1 /* -----------------------------------------------------------------------------
4 * Copyright (c) The GHC Team, 1994-2002.
5 * ---------------------------------------------------------------------------*/
7 #include "PosixSource.h"
16 #include "LdvProfile.h"
21 #include "Bytecodes.h"
23 #include "Disassembler.h"
24 #include "Interpreter.h"
26 #include <string.h> /* for memcpy */
32 /* --------------------------------------------------------------------------
33 * The bytecode interpreter
34 * ------------------------------------------------------------------------*/
36 /* Gather stats about entry, opcode, opcode-pair frequencies. For
37 tuning the interpreter. */
39 /* #define INTERP_STATS */
42 /* Sp points to the lowest live word on the stack. */
44 #define BCO_NEXT instrs[bciPtr++]
45 #define BCO_PTR(n) (W_)ptrs[n]
46 #define BCO_LIT(n) (W_)literals[n]
47 #define BCO_ITBL(n) itbls[n]
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;
54 #define SAVE_STACK_POINTERS \
55 cap->r.rCurrentTSO->sp = Sp
57 #define RETURN_TO_SCHEDULER(todo,retcode) \
58 SAVE_STACK_POINTERS; \
59 cap->r.rCurrentTSO->what_next = (todo); \
64 allocate_UPD (int n_words)
66 return allocate(stg_max(sizeofW(StgHeader)+MIN_UPD_SIZE, n_words));
70 allocate_NONUPD (int n_words)
72 return allocate(stg_max(sizeofW(StgHeader)+MIN_NONUPD_SIZE, n_words));
78 /* Hacky stats, for tuning the interpreter ... */
79 int it_unknown_entries[N_CLOSURE_TYPES];
80 int it_total_unknown_entries;
92 int it_oofreq[27][27];
95 #define INTERP_TICK(n) (n)++
97 void interp_startup ( void )
100 it_retto_BCO = it_retto_UPDATE = it_retto_other = 0;
101 it_total_entries = it_total_unknown_entries = 0;
102 for (i = 0; i < N_CLOSURE_TYPES; i++)
103 it_unknown_entries[i] = 0;
104 it_slides = it_insns = it_BCO_entries = 0;
105 for (i = 0; i < 27; i++) it_ofreq[i] = 0;
106 for (i = 0; i < 27; i++)
107 for (j = 0; j < 27; j++)
112 void interp_shutdown ( void )
114 int i, j, k, o_max, i_max, j_max;
115 debugBelch("%d constrs entered -> (%d BCO, %d UPD, %d ??? )\n",
116 it_retto_BCO + it_retto_UPDATE + it_retto_other,
117 it_retto_BCO, it_retto_UPDATE, it_retto_other );
118 debugBelch("%d total entries, %d unknown entries \n",
119 it_total_entries, it_total_unknown_entries);
120 for (i = 0; i < N_CLOSURE_TYPES; i++) {
121 if (it_unknown_entries[i] == 0) continue;
122 debugBelch(" type %2d: unknown entries (%4.1f%%) == %d\n",
123 i, 100.0 * ((double)it_unknown_entries[i]) /
124 ((double)it_total_unknown_entries),
125 it_unknown_entries[i]);
127 debugBelch("%d insns, %d slides, %d BCO_entries\n",
128 it_insns, it_slides, it_BCO_entries);
129 for (i = 0; i < 27; i++)
130 debugBelch("opcode %2d got %d\n", i, it_ofreq[i] );
132 for (k = 1; k < 20; k++) {
135 for (i = 0; i < 27; i++) {
136 for (j = 0; j < 27; j++) {
137 if (it_oofreq[i][j] > o_max) {
138 o_max = it_oofreq[i][j];
139 i_max = i; j_max = j;
144 debugBelch("%d: count (%4.1f%%) %6d is %d then %d\n",
145 k, ((double)o_max) * 100.0 / ((double)it_insns), o_max,
147 it_oofreq[i_max][j_max] = 0;
152 #else // !INTERP_STATS
154 #define INTERP_TICK(n) /* nothing */
158 static StgWord app_ptrs_itbl[] = {
161 (W_)&stg_ap_ppp_info,
162 (W_)&stg_ap_pppp_info,
163 (W_)&stg_ap_ppppp_info,
164 (W_)&stg_ap_pppppp_info,
168 interpretBCO (Capability* cap)
170 // Use of register here is primarily to make it clear to compilers
171 // that these entities are non-aliasable.
