Remove CONSTR_CHARLIKE and CONSTR_INTLIKE closure types
[ghc.git] / rts / Interpreter.c
1 /* -----------------------------------------------------------------------------
2 * Bytecode interpreter
3 *
4 * Copyright (c) The GHC Team, 1994-2002.
5 * ---------------------------------------------------------------------------*/
6
7 #include "PosixSource.h"
8 #include "Rts.h"
9 #include "RtsAPI.h"
10 #include "RtsUtils.h"
11 #include "Closures.h"
12 #include "TSO.h"
13 #include "Schedule.h"
14 #include "RtsFlags.h"
15 #include "Storage.h"
16 #include "LdvProfile.h"
17 #include "Updates.h"
18 #include "Sanity.h"
19 #include "Liveness.h"
20
21 #include "Bytecodes.h"
22 #include "Printer.h"
23 #include "Disassembler.h"
24 #include "Interpreter.h"
25
26 #include <string.h> /* for memcpy */
27 #ifdef HAVE_ERRNO_H
28 #include <errno.h>
29 #endif
30
31
32 /* --------------------------------------------------------------------------
33 * The bytecode interpreter
34 * ------------------------------------------------------------------------*/
35
36 /* Gather stats about entry, opcode, opcode-pair frequencies. For
37 tuning the interpreter. */
38
39 /* #define INTERP_STATS */
40
41
42 /* Sp points to the lowest live word on the stack. */
43
44 #define BCO_NEXT instrs[bciPtr++]
45 #define BCO_PTR(n) (W_)ptrs[n]
46 #define BCO_LIT(n) literals[n]
47 #define BCO_ITBL(n) itbls[n]
48
49 #define LOAD_STACK_POINTERS \
50 Sp = cap->r.rCurrentTSO->sp; \
51 /* We don't change this ... */ \
52 SpLim = cap->r.rCurrentTSO->stack + RESERVED_STACK_WORDS;
53
54 #define SAVE_STACK_POINTERS \
55 cap->r.rCurrentTSO->sp = Sp
56
57 #define RETURN_TO_SCHEDULER(todo,retcode) \
58 SAVE_STACK_POINTERS; \
59 cap->r.rCurrentTSO->what_next = (todo); \
60 threadPaused(cap,cap->r.rCurrentTSO); \
61 cap->r.rRet = (retcode); \
62 return cap;
63
64 #define RETURN_TO_SCHEDULER_NO_PAUSE(todo,retcode) \
65 SAVE_STACK_POINTERS; \
66 cap->r.rCurrentTSO->what_next = (todo); \
67 cap->r.rRet = (retcode); \
68 return cap;
69
70
71 STATIC_INLINE StgPtr
72 allocate_NONUPD (int n_words)
73 {
74 return allocate(stg_max(sizeofW(StgHeader)+MIN_PAYLOAD_SIZE, n_words));
75 }
76
77
78 #ifdef INTERP_STATS
79
80 /* Hacky stats, for tuning the interpreter ... */
81 int it_unknown_entries[N_CLOSURE_TYPES];
82 int it_total_unknown_entries;
83 int it_total_entries;
84
85 int it_retto_BCO;
86 int it_retto_UPDATE;
87 int it_retto_other;
88
89 int it_slides;
90 int it_insns;
91 int it_BCO_entries;
92
93 int it_ofreq[27];
94 int it_oofreq[27][27];
95 int it_lastopc;
96
97 #define INTERP_TICK(n) (n)++
98
99 void interp_startup ( void )
100 {
101 int i, j;
102 it_retto_BCO = it_retto_UPDATE = it_retto_other = 0;
103 it_total_entries = it_total_unknown_entries = 0;
104 for (i = 0; i < N_CLOSURE_TYPES; i++)
105 it_unknown_entries[i] = 0;
106 it_slides = it_insns = it_BCO_entries = 0;
107 for (i = 0; i < 27; i++) it_ofreq[i] = 0;
108 for (i = 0; i < 27; i++)
109 for (j = 0; j < 27; j++)
110 it_oofreq[i][j] = 0;
111 it_lastopc = 0;
112 }
113
114 void interp_shutdown ( void )
115 {
116 int i, j, k, o_max, i_max, j_max;
117 debugBelch("%d constrs entered -> (%d BCO, %d UPD, %d ??? )\n",
118 it_retto_BCO + it_retto_UPDATE + it_retto_other,
119 it_retto_BCO, it_retto_UPDATE, it_retto_other );
120 debugBelch("%d total entries, %d unknown entries \n",
121 it_total_entries, it_total_unknown_entries);
122 for (i = 0; i < N_CLOSURE_TYPES; i++) {
123 if (it_unknown_entries[i] == 0) continue;
124 debugBelch(" type %2d: unknown entries (%4.1f%%) == %d\n",
125 i, 100.0 * ((double)it_unknown_entries[i]) /
126 ((double)it_total_unknown_entries),
127 it_unknown_entries[i]);
128 }
129 debugBelch("%d insns, %d slides, %d BCO_entries\n",
130 it_insns, it_slides, it_BCO_entries);
131 for (i = 0; i < 27; i++)
132 debugBelch("opcode %2d got %d\n", i, it_ofreq[i] );
133
134 for (k = 1; k < 20; k++) {
135 o_max = 0;
136 i_max = j_max = 0;
137 for (i = 0; i < 27; i++) {
138 for (j = 0; j < 27; j++) {
139 if (it_oofreq[i][j] > o_max) {
140 o_max = it_oofreq[i][j];
141 i_max = i; j_max = j;
142 }
143 }
144 }
145
146 debugBelch("%d: count (%4.1f%%) %6d is %d then %d\n",
147 k, ((double)o_max) * 100.0 / ((double)it_insns), o_max,
148 i_max, j_max );
149 it_oofreq[i_max][j_max] = 0;
150
151 }
152 }
153
154 #else // !INTERP_STATS
155
156 #define INTERP_TICK(n) /* nothing */
157
158 #endif
159
160 static StgWord app_ptrs_itbl[] = {
161 (W_)&stg_ap_p_info,
162 (W_)&stg_ap_pp_info,
163 (W_)&stg_ap_ppp_info,
164 (W_)&stg_ap_pppp_info,
165 (W_)&stg_ap_ppppp_info,
166 (W_)&stg_ap_pppppp_info,
167 };
168
169 Capability *
170 interpretBCO (Capability* cap)
171 {
172 // Use of register here is primarily to make it clear to compilers
173 // that these entities are non-aliasable.
