i, reg);
126 }
127 
128 
129 static void luaK_patchlistaux (FuncState *fs, int list,
130  int ttarget, int treg, int ftarget, int freg, int dtarget)
131  /*@modifies fs @*/
132 {
133  while (list != NO_JUMP) {
134  int next = luaK_getjump(fs, list);
135  Instruction *i = getjumpcontrol(fs, list);
136  if (GET_OPCODE(*i) != OP_TEST) {
137  lua_assert(dtarget != NO_JUMP);
138  luaK_fixjump(fs, list, dtarget); /* jump to default target */
139  }
140  else {
141  if (GETARG_C(*i)) {
142  lua_assert(ttarget != NO_JUMP);
143  patchtestreg(i, treg);
144  luaK_fixjump(fs, list, ttarget);
145  }
146  else {
147  lua_assert(ftarget != NO_JUMP);
148  patchtestreg(i, freg);
149  luaK_fixjump(fs, list, ftarget);
150  }
151  }
152  list = next;
153  }
154 }
155 
156 
157 static void luaK_dischargejpc (FuncState *fs)
158  /*@modifies fs @*/
159 {
160  luaK_patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc, NO_REG, fs->pc);
161  fs->jpc = NO_JUMP;
162 }
163 
164 
165 void luaK_patchlist (FuncState *fs, int list, int target) {
166  if (target == fs->pc)
167  luaK_patchtohere(fs, list);
168  else {
169  lua_assert(target < fs->pc);
170  luaK_patchlistaux(fs, list, target, NO_REG, target, NO_REG, target);
171  }
172 }
173 
174 
175 void luaK_patchtohere (FuncState *fs, int list) {
176  luaK_getlabel(fs);
177  luaK_concat(fs, &fs->jpc, list);
178 }
179 
180 
181 void luaK_concat (FuncState *fs, int *l1, int l2) {
182  if (l2 == NO_JUMP) return;
183  else if (*l1 == NO_JUMP)
184  *l1 = l2;
185  else {
186  int list = *l1;
187  int next;
188  while ((next = luaK_getjump(fs, list)) != NO_JUMP) /* find last element */
189  list = next;
190  luaK_fixjump(fs, list, l2);
191  }
192 }
193 
194 
195 void luaK_checkstack (FuncState *fs, int n) {
196  int newstack = fs->freereg + n;
197  if (newstack > fs->f->maxstacksize) {
198  if (newstack >= MAXSTACK)
199  luaX_syntaxerror(fs->ls, "function or expression too complex");
200  fs->f->maxstacksize = cast(lu_byte, newstack);
201  }
202 }
203 
204 
205 void luaK_reserveregs (FuncState *fs, int n) {
206  luaK_checkstack(fs, n);
207  fs->freereg += n;
208 }
209 
210 
211 static void freereg (FuncState *fs, int reg)
212  /*@modifies fs @*/
213 {
214  if (reg >= fs->nactvar && reg < MAXSTACK) {
215  fs->freereg--;
216  lua_assert(reg == fs->freereg);
217  }
218 }
219 
220 
221 static void freeexp (FuncState *fs, expdesc *e)
222  /*@modifies fs @*/
223 {
224  if (e->k == VNONRELOC)
225  freereg(fs, e->info);
226 }
227 
228 
229 static int addk (FuncState *fs, TObject *k, TObject *v)
230  /*@modifies fs @*/
231 {
232  const TObject *idx = luaH_get(fs->h, k);
233  if (ttisnumber(idx)) {
234  lua_assert(luaO_rawequalObj(&fs->f->k[cast(int, nvalue(idx))], v));
235  return cast(int, nvalue(idx));
236  }
237  else { /* constant not found; create a new entry */
238  Proto *f = fs->f;
239  luaM_growvector(fs->L, f->k, fs->nk, f->sizek, TObject,
240  MAXARG_Bx, "constant table overflow");
241  setobj2n(&f->k[fs->nk], v);
242  setnvalue(luaH_set(fs->L, fs->h, k), cast(lua_Number, fs->nk));
243  return fs->nk++;
244  }
245 }
246 
247 
249  TObject o;
250  setsvalue(&o, s);