172 register StgPtr Sp; // local state -- stack pointer
173 register StgPtr SpLim; // local state -- stack lim pointer
174 register StgClosure* obj;
179 // ------------------------------------------------------------------------
182 // We have a closure to evaluate. Stack looks like:
186 // Sp | -------------------> closure
189 if (Sp[0] == (W_)&stg_enter_info) {
194 // ------------------------------------------------------------------------
197 // We have a BCO application to perform. Stack looks like:
208 else if (Sp[0] == (W_)&stg_apply_interp_info) {
209 obj = (StgClosure *)Sp[1];
214 // ------------------------------------------------------------------------
217 // We have an unboxed value to return. See comment before
218 // do_return_unboxed, below.
221 goto do_return_unboxed;
224 // Evaluate the object on top of the stack.
226 obj = (StgClosure*)Sp[0]; Sp++;
229 INTERP_TICK(it_total_evals);
231 IF_DEBUG(interpreter,
233 "\n---------------------------------------------------------------\n");
234 debugBelch("Evaluating: "); printObj(obj);
235 debugBelch("Sp = %p\n", Sp);
238 printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
242 IF_DEBUG(sanity,checkStackChunk(Sp, cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size));
244 switch ( get_itbl(obj)->type ) {
249 case IND_OLDGEN_PERM:
252 obj = ((StgInd*)obj)->indirectee;
263 case CONSTR_CHARLIKE:
265 case CONSTR_NOCAF_STATIC:
278 ASSERT(((StgBCO *)obj)->arity > 0);
281 case AP: /* Copied from stg_AP_entry. */
290 if (Sp - (words+sizeofW(StgUpdateFrame)) < SpLim) {
293 Sp[0] = (W_)&stg_enter_info;
294 RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
297 /* Ok; we're safe. Party on. Push an update frame. */
298 Sp -= sizeofW(StgUpdateFrame);
300 StgUpdateFrame *__frame;
301 __frame = (StgUpdateFrame *)Sp;
302 SET_INFO(__frame, (StgInfoTable *)&stg_upd_frame_info);
303 __frame->updatee = (StgClosure *)(ap);
306 /* Reload the stack */
308 for (i=0; i < words; i++) {
309 Sp[i] = (W_)ap->payload[i];
312 obj = (StgClosure*)ap->fun;
313 ASSERT(get_itbl(obj)->type == BCO);
322 j = get_itbl(obj)->type;
323 ASSERT(j >= 0 && j < N_CLOSURE_TYPES);
324 it_unknown_entries[j]++;
325 it_total_unknown_entries++;
329 // Can't handle this object; yield to scheduler
330 IF_DEBUG(interpreter,
331 debugBelch("evaluating unknown closure -- yielding to sched\n");
336 Sp[0] = (W_)&stg_enter_info;
337 RETURN_TO_SCHEDULER(ThreadRunGHC, ThreadYielding);
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.
345 ASSERT(closure_HNF(obj));
347 IF_DEBUG(interpreter,
349 "\n---------------------------------------------------------------\n");
350 debugBelch("Returning: "); printObj(obj);
351 debugBelch("Sp = %p\n", Sp);
353 printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
357 IF_DEBUG(sanity,checkStackChunk(Sp, cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size));
359 switch (get_itbl((StgClosure *)Sp)->type) {
362 const StgInfoTable *info;
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;
369 if (info == (StgInfoTable *)&stg_ap_f_info) {
370 n = 1; m = 1; goto do_apply;
372 if (info == (StgInfoTable *)&stg_ap_d_info) {
373 n = 1; m = sizeofW(StgDouble); goto do_apply;
375 if (info == (StgInfoTable *)&stg_ap_l_info) {
376 n = 1; m = sizeofW(StgInt64); goto do_apply;
378 if (info == (StgInfoTable *)&stg_ap_n_info) {
379 n = 1; m = 1; goto do_apply;
381 if (info == (StgInfoTable *)&stg_ap_p_info) {
382 n = 1; m = 1; goto do_apply;
384 if (info == (StgInfoTable *)&stg_ap_pp_info) {
385 n = 2; m = 2; goto do_apply;
387 if (info == (StgInfoTable *)&stg_ap_ppp_info) {
388 n = 3; m = 3; goto do_apply;
390 if (info == (StgInfoTable *)&stg_ap_pppp_info) {
391 n = 4; m = 4; goto do_apply;
393 if (info == (StgInfoTable *)&stg_ap_ppppp_info) {
394 n = 5; m = 5; goto do_apply;
396 if (info == (StgInfoTable *)&stg_ap_pppppp_info) {
397 n = 6; m = 6; goto do_apply;
399 goto do_return_unrecognised;
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);
411 // Returning to an interpreted continuation: put the object on
412 // the stack, and start executing the BCO.
