1 /* -----------------------------------------------------------------------------
4 * Copyright (c) The GHC Team, 1994-2002.
5 * ---------------------------------------------------------------------------*/
7 #include "PosixSource.h"
15 #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_NEXT_32 (bciPtr += 2, (((StgWord) instrs[bciPtr-2]) << 16) + ((StgWord) instrs[bciPtr-1]))
46 #define BCO_NEXT_64 (bciPtr += 4, (((StgWord) instrs[bciPtr-4]) << 48) + (((StgWord) instrs[bciPtr-3]) << 32) + (((StgWord) instrs[bciPtr-2]) << 16) + ((StgWord) instrs[bciPtr-1]))
47 #if WORD_SIZE_IN_BITS == 32
48 #define BCO_NEXT_WORD BCO_NEXT_32
49 #elif WORD_SIZE_IN_BITS == 64
50 #define BCO_NEXT_WORD BCO_NEXT_64
52 #error Cannot cope with WORD_SIZE_IN_BITS being nether 32 nor 64
54 #define BCO_GET_LARGE_ARG ((bci & bci_FLAG_LARGE_ARGS) ? BCO_NEXT_WORD : BCO_NEXT)
56 #define BCO_PTR(n) (W_)ptrs[n]
57 #define BCO_LIT(n) literals[n]
59 #define LOAD_STACK_POINTERS \
60 Sp = cap->r.rCurrentTSO->sp; \
61 /* We don't change this ... */ \
62 SpLim = cap->r.rCurrentTSO->stack + RESERVED_STACK_WORDS;
64 #define SAVE_STACK_POINTERS \
65 cap->r.rCurrentTSO->sp = Sp
67 #define RETURN_TO_SCHEDULER(todo,retcode) \
68 SAVE_STACK_POINTERS; \
69 cap->r.rCurrentTSO->what_next = (todo); \
70 threadPaused(cap,cap->r.rCurrentTSO); \
71 cap->r.rRet = (retcode); \
74 #define RETURN_TO_SCHEDULER_NO_PAUSE(todo,retcode) \
75 SAVE_STACK_POINTERS; \
76 cap->r.rCurrentTSO->what_next = (todo); \
77 cap->r.rRet = (retcode); \
82 allocate_NONUPD (int n_words)
84 return allocate(stg_max(sizeofW(StgHeader)+MIN_PAYLOAD_SIZE, n_words));
87 int rts_stop_next_breakpoint = 0;
88 int rts_stop_on_exception = 0;
92 /* Hacky stats, for tuning the interpreter ... */
93 int it_unknown_entries[N_CLOSURE_TYPES];
94 int it_total_unknown_entries;
106 int it_oofreq[27][27];
110 #define INTERP_TICK(n) (n)++
112 void interp_startup ( void )
115 it_retto_BCO = it_retto_UPDATE = it_retto_other = 0;
116 it_total_entries = it_total_unknown_entries = 0;
117 for (i = 0; i < N_CLOSURE_TYPES; i++)
118 it_unknown_entries[i] = 0;
119 it_slides = it_insns = it_BCO_entries = 0;
120 for (i = 0; i < 27; i++) it_ofreq[i] = 0;
121 for (i = 0; i < 27; i++)
122 for (j = 0; j < 27; j++)
127 void interp_shutdown ( void )
129 int i, j, k, o_max, i_max, j_max;
130 debugBelch("%d constrs entered -> (%d BCO, %d UPD, %d ??? )\n",
131 it_retto_BCO + it_retto_UPDATE + it_retto_other,
132 it_retto_BCO, it_retto_UPDATE, it_retto_other );
133 debugBelch("%d total entries, %d unknown entries \n",
134 it_total_entries, it_total_unknown_entries);
135 for (i = 0; i < N_CLOSURE_TYPES; i++) {
136 if (it_unknown_entries[i] == 0) continue;
137 debugBelch(" type %2d: unknown entries (%4.1f%%) == %d\n",
138 i, 100.0 * ((double)it_unknown_entries[i]) /
139 ((double)it_total_unknown_entries),
140 it_unknown_entries[i]);
142 debugBelch("%d insns, %d slides, %d BCO_entries\n",
143 it_insns, it_slides, it_BCO_entries);
144 for (i = 0; i < 27; i++)
145 debugBelch("opcode %2d got %d\n", i, it_ofreq[i] );
147 for (k = 1; k < 20; k++) {
150 for (i = 0; i < 27; i++) {
151 for (j = 0; j < 27; j++) {
152 if (it_oofreq[i][j] > o_max) {
153 o_max = it_oofreq[i][j];
154 i_max = i; j_max = j;
159 debugBelch("%d: count (%4.1f%%) %6d is %d then %d\n",
160 k, ((double)o_max) * 100.0 / ((double)it_insns), o_max,
162 it_oofreq[i_max][j_max] = 0;
167 #else // !INTERP_STATS
169 #define INTERP_TICK(n) /* nothing */
173 static StgWord app_ptrs_itbl[] = {
176 (W_)&stg_ap_ppp_info,
177 (W_)&stg_ap_pppp_info,
178 (W_)&stg_ap_ppppp_info,
179 (W_)&stg_ap_pppppp_info,
182 HsStablePtr rts_breakpoint_io_action; // points to the IO action which is executed on a breakpoint
183 // it is set in main/GHC.hs:runStmt
186 interpretBCO (Capability* cap)
188 // Use of register here is primarily to make it clear to compilers
189 // that these entities are non-aliasable.