251  return addk(fs, &o, &o);
252 }
253 
254 
255 int luaK_numberK (FuncState *fs, lua_Number r) {
256  TObject o;
257  setnvalue(&o, r);
258  return addk(fs, &o, &o);
259 }
260 
261 
262 static int nil_constant (FuncState *fs)
263  /*@modifies fs @*/
264 {
265  TObject k, v;
266  setnilvalue(&v);
267  sethvalue(&k, fs->h); /* cannot use nil as key; instead use table itself */
268  return addk(fs, &k, &v);
269 }
270 
271 
272 void luaK_setcallreturns (FuncState *fs, expdesc *e, int nresults) {
273  if (e->k == VCALL) { /* expression is an open function call? */
274  SETARG_C(getcode(fs, e), nresults+1);
275  if (nresults == 1) { /* `regular' expression? */
276  e->k = VNONRELOC;
277  e->info = GETARG_A(getcode(fs, e));
278  }
279  }
280 }
281 
282 
284  switch (e->k) {
285  case VLOCAL: {
286  e->k = VNONRELOC;
287  break;
288  }
289  case VUPVAL: {
290  e->info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->info, 0);
291  e->k = VRELOCABLE;
292  break;
293  }
294  case VGLOBAL: {
295  e->info = luaK_codeABx(fs, OP_GETGLOBAL, 0, e->info);
296  e->k = VRELOCABLE;
297  break;
298  }
299  case VINDEXED: {
300  freereg(fs, e->aux);
301  freereg(fs, e->info);
302  e->info = luaK_codeABC(fs, OP_GETTABLE, 0, e->info, e->aux);
303  e->k = VRELOCABLE;
304  break;
305  }
306  case VCALL: {
307  luaK_setcallreturns(fs, e, 1);
308  break;
309  }
310  default: break; /* there is one value available (somewhere) */
311  }
312 }
313 
314 
315 static int code_label (FuncState *fs, int A, int b, int jump)
316  /*@modifies fs @*/
317 {
318  luaK_getlabel(fs); /* those instructions may be jump targets */
319  return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);
320 }
321 
322 
323 static void discharge2reg (FuncState *fs, expdesc *e, int reg)
324  /*@modifies fs, e @*/
325 {
326  luaK_dischargevars(fs, e);
327  switch (e->k) {
328  case VNIL: {
329  luaK_nil(fs, reg, 1);
330  break;
331  }
332  case VFALSE: case VTRUE: {
333  luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0);
334  break;
335  }
336  case VK: {
337  luaK_codeABx(fs, OP_LOADK, reg, e->info);
338  break;
339  }
340  case VRELOCABLE: {
341  Instruction *pc = &getcode(fs, e);
342  SETARG_A(*pc, reg);
343  break;
344  }
345  case VNONRELOC: {
346  if (reg != e->info)
347  luaK_codeABC(fs, OP_MOVE, reg, e->info, 0);
348  break;
349  }
350  default: {
351  lua_assert(e->k == VVOID || e->k == VJMP);
352  return; /* nothing to do... */
353  }
354  }
355  e->info = reg;
356  e->k = VNONRELOC;
357 }
358 
359 
360 static void discharge2anyreg (FuncState *fs, expdesc *e)
361  /*@modifies fs, e @*/
362 {
363  if (e->k != VNONRELOC) {
364  luaK_reserveregs(fs, 1);
365  discharge2reg(fs, e, fs->freereg-1);
366  }
367 }
368 
369 
370 static void luaK_exp2reg (FuncState *fs, expdesc *e, int reg)
371  /*@modifies fs, e @*/
372 {
373  discharge2reg(fs, e, reg);
374  if (e->k == VJMP)
375  luaK_concat(fs, &e->t, e->info); /* put this jump in `t' list */
376  if (hasjumps(e)) {
377  int final; /* position after whole expression */
378  int p_f = NO_JUMP; /* position of an eventual LOAD false */
