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comparison luabuild/lua-5.2.1/src/lcode.c @ 1087:07b68c71b89c

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<GreyKnight> (cd luabuild; tar -xvf lua-5.2.1.tar.gz)
author HackBot
date Fri, 14 Dec 2012 20:33:11 +0000
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1086:64bb613b689c 1087:07b68c71b89c
1 /*
2 ** $Id: lcode.c,v 2.60 2011/08/30 16:26:41 roberto 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 #define LUA_CORE
12
13 #include "lua.h"
14
15 #include "lcode.h"
16 #include "ldebug.h"
17 #include "ldo.h"
18 #include "lgc.h"
19 #include "llex.h"
20 #include "lmem.h"
21 #include "lobject.h"
22 #include "lopcodes.h"
23 #include "lparser.h"
24 #include "lstring.h"
25 #include "ltable.h"
26 #include "lvm.h"
27
28
29 #define hasjumps(e) ((e)->t != (e)->f)
30
31
32 static int isnumeral(expdesc *e) {
33 return (e->k == VKNUM && e->t == NO_JUMP && e->f == NO_JUMP);
34 }
35
36
37 void luaK_nil (FuncState *fs, int from, int n) {
38 Instruction *previous;
39 int l = from + n - 1; /* last register to set nil */
40 if (fs->pc > fs->lasttarget) { /* no jumps to current position? */
41 previous = &fs->f->code[fs->pc-1];
42 if (GET_OPCODE(*previous) == OP_LOADNIL) {
43 int pfrom = GETARG_A(*previous);
44 int pl = pfrom + GETARG_B(*previous);
45 if ((pfrom <= from && from <= pl + 1) ||
46 (from <= pfrom && pfrom <= l + 1)) { /* can connect both? */
47 if (pfrom < from) from = pfrom; /* from = min(from, pfrom) */
48 if (pl > l) l = pl; /* l = max(l, pl) */
49 SETARG_A(*previous, from);
50 SETARG_B(*previous, l - from);
51 return;
52 }
53 } /* else go through */
54 }
55 luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0); /* else no optimization */
56 }
57
58
59 int luaK_jump (FuncState *fs) {
60 int jpc = fs->jpc; /* save list of jumps to here */
61 int j;
62 fs->jpc = NO_JUMP;
63 j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
64 luaK_concat(fs, &j, jpc); /* keep them on hold */
65 return j;
66 }
67
68
69 void luaK_ret (FuncState *fs, int first, int nret) {
70 luaK_codeABC(fs, OP_RETURN, first, nret+1, 0);
71 }
72
73
74 static int condjump (FuncState *fs, OpCode op, int A, int B, int C) {
75 luaK_codeABC(fs, op, A, B, C);
76 return luaK_jump(fs);
77 }
78
79
80 static void fixjump (FuncState *fs, int pc, int dest) {
81 Instruction *jmp = &fs->f->code[pc];
82 int offset = dest-(pc+1);
83 lua_assert(dest != NO_JUMP);
84 if (abs(offset) > MAXARG_sBx)
85 luaX_syntaxerror(fs->ls, "control structure too long");
86 SETARG_sBx(*jmp, offset);
87 }
88
89
90 /*
91 ** returns current `pc' and marks it as a jump target (to avoid wrong
92 ** optimizations with consecutive instructions not in the same basic block).