413 INTERP_TICK(it_retto_BCO);
416 obj = (StgClosure*)Sp[2];
417 ASSERT(get_itbl(obj)->type == BCO);
421 do_return_unrecognised:
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);
431 Sp[0] = (W_)&stg_enter_info;
432 RETURN_TO_SCHEDULER(ThreadRunGHC, ThreadYielding);
436 // -------------------------------------------------------------------------
437 // Returning an unboxed value. The stack looks like this:
454 // where XXXX_info is one of the stg_gc_unbx_r1_info family.
456 // We're only interested in the case when the real return address
457 // is a BCO; otherwise we'll return to the scheduler.
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
471 // get the offset of the stg_ctoi_ret_XXX itbl
472 offset = stack_frame_sizeW((StgClosure *)Sp);
474 switch (get_itbl((StgClosure *)Sp+offset)->type) {
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;
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);
492 RETURN_TO_SCHEDULER(ThreadRunGHC, ThreadYielding);
499 // -------------------------------------------------------------------------
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.
507 switch (get_itbl(obj)->type) {
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;
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...
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++) {
533 Sp[arity-1] = app_ptrs_itbl[n-arity-1];
535 // unpack the PAP's arguments onto the stack
537 for (i = 0; i < pap->n_args; i++) {
538 Sp[i] = (W_)pap->payload[i];
543 else if (arity == n) {
545 for (i = 0; i < pap->n_args; i++) {
546 Sp[i] = (W_)pap->payload[i];
551 else /* arity > n */ {
552 // build a new PAP and return it.
555 size = PAP_sizeW(pap->n_args + m);
556 new_pap = (StgPAP *)allocate(size);
557 SET_HDR(new_pap,&stg_PAP_info,CCCS);
558 new_pap->arity = pap->arity - n;
559 new_pap->n_args = pap->n_args + m;
560 new_pap->fun = pap->fun;
561 for (i = 0; i < pap->n_args; i++) {
562 new_pap->payload[i] = pap->payload[i];
564 for (i = 0; i < m; i++) {
565 new_pap->payload[pap->n_args + i] = (StgClosure *)Sp[i];
567 obj = (StgClosure *)new_pap;
577 arity = ((StgBCO *)obj)->arity;
580 // n must be greater than 1, and the only kinds of
581 // application we support with more than one argument
582 // are all pointers...
584 // Shuffle the args for this function down, and put
585 // the appropriate info table in the gap.
586 for (i = 0; i < arity; i++) {
589 Sp[arity-1] = app_ptrs_itbl[n-arity-1];
593 else if (arity == n) {
596 else /* arity > n */ {
597 // build a PAP and return it.
601 pap = (StgPAP *)allocate(size);
602 SET_HDR(pap, &stg_PAP_info,CCCS);
603 pap->arity = arity - n;
606 for (i = 0; i < m; i++) {
607 pap->payload[i] = (StgClosure *)Sp[i];
609 obj = (StgClosure *)pap;
615 // No point in us applying machine-code functions
617 defer_apply_to_sched:
620 Sp[0] = (W_)&stg_enter_info;
621 RETURN_TO_SCHEDULER(ThreadRunGHC, ThreadYielding);
624 // ------------------------------------------------------------------------
625 // Ok, we now have a bco (obj), and its arguments are all on the
626 // stack. We can start executing the byte codes.