379  int p_t = NO_JUMP; /* position of an eventual LOAD true */
380  if (need_value(fs, e->t, 1) || need_value(fs, e->f, 0)) {
381  int fj = NO_JUMP; /* first jump (over LOAD ops.) */
382  if (e->k != VJMP)
383  fj = luaK_jump(fs);
384  p_f = code_label(fs, reg, 0, 1);
385  p_t = code_label(fs, reg, 1, 0);
386  luaK_patchtohere(fs, fj);
387  }
388  final = luaK_getlabel(fs);
389  luaK_patchlistaux(fs, e->f, p_f, NO_REG, final, reg, p_f);
390  luaK_patchlistaux(fs, e->t, final, reg, p_t, NO_REG, p_t);
391  }
392  e->f = e->t = NO_JUMP;
393  e->info = reg;
394  e->k = VNONRELOC;
395 }
396 
397 
399  luaK_dischargevars(fs, e);
400  freeexp(fs, e);
401  luaK_reserveregs(fs, 1);
402  luaK_exp2reg(fs, e, fs->freereg - 1);
403 }
404 
405 
407  luaK_dischargevars(fs, e);
408  if (e->k == VNONRELOC) {
409  if (!hasjumps(e)) return e->info; /* exp is already in a register */
410  if (e->info >= fs->nactvar) { /* reg. is not a local? */
411  luaK_exp2reg(fs, e, e->info); /* put value on it */
412  return e->info;
413  }
414  }
415  luaK_exp2nextreg(fs, e); /* default */
416  return e->info;
417 }
418 
419 
421  if (hasjumps(e))
422  luaK_exp2anyreg(fs, e);
423  else
424  luaK_dischargevars(fs, e);
425 }
426 
427 
429  luaK_exp2val(fs, e);
430  switch (e->k) {
431  case VNIL: {
432  if (fs->nk + MAXSTACK <= MAXARG_C) { /* constant fit in argC? */
433  e->info = nil_constant(fs);
434  e->k = VK;
435  return e->info + MAXSTACK;
436  }
437  else break;
438  }
439  case VK: {
440  if (e->info + MAXSTACK <= MAXARG_C) /* constant fit in argC? */
441  return e->info + MAXSTACK;
442  else break;
443  }
444  default: break;
445  }
446  /* not a constant in the right range: put it in a register */
447  return luaK_exp2anyreg(fs, e);
448 }
449 
450 
451 void luaK_storevar (FuncState *fs, expdesc *var, expdesc *exp) {
452  switch (var->k) {
453  case VLOCAL: {
454  freeexp(fs, exp);
455  luaK_exp2reg(fs, exp, var->info);
456  return;
457  }
458  case VUPVAL: {
459  int e = luaK_exp2anyreg(fs, exp);
460  luaK_codeABC(fs, OP_SETUPVAL, e, var->info, 0);
461  break;
462  }
463  case VGLOBAL: {
464  int e = luaK_exp2anyreg(fs, exp);
465  luaK_codeABx(fs, OP_SETGLOBAL, e, var->info);
466  break;
467  }
468  case VINDEXED: {
469  int e = luaK_exp2RK(fs, exp);
470  luaK_codeABC(fs, OP_SETTABLE, var->info, var->aux, e);
471  break;
472  }
473  default: {
474  lua_assert(0); /* invalid var kind to store */
475  break;
476  }
477  }
478  freeexp(fs, exp);
479 }
480 
481 
482 void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {
483  int func;
484  luaK_exp2anyreg(fs, e);
485  freeexp(fs, e);
486  func = fs->freereg;
487  luaK_reserveregs(fs, 2);
488  luaK_codeABC(fs, OP_SELF, func, e->info, luaK_exp2RK(fs, key));
489  freeexp(fs, key);
490  e->info = func;
491  e->k = VNONRELOC;
492 }
493 
494 
495 static void invertjump (FuncState *fs, expdesc *e)
496  /*@*/
497 {
498  Instruction *pc = getjumpcontrol(fs, e->info);
500  GET_OPCODE(*pc) != OP_TEST);
501  SETARG_A(*pc, !(GETARG_A(*pc)));
502 }
503 
504 
505 static int jumponcond (FuncState *fs, expdesc *e, int cond)
506  /*@modifies fs, e @*/
507 {
508  if (e->k == VRELOCABLE) {