93 */
94 int luaK_getlabel (FuncState *fs) {
95 fs->lasttarget = fs->pc;
96 return fs->pc;
97 }
98
99
100 static int getjump (FuncState *fs, int pc) {
101 int offset = GETARG_sBx(fs->f->code[pc]);
102 if (offset == NO_JUMP) /* point to itself represents end of list */
103 return NO_JUMP; /* end of list */
104 else
105 return (pc+1)+offset; /* turn offset into absolute position */
106 }
107
108
109 static Instruction *getjumpcontrol (FuncState *fs, int pc) {
110 Instruction *pi = &fs->f->code[pc];
111 if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1))))
112 return pi-1;
113 else
114 return pi;
115 }
116
117
118 /*
119 ** check whether list has any jump that do not produce a value
120 ** (or produce an inverted value)
121 */
122 static int need_value (FuncState *fs, int list) {
123 for (; list != NO_JUMP; list = getjump(fs, list)) {
124 Instruction i = *getjumpcontrol(fs, list);
125 if (GET_OPCODE(i) != OP_TESTSET) return 1;
126 }
127 return 0; /* not found */
128 }
129
130
131 static int patchtestreg (FuncState *fs, int node, int reg) {
132 Instruction *i = getjumpcontrol(fs, node);
133 if (GET_OPCODE(*i) != OP_TESTSET)
134 return 0; /* cannot patch other instructions */
135 if (reg != NO_REG && reg != GETARG_B(*i))
136 SETARG_A(*i, reg);
137 else /* no register to put value or register already has the value */
138 *i = CREATE_ABC(OP_TEST, GETARG_B(*i), 0, GETARG_C(*i));
139
140 return 1;
141 }
142
143
144 static void removevalues (FuncState *fs, int list) {
145 for (; list != NO_JUMP; list = getjump(fs, list))
146 patchtestreg(fs, list, NO_REG);
147 }
148
149
150 static void patchlistaux (FuncState *fs, int list, int vtarget, int reg,
151 int dtarget) {
152 while (list != NO_JUMP) {
153 int next = getjump(fs, list);
154 if (patchtestreg(fs, list, reg))
155 fixjump(fs, list, vtarget);
156 else
157 fixjump(fs, list, dtarget); /* jump to default target */
158 list = next;
159 }
160 }
161
162
163 static void dischargejpc (FuncState *fs) {
164 patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc);
165 fs->jpc = NO_JUMP;
166 }
167
168
169 void luaK_patchlist (FuncState *fs, int list, int target) {
170 if (target == fs->pc)
171 luaK_patchtohere(fs, list);
172 else {
173 lua_assert(target < fs->pc);
174 patchlistaux(fs, list, target, NO_REG, target);
175 }
176 }
177
178
179 LUAI_FUNC void luaK_patchclose (FuncState *fs, int list, int level) {
180 level++; /* argument is +1 to reserve 0 as non-op */
181 while (list != NO_JUMP) {
182 int next = getjump(fs, list);
183 lua_assert(GET_OPCODE(fs->f->code[list]) == OP_JMP &&
184 (GETARG_A(fs->f->code[list]) == 0 ||
185 GETARG_A(fs->f->code[list]) >= level));
186 SETARG_A(fs->f->code[list], level);
187 list = next;
188 }
189 }
190
191
192 void luaK_patchtohere (FuncState *fs, int list) {
193 luaK_getlabel(fs);
194 luaK_concat(fs, &fs->jpc, list);
195 }
196
197
198 void luaK_concat (FuncState *fs, int *l1, int l2) {
199 if (l2 == NO_JUMP) return;
200 else if (*l1 == NO_JUMP)
201 *l1 = l2;
202 else {
203 int list = *l1;
204 int next;
205 while ((next = getjump(fs, list)) != NO_JUMP) /* find last element */
206 list = next;
207 fixjump(fs, list, l2);
208 }
209 }
210
211
212 static int luaK_code (FuncState *fs, Instruction i) {
213 Proto *f = fs->f;
214 dischargejpc(fs); /* `pc' will change */
215 /* put new instruction in code array */
216 luaM_growvector(fs->ls->L, f->code, fs->pc, f->sizecode, Instruction,
217 MAX_INT, "opcodes");
218 f->code[fs->pc] = i;