174 register StgPtr Sp; // local state -- stack pointer
175 register StgPtr SpLim; // local state -- stack lim pointer
176 register StgClosure* obj;
177 nat n, m;
178
179 LOAD_STACK_POINTERS;
180
181 // ------------------------------------------------------------------------
182 // Case 1:
183 //
184 // We have a closure to evaluate. Stack looks like:
185 //
186 // | XXXX_info |
187 // +---------------+
188 // Sp | -------------------> closure
189 // +---------------+
190 //
191 if (Sp[0] == (W_)&stg_enter_info) {
192 Sp++;
193 goto eval;
194 }
195
196 // ------------------------------------------------------------------------
197 // Case 2:
198 //
199 // We have a BCO application to perform. Stack looks like:
200 //
201 // | .... |
202 // +---------------+
203 // | arg1 |
204 // +---------------+
205 // | BCO |
206 // +---------------+
207 // Sp | RET_BCO |
208 // +---------------+
209 //
210 else if (Sp[0] == (W_)&stg_apply_interp_info) {
211 obj = (StgClosure *)Sp[1];
212 Sp += 2;
213 goto run_BCO_fun;
214 }
215
216 // ------------------------------------------------------------------------
217 // Case 3:
218 //
219 // We have an unboxed value to return. See comment before
220 // do_return_unboxed, below.
221 //
222 else {
223 goto do_return_unboxed;
224 }
225
226 // Evaluate the object on top of the stack.
227 eval:
228 obj = (StgClosure*)Sp[0]; Sp++;
229
230 eval_obj:
231 INTERP_TICK(it_total_evals);
232
233 IF_DEBUG(interpreter,
234 debugBelch(
235 "\n---------------------------------------------------------------\n");
236 debugBelch("Evaluating: "); printObj(obj);
237 debugBelch("Sp = %p\n", Sp);
238 debugBelch("\n" );
239
240 printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
241 debugBelch("\n\n");
242 );
243
244 IF_DEBUG(sanity,checkStackChunk(Sp, cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size));
245
246 switch ( get_itbl(obj)->type ) {
247
248 case IND:
249 case IND_OLDGEN:
250 case IND_PERM:
251 case IND_OLDGEN_PERM:
252 case IND_STATIC:
253 {
254 obj = ((StgInd*)obj)->indirectee;
255 goto eval_obj;
256 }
257
258 case CONSTR:
259 case CONSTR_1_0:
260 case CONSTR_0_1:
261 case CONSTR_2_0:
262 case CONSTR_1_1:
263 case CONSTR_0_2:
264 case CONSTR_STATIC:
265 case CONSTR_NOCAF_STATIC:
266 case FUN:
267 case FUN_1_0:
268 case FUN_0_1:
269 case FUN_2_0:
270 case FUN_1_1:
271 case FUN_0_2:
272 case FUN_STATIC:
273 case PAP:
274 // already in WHNF
275 break;
276
277 case BCO:
278 ASSERT(((StgBCO *)obj)->arity > 0);
279 break;
280
281 case AP: /* Copied from stg_AP_entry. */
282 {
283 nat i, words;
284 StgAP *ap;
285
286 ap = (StgAP*)obj;
287 words = ap->n_args;
288
289 // Stack check
290 if (Sp - (words+sizeofW(StgUpdateFrame)) < SpLim) {
291 Sp -= 2;
292 Sp[1] = (W_)obj;
293 Sp[0] = (W_)&stg_enter_info;
294 RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
295 }
296
297 /* Ok; we're safe. Party on. Push an update frame. */
298 Sp -= sizeofW(StgUpdateFrame);
299 {
300 StgUpdateFrame *__frame;
301 __frame = (StgUpdateFrame *)Sp;
302 SET_INFO(__frame, (StgInfoTable *)&stg_upd_frame_info);
303 __frame->updatee = (StgClosure *)(ap);
304 }
305
306 /* Reload the stack */
307 Sp -= words;
308 for (i=0; i < words; i++) {
309 Sp[i] = (W_)ap->payload[i];
310 }
311
312 obj = (StgClosure*)ap->fun;
313 ASSERT(get_itbl(obj)->type == BCO);
314 goto run_BCO_fun;
315 }
316
317 default:
318 #ifdef INTERP_STATS
319 {
320 int j;
321
322 j = get_itbl(obj)->type;
323 ASSERT(j >= 0 && j < N_CLOSURE_TYPES);
324 it_unknown_entries[j]++;
325 it_total_unknown_entries++;
326 }
327 #endif
328 {
329 // Can't handle this object; yield to scheduler
330 IF_DEBUG(interpreter,
331 debugBelch("evaluating unknown closure -- yielding to sched\n");
332 printObj(obj);
333 );
334 Sp -= 2;
335 Sp[1] = (W_)obj;
336 Sp[0] = (W_)&stg_enter_info;
337 RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
338 }
339 }
340
341 // ------------------------------------------------------------------------
342 // We now have an evaluated object (obj). The next thing to
343 // do is return it to the stack frame on top of the stack.