190 register StgPtr Sp; // local state -- stack pointer
191 register StgPtr SpLim; // local state -- stack lim pointer
192 register StgClosure* obj;
197 // ------------------------------------------------------------------------
200 // We have a closure to evaluate. Stack looks like:
204 // Sp | -------------------> closure
207 if (Sp[0] == (W_)&stg_enter_info) {
212 // ------------------------------------------------------------------------
215 // We have a BCO application to perform. Stack looks like:
226 else if (Sp[0] == (W_)&stg_apply_interp_info) {
227 obj = UNTAG_CLOSURE((StgClosure *)Sp[1]);
232 // ------------------------------------------------------------------------
235 // We have an unboxed value to return. See comment before
236 // do_return_unboxed, below.
239 goto do_return_unboxed;
242 // Evaluate the object on top of the stack.
244 obj = (StgClosure*)Sp[0]; Sp++;
247 obj = UNTAG_CLOSURE(obj);
248 INTERP_TICK(it_total_evals);
250 IF_DEBUG(interpreter,
252 "\n---------------------------------------------------------------\n");
253 debugBelch("Evaluating: "); printObj(obj);
254 debugBelch("Sp = %p\n", Sp);
257 printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
261 IF_DEBUG(sanity,checkStackChunk(Sp, cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size));
263 switch ( get_itbl(obj)->type ) {
268 case IND_OLDGEN_PERM:
271 obj = ((StgInd*)obj)->indirectee;
282 case CONSTR_NOCAF_STATIC:
296 ASSERT(((StgBCO *)obj)->arity > 0);
300 case AP: /* Copied from stg_AP_entry. */
309 if (Sp - (words+sizeofW(StgUpdateFrame)) < SpLim) {
312 Sp[0] = (W_)&stg_enter_info;
313 RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
316 /* Ok; we're safe. Party on. Push an update frame. */
317 Sp -= sizeofW(StgUpdateFrame);
319 StgUpdateFrame *__frame;
320 __frame = (StgUpdateFrame *)Sp;
321 SET_INFO(__frame, (StgInfoTable *)&stg_upd_frame_info);
322 __frame->updatee = (StgClosure *)(ap);
325 /* Reload the stack */
327 for (i=0; i < words; i++) {
328 Sp[i] = (W_)ap->payload[i];
331 obj = UNTAG_CLOSURE((StgClosure*)ap->fun);
332 ASSERT(get_itbl(obj)->type == BCO);
341 j = get_itbl(obj)->type;
342 ASSERT(j >= 0 && j < N_CLOSURE_TYPES);
343 it_unknown_entries[j]++;
344 it_total_unknown_entries++;
348 // Can't handle this object; yield to scheduler
349 IF_DEBUG(interpreter,
350 debugBelch("evaluating unknown closure -- yielding to sched\n");
355 Sp[0] = (W_)&stg_enter_info;
356 RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
360 // ------------------------------------------------------------------------
361 // We now have an evaluated object (obj). The next thing to
362 // do is return it to the stack frame on top of the stack.
364 ASSERT(closure_HNF(obj));
366 IF_DEBUG(interpreter,
368 "\n---------------------------------------------------------------\n");
369 debugBelch("Returning: "); printObj(obj);
370 debugBelch("Sp = %p\n", Sp);
372 printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
376 IF_DEBUG(sanity,checkStackChunk(Sp, cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size));
378 switch (get_itbl((StgClosure *)Sp)->type) {
381 const StgInfoTable *info;
383 // NOTE: not using get_itbl().