509  Instruction ie = getcode(fs, e);
510  if (GET_OPCODE(ie) == OP_NOT) {
511  fs->pc--; /* remove previous OP_NOT */
512  return luaK_condjump(fs, OP_TEST, NO_REG, GETARG_B(ie), !cond);
513  }
514  /* else go through */
515  }
516  discharge2anyreg(fs, e);
517  freeexp(fs, e);
518  return luaK_condjump(fs, OP_TEST, NO_REG, e->info, cond);
519 }
520 
521 
523  int pc; /* pc of last jump */
524  luaK_dischargevars(fs, e);
525  switch (e->k) {
526  case VK: case VTRUE: {
527  pc = NO_JUMP; /* always true; do nothing */
528  break;
529  }
530  case VFALSE: {
531  pc = luaK_jump(fs); /* always jump */
532  break;
533  }
534  case VJMP: {
535  invertjump(fs, e);
536  pc = e->info;
537  break;
538  }
539  default: {
540  pc = jumponcond(fs, e, 0);
541  break;
542  }
543  }
544  luaK_concat(fs, &e->f, pc); /* insert last jump in `f' list */
545 }
546 
547 
549  int pc; /* pc of last jump */
550  luaK_dischargevars(fs, e);
551  switch (e->k) {
552  case VNIL: case VFALSE: {
553  pc = NO_JUMP; /* always false; do nothing */
554  break;
555  }
556  case VTRUE: {
557  pc = luaK_jump(fs); /* always jump */
558  break;
559  }
560  case VJMP: {
561  pc = e->info;
562  break;
563  }
564  default: {
565  pc = jumponcond(fs, e, 1);
566  break;
567  }
568  }
569  luaK_concat(fs, &e->t, pc); /* insert last jump in `t' list */
570 }
571 
572 
573 static void codenot (FuncState *fs, expdesc *e)
574  /*@modifies fs, e @*/
575 {
576  luaK_dischargevars(fs, e);
577  switch (e->k) {
578  case VNIL: case VFALSE: {
579  e->k = VTRUE;
580  break;
581  }
582  case VK: case VTRUE: {
583  e->k = VFALSE;
584  break;
585  }
586  case VJMP: {
587  invertjump(fs, e);
588  break;
589  }
590  case VRELOCABLE:
591  case VNONRELOC: {
592  discharge2anyreg(fs, e);
593  freeexp(fs, e);
594  e->info = luaK_codeABC(fs, OP_NOT, 0, e->info, 0);
595  e->k = VRELOCABLE;
596  break;
597  }
598  default: {
599  lua_assert(0); /* cannot happen */
600  break;
601  }
602  }
603  /* interchange true and false lists */
604  { int temp = e->f; e->f = e->t; e->t = temp; }
605 }
606 
607 
608 void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
609  t->aux = luaK_exp2RK(fs, k);
610  t->k = VINDEXED;
611 }
612 
613 
614 void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e) {
615  if (op == OPR_MINUS) {
616  luaK_exp2val(fs, e);
617  if (e->k == VK && ttisnumber(&fs->f->k[e->info]))
618  e->info = luaK_numberK(fs, -nvalue(&fs->f->k[e->info]));
619  else {
620  luaK_exp2anyreg(fs, e);
621  freeexp(fs, e);
622  e->info = luaK_codeABC(fs, OP_UNM, 0, e->info, 0);
623  e->k = VRELOCABLE;
624  }
625  }
626  else /* op == NOT */
627  codenot(fs, e);
628 }
629 
630 
631 void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
632  switch (op) {
633  case OPR_AND: {
634  luaK_goiftrue(fs, v);
635  luaK_patchtohere(fs, v->t);
636  v->t = NO_JUMP;
637  break;
638  }
639  case OPR_OR: {
640  luaK_goiffalse(fs, v);
641  luaK_patchtohere(fs, v->f);
642  v->f = NO_JUMP;
643  break;
644  }
645  case OPR_CONCAT: {
646  luaK_exp2nextreg(fs, v); /* operand must be on the `stack' */
647  break;
648  }
649  default: {
650  luaK_exp2RK(fs, v);