344 do_return:
345 ASSERT(closure_HNF(obj));
346
347 IF_DEBUG(interpreter,
348 debugBelch(
349 "\n---------------------------------------------------------------\n");
350 debugBelch("Returning: "); printObj(obj);
351 debugBelch("Sp = %p\n", Sp);
352 debugBelch("\n" );
353 printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
354 debugBelch("\n\n");
355 );
356
357 IF_DEBUG(sanity,checkStackChunk(Sp, cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size));
358
359 switch (get_itbl((StgClosure *)Sp)->type) {
360
361 case RET_SMALL: {
362 const StgInfoTable *info;
363
364 // NOTE: not using get_itbl().
365 info = ((StgClosure *)Sp)->header.info;
366 if (info == (StgInfoTable *)&stg_ap_v_info) {
367 n = 1; m = 0; goto do_apply;
368 }
369 if (info == (StgInfoTable *)&stg_ap_f_info) {
370 n = 1; m = 1; goto do_apply;
371 }
372 if (info == (StgInfoTable *)&stg_ap_d_info) {
373 n = 1; m = sizeofW(StgDouble); goto do_apply;
374 }
375 if (info == (StgInfoTable *)&stg_ap_l_info) {
376 n = 1; m = sizeofW(StgInt64); goto do_apply;
377 }
378 if (info == (StgInfoTable *)&stg_ap_n_info) {
379 n = 1; m = 1; goto do_apply;
380 }
381 if (info == (StgInfoTable *)&stg_ap_p_info) {
382 n = 1; m = 1; goto do_apply;
383 }
384 if (info == (StgInfoTable *)&stg_ap_pp_info) {
385 n = 2; m = 2; goto do_apply;
386 }
387 if (info == (StgInfoTable *)&stg_ap_ppp_info) {
388 n = 3; m = 3; goto do_apply;
389 }
390 if (info == (StgInfoTable *)&stg_ap_pppp_info) {
391 n = 4; m = 4; goto do_apply;
392 }
393 if (info == (StgInfoTable *)&stg_ap_ppppp_info) {
394 n = 5; m = 5; goto do_apply;
395 }
396 if (info == (StgInfoTable *)&stg_ap_pppppp_info) {
397 n = 6; m = 6; goto do_apply;
398 }
399 goto do_return_unrecognised;
400 }
401
402 case UPDATE_FRAME:
403 // Returning to an update frame: do the update, pop the update
404 // frame, and continue with the next stack frame.
405 INTERP_TICK(it_retto_UPDATE);
406 UPD_IND(((StgUpdateFrame *)Sp)->updatee, obj);
407 Sp += sizeofW(StgUpdateFrame);
408 goto do_return;
409
410 case RET_BCO:
411 // Returning to an interpreted continuation: put the object on
412 // the stack, and start executing the BCO.
413 INTERP_TICK(it_retto_BCO);
414 Sp--;
415 Sp[0] = (W_)obj;
416 obj = (StgClosure*)Sp[2];
417 ASSERT(get_itbl(obj)->type == BCO);
418 goto run_BCO_return;
419
420 default:
421 do_return_unrecognised:
422 {
423 // Can't handle this return address; yield to scheduler
424 INTERP_TICK(it_retto_other);
425 IF_DEBUG(interpreter,
426 debugBelch("returning to unknown frame -- yielding to sched\n");
427 printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
428 );
429 Sp -= 2;
430 Sp[1] = (W_)obj;
431 Sp[0] = (W_)&stg_enter_info;
432 RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
433 }
434 }
435
436 // -------------------------------------------------------------------------
437 // Returning an unboxed value. The stack looks like this:
438 //
439 // | .... |
440 // +---------------+
441 // | fv2 |
442 // +---------------+
443 // | fv1 |
444 // +---------------+
445 // | BCO |
446 // +---------------+
447 // | stg_ctoi_ret_ |
448 // +---------------+
449 // | retval |
450 // +---------------+
451 // | XXXX_info |
452 // +---------------+
453 //
454 // where XXXX_info is one of the stg_gc_unbx_r1_info family.
455 //
456 // We're only interested in the case when the real return address
457 // is a BCO; otherwise we'll return to the scheduler.
458
459 do_return_unboxed:
460 {
461 int offset;
462
463 ASSERT( Sp[0] == (W_)&stg_gc_unbx_r1_info
464 || Sp[0] == (W_)&stg_gc_unpt_r1_info
465 || Sp[0] == (W_)&stg_gc_f1_info
466 || Sp[0] == (W_)&stg_gc_d1_info
467 || Sp[0] == (W_)&stg_gc_l1_info
468 || Sp[0] == (W_)&stg_gc_void_info // VoidRep
469 );
470
471 // get the offset of the stg_ctoi_ret_XXX itbl
472 offset = stack_frame_sizeW((StgClosure *)Sp);
473
474 switch (get_itbl((StgClosure *)Sp+offset)->type) {
475
476 case RET_BCO:
477 // Returning to an interpreted continuation: put the object on
478 // the stack, and start executing the BCO.
479 INTERP_TICK(it_retto_BCO);
480 obj = (StgClosure*)Sp[offset+1];
481 ASSERT(get_itbl(obj)->type == BCO);
482 goto run_BCO_return_unboxed;
483
484 default:
485 {
486 // Can't handle this return address; yield to scheduler
487 INTERP_TICK(it_retto_other);
488 IF_DEBUG(interpreter,
489 debugBelch("returning to unknown frame -- yielding to sched\n");
490 printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
491 );
492 RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
493 }
494 }
495 }
496 // not reached.
497
498
499 // -------------------------------------------------------------------------
500 // Application...