384 info = ((StgClosure *)Sp)->header.info;
385 if (info == (StgInfoTable *)&stg_ap_v_info) {
386 n = 1; m = 0; goto do_apply;
388 if (info == (StgInfoTable *)&stg_ap_f_info) {
389 n = 1; m = 1; goto do_apply;
391 if (info == (StgInfoTable *)&stg_ap_d_info) {
392 n = 1; m = sizeofW(StgDouble); goto do_apply;
394 if (info == (StgInfoTable *)&stg_ap_l_info) {
395 n = 1; m = sizeofW(StgInt64); goto do_apply;
397 if (info == (StgInfoTable *)&stg_ap_n_info) {
398 n = 1; m = 1; goto do_apply;
400 if (info == (StgInfoTable *)&stg_ap_p_info) {
401 n = 1; m = 1; goto do_apply;
403 if (info == (StgInfoTable *)&stg_ap_pp_info) {
404 n = 2; m = 2; goto do_apply;
406 if (info == (StgInfoTable *)&stg_ap_ppp_info) {
407 n = 3; m = 3; goto do_apply;
409 if (info == (StgInfoTable *)&stg_ap_pppp_info) {
410 n = 4; m = 4; goto do_apply;
412 if (info == (StgInfoTable *)&stg_ap_ppppp_info) {
413 n = 5; m = 5; goto do_apply;
415 if (info == (StgInfoTable *)&stg_ap_pppppp_info) {
416 n = 6; m = 6; goto do_apply;
418 goto do_return_unrecognised;
422 // Returning to an update frame: do the update, pop the update
423 // frame, and continue with the next stack frame.
424 INTERP_TICK(it_retto_UPDATE);
425 UPD_IND(((StgUpdateFrame *)Sp)->updatee, obj);
426 Sp += sizeofW(StgUpdateFrame);
430 // Returning to an interpreted continuation: put the object on
431 // the stack, and start executing the BCO.
432 INTERP_TICK(it_retto_BCO);
435 obj = (StgClosure*)Sp[2];
436 ASSERT(get_itbl(obj)->type == BCO);
440 do_return_unrecognised:
442 // Can't handle this return address; yield to scheduler
443 INTERP_TICK(it_retto_other);
444 IF_DEBUG(interpreter,
445 debugBelch("returning to unknown frame -- yielding to sched\n");
446 printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
450 Sp[0] = (W_)&stg_enter_info;
451 RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
455 // -------------------------------------------------------------------------
456 // Returning an unboxed value. The stack looks like this:
473 // where XXXX_info is one of the stg_gc_unbx_r1_info family.
475 // We're only interested in the case when the real return address
476 // is a BCO; otherwise we'll return to the scheduler.
482 ASSERT( Sp[0] == (W_)&stg_gc_unbx_r1_info
483 || Sp[0] == (W_)&stg_gc_unpt_r1_info
484 || Sp[0] == (W_)&stg_gc_f1_info
485 || Sp[0] == (W_)&stg_gc_d1_info
486 || Sp[0] == (W_)&stg_gc_l1_info
487 || Sp[0] == (W_)&stg_gc_void_info // VoidRep
490 // get the offset of the stg_ctoi_ret_XXX itbl
491 offset = stack_frame_sizeW((StgClosure *)Sp);
493 switch (get_itbl((StgClosure *)Sp+offset)->type) {
496 // Returning to an interpreted continuation: put the object on
497 // the stack, and start executing the BCO.
498 INTERP_TICK(it_retto_BCO);
499 obj = (StgClosure*)Sp[offset+1];
500 ASSERT(get_itbl(obj)->type == BCO);
501 goto run_BCO_return_unboxed;
505 // Can't handle this return address; yield to scheduler
506 INTERP_TICK(it_retto_other);
507 IF_DEBUG(interpreter,
508 debugBelch("returning to unknown frame -- yielding to sched\n");
509 printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
511 RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
518 // -------------------------------------------------------------------------
522 // we have a function to apply (obj), and n arguments taking up m
523 // words on the stack. The info table (stg_ap_pp_info or whatever)
524 // is on top of the arguments on the stack.
526 switch (get_itbl(obj)->type) {
534 // we only cope with PAPs whose function is a BCO
535 if (get_itbl(UNTAG_CLOSURE(pap->fun))->type != BCO) {
536 goto defer_apply_to_sched;
543 // n must be greater than 1, and the only kinds of
544 // application we support with more than one argument
545 // are all pointers...
547 // Shuffle the args for this function down, and put
548 // the appropriate info table in the gap.
549 for (i = 0; i < arity; i++) {
550 Sp[(int)i-1] = Sp[i];
551 // ^^^^^ careful, i-1 might be negative, but i in unsigned
553 Sp[arity-1] = app_ptrs_itbl[n-arity-1];
555 // unpack the PAP's arguments onto the stack
557 for (i = 0; i < pap->n_args; i++) {
558 Sp[i] = (W_)pap->payload[i];
560 obj = UNTAG_CLOSURE(pap->fun);
563 else if (arity == n) {
565 for (i = 0; i < pap->n_args; i++) {
566 Sp[i] = (W_)pap->payload[i];
568 obj = UNTAG_CLOSURE(pap->fun);
571 else /* arity > n */ {
572 // build a new PAP and return it.