628 // The stack is in one of two states. First, if this BCO is a
638 // Second, if this BCO is a continuation:
653 // where retval is the value being returned to this continuation.
654 // In the event of a stack check, heap check, or context switch,
655 // we need to leave the stack in a sane state so the garbage
656 // collector can find all the pointers.
658 // (1) BCO is a function: the BCO's bitmap describes the
659 // pointerhood of the arguments.
661 // (2) BCO is a continuation: BCO's bitmap describes the
662 // pointerhood of the free variables.
664 // Sadly we have three different kinds of stack/heap/cswitch check
669 if (doYouWantToGC()) {
670 Sp--; Sp[0] = (W_)&stg_enter_info;
671 RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
673 // Stack checks aren't necessary at return points, the stack use
674 // is aggregated into the enclosing function entry point.
677 run_BCO_return_unboxed:
679 if (doYouWantToGC()) {
680 RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
682 // Stack checks aren't necessary at return points, the stack use
683 // is aggregated into the enclosing function entry point.
690 Sp[0] = (W_)&stg_apply_interp_info;
691 checkStackChunk(Sp,SpLim);
696 if (doYouWantToGC()) {
699 Sp[0] = (W_)&stg_apply_interp_info; // placeholder, really
700 RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
704 if (Sp - INTERP_STACK_CHECK_THRESH < SpLim) {
707 Sp[0] = (W_)&stg_apply_interp_info; // placeholder, really
708 RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
712 // Now, actually interpret the BCO... (no returning to the
713 // scheduler again until the stack is in an orderly state).
715 INTERP_TICK(it_BCO_entries);
717 register int bciPtr = 1; /* instruction pointer */
718 register StgBCO* bco = (StgBCO*)obj;
719 register StgWord16* instrs = (StgWord16*)(bco->instrs->payload);
720 register StgWord* literals = (StgWord*)(&bco->literals->payload[0]);
721 register StgPtr* ptrs = (StgPtr*)(&bco->ptrs->payload[0]);
722 register StgInfoTable** itbls = (StgInfoTable**)
723 (&bco->itbls->payload[0]);
726 it_lastopc = 0; /* no opcode */
730 ASSERT(bciPtr <= instrs[0]);
731 IF_DEBUG(interpreter,
732 //if (do_print_stack) {
733 //debugBelch("\n-- BEGIN stack\n");
734 //printStack(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size,iSu);
735 //debugBelch("-- END stack\n\n");
737 debugBelch("Sp = %p pc = %d ", Sp, bciPtr);
738 disInstr(bco,bciPtr);
741 for (i = 8; i >= 0; i--) {
742 debugBelch("%d %p\n", i, (StgPtr)(*(Sp+i)));
746 //if (do_print_stack) checkStack(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size,iSu);
749 INTERP_TICK(it_insns);
752 ASSERT( (int)instrs[bciPtr] >= 0 && (int)instrs[bciPtr] < 27 );
753 it_ofreq[ (int)instrs[bciPtr] ] ++;
754 it_oofreq[ it_lastopc ][ (int)instrs[bciPtr] ] ++;
755 it_lastopc = (int)instrs[bciPtr];
761 // Explicit stack check at the beginning of a function
762 // *only* (stack checks in case alternatives are
763 // propagated to the enclosing function).