501
502 do_apply:
503 // we have a function to apply (obj), and n arguments taking up m
504 // words on the stack. The info table (stg_ap_pp_info or whatever)
505 // is on top of the arguments on the stack.
506 {
507 switch (get_itbl(obj)->type) {
508
509 case PAP: {
510 StgPAP *pap;
511 nat i, arity;
512
513 pap = (StgPAP *)obj;
514
515 // we only cope with PAPs whose function is a BCO
516 if (get_itbl(pap->fun)->type != BCO) {
517 goto defer_apply_to_sched;
518 }
519
520 Sp++;
521 arity = pap->arity;
522 ASSERT(arity > 0);
523 if (arity < n) {
524 // n must be greater than 1, and the only kinds of
525 // application we support with more than one argument
526 // are all pointers...
527 //
528 // Shuffle the args for this function down, and put
529 // the appropriate info table in the gap.
530 for (i = 0; i < arity; i++) {
531 Sp[(int)i-1] = Sp[i];
532 // ^^^^^ careful, i-1 might be negative, but i in unsigned
533 }
534 Sp[arity-1] = app_ptrs_itbl[n-arity-1];
535 Sp--;
536 // unpack the PAP's arguments onto the stack
537 Sp -= pap->n_args;
538 for (i = 0; i < pap->n_args; i++) {
539 Sp[i] = (W_)pap->payload[i];
540 }
541 obj = pap->fun;
542 goto run_BCO_fun;
543 }
544 else if (arity == n) {
545 Sp -= pap->n_args;
546 for (i = 0; i < pap->n_args; i++) {
547 Sp[i] = (W_)pap->payload[i];
548 }
549 obj = pap->fun;
550 goto run_BCO_fun;
551 }
552 else /* arity > n */ {
553 // build a new PAP and return it.
554 StgPAP *new_pap;
555 new_pap = (StgPAP *)allocate(PAP_sizeW(pap->n_args + m));
556 SET_HDR(new_pap,&stg_PAP_info,CCCS);
557 new_pap->arity = pap->arity - n;
558 new_pap->n_args = pap->n_args + m;
559 new_pap->fun = pap->fun;
560 for (i = 0; i < pap->n_args; i++) {
561 new_pap->payload[i] = pap->payload[i];
562 }
563 for (i = 0; i < m; i++) {
564 new_pap->payload[pap->n_args + i] = (StgClosure *)Sp[i];
565 }
566 obj = (StgClosure *)new_pap;
567 Sp += m;
568 goto do_return;
569 }
570 }
571
572 case BCO: {
573 nat arity, i;
574
575 Sp++;
576 arity = ((StgBCO *)obj)->arity;
577 ASSERT(arity > 0);
578 if (arity < n) {
579 // n must be greater than 1, and the only kinds of
580 // application we support with more than one argument
581 // are all pointers...
582 //
583 // Shuffle the args for this function down, and put
584 // the appropriate info table in the gap.
585 for (i = 0; i < arity; i++) {
586 Sp[(int)i-1] = Sp[i];
587 // ^^^^^ careful, i-1 might be negative, but i in unsigned
588 }
589 Sp[arity-1] = app_ptrs_itbl[n-arity-1];
590 Sp--;
591 goto run_BCO_fun;
592 }
593 else if (arity == n) {
594 goto run_BCO_fun;
595 }
596 else /* arity > n */ {
597 // build a PAP and return it.
598 StgPAP *pap;
599 nat i;
600 pap = (StgPAP *)allocate(PAP_sizeW(m));
601 SET_HDR(pap, &stg_PAP_info,CCCS);
602 pap->arity = arity - n;
603 pap->fun = obj;
604 pap->n_args = m;
605 for (i = 0; i < m; i++) {
606 pap->payload[i] = (StgClosure *)Sp[i];
607 }
608 obj = (StgClosure *)pap;
609 Sp += m;
610 goto do_return;
611 }
612 }
613
614 // No point in us applying machine-code functions
615 default:
616 defer_apply_to_sched:
617 Sp -= 2;
618 Sp[1] = (W_)obj;
619 Sp[0] = (W_)&stg_enter_info;
620 RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
621 }
622
623 // ------------------------------------------------------------------------
624 // Ok, we now have a bco (obj), and its arguments are all on the
625 // stack. We can start executing the byte codes.
626 //
627 // The stack is in one of two states. First, if this BCO is a
628 // function:
629 //
630 // | .... |
631 // +---------------+
632 // | arg2 |
633 // +---------------+
634 // | arg1 |
635 // +---------------+
636 //
637 // Second, if this BCO is a continuation:
638 //
639 // | .... |
640 // +---------------+
641 // | fv2 |
642 // +---------------+
643 // | fv1 |
644 // +---------------+
645 // | BCO |
646 // +---------------+
647 // | stg_ctoi_ret_ |
648 // +---------------+
649 // | retval |
650 // +---------------+
651 //
652 // where retval is the value being returned to this continuation.
653 // In the event of a stack check, heap check, or context switch,
654 // we need to leave the stack in a sane state so the garbage
655 // collector can find all the pointers.
656 //
657 // (1) BCO is a function: the BCO's bitmap describes the
658 // pointerhood of the arguments.
659 //
660 // (2) BCO is a continuation: BCO's bitmap describes the
661 // pointerhood of the free variables.
662 //
663 // Sadly we have three different kinds of stack/heap/cswitch check
664 // to do:
665
666 run_BCO_return:
667 // Heap check
668 if (doYouWantToGC()) {
669 Sp--; Sp[0] = (W_)&stg_enter_info;
670 RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
671 }
672 // Stack checks aren't necessary at return points, the stack use
673 // is aggregated into the enclosing function entry point.