574 new_pap = (StgPAP *)allocate(PAP_sizeW(pap->n_args + m));
575 SET_HDR(new_pap,&stg_PAP_info,CCCS);
576 new_pap->arity = pap->arity - n;
577 new_pap->n_args = pap->n_args + m;
578 new_pap->fun = pap->fun;
579 for (i = 0; i < pap->n_args; i++) {
580 new_pap->payload[i] = pap->payload[i];
582 for (i = 0; i < m; i++) {
583 new_pap->payload[pap->n_args + i] = (StgClosure *)Sp[i];
585 obj = (StgClosure *)new_pap;
595 arity = ((StgBCO *)obj)->arity;
598 // n must be greater than 1, and the only kinds of
599 // application we support with more than one argument
600 // are all pointers...
602 // Shuffle the args for this function down, and put
603 // the appropriate info table in the gap.
604 for (i = 0; i < arity; i++) {
605 Sp[(int)i-1] = Sp[i];
606 // ^^^^^ careful, i-1 might be negative, but i in unsigned
608 Sp[arity-1] = app_ptrs_itbl[n-arity-1];
612 else if (arity == n) {
615 else /* arity > n */ {
616 // build a PAP and return it.
619 pap = (StgPAP *)allocate(PAP_sizeW(m));
620 SET_HDR(pap, &stg_PAP_info,CCCS);
621 pap->arity = arity - n;
624 for (i = 0; i < m; i++) {
625 pap->payload[i] = (StgClosure *)Sp[i];
627 obj = (StgClosure *)pap;
633 // No point in us applying machine-code functions
635 defer_apply_to_sched:
638 Sp[0] = (W_)&stg_enter_info;
639 RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
642 // ------------------------------------------------------------------------
643 // Ok, we now have a bco (obj), and its arguments are all on the
644 // stack. We can start executing the byte codes.
646 // The stack is in one of two states. First, if this BCO is a
656 // Second, if this BCO is a continuation:
671 // where retval is the value being returned to this continuation.
672 // In the event of a stack check, heap check, or context switch,
673 // we need to leave the stack in a sane state so the garbage
674 // collector can find all the pointers.
676 // (1) BCO is a function: the BCO's bitmap describes the
677 // pointerhood of the arguments.
679 // (2) BCO is a continuation: BCO's bitmap describes the
680 // pointerhood of the free variables.
682 // Sadly we have three different kinds of stack/heap/cswitch check
688 if (doYouWantToGC()) {
689 Sp--; Sp[0] = (W_)&stg_enter_info;
690 RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
692 // Stack checks aren't necessary at return points, the stack use
693 // is aggregated into the enclosing function entry point.
697 run_BCO_return_unboxed:
699 if (doYouWantToGC()) {
700 RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
702 // Stack checks aren't necessary at return points, the stack use
703 // is aggregated into the enclosing function entry point.
711 Sp[0] = (W_)&stg_apply_interp_info;
712 checkStackChunk(Sp,SpLim);
717 if (doYouWantToGC()) {
720 Sp[0] = (W_)&stg_apply_interp_info; // placeholder, really
721 RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
725 if (Sp - INTERP_STACK_CHECK_THRESH < SpLim) {
728 Sp[0] = (W_)&stg_apply_interp_info; // placeholder, really
729 RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
734 // Now, actually interpret the BCO... (no returning to the
735 // scheduler again until the stack is in an orderly state).
737 INTERP_TICK(it_BCO_entries);
739 register int bciPtr = 1; /* instruction pointer */
740 register StgWord16 bci;
741 register StgBCO* bco = (StgBCO*)obj;
742 register StgWord16* instrs = (StgWord16*)(bco->instrs->payload);
743 register StgWord* literals = (StgWord*)(&bco->literals->payload[0]);
744 register StgPtr* ptrs = (StgPtr*)(&bco->ptrs->payload[0]);
747 it_lastopc = 0; /* no opcode */
751 ASSERT(bciPtr <= instrs[0]);
752 IF_DEBUG(interpreter,
753 //if (do_print_stack) {
754 //debugBelch("\n-- BEGIN stack\n");
755 //printStack(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size,iSu);
756 //debugBelch("-- END stack\n\n");
758 debugBelch("Sp = %p pc = %d ", Sp, bciPtr);
759 disInstr(bco,bciPtr);
762 for (i = 8; i >= 0; i--) {
763 debugBelch("%d %p\n", i, (StgPtr)(*(Sp+i)));
767 //if (do_print_stack) checkStack(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size,iSu);
771 INTERP_TICK(it_insns);
774 ASSERT( (int)instrs[bciPtr] >= 0 && (int)instrs[bciPtr] < 27 );
775 it_ofreq[ (int)instrs[bciPtr] ] ++;
776 it_oofreq[ it_lastopc ][ (int)instrs[bciPtr] ] ++;
777 it_lastopc = (int)instrs[bciPtr];
781 /* We use the high 8 bits for flags, only the highest of which is
782 * currently allocated */
783 ASSERT((bci & 0xFF00) == (bci & 0x8000));
785 switch (bci & 0xFF) {
787 /* check for a breakpoint on the beginning of a let binding */
790 int arg1_brk_array, arg2_array_index, arg3_freeVars;
791 StgArrWords *breakPoints;
792 int returning_from_break; // are we resuming execution from a breakpoint?