219 /* save corresponding line information */
220 luaM_growvector(fs->ls->L, f->lineinfo, fs->pc, f->sizelineinfo, int,
221 MAX_INT, "opcodes");
222 f->lineinfo[fs->pc] = fs->ls->lastline;
223 return fs->pc++;
224 }
225
226
227 int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
228 lua_assert(getOpMode(o) == iABC);
229 lua_assert(getBMode(o) != OpArgN || b == 0);
230 lua_assert(getCMode(o) != OpArgN || c == 0);
231 lua_assert(a <= MAXARG_A && b <= MAXARG_B && c <= MAXARG_C);
232 return luaK_code(fs, CREATE_ABC(o, a, b, c));
233 }
234
235
236 int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {
237 lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx);
238 lua_assert(getCMode(o) == OpArgN);
239 lua_assert(a <= MAXARG_A && bc <= MAXARG_Bx);
240 return luaK_code(fs, CREATE_ABx(o, a, bc));
241 }
242
243
244 static int codeextraarg (FuncState *fs, int a) {
245 lua_assert(a <= MAXARG_Ax);
246 return luaK_code(fs, CREATE_Ax(OP_EXTRAARG, a));
247 }
248
249
250 int luaK_codek (FuncState *fs, int reg, int k) {
251 if (k <= MAXARG_Bx)
252 return luaK_codeABx(fs, OP_LOADK, reg, k);
253 else {
254 int p = luaK_codeABx(fs, OP_LOADKX, reg, 0);
255 codeextraarg(fs, k);
256 return p;
257 }
258 }
259
260
261 void luaK_checkstack (FuncState *fs, int n) {
262 int newstack = fs->freereg + n;
263 if (newstack > fs->f->maxstacksize) {
264 if (newstack >= MAXSTACK)
265 luaX_syntaxerror(fs->ls, "function or expression too complex");
266 fs->f->maxstacksize = cast_byte(newstack);
267 }
268 }
269
270
271 void luaK_reserveregs (FuncState *fs, int n) {
272 luaK_checkstack(fs, n);
273 fs->freereg += n;
274 }
275
276
277 static void freereg (FuncState *fs, int reg) {
278 if (!ISK(reg) && reg >= fs->nactvar) {
279 fs->freereg--;
280 lua_assert(reg == fs->freereg);
281 }
282 }
283
284
285 static void freeexp (FuncState *fs, expdesc *e) {
286 if (e->k == VNONRELOC)
287 freereg(fs, e->u.info);
288 }
289
290
291 static int addk (FuncState *fs, TValue *key, TValue *v) {
292 lua_State *L = fs->ls->L;
293 TValue *idx = luaH_set(L, fs->h, key);
294 Proto *f = fs->f;
295 int k, oldsize;
296 if (ttisnumber(idx)) {
297 lua_Number n = nvalue(idx);
298 lua_number2int(k, n);
299 if (luaV_rawequalobj(&f->k[k], v))
300 return k;
301 /* else may be a collision (e.g., between 0.0 and "\0\0\0\0\0\0\0\0");
302 go through and create a new entry for this value */
303 }
304 /* constant not found; create a new entry */
305 oldsize = f->sizek;
306 k = fs->nk;
307 /* numerical value does not need GC barrier;
308 table has no metatable, so it does not need to invalidate cache */
309 setnvalue(idx, cast_num(k));
310 luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants");
311 while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]);
312 setobj(L, &f->k[k], v);
313 fs->nk++;
314 luaC_barrier(L, f, v);
315 return k;
316 }
317
318
319 int luaK_stringK (FuncState *fs, TString *s) {
320 TValue o;
321 setsvalue(fs->ls->L, &o, s);
322 return addk(fs, &o, &o);
323 }
324
325
326 int luaK_numberK (FuncState *fs, lua_Number r) {
327 int n;
328 lua_State *L = fs->ls->L;
329 TValue o;
330 setnvalue(&o, r);
331 if (r == 0 || luai_numisnan(NULL, r)) { /* handle -0 and NaN */
332 /* use raw representation as key to avoid numeric problems */
333 setsvalue(L, L->top, luaS_newlstr(L, (char *)&r, sizeof(r)));
334 incr_top(L);
335 n = addk(fs, L->top - 1, &o);
336 L->top--;
337 }
338 else
339 n = addk(fs, &o, &o); /* regular case */