674 goto run_BCO;
675
676 run_BCO_return_unboxed:
677 // Heap check
678 if (doYouWantToGC()) {
679 RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
680 }
681 // Stack checks aren't necessary at return points, the stack use
682 // is aggregated into the enclosing function entry point.
683 goto run_BCO;
684
685 run_BCO_fun:
686 IF_DEBUG(sanity,
687 Sp -= 2;
688 Sp[1] = (W_)obj;
689 Sp[0] = (W_)&stg_apply_interp_info;
690 checkStackChunk(Sp,SpLim);
691 Sp += 2;
692 );
693
694 // Heap check
695 if (doYouWantToGC()) {
696 Sp -= 2;
697 Sp[1] = (W_)obj;
698 Sp[0] = (W_)&stg_apply_interp_info; // placeholder, really
699 RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
700 }
701
702 // Stack check
703 if (Sp - INTERP_STACK_CHECK_THRESH < SpLim) {
704 Sp -= 2;
705 Sp[1] = (W_)obj;
706 Sp[0] = (W_)&stg_apply_interp_info; // placeholder, really
707 RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
708 }
709 goto run_BCO;
710
711 // Now, actually interpret the BCO... (no returning to the
712 // scheduler again until the stack is in an orderly state).
713 run_BCO:
714 INTERP_TICK(it_BCO_entries);
715 {
716 register int bciPtr = 1; /* instruction pointer */
717 register StgBCO* bco = (StgBCO*)obj;
718 register StgWord16* instrs = (StgWord16*)(bco->instrs->payload);
719 register StgWord* literals = (StgWord*)(&bco->literals->payload[0]);
720 register StgPtr* ptrs = (StgPtr*)(&bco->ptrs->payload[0]);
721 register StgInfoTable** itbls = (StgInfoTable**)
722 (&bco->itbls->payload[0]);
723
724 #ifdef INTERP_STATS
725 it_lastopc = 0; /* no opcode */
726 #endif
727
728 nextInsn:
729 ASSERT(bciPtr <= instrs[0]);
730 IF_DEBUG(interpreter,
731 //if (do_print_stack) {
732 //debugBelch("\n-- BEGIN stack\n");
733 //printStack(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size,iSu);
734 //debugBelch("-- END stack\n\n");
735 //}
736 debugBelch("Sp = %p pc = %d ", Sp, bciPtr);
737 disInstr(bco,bciPtr);
738 if (0) { int i;
739 debugBelch("\n");
740 for (i = 8; i >= 0; i--) {
741 debugBelch("%d %p\n", i, (StgPtr)(*(Sp+i)));
742 }
743 debugBelch("\n");
744 }
745 //if (do_print_stack) checkStack(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size,iSu);
746 );
747
748 INTERP_TICK(it_insns);
749
750 #ifdef INTERP_STATS
751 ASSERT( (int)instrs[bciPtr] >= 0 && (int)instrs[bciPtr] < 27 );
752 it_ofreq[ (int)instrs[bciPtr] ] ++;
753 it_oofreq[ it_lastopc ][ (int)instrs[bciPtr] ] ++;
754 it_lastopc = (int)instrs[bciPtr];
755 #endif
756
757 switch (BCO_NEXT) {
758
759 case bci_STKCHECK: {
760 // Explicit stack check at the beginning of a function
761 // *only* (stack checks in case alternatives are
762 // propagated to the enclosing function).
763 int stk_words_reqd = BCO_NEXT + 1;
764 if (Sp - stk_words_reqd < SpLim) {
765 Sp -= 2;
766 Sp[1] = (W_)obj;
767 Sp[0] = (W_)&stg_apply_interp_info;
768 RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
769 } else {
770 goto nextInsn;
771 }
772 }
773
774 case bci_PUSH_L: {
775 int o1 = BCO_NEXT;
776 Sp[-1] = Sp[o1];
777 Sp--;
778 goto nextInsn;
779 }
780
781 case bci_PUSH_LL: {
782 int o1 = BCO_NEXT;
783 int o2 = BCO_NEXT;
784 Sp[-1] = Sp[o1];
785 Sp[-2] = Sp[o2];
786 Sp -= 2;
787 goto nextInsn;
788 }
789
790 case bci_PUSH_LLL: {
791 int o1 = BCO_NEXT;
792 int o2 = BCO_NEXT;
793 int o3 = BCO_NEXT;
794 Sp[-1] = Sp[o1];
795 Sp[-2] = Sp[o2];
796 Sp[-3] = Sp[o3];
797 Sp -= 3;
798 goto nextInsn;
799 }
800
801 case bci_PUSH_G: {
802 int o1 = BCO_NEXT;
803 Sp[-1] = BCO_PTR(o1);