793 // if yes, then don't break this time around
794 StgClosure *ioAction; // the io action to run at a breakpoint
796 StgAP_STACK *new_aps; // a closure to save the top stack frame on the heap
800 arg1_brk_array = BCO_NEXT; // 1st arg of break instruction
801 arg2_array_index = BCO_NEXT; // 2nd arg of break instruction
802 arg3_freeVars = BCO_NEXT; // 3rd arg of break instruction
804 // check if we are returning from a breakpoint - this info
805 // is stored in the flags field of the current TSO
806 returning_from_break = cap->r.rCurrentTSO->flags & TSO_STOPPED_ON_BREAKPOINT;
808 // if we are returning from a break then skip this section
809 // and continue executing
810 if (!returning_from_break)
812 breakPoints = (StgArrWords *) BCO_PTR(arg1_brk_array);
814 // stop the current thread if either the
815 // "rts_stop_next_breakpoint" flag is true OR if the
816 // breakpoint flag for this particular expression is
818 if (rts_stop_next_breakpoint == rtsTrue ||
819 breakPoints->payload[arg2_array_index] == rtsTrue)
821 // make sure we don't automatically stop at the
823 rts_stop_next_breakpoint = rtsFalse;
825 // allocate memory for a new AP_STACK, enough to
826 // store the top stack frame plus an
827 // stg_apply_interp_info pointer and a pointer to
829 size_words = BCO_BITMAP_SIZE(obj) + 2;
830 new_aps = (StgAP_STACK *) allocate (AP_STACK_sizeW(size_words));
831 SET_HDR(new_aps,&stg_AP_STACK_info,CCS_SYSTEM);
832 new_aps->size = size_words;
833 new_aps->fun = &stg_dummy_ret_closure;
835 // fill in the payload of the AP_STACK
836 new_aps->payload[0] = (StgClosure *)&stg_apply_interp_info;
837 new_aps->payload[1] = (StgClosure *)obj;
839 // copy the contents of the top stack frame into the AP_STACK
840 for (i = 2; i < size_words; i++)
842 new_aps->payload[i] = (StgClosure *)Sp[i-2];
845 // prepare the stack so that we can call the
846 // rts_breakpoint_io_action and ensure that the stack is
847 // in a reasonable state for the GC and so that
848 // execution of this BCO can continue when we resume
849 ioAction = (StgClosure *) deRefStablePtr (rts_breakpoint_io_action);
852 Sp[7] = (W_)&stg_apply_interp_info;
853 Sp[6] = (W_)&stg_noforceIO_info; // see [unreg] below
854 Sp[5] = (W_)new_aps; // the AP_STACK
855 Sp[4] = (W_)BCO_PTR(arg3_freeVars); // the info about local vars of the breakpoint
856 Sp[3] = (W_)False_closure; // True <=> a breakpoint
857 Sp[2] = (W_)&stg_ap_pppv_info;
858 Sp[1] = (W_)ioAction; // apply the IO action to its two arguments above
859 Sp[0] = (W_)&stg_enter_info; // get ready to run the IO action
860 // Note [unreg]: in unregisterised mode, the return
861 // convention for IO is different. The
862 // stg_noForceIO_info stack frame is necessary to
863 // account for this difference.
865 // set the flag in the TSO to say that we are now
866 // stopping at a breakpoint so that when we resume
867 // we don't stop on the same breakpoint that we
868 // already stopped at just now
869 cap->r.rCurrentTSO->flags |= TSO_STOPPED_ON_BREAKPOINT;
871 // stop this thread and return to the scheduler -
872 // eventually we will come back and the IO action on
873 // the top of the stack will be executed
874 RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
877 // record that this thread is not stopped at a breakpoint anymore
878 cap->r.rCurrentTSO->flags &= ~TSO_STOPPED_ON_BREAKPOINT;
880 // continue normal execution of the byte code instructions
885 // Explicit stack check at the beginning of a function
886 // *only* (stack checks in case alternatives are
887 // propagated to the enclosing function).