340 return n;
341 }
342
343
344 static int boolK (FuncState *fs, int b) {
345 TValue o;
346 setbvalue(&o, b);
347 return addk(fs, &o, &o);
348 }
349
350
351 static int nilK (FuncState *fs) {
352 TValue k, v;
353 setnilvalue(&v);
354 /* cannot use nil as key; instead use table itself to represent nil */
355 sethvalue(fs->ls->L, &k, fs->h);
356 return addk(fs, &k, &v);
357 }
358
359
360 void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) {
361 if (e->k == VCALL) { /* expression is an open function call? */
362 SETARG_C(getcode(fs, e), nresults+1);
363 }
364 else if (e->k == VVARARG) {
365 SETARG_B(getcode(fs, e), nresults+1);
366 SETARG_A(getcode(fs, e), fs->freereg);
367 luaK_reserveregs(fs, 1);
368 }
369 }
370
371
372 void luaK_setoneret (FuncState *fs, expdesc *e) {
373 if (e->k == VCALL) { /* expression is an open function call? */
374 e->k = VNONRELOC;
375 e->u.info = GETARG_A(getcode(fs, e));
376 }
377 else if (e->k == VVARARG) {
378 SETARG_B(getcode(fs, e), 2);
379 e->k = VRELOCABLE; /* can relocate its simple result */
380 }
381 }
382
383
384 void luaK_dischargevars (FuncState *fs, expdesc *e) {
385 switch (e->k) {
386 case VLOCAL: {
387 e->k = VNONRELOC;
388 break;
389 }
390 case VUPVAL: {
391 e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0);
392 e->k = VRELOCABLE;
393 break;
394 }
395 case VINDEXED: {
396 OpCode op = OP_GETTABUP; /* assume 't' is in an upvalue */
397 freereg(fs, e->u.ind.idx);
398 if (e->u.ind.vt == VLOCAL) { /* 't' is in a register? */
399 freereg(fs, e->u.ind.t);
400 op = OP_GETTABLE;
401 }
402 e->u.info = luaK_codeABC(fs, op, 0, e->u.ind.t, e->u.ind.idx);
403 e->k = VRELOCABLE;
404 break;
405 }
406 case VVARARG:
407 case VCALL: {
408 luaK_setoneret(fs, e);
409 break;
410 }
411 default: break; /* there is one value available (somewhere) */
412 }
413 }
414
415
416 static int code_label (FuncState *fs, int A, int b, int jump) {
417 luaK_getlabel(fs); /* those instructions may be jump targets */
418 return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);
419 }
420
421
422 static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
423 luaK_dischargevars(fs, e);
424 switch (e->k) {
425 case VNIL: {
426 luaK_nil(fs, reg, 1);
427 break;
428 }
429 case VFALSE: case VTRUE: {
430 luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0);
431 break;
432 }
433 case VK: {
434 luaK_codek(fs, reg, e->u.info);
435 break;
436 }
437 case VKNUM: {
438 luaK_codek(fs, reg, luaK_numberK(fs, e->u.nval));
439 break;
440 }
441 case VRELOCABLE: {
442 Instruction *pc = &getcode(fs, e);
443 SETARG_A(*pc, reg);
444 break;
445 }
446 case VNONRELOC: {
447 if (reg != e->u.info)
448 luaK_codeABC(fs, OP_MOVE, reg, e->u.info, 0);
449 break;
450 }
451 default: {
452 lua_assert(e->k == VVOID || e->k == VJMP);
453 return; /* nothing to do... */
454 }
455 }
456 e->u.info = reg;
457 e->k = VNONRELOC;
458 }
459
460
461 static void discharge2anyreg (FuncState *fs, expdesc *e) {
462 if (e->k != VNONRELOC) {
463 luaK_reserveregs(fs, 1);
464 discharge2reg(fs, e, fs->freereg-1);
465 }
466 }
467
468
469 static void exp2reg (FuncState *fs, expdesc *e, int reg) {
470 discharge2reg(fs, e, reg);
471 if (e->k == VJMP)
472 luaK_concat(fs, &e->t, e->u.info); /* put this jump in `t' list */
473 if (hasjumps(e)) {
474 int final; /* position after whole expression */
475 int p_f = NO_JUMP; /* position of an eventual LOAD false */
476 int p_t = NO_JUMP; /* position of an eventual LOAD true */