764 int stk_words_reqd = BCO_NEXT + 1;
765 if (Sp - stk_words_reqd < SpLim) {
768 Sp[0] = (W_)&stg_apply_interp_info;
769 RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
804 Sp[-1] = BCO_PTR(o1);
809 case bci_PUSH_ALTS: {
810 int o_bco = BCO_NEXT;
811 Sp[-2] = (W_)&stg_ctoi_R1p_info;
812 Sp[-1] = BCO_PTR(o_bco);
817 case bci_PUSH_ALTS_P: {
818 int o_bco = BCO_NEXT;
819 Sp[-2] = (W_)&stg_ctoi_R1unpt_info;
820 Sp[-1] = BCO_PTR(o_bco);
825 case bci_PUSH_ALTS_N: {
826 int o_bco = BCO_NEXT;
827 Sp[-2] = (W_)&stg_ctoi_R1n_info;
828 Sp[-1] = BCO_PTR(o_bco);
833 case bci_PUSH_ALTS_F: {
834 int o_bco = BCO_NEXT;
835 Sp[-2] = (W_)&stg_ctoi_F1_info;
836 Sp[-1] = BCO_PTR(o_bco);
841 case bci_PUSH_ALTS_D: {
842 int o_bco = BCO_NEXT;
843 Sp[-2] = (W_)&stg_ctoi_D1_info;
844 Sp[-1] = BCO_PTR(o_bco);
849 case bci_PUSH_ALTS_L: {
850 int o_bco = BCO_NEXT;
851 Sp[-2] = (W_)&stg_ctoi_L1_info;
852 Sp[-1] = BCO_PTR(o_bco);
857 case bci_PUSH_ALTS_V: {
858 int o_bco = BCO_NEXT;
859 Sp[-2] = (W_)&stg_ctoi_V_info;
860 Sp[-1] = BCO_PTR(o_bco);
865 case bci_PUSH_APPLY_N:
866 Sp--; Sp[0] = (W_)&stg_ap_n_info;
868 case bci_PUSH_APPLY_V:
869 Sp--; Sp[0] = (W_)&stg_ap_v_info;
871 case bci_PUSH_APPLY_F:
872 Sp--; Sp[0] = (W_)&stg_ap_f_info;
874 case bci_PUSH_APPLY_D:
875 Sp--; Sp[0] = (W_)&stg_ap_d_info;
877 case bci_PUSH_APPLY_L:
878 Sp--; Sp[0] = (W_)&stg_ap_l_info;
880 case bci_PUSH_APPLY_P:
881 Sp--; Sp[0] = (W_)&stg_ap_p_info;
883 case bci_PUSH_APPLY_PP:
884 Sp--; Sp[0] = (W_)&stg_ap_pp_info;
886 case bci_PUSH_APPLY_PPP:
887 Sp--; Sp[0] = (W_)&stg_ap_ppp_info;
889 case bci_PUSH_APPLY_PPPP:
890 Sp--; Sp[0] = (W_)&stg_ap_pppp_info;
892 case bci_PUSH_APPLY_PPPPP:
893 Sp--; Sp[0] = (W_)&stg_ap_ppppp_info;
895 case bci_PUSH_APPLY_PPPPPP:
896 Sp--; Sp[0] = (W_)&stg_ap_pppppp_info;
901 int o_lits = BCO_NEXT;
902 int n_words = BCO_NEXT;
904 for (i = 0; i < n_words; i++) {
905 Sp[i] = BCO_LIT(o_lits+i);
913 /* a_1, .. a_n, b_1, .. b_by, s => a_1, .. a_n, s */
918 INTERP_TICK(it_slides);
924 int n_payload = BCO_NEXT;
925 int request = PAP_sizeW(n_payload);
926 ap = (StgAP*)allocate_UPD(request);
928 ap->n_args = n_payload;
929 SET_HDR(ap, &stg_AP_info, CCS_SYSTEM/*ToDo*/)
934 case bci_ALLOC_PAP: {
936 int arity = BCO_NEXT;
937 int n_payload = BCO_NEXT;
938 int request = PAP_sizeW(n_payload);
939 pap = (StgPAP*)allocate_NONUPD(request);
941 pap->n_args = n_payload;
943 SET_HDR(pap, &stg_PAP_info, CCS_SYSTEM/*ToDo*/)
950 int stkoff = BCO_NEXT;
951 int n_payload = BCO_NEXT;
952 StgAP* ap = (StgAP*)Sp[stkoff];
953 ASSERT((int)ap->n_args == n_payload);
954 ap->fun = (StgClosure*)Sp[0];
956 // The function should be a BCO, and its bitmap should
957 // cover the payload of the AP correctly.