888 StgWord stk_words_reqd = BCO_GET_LARGE_ARG + 1;
889 if (Sp - stk_words_reqd < SpLim) {
892 Sp[0] = (W_)&stg_apply_interp_info;
893 RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
928 Sp[-1] = BCO_PTR(o1);
933 case bci_PUSH_ALTS: {
934 int o_bco = BCO_NEXT;
935 Sp[-2] = (W_)&stg_ctoi_R1p_info;
936 Sp[-1] = BCO_PTR(o_bco);
941 case bci_PUSH_ALTS_P: {
942 int o_bco = BCO_NEXT;
943 Sp[-2] = (W_)&stg_ctoi_R1unpt_info;
944 Sp[-1] = BCO_PTR(o_bco);
949 case bci_PUSH_ALTS_N: {
950 int o_bco = BCO_NEXT;
951 Sp[-2] = (W_)&stg_ctoi_R1n_info;
952 Sp[-1] = BCO_PTR(o_bco);
957 case bci_PUSH_ALTS_F: {
958 int o_bco = BCO_NEXT;
959 Sp[-2] = (W_)&stg_ctoi_F1_info;
960 Sp[-1] = BCO_PTR(o_bco);
965 case bci_PUSH_ALTS_D: {
966 int o_bco = BCO_NEXT;
967 Sp[-2] = (W_)&stg_ctoi_D1_info;
968 Sp[-1] = BCO_PTR(o_bco);
973 case bci_PUSH_ALTS_L: {
974 int o_bco = BCO_NEXT;
975 Sp[-2] = (W_)&stg_ctoi_L1_info;
976 Sp[-1] = BCO_PTR(o_bco);
981 case bci_PUSH_ALTS_V: {
982 int o_bco = BCO_NEXT;
983 Sp[-2] = (W_)&stg_ctoi_V_info;
984 Sp[-1] = BCO_PTR(o_bco);
989 case bci_PUSH_APPLY_N:
990 Sp--; Sp[0] = (W_)&stg_ap_n_info;
992 case bci_PUSH_APPLY_V:
993 Sp--; Sp[0] = (W_)&stg_ap_v_info;
995 case bci_PUSH_APPLY_F:
996 Sp--; Sp[0] = (W_)&stg_ap_f_info;
998 case bci_PUSH_APPLY_D:
999 Sp--; Sp[0] = (W_)&stg_ap_d_info;
1001 case bci_PUSH_APPLY_L:
1002 Sp--; Sp[0] = (W_)&stg_ap_l_info;
1004 case bci_PUSH_APPLY_P:
1005 Sp--; Sp[0] = (W_)&stg_ap_p_info;
1007 case bci_PUSH_APPLY_PP:
1008 Sp--; Sp[0] = (W_)&stg_ap_pp_info;
1010 case bci_PUSH_APPLY_PPP:
1011 Sp--; Sp[0] = (W_)&stg_ap_ppp_info;
1013 case bci_PUSH_APPLY_PPPP:
1014 Sp--; Sp[0] = (W_)&stg_ap_pppp_info;
1016 case bci_PUSH_APPLY_PPPPP:
1017 Sp--; Sp[0] = (W_)&stg_ap_ppppp_info;
1019 case bci_PUSH_APPLY_PPPPPP:
1020 Sp--; Sp[0] = (W_)&stg_ap_pppppp_info;
1023 case bci_PUSH_UBX: {
1025 int o_lits = BCO_NEXT;
1026 int n_words = BCO_NEXT;
1028 for (i = 0; i < n_words; i++) {
1029 Sp[i] = (W_)BCO_LIT(o_lits+i);
1037 /* a_1, .. a_n, b_1, .. b_by, s => a_1, .. a_n, s */
1042 INTERP_TICK(it_slides);
1046 case bci_ALLOC_AP: {
1048 int n_payload = BCO_NEXT;
1049 ap = (StgAP*)allocate(AP_sizeW(n_payload));
1051 ap->n_args = n_payload;
1052 SET_HDR(ap, &stg_AP_info, CCS_SYSTEM/*ToDo*/)
1057 case bci_ALLOC_AP_NOUPD: {
1059 int n_payload = BCO_NEXT;
1060 ap = (StgAP*)allocate(AP_sizeW(n_payload));
1062 ap->n_args = n_payload;
1063 SET_HDR(ap, &stg_AP_NOUPD_info, CCS_SYSTEM/*ToDo*/)
1068 case bci_ALLOC_PAP: {
1070 int arity = BCO_NEXT;
1071 int n_payload = BCO_NEXT;
1072 pap = (StgPAP*)allocate(PAP_sizeW(n_payload));
1074 pap->n_args = n_payload;
1076 SET_HDR(pap, &stg_PAP_info, CCS_SYSTEM/*ToDo*/)
1083 int stkoff = BCO_NEXT;
1084 int n_payload = BCO_NEXT;
1085 StgAP* ap = (StgAP*)Sp[stkoff];
1086 ASSERT((int)ap->n_args == n_payload);
1087 ap->fun = (StgClosure*)Sp[0];
1089 // The function should be a BCO, and its bitmap should
1090 // cover the payload of the AP correctly.