651  break;
652  }
653  }
654 }
655 
656 
657 static void codebinop (FuncState *fs, expdesc *res, BinOpr op,
658  int o1, int o2)
659  /*@modifies fs, res @*/
660 {
661  if (op <= OPR_POW) { /* arithmetic operator? */
662  OpCode opc = cast(OpCode, (op - OPR_ADD) + OP_ADD); /* ORDER OP */
663  res->info = luaK_codeABC(fs, opc, 0, o1, o2);
664  res->k = VRELOCABLE;
665  }
666  else { /* test operator */
667  static const OpCode ops[] = {OP_EQ, OP_EQ, OP_LT, OP_LE, OP_LT, OP_LE};
668  int cond = 1;
669  if (op >= OPR_GT) { /* `>' or `>='? */
670  int temp; /* exchange args and replace by `<' or `<=' */
671  temp = o1; o1 = o2; o2 = temp; /* o1 <==> o2 */
672  }
673  else if (op == OPR_NE) cond = 0;
674  res->info = luaK_condjump(fs, ops[op - OPR_NE], cond, o1, o2);
675  res->k = VJMP;
676  }
677 }
678 
679 
680 void luaK_posfix (FuncState *fs, BinOpr op, expdesc *e1, expdesc *e2) {
681  switch (op) {
682  case OPR_AND: {
683  lua_assert(e1->t == NO_JUMP); /* list must be closed */
684  luaK_dischargevars(fs, e2);
685  luaK_concat(fs, &e1->f, e2->f);
686  e1->k = e2->k; e1->info = e2->info; e1->aux = e2->aux; e1->t = e2->t;
687  break;
688  }
689  case OPR_OR: {
690  lua_assert(e1->f == NO_JUMP); /* list must be closed */
691  luaK_dischargevars(fs, e2);
692  luaK_concat(fs, &e1->t, e2->t);
693  e1->k = e2->k; e1->info = e2->info; e1->aux = e2->aux; e1->f = e2->f;
694  break;
695  }
696  case OPR_CONCAT: {
697  luaK_exp2val(fs, e2);
698  if (e2->k == VRELOCABLE && GET_OPCODE(getcode(fs, e2)) == OP_CONCAT) {
699  lua_assert(e1->info == GETARG_B(getcode(fs, e2))-1);
700  freeexp(fs, e1);
701  SETARG_B(getcode(fs, e2), e1->info);
702  e1->k = e2->k; e1->info = e2->info;
703  }
704  else {
705  luaK_exp2nextreg(fs, e2);
706  freeexp(fs, e2);
707  freeexp(fs, e1);
708  e1->info = luaK_codeABC(fs, OP_CONCAT, 0, e1->info, e2->info);
709  e1->k = VRELOCABLE;
710  }
711  break;
712  }
713  default: {
714  int o1 = luaK_exp2RK(fs, e1);
715  int o2 = luaK_exp2RK(fs, e2);
716  freeexp(fs, e2);
717  freeexp(fs, e1);
718  codebinop(fs, e1, op, o1, o2);
719  }
720  }
721 }
722 
723 
724 void luaK_fixline (FuncState *fs, int line) {
725  fs->f->lineinfo[fs->pc - 1] = line;
726 }
727 
728 
729 int luaK_code (FuncState *fs, Instruction i, int line) {
730  Proto *f = fs->f;
731  luaK_dischargejpc(fs); /* `pc' will change */
732  /* put new instruction in code array */
733  luaM_growvector(fs->L, f->code, fs->pc, f->sizecode, Instruction,
734  MAX_INT, "code size overflow");
735  f->code[fs->pc] = i;
736  /* save corresponding line information */
737  luaM_growvector(fs->L, f->lineinfo, fs->pc, f->sizelineinfo, int,
738  MAX_INT, "code size overflow");
739  f->lineinfo[fs->pc] = line;
740  return fs->pc++;
741 }
742 
743 
744 int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
745  lua_assert(getOpMode(o) == iABC);
746  return luaK_code(fs, CREATE_ABC(o, a, b, c), fs->ls->lastline);
747 }
748 
749 
750 int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {
751  lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx);
752  return luaK_code(fs, CREATE_ABx(o, a, bc), fs->ls->lastline);
753 }
754