958 ASSERT(get_itbl(ap->fun)->type == BCO
959 && (get_itbl(ap)->type == PAP ||
960 BCO_BITMAP_SIZE(ap->fun) == ap->n_args));
962 for (i = 0; i < n_payload; i++)
963 ap->payload[i] = (StgClosure*)Sp[i+1];
965 IF_DEBUG(interpreter,
966 debugBelch("\tBuilt ");
967 printObj((StgClosure*)ap);
973 /* Unpack N ptr words from t.o.s constructor */
975 int n_words = BCO_NEXT;
976 StgClosure* con = (StgClosure*)Sp[0];
978 for (i = 0; i < n_words; i++) {
979 Sp[i] = (W_)con->payload[i];
986 int o_itbl = BCO_NEXT;
987 int n_words = BCO_NEXT;
988 StgInfoTable* itbl = INFO_PTR_TO_STRUCT(BCO_ITBL(o_itbl));
989 int request = CONSTR_sizeW( itbl->layout.payload.ptrs,
990 itbl->layout.payload.nptrs );
991 StgClosure* con = (StgClosure*)allocate_NONUPD(request);
992 ASSERT( itbl->layout.payload.ptrs + itbl->layout.payload.nptrs > 0);
993 SET_HDR(con, BCO_ITBL(o_itbl), CCS_SYSTEM/*ToDo*/);
994 for (i = 0; i < n_words; i++) {
995 con->payload[i] = (StgClosure*)Sp[i];
1000 IF_DEBUG(interpreter,
1001 debugBelch("\tBuilt ");
1002 printObj((StgClosure*)con);
1007 case bci_TESTLT_P: {
1008 int discr = BCO_NEXT;
1009 int failto = BCO_NEXT;
1010 StgClosure* con = (StgClosure*)Sp[0];
1011 if (GET_TAG(con) >= discr) {
1017 case bci_TESTEQ_P: {
1018 int discr = BCO_NEXT;
1019 int failto = BCO_NEXT;
1020 StgClosure* con = (StgClosure*)Sp[0];
1021 if (GET_TAG(con) != discr) {
1027 case bci_TESTLT_I: {
1028 // There should be an Int at Sp[1], and an info table at Sp[0].
1029 int discr = BCO_NEXT;
1030 int failto = BCO_NEXT;
1031 I_ stackInt = (I_)Sp[1];
1032 if (stackInt >= (I_)BCO_LIT(discr))
1037 case bci_TESTEQ_I: {
1038 // There should be an Int at Sp[1], and an info table at Sp[0].
1039 int discr = BCO_NEXT;
1040 int failto = BCO_NEXT;
1041 I_ stackInt = (I_)Sp[1];
1042 if (stackInt != (I_)BCO_LIT(discr)) {
1048 case bci_TESTLT_D: {
1049 // There should be a Double at Sp[1], and an info table at Sp[0].
1050 int discr = BCO_NEXT;
1051 int failto = BCO_NEXT;
1052 StgDouble stackDbl, discrDbl;
1053 stackDbl = PK_DBL( & Sp[1] );
1054 discrDbl = PK_DBL( & BCO_LIT(discr) );
1055 if (stackDbl >= discrDbl) {
1061 case bci_TESTEQ_D: {
1062 // There should be a Double at Sp[1], and an info table at Sp[0].
1063 int discr = BCO_NEXT;
1064 int failto = BCO_NEXT;
1065 StgDouble stackDbl, discrDbl;
1066 stackDbl = PK_DBL( & Sp[1] );
1067 discrDbl = PK_DBL( & BCO_LIT(discr) );
1068 if (stackDbl != discrDbl) {
1074 case bci_TESTLT_F: {
1075 // There should be a Float at Sp[1], and an info table at Sp[0].
1076 int discr = BCO_NEXT;
1077 int failto = BCO_NEXT;
1078 StgFloat stackFlt, discrFlt;
1079 stackFlt = PK_FLT( & Sp[1] );
1080 discrFlt = PK_FLT( & BCO_LIT(discr) );
1081 if (stackFlt >= discrFlt) {
1087 case bci_TESTEQ_F: {
1088 // There should be a Float at Sp[1], and an info table at Sp[0].
1089 int discr = BCO_NEXT;
1090 int failto = BCO_NEXT;
1091 StgFloat stackFlt, discrFlt;
1092 stackFlt = PK_FLT( & Sp[1] );
1093 discrFlt = PK_FLT( & BCO_LIT(discr) );
1094 if (stackFlt != discrFlt) {
1100 // Control-flow ish things
1102 // Context-switch check. We put it here to ensure that
1103 // the interpreter has done at least *some* work before
1104 // context switching: sometimes the scheduler can invoke
1105 // the interpreter with context_switch == 1, particularly
1106 // if the -C0 flag has been given on the cmd line.