1091 ASSERT(get_itbl(ap->fun)->type == BCO
1092 && BCO_BITMAP_SIZE(ap->fun) == ap->n_args);
1094 for (i = 0; i < n_payload; i++)
1095 ap->payload[i] = (StgClosure*)Sp[i+1];
1097 IF_DEBUG(interpreter,
1098 debugBelch("\tBuilt ");
1099 printObj((StgClosure*)ap);
1106 int stkoff = BCO_NEXT;
1107 int n_payload = BCO_NEXT;
1108 StgPAP* pap = (StgPAP*)Sp[stkoff];
1109 ASSERT((int)pap->n_args == n_payload);
1110 pap->fun = (StgClosure*)Sp[0];
1112 // The function should be a BCO
1113 ASSERT(get_itbl(pap->fun)->type == BCO);
1115 for (i = 0; i < n_payload; i++)
1116 pap->payload[i] = (StgClosure*)Sp[i+1];
1118 IF_DEBUG(interpreter,
1119 debugBelch("\tBuilt ");
1120 printObj((StgClosure*)pap);
1126 /* Unpack N ptr words from t.o.s constructor */
1128 int n_words = BCO_NEXT;
1129 StgClosure* con = (StgClosure*)Sp[0];
1131 for (i = 0; i < n_words; i++) {
1132 Sp[i] = (W_)con->payload[i];
1139 int o_itbl = BCO_NEXT;
1140 int n_words = BCO_NEXT;
1141 StgInfoTable* itbl = INFO_PTR_TO_STRUCT(BCO_LIT(o_itbl));
1142 int request = CONSTR_sizeW( itbl->layout.payload.ptrs,
1143 itbl->layout.payload.nptrs );
1144 StgClosure* con = (StgClosure*)allocate_NONUPD(request);
1145 ASSERT( itbl->layout.payload.ptrs + itbl->layout.payload.nptrs > 0);
1146 SET_HDR(con, (StgInfoTable*)BCO_LIT(o_itbl), CCS_SYSTEM/*ToDo*/);
1147 for (i = 0; i < n_words; i++) {
1148 con->payload[i] = (StgClosure*)Sp[i];
1153 IF_DEBUG(interpreter,
1154 debugBelch("\tBuilt ");
1155 printObj((StgClosure*)con);
1160 case bci_TESTLT_P: {
1161 unsigned int discr = BCO_NEXT;
1162 int failto = BCO_NEXT;
1163 StgClosure* con = (StgClosure*)Sp[0];
1164 if (GET_TAG(con) >= discr) {
1170 case bci_TESTEQ_P: {
1171 unsigned int discr = BCO_NEXT;
1172 int failto = BCO_NEXT;
1173 StgClosure* con = (StgClosure*)Sp[0];
1174 if (GET_TAG(con) != discr) {
1180 case bci_TESTLT_I: {
1181 // There should be an Int at Sp[1], and an info table at Sp[0].
1182 int discr = BCO_NEXT;
1183 int failto = BCO_NEXT;
1184 I_ stackInt = (I_)Sp[1];
1185 if (stackInt >= (I_)BCO_LIT(discr))
1190 case bci_TESTEQ_I: {
1191 // There should be an Int at Sp[1], and an info table at Sp[0].
1192 int discr = BCO_NEXT;
1193 int failto = BCO_NEXT;
1194 I_ stackInt = (I_)Sp[1];
1195 if (stackInt != (I_)BCO_LIT(discr)) {
1201 case bci_TESTLT_D: {
1202 // There should be a Double at Sp[1], and an info table at Sp[0].
1203 int discr = BCO_NEXT;
1204 int failto = BCO_NEXT;
1205 StgDouble stackDbl, discrDbl;
1206 stackDbl = PK_DBL( & Sp[1] );
1207 discrDbl = PK_DBL( & BCO_LIT(discr) );
1208 if (stackDbl >= discrDbl) {
1214 case bci_TESTEQ_D: {
1215 // There should be a Double at Sp[1], and an info table at Sp[0].
1216 int discr = BCO_NEXT;
1217 int failto = BCO_NEXT;
1218 StgDouble stackDbl, discrDbl;
1219 stackDbl = PK_DBL( & Sp[1] );
1220 discrDbl = PK_DBL( & BCO_LIT(discr) );
1221 if (stackDbl != discrDbl) {
1227 case bci_TESTLT_F: {
1228 // There should be a Float at Sp[1], and an info table at Sp[0].
1229 int discr = BCO_NEXT;
1230 int failto = BCO_NEXT;
1231 StgFloat stackFlt, discrFlt;
1232 stackFlt = PK_FLT( & Sp[1] );
1233 discrFlt = PK_FLT( & BCO_LIT(discr) );
1234 if (stackFlt >= discrFlt) {
1240 case bci_TESTEQ_F: {
1241 // There should be a Float at Sp[1], and an info table at Sp[0].