804 Sp -= 1;
805 goto nextInsn;
806 }
807
808 case bci_PUSH_ALTS: {
809 int o_bco = BCO_NEXT;
810 Sp[-2] = (W_)&stg_ctoi_R1p_info;
811 Sp[-1] = BCO_PTR(o_bco);
812 Sp -= 2;
813 goto nextInsn;
814 }
815
816 case bci_PUSH_ALTS_P: {
817 int o_bco = BCO_NEXT;
818 Sp[-2] = (W_)&stg_ctoi_R1unpt_info;
819 Sp[-1] = BCO_PTR(o_bco);
820 Sp -= 2;
821 goto nextInsn;
822 }
823
824 case bci_PUSH_ALTS_N: {
825 int o_bco = BCO_NEXT;
826 Sp[-2] = (W_)&stg_ctoi_R1n_info;
827 Sp[-1] = BCO_PTR(o_bco);
828 Sp -= 2;
829 goto nextInsn;
830 }
831
832 case bci_PUSH_ALTS_F: {
833 int o_bco = BCO_NEXT;
834 Sp[-2] = (W_)&stg_ctoi_F1_info;
835 Sp[-1] = BCO_PTR(o_bco);
836 Sp -= 2;
837 goto nextInsn;
838 }
839
840 case bci_PUSH_ALTS_D: {
841 int o_bco = BCO_NEXT;
842 Sp[-2] = (W_)&stg_ctoi_D1_info;
843 Sp[-1] = BCO_PTR(o_bco);
844 Sp -= 2;
845 goto nextInsn;
846 }
847
848 case bci_PUSH_ALTS_L: {
849 int o_bco = BCO_NEXT;
850 Sp[-2] = (W_)&stg_ctoi_L1_info;
851 Sp[-1] = BCO_PTR(o_bco);
852 Sp -= 2;
853 goto nextInsn;
854 }
855
856 case bci_PUSH_ALTS_V: {
857 int o_bco = BCO_NEXT;
858 Sp[-2] = (W_)&stg_ctoi_V_info;
859 Sp[-1] = BCO_PTR(o_bco);
860 Sp -= 2;
861 goto nextInsn;
862 }
863
864 case bci_PUSH_APPLY_N:
865 Sp--; Sp[0] = (W_)&stg_ap_n_info;
866 goto nextInsn;
867 case bci_PUSH_APPLY_V:
868 Sp--; Sp[0] = (W_)&stg_ap_v_info;
869 goto nextInsn;
870 case bci_PUSH_APPLY_F:
871 Sp--; Sp[0] = (W_)&stg_ap_f_info;
872 goto nextInsn;
873 case bci_PUSH_APPLY_D:
874 Sp--; Sp[0] = (W_)&stg_ap_d_info;
875 goto nextInsn;
876 case bci_PUSH_APPLY_L:
877 Sp--; Sp[0] = (W_)&stg_ap_l_info;
878 goto nextInsn;
879 case bci_PUSH_APPLY_P:
880 Sp--; Sp[0] = (W_)&stg_ap_p_info;
881 goto nextInsn;
882 case bci_PUSH_APPLY_PP:
883 Sp--; Sp[0] = (W_)&stg_ap_pp_info;
884 goto nextInsn;
885 case bci_PUSH_APPLY_PPP:
886 Sp--; Sp[0] = (W_)&stg_ap_ppp_info;
887 goto nextInsn;
888 case bci_PUSH_APPLY_PPPP:
889 Sp--; Sp[0] = (W_)&stg_ap_pppp_info;
890 goto nextInsn;
891 case bci_PUSH_APPLY_PPPPP:
892 Sp--; Sp[0] = (W_)&stg_ap_ppppp_info;
893 goto nextInsn;
894 case bci_PUSH_APPLY_PPPPPP:
895 Sp--; Sp[0] = (W_)&stg_ap_pppppp_info;
896 goto nextInsn;
897
898 case bci_PUSH_UBX: {
899 int i;
900 int o_lits = BCO_NEXT;
901 int n_words = BCO_NEXT;
902 Sp -= n_words;
903 for (i = 0; i < n_words; i++) {
904 Sp[i] = (W_)BCO_LIT(o_lits+i);
905 }
906 goto nextInsn;
907 }
908
909 case bci_SLIDE: {
910 int n = BCO_NEXT;
911 int by = BCO_NEXT;
912 /* a_1, .. a_n, b_1, .. b_by, s => a_1, .. a_n, s */
913 while(--n >= 0) {
914 Sp[n+by] = Sp[n];
915 }
916 Sp += by;
917 INTERP_TICK(it_slides);
918 goto nextInsn;
919 }
920
921 case bci_ALLOC_AP: {
922 StgAP* ap;
923 int n_payload = BCO_NEXT;
924 ap = (StgAP*)allocate(AP_sizeW(n_payload));
925 Sp[-1] = (W_)ap;
926 ap->n_args = n_payload;
927 SET_HDR(ap, &stg_AP_info, CCS_SYSTEM/*ToDo*/)
928 Sp --;
929 goto nextInsn;
930 }
931
932 case bci_ALLOC_PAP: {
933 StgPAP* pap;
934 int arity = BCO_NEXT;
935 int n_payload = BCO_NEXT;
936 pap = (StgPAP*)allocate(PAP_sizeW(n_payload));
937 Sp[-1] = (W_)pap;
938 pap->n_args = n_payload;
939 pap->arity = arity;
940 SET_HDR(pap, &stg_PAP_info, CCS_SYSTEM/*ToDo*/)
941 Sp --;
942 goto nextInsn;
943 }
944
945 case bci_MKAP: {
946 int i;
947 int stkoff = BCO_NEXT;
948 int n_payload = BCO_NEXT;
949 StgAP* ap = (StgAP*)Sp[stkoff];
950 ASSERT((int)ap->n_args == n_payload);
951 ap->fun = (StgClosure*)Sp[0];
952
953 // The function should be a BCO, and its bitmap should
954 // cover the payload of the AP correctly.