1107 if (context_switch) {
1108 Sp--; Sp[0] = (W_)&stg_enter_info;
1109 RETURN_TO_SCHEDULER(ThreadInterpret, ThreadYielding);
1114 obj = (StgClosure *)Sp[0];
1120 Sp[0] = (W_)&stg_gc_unpt_r1_info;
1121 goto do_return_unboxed;
1124 Sp[0] = (W_)&stg_gc_unbx_r1_info;
1125 goto do_return_unboxed;
1128 Sp[0] = (W_)&stg_gc_f1_info;
1129 goto do_return_unboxed;
1132 Sp[0] = (W_)&stg_gc_d1_info;
1133 goto do_return_unboxed;
1136 Sp[0] = (W_)&stg_gc_l1_info;
1137 goto do_return_unboxed;
1140 Sp[0] = (W_)&stg_gc_void_info;
1141 goto do_return_unboxed;
1144 int stkoff = BCO_NEXT;
1145 signed short n = (signed short)(BCO_NEXT);
1146 Sp[stkoff] += (W_)n;
1152 int stk_offset = BCO_NEXT;
1153 int o_itbl = BCO_NEXT;
1154 void(*marshall_fn)(void*) = (void (*)(void*))BCO_LIT(o_itbl);
1156 RET_DYN_BITMAP_SIZE + RET_DYN_NONPTR_REGS_SIZE
1157 + sizeofW(StgRetDyn);
1159 #ifdef RTS_SUPPORTS_THREADS
1161 // Arguments on the TSO stack are not good, because garbage
1162 // collection might move the TSO as soon as we call
1163 // suspendThread below.
1165 W_ arguments[stk_offset];
1167 memcpy(arguments, Sp, sizeof(W_) * stk_offset);
1170 // Restore the Haskell thread's current value of errno
1171 errno = cap->r.rCurrentTSO->saved_errno;
1173 // There are a bunch of non-ptr words on the stack (the
1174 // ccall args, the ccall fun address and space for the
1175 // result), which we need to cover with an info table
1176 // since we might GC during this call.
1178 // We know how many (non-ptr) words there are before the
1179 // next valid stack frame: it is the stk_offset arg to the
1180 // CCALL instruction. So we build a RET_DYN stack frame
1181 // on the stack frame to describe this chunk of stack.
1184 ((StgRetDyn *)Sp)->liveness = NO_PTRS | N_NONPTRS(stk_offset);
1185 ((StgRetDyn *)Sp)->info = (StgInfoTable *)&stg_gc_gen_info;
1187 SAVE_STACK_POINTERS;
1188 tok = suspendThread(&cap->r);
1190 #ifndef RTS_SUPPORTS_THREADS
1192 // suspendThread might have shifted the stack
1193 // around (stack squeezing), so we have to grab the real
1194 // Sp out of the TSO to find the ccall args again.
1196 marshall_fn ( (void*)(cap->r.rCurrentTSO->sp + ret_dyn_size) );
1199 // We already made a copy of the arguments above.
1201 marshall_fn ( arguments );
1204 // And restart the thread again, popping the RET_DYN frame.
1205 cap = (Capability *)((void *)((unsigned char*)resumeThread(tok) - sizeof(StgFunTable)));
1206 LOAD_STACK_POINTERS;
1209 // Save the Haskell thread's current value of errno
1210 cap->r.rCurrentTSO->saved_errno = errno;
1212 #ifdef RTS_SUPPORTS_THREADS
1214 // Copy the "arguments", which might include a return value,
1215 // back to the TSO stack. It would of course be enough to
1216 // just copy the return value, but we don't know the offset.
1217 memcpy(Sp, arguments, sizeof(W_) * stk_offset);
1224 /* BCO_NEXT modifies bciPtr, so be conservative. */
1225 int nextpc = BCO_NEXT;
1231 barf("interpretBCO: hit a CASEFAIL");
1235 barf("interpretBCO: unknown or unimplemented opcode");
1237 } /* switch on opcode */
1241 barf("interpretBCO: fell off end of the interpreter");