477 if (need_value(fs, e->t) || need_value(fs, e->f)) {
478 int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs);
479 p_f = code_label(fs, reg, 0, 1);
480 p_t = code_label(fs, reg, 1, 0);
481 luaK_patchtohere(fs, fj);
482 }
483 final = luaK_getlabel(fs);
484 patchlistaux(fs, e->f, final, reg, p_f);
485 patchlistaux(fs, e->t, final, reg, p_t);
486 }
487 e->f = e->t = NO_JUMP;
488 e->u.info = reg;
489 e->k = VNONRELOC;
490 }
491
492
493 void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
494 luaK_dischargevars(fs, e);
495 freeexp(fs, e);
496 luaK_reserveregs(fs, 1);
497 exp2reg(fs, e, fs->freereg - 1);
498 }
499
500
501 int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
502 luaK_dischargevars(fs, e);
503 if (e->k == VNONRELOC) {
504 if (!hasjumps(e)) return e->u.info; /* exp is already in a register */
505 if (e->u.info >= fs->nactvar) { /* reg. is not a local? */
506 exp2reg(fs, e, e->u.info); /* put value on it */
507 return e->u.info;
508 }
509 }
510 luaK_exp2nextreg(fs, e); /* default */
511 return e->u.info;
512 }
513
514
515 void luaK_exp2anyregup (FuncState *fs, expdesc *e) {
516 if (e->k != VUPVAL || hasjumps(e))
517 luaK_exp2anyreg(fs, e);
518 }
519
520
521 void luaK_exp2val (FuncState *fs, expdesc *e) {
522 if (hasjumps(e))
523 luaK_exp2anyreg(fs, e);
524 else
525 luaK_dischargevars(fs, e);
526 }
527
528
529 int luaK_exp2RK (FuncState *fs, expdesc *e) {
530 luaK_exp2val(fs, e);
531 switch (e->k) {
532 case VTRUE:
533 case VFALSE:
534 case VNIL: {
535 if (fs->nk <= MAXINDEXRK) { /* constant fits in RK operand? */
536 e->u.info = (e->k == VNIL) ? nilK(fs) : boolK(fs, (e->k == VTRUE));
537 e->k = VK;
538 return RKASK(e->u.info);
539 }
540 else break;
541 }
542 case VKNUM: {
543 e->u.info = luaK_numberK(fs, e->u.nval);
544 e->k = VK;
545 /* go through */
546 }
547 case VK: {
548 if (e->u.info <= MAXINDEXRK) /* constant fits in argC? */
549 return RKASK(e->u.info);
550 else break;
551 }
552 default: break;
553 }
554 /* not a constant in the right range: put it in a register */
555 return luaK_exp2anyreg(fs, e);
556 }
557
558
559 void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {
560 switch (var->k) {
561 case VLOCAL: {
562 freeexp(fs, ex);
563 exp2reg(fs, ex, var->u.info);
564 return;
565 }
566 case VUPVAL: {
567 int e = luaK_exp2anyreg(fs, ex);
568 luaK_codeABC(fs, OP_SETUPVAL, e, var->u.info, 0);
569 break;
570 }
571 case VINDEXED: {
572 OpCode op = (var->u.ind.vt == VLOCAL) ? OP_SETTABLE : OP_SETTABUP;
573 int e = luaK_exp2RK(fs, ex);
574 luaK_codeABC(fs, op, var->u.ind.t, var->u.ind.idx, e);
575 break;
576 }
577 default: {
578 lua_assert(0); /* invalid var kind to store */
579 break;
580 }
581 }
582 freeexp(fs, ex);
583 }
584
585
586 void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {
587 int ereg;
588 luaK_exp2anyreg(fs, e);
589 ereg = e->u.info; /* register where 'e' was placed */
590 freeexp(fs, e);
591 e->u.info = fs->freereg; /* base register for op_self */
592 e->k = VNONRELOC;
593 luaK_reserveregs(fs, 2); /* function and 'self' produced by op_self */
594 luaK_codeABC(fs, OP_SELF, e->u.info, ereg, luaK_exp2RK(fs, key));
595 freeexp(fs, key);
596 }
597
598
599 static void invertjump (FuncState *fs, expdesc *e) {
600 Instruction *pc = getjumpcontrol(fs, e->u.info);
601 lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET &&
602 GET_OPCODE(*pc) != OP_TEST);
603 SETARG_A(*pc, !(GETARG_A(*pc)));
604 }
605
606
607 static int jumponcond (FuncState *fs, expdesc *e, int cond) {