955 ASSERT(get_itbl(ap->fun)->type == BCO
956 && BCO_BITMAP_SIZE(ap->fun) == ap->n_args);
957
958 for (i = 0; i < n_payload; i++)
959 ap->payload[i] = (StgClosure*)Sp[i+1];
960 Sp += n_payload+1;
961 IF_DEBUG(interpreter,
962 debugBelch("\tBuilt ");
963 printObj((StgClosure*)ap);
964 );
965 goto nextInsn;
966 }
967
968 case bci_MKPAP: {
969 int i;
970 int stkoff = BCO_NEXT;
971 int n_payload = BCO_NEXT;
972 StgPAP* pap = (StgPAP*)Sp[stkoff];
973 ASSERT((int)pap->n_args == n_payload);
974 pap->fun = (StgClosure*)Sp[0];
975
976 // The function should be a BCO
977 ASSERT(get_itbl(pap->fun)->type == BCO);
978
979 for (i = 0; i < n_payload; i++)
980 pap->payload[i] = (StgClosure*)Sp[i+1];
981 Sp += n_payload+1;
982 IF_DEBUG(interpreter,
983 debugBelch("\tBuilt ");
984 printObj((StgClosure*)pap);
985 );
986 goto nextInsn;
987 }
988
989 case bci_UNPACK: {
990 /* Unpack N ptr words from t.o.s constructor */
991 int i;
992 int n_words = BCO_NEXT;
993 StgClosure* con = (StgClosure*)Sp[0];
994 Sp -= n_words;
995 for (i = 0; i < n_words; i++) {
996 Sp[i] = (W_)con->payload[i];
997 }
998 goto nextInsn;
999 }
1000
1001 case bci_PACK: {
1002 int i;
1003 int o_itbl = BCO_NEXT;
1004 int n_words = BCO_NEXT;
1005 StgInfoTable* itbl = INFO_PTR_TO_STRUCT(BCO_ITBL(o_itbl));
1006 int request = CONSTR_sizeW( itbl->layout.payload.ptrs,
1007 itbl->layout.payload.nptrs );
1008 StgClosure* con = (StgClosure*)allocate_NONUPD(request);
1009 ASSERT( itbl->layout.payload.ptrs + itbl->layout.payload.nptrs > 0);
1010 SET_HDR(con, BCO_ITBL(o_itbl), CCS_SYSTEM/*ToDo*/);
1011 for (i = 0; i < n_words; i++) {
1012 con->payload[i] = (StgClosure*)Sp[i];
1013 }
1014 Sp += n_words;
1015 Sp --;
1016 Sp[0] = (W_)con;
1017 IF_DEBUG(interpreter,
1018 debugBelch("\tBuilt ");
1019 printObj((StgClosure*)con);
1020 );
1021 goto nextInsn;
1022 }
1023
1024 case bci_TESTLT_P: {
1025 unsigned int discr = BCO_NEXT;
1026 int failto = BCO_NEXT;
1027 StgClosure* con = (StgClosure*)Sp[0];
1028 if (GET_TAG(con) >= discr) {
1029 bciPtr = failto;
1030 }
1031 goto nextInsn;
1032 }
1033
1034 case bci_TESTEQ_P: {
1035 unsigned int discr = BCO_NEXT;
1036 int failto = BCO_NEXT;
1037 StgClosure* con = (StgClosure*)Sp[0];
1038 if (GET_TAG(con) != discr) {
1039 bciPtr = failto;
1040 }
1041 goto nextInsn;
1042 }
1043
1044 case bci_TESTLT_I: {
1045 // There should be an Int at Sp[1], and an info table at Sp[0].
1046 int discr = BCO_NEXT;
1047 int failto = BCO_NEXT;
1048 I_ stackInt = (I_)Sp[1];
1049 if (stackInt >= (I_)BCO_LIT(discr))
1050 bciPtr = failto;
1051 goto nextInsn;
1052 }
1053
1054 case bci_TESTEQ_I: {
1055 // There should be an Int at Sp[1], and an info table at Sp[0].
1056 int discr = BCO_NEXT;
1057 int failto = BCO_NEXT;
1058 I_ stackInt = (I_)Sp[1];
1059 if (stackInt != (I_)BCO_LIT(discr)) {
1060 bciPtr = failto;
1061 }
1062 goto nextInsn;
1063 }
1064
1065 case bci_TESTLT_D: {
1066 // There should be a Double at Sp[1], and an info table at Sp[0].
1067 int discr = BCO_NEXT;
1068 int failto = BCO_NEXT;
1069 StgDouble stackDbl, discrDbl;
1070 stackDbl = PK_DBL( & Sp[1] );
1071 discrDbl = PK_DBL( & BCO_LIT(discr) );
1072 if (stackDbl >= discrDbl) {
1073 bciPtr = failto;
1074 }
1075 goto nextInsn;
1076 }
1077
1078 case bci_TESTEQ_D: {
1079 // There should be a Double at Sp[1], and an info table at Sp[0].
1080 int discr = BCO_NEXT;
1081 int failto = BCO_NEXT;
1082 StgDouble stackDbl, discrDbl;
1083 stackDbl = PK_DBL( & Sp[1] );
1084 discrDbl = PK_DBL( & BCO_LIT(discr) );
1085 if (stackDbl != discrDbl) {
1086 bciPtr = failto;
1087 }
1088 goto nextInsn;
1089 }
1090
1091 case bci_TESTLT_F: {
1092 // There should be a Float at Sp[1], and an info table at Sp[0].
1093 int discr = BCO_NEXT;
1094 int failto = BCO_NEXT;
1095 StgFloat stackFlt, discrFlt;
1096 stackFlt = PK_FLT( & Sp[1] );
1097 discrFlt = PK_FLT( & BCO_LIT(discr) );
1098 if (stackFlt >= discrFlt) {
1099 bciPtr = failto;
1100 }
1101 goto nextInsn;
1102 }
1103
1104 case bci_TESTEQ_F: {
1105 // There should be a Float at Sp[1], and an info table at Sp[0].
1106 int discr = BCO_NEXT;
1107 int failto = BCO_NEXT;
1108 StgFloat stackFlt, discrFlt;
1109 stackFlt = PK_FLT( & Sp[1] );
1110 discrFlt = PK_FLT( & BCO_LIT(discr) );
1111 if (stackFlt != discrFlt) {
1112 bciPtr = failto;
1113 }
1114 goto nextInsn;
1115 }
1116
1117 // Control-flow ish things
1118 case bci_ENTER:
1119 // Context-switch check. We put it here to ensure that
1120 // the interpreter has done at least *some* work before
1121 // context switching: sometimes the scheduler can invoke
1122 // the interpreter with context_switch == 1, particularly
1123 // if the -C0 flag has been given on the cmd line.