608 if (e->k == VRELOCABLE) {
609 Instruction ie = getcode(fs, e);
610 if (GET_OPCODE(ie) == OP_NOT) {
611 fs->pc--; /* remove previous OP_NOT */
612 return condjump(fs, OP_TEST, GETARG_B(ie), 0, !cond);
613 }
614 /* else go through */
615 }
616 discharge2anyreg(fs, e);
617 freeexp(fs, e);
618 return condjump(fs, OP_TESTSET, NO_REG, e->u.info, cond);
619 }
620
621
622 void luaK_goiftrue (FuncState *fs, expdesc *e) {
623 int pc; /* pc of last jump */
624 luaK_dischargevars(fs, e);
625 switch (e->k) {
626 case VJMP: {
627 invertjump(fs, e);
628 pc = e->u.info;
629 break;
630 }
631 case VK: case VKNUM: case VTRUE: {
632 pc = NO_JUMP; /* always true; do nothing */
633 break;
634 }
635 default: {
636 pc = jumponcond(fs, e, 0);
637 break;
638 }
639 }
640 luaK_concat(fs, &e->f, pc); /* insert last jump in `f' list */
641 luaK_patchtohere(fs, e->t);
642 e->t = NO_JUMP;
643 }
644
645
646 void luaK_goiffalse (FuncState *fs, expdesc *e) {
647 int pc; /* pc of last jump */
648 luaK_dischargevars(fs, e);
649 switch (e->k) {
650 case VJMP: {
651 pc = e->u.info;
652 break;
653 }
654 case VNIL: case VFALSE: {
655 pc = NO_JUMP; /* always false; do nothing */
656 break;
657 }
658 default: {
659 pc = jumponcond(fs, e, 1);
660 break;
661 }
662 }
663 luaK_concat(fs, &e->t, pc); /* insert last jump in `t' list */
664 luaK_patchtohere(fs, e->f);
665 e->f = NO_JUMP;
666 }
667
668
669 static void codenot (FuncState *fs, expdesc *e) {
670 luaK_dischargevars(fs, e);
671 switch (e->k) {
672 case VNIL: case VFALSE: {
673 e->k = VTRUE;
674 break;
675 }
676 case VK: case VKNUM: case VTRUE: {
677 e->k = VFALSE;
678 break;
679 }
680 case VJMP: {
681 invertjump(fs, e);
682 break;
683 }
684 case VRELOCABLE:
685 case VNONRELOC: {
686 discharge2anyreg(fs, e);
687 freeexp(fs, e);
688 e->u.info = luaK_codeABC(fs, OP_NOT, 0, e->u.info, 0);
689 e->k = VRELOCABLE;
690 break;
691 }
692 default: {
693 lua_assert(0); /* cannot happen */
694 break;
695 }
696 }
697 /* interchange true and false lists */
698 { int temp = e->f; e->f = e->t; e->t = temp; }
699 removevalues(fs, e->f);
700 removevalues(fs, e->t);
701 }
702
703
704 void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
705 lua_assert(!hasjumps(t));
706 t->u.ind.t = t->u.info;
707 t->u.ind.idx = luaK_exp2RK(fs, k);
708 t->u.ind.vt = (t->k == VUPVAL) ? VUPVAL
709 : check_exp(vkisinreg(t->k), VLOCAL);
710 t->k = VINDEXED;
711 }
712
713
714 static int constfolding (OpCode op, expdesc *e1, expdesc *e2) {
715 lua_Number r;
716 if (!isnumeral(e1) || !isnumeral(e2)) return 0;
717 if ((op == OP_DIV || op == OP_MOD) && e2->u.nval == 0)
718 return 0; /* do not attempt to divide by 0 */
719 r = luaO_arith(op - OP_ADD + LUA_OPADD, e1->u.nval, e2->u.nval);
720 e1->u.nval = r;
721 return 1;
722 }
723
724
725 static void codearith (FuncState *fs, OpCode op,
726 expdesc *e1, expdesc *e2, int line) {
727 if (constfolding(op, e1, e2))
728 return;
729 else {
730 int o2 = (op != OP_UNM && op != OP_LEN) ? luaK_exp2RK(fs, e2) : 0;
731 int o1 = luaK_exp2RK(fs, e1);
732 if (o1 > o2) {
733 freeexp(fs, e1);
734 freeexp(fs, e2);
735 }
736 else {
737 freeexp(fs, e2);
738 freeexp(fs, e1);
739 }
740 e1->u.info = luaK_codeABC(fs, op, 0, o1, o2);
741 e1->k = VRELOCABLE;
742 luaK_fixline(fs, line);
743 }
744 }
745
746
747 static void codecomp (FuncState *fs, OpCode op, int cond, expdesc *e1,
748 expdesc *e2) {
749 int o1 = luaK_exp2RK(fs, e1);
750 int o2 = luaK_exp2RK(fs, e2);
751 freeexp(fs, e2);
752 freeexp(fs, e1);
753 if (cond == 0 && op != OP_EQ) {
754 int temp; /* exchange args to replace by `<' or `<=' */
755 temp = o1; o1 = o2; o2 = temp; /* o1 <==> o2 */
756 cond = 1;
757 }
758 e1->u.info = condjump(fs, op, cond, o1, o2);
759 e1->k = VJMP;
760 }
761
762
763 void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e, int line) {
764 expdesc e2;
765 e2.t = e2.f = NO_JUMP; e2.k = VKNUM; e2.u.nval = 0;
766 switch (op) {
767 case OPR_MINUS: {
768 if (isnumeral(e)) /* minus constant? */
769 e->u.nval = luai_numunm(NULL, e->u.nval); /* fold it */
770 else {
771 luaK_exp2anyreg(fs, e);
772 codearith(fs, OP_UNM, e, &e2, line);
773 }
774 break;
775 }
776 case OPR_NOT: codenot(fs, e); break;
777 case OPR_LEN: {
778 luaK_exp2anyreg(fs, e); /* cannot operate on constants */
779 codearith(fs, OP_LEN, e, &e2, line);
780 break;
781 }
782 default: lua_assert(0);
783 }
784 }
785
786
787 void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
788 switch (op) {
789 case OPR_AND: {
790 luaK_goiftrue(fs, v);
791 break;
792 }
793 case OPR_OR: {
794 luaK_goiffalse(fs, v);
795 break;
796 }
797 case OPR_CONCAT: {
798 luaK_exp2nextreg(fs, v); /* operand must be on the `stack' */
799 break;
800 }
801 case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:
802 case OPR_MOD: case OPR_POW: {
803 if (!isnumeral(v)) luaK_exp2RK(fs, v);
804 break;
805 }
806 default: {
807 luaK_exp2RK(fs, v);
808 break;
809 }
810 }
811 }
812
813
814 void luaK_posfix (FuncState *fs, BinOpr op,
815 expdesc *e1, expdesc *e2, int line) {
816 switch (op) {
817 case OPR_AND: {
818 lua_assert(e1->t == NO_JUMP); /* list must be closed */
819 luaK_dischargevars(fs, e2);
820 luaK_concat(fs, &e2->f, e1->f);
821 *e1 = *e2;
822 break;
823 }
824 case OPR_OR: {
825 lua_assert(e1->f == NO_JUMP); /* list must be closed */
826 luaK_dischargevars(fs, e2);
827 luaK_concat(fs, &e2->t, e1->t);
828 *e1 = *e2;
829 break;
830 }
831 case OPR_CONCAT: {
832 luaK_exp2val(fs, e2);
833 if (e2->k == VRELOCABLE && GET_OPCODE(getcode(fs, e2)) == OP_CONCAT) {
834 lua_assert(e1->u.info == GETARG_B(getcode(fs, e2))-1);
835 freeexp(fs, e1);
836 SETARG_B(getcode(fs, e2), e1->u.info);
837 e1->k = VRELOCABLE; e1->u.info = e2->u.info;
838 }
839 else {
840 luaK_exp2nextreg(fs, e2); /* operand must be on the 'stack' */
841 codearith(fs, OP_CONCAT, e1, e2, line);
842 }
843 break;
844 }
845 case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:
846 case OPR_MOD: case OPR_POW: {
847 codearith(fs, cast(OpCode, op - OPR_ADD + OP_ADD), e1, e2, line);
848 break;
849 }
850 case OPR_EQ: case OPR_LT: case OPR_LE: {
851 codecomp(fs, cast(OpCode, op - OPR_EQ + OP_EQ), 1, e1, e2);
852 break;
853 }
854 case OPR_NE: case OPR_GT: case OPR_GE: {
855 codecomp(fs, cast(OpCode, op - OPR_NE + OP_EQ), 0, e1, e2);
856 break;
857 }
858 default: lua_assert(0);
859 }
860 }
861
862
863 void luaK_fixline (FuncState *fs, int line) {
864 fs->f->lineinfo[fs->pc - 1] = line;
865 }
866
867
868 void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) {
869 int c = (nelems - 1)/LFIELDS_PER_FLUSH + 1;
870 int b = (tostore == LUA_MULTRET) ? 0 : tostore;
871 lua_assert(tostore != 0);
872 if (c <= MAXARG_C)
873 luaK_codeABC(fs, OP_SETLIST, base, b, c);
874 else if (c <= MAXARG_Ax) {
875 luaK_codeABC(fs, OP_SETLIST, base, b, 0);
876 codeextraarg(fs, c);
877 }
878 else
879 luaX_syntaxerror(fs->ls, "constructor too long");
880 fs->freereg = base + 1; /* free registers with list values */
881 }
882