1124 if (context_switch) {
1125 Sp--; Sp[0] = (W_)&stg_enter_info;
1126 RETURN_TO_SCHEDULER(ThreadInterpret, ThreadYielding);
1127 }
1128 goto eval;
1129
1130 case bci_RETURN:
1131 obj = (StgClosure *)Sp[0];
1132 Sp++;
1133 goto do_return;
1134
1135 case bci_RETURN_P:
1136 Sp--;
1137 Sp[0] = (W_)&stg_gc_unpt_r1_info;
1138 goto do_return_unboxed;
1139 case bci_RETURN_N:
1140 Sp--;
1141 Sp[0] = (W_)&stg_gc_unbx_r1_info;
1142 goto do_return_unboxed;
1143 case bci_RETURN_F:
1144 Sp--;
1145 Sp[0] = (W_)&stg_gc_f1_info;
1146 goto do_return_unboxed;
1147 case bci_RETURN_D:
1148 Sp--;
1149 Sp[0] = (W_)&stg_gc_d1_info;
1150 goto do_return_unboxed;
1151 case bci_RETURN_L:
1152 Sp--;
1153 Sp[0] = (W_)&stg_gc_l1_info;
1154 goto do_return_unboxed;
1155 case bci_RETURN_V:
1156 Sp--;
1157 Sp[0] = (W_)&stg_gc_void_info;
1158 goto do_return_unboxed;
1159
1160 case bci_SWIZZLE: {
1161 int stkoff = BCO_NEXT;
1162 signed short n = (signed short)(BCO_NEXT);
1163 Sp[stkoff] += (W_)n;
1164 goto nextInsn;
1165 }
1166
1167 case bci_CCALL: {
1168 void *tok;
1169 int stk_offset = BCO_NEXT;
1170 int o_itbl = BCO_NEXT;
1171 void(*marshall_fn)(void*) = (void (*)(void*))BCO_LIT(o_itbl);
1172 int ret_dyn_size =
1173 RET_DYN_BITMAP_SIZE + RET_DYN_NONPTR_REGS_SIZE
1174 + sizeofW(StgRetDyn);
1175
1176 #ifdef THREADED_RTS
1177 // Threaded RTS:
1178 // Arguments on the TSO stack are not good, because garbage
1179 // collection might move the TSO as soon as we call
1180 // suspendThread below.
1181
1182 W_ arguments[stk_offset];
1183
1184 memcpy(arguments, Sp, sizeof(W_) * stk_offset);
1185 #endif
1186
1187 // Restore the Haskell thread's current value of errno
1188 errno = cap->r.rCurrentTSO->saved_errno;
1189
1190 // There are a bunch of non-ptr words on the stack (the
1191 // ccall args, the ccall fun address and space for the
1192 // result), which we need to cover with an info table
1193 // since we might GC during this call.
1194 //
1195 // We know how many (non-ptr) words there are before the
1196 // next valid stack frame: it is the stk_offset arg to the
1197 // CCALL instruction. So we build a RET_DYN stack frame
1198 // on the stack frame to describe this chunk of stack.
1199 //
1200 Sp -= ret_dyn_size;
1201 ((StgRetDyn *)Sp)->liveness = NO_PTRS | N_NONPTRS(stk_offset);
1202 ((StgRetDyn *)Sp)->info = (StgInfoTable *)&stg_gc_gen_info;
1203
1204 SAVE_STACK_POINTERS;
1205 tok = suspendThread(&cap->r);
1206
1207 #ifndef THREADED_RTS
1208 // Careful:
1209 // suspendThread might have shifted the stack
1210 // around (stack squeezing), so we have to grab the real
1211 // Sp out of the TSO to find the ccall args again.
1212
1213 marshall_fn ( (void*)(cap->r.rCurrentTSO->sp + ret_dyn_size) );
1214 #else
1215 // Threaded RTS:
1216 // We already made a copy of the arguments above.
1217
1218 marshall_fn ( arguments );
1219 #endif
1220
1221 // And restart the thread again, popping the RET_DYN frame.
1222 cap = (Capability *)((void *)((unsigned char*)resumeThread(tok) - sizeof(StgFunTable)));
1223 LOAD_STACK_POINTERS;
1224 Sp += ret_dyn_size;
1225
1226 // Save the Haskell thread's current value of errno
1227 cap->r.rCurrentTSO->saved_errno = errno;
1228
1229 #ifdef THREADED_RTS
1230 // Threaded RTS:
1231 // Copy the "arguments", which might include a return value,
1232 // back to the TSO stack. It would of course be enough to
1233 // just copy the return value, but we don't know the offset.
1234 memcpy(Sp, arguments, sizeof(W_) * stk_offset);
1235 #endif
1236
1237 goto nextInsn;
1238 }
1239
1240 case bci_JMP: {
1241 /* BCO_NEXT modifies bciPtr, so be conservative. */
1242 int nextpc = BCO_NEXT;
1243 bciPtr = nextpc;
1244 goto nextInsn;
1245 }
1246
1247 case bci_CASEFAIL:
1248 barf("interpretBCO: hit a CASEFAIL");
1249
1250 // Errors
1251 default:
1252 barf("interpretBCO: unknown or unimplemented opcode");
1253
1254 } /* switch on opcode */
1255 }
1256 }
1257
1258 barf("interpretBCO: fell off end of the interpreter");
1259 }