1242 int discr = BCO_NEXT;
1243 int failto = BCO_NEXT;
1244 StgFloat stackFlt, discrFlt;
1245 stackFlt = PK_FLT( & Sp[1] );
1246 discrFlt = PK_FLT( & BCO_LIT(discr) );
1247 if (stackFlt != discrFlt) {
1253 // Control-flow ish things
1255 // Context-switch check. We put it here to ensure that
1256 // the interpreter has done at least *some* work before
1257 // context switching: sometimes the scheduler can invoke
1258 // the interpreter with context_switch == 1, particularly
1259 // if the -C0 flag has been given on the cmd line.
1260 if (context_switch) {
1261 Sp--; Sp[0] = (W_)&stg_enter_info;
1262 RETURN_TO_SCHEDULER(ThreadInterpret, ThreadYielding);
1267 obj = (StgClosure *)Sp[0];
1273 Sp[0] = (W_)&stg_gc_unpt_r1_info;
1274 goto do_return_unboxed;
1277 Sp[0] = (W_)&stg_gc_unbx_r1_info;
1278 goto do_return_unboxed;
1281 Sp[0] = (W_)&stg_gc_f1_info;
1282 goto do_return_unboxed;
1285 Sp[0] = (W_)&stg_gc_d1_info;
1286 goto do_return_unboxed;
1289 Sp[0] = (W_)&stg_gc_l1_info;
1290 goto do_return_unboxed;
1293 Sp[0] = (W_)&stg_gc_void_info;
1294 goto do_return_unboxed;
1297 int stkoff = BCO_NEXT;
1298 signed short n = (signed short)(BCO_NEXT);
1299 Sp[stkoff] += (W_)n;
1305 int stk_offset = BCO_NEXT;
1306 int o_itbl = BCO_NEXT;
1307 void(*marshall_fn)(void*) = (void (*)(void*))BCO_LIT(o_itbl);
1309 RET_DYN_BITMAP_SIZE + RET_DYN_NONPTR_REGS_SIZE
1310 + sizeofW(StgRetDyn);
1314 // Arguments on the TSO stack are not good, because garbage
1315 // collection might move the TSO as soon as we call
1316 // suspendThread below.
1318 W_ arguments[stk_offset];
1320 memcpy(arguments, Sp, sizeof(W_) * stk_offset);
1323 // Restore the Haskell thread's current value of errno
1324 errno = cap->r.rCurrentTSO->saved_errno;
1326 // There are a bunch of non-ptr words on the stack (the
1327 // ccall args, the ccall fun address and space for the
1328 // result), which we need to cover with an info table
1329 // since we might GC during this call.
1331 // We know how many (non-ptr) words there are before the
1332 // next valid stack frame: it is the stk_offset arg to the
1333 // CCALL instruction. So we build a RET_DYN stack frame
1334 // on the stack frame to describe this chunk of stack.
1337 ((StgRetDyn *)Sp)->liveness = R1_PTR | N_NONPTRS(stk_offset);
1338 ((StgRetDyn *)Sp)->info = (StgInfoTable *)&stg_gc_gen_info;
1340 // save obj (pointer to the current BCO), since this
1341 // might move during the call. We use the R1 slot in the
1342 // RET_DYN frame for this, hence R1_PTR above.
1343 ((StgRetDyn *)Sp)->payload[0] = (StgClosure *)obj;
1345 SAVE_STACK_POINTERS;
1346 tok = suspendThread(&cap->r);
1348 #ifndef THREADED_RTS
1350 // suspendThread might have shifted the stack
1351 // around (stack squeezing), so we have to grab the real
1352 // Sp out of the TSO to find the ccall args again.
1354 marshall_fn ( (void*)(cap->r.rCurrentTSO->sp + ret_dyn_size) );
1357 // We already made a copy of the arguments above.
1359 marshall_fn ( arguments );
1362 // And restart the thread again, popping the RET_DYN frame.
1363 cap = (Capability *)((void *)((unsigned char*)resumeThread(tok) - sizeof(StgFunTable)));
1364 LOAD_STACK_POINTERS;
1366 // Re-load the pointer to the BCO from the RET_DYN frame,
1367 // it might have moved during the call. Also reload the
1368 // pointers to the components of the BCO.
1369 obj = ((StgRetDyn *)Sp)->payload[0];
1371 instrs = (StgWord16*)(bco->instrs->payload);
1372 literals = (StgWord*)(&bco->literals->payload[0]);
1373 ptrs = (StgPtr*)(&bco->ptrs->payload[0]);
1377 // Save the Haskell thread's current value of errno
1378 cap->r.rCurrentTSO->saved_errno = errno;
1382 // Copy the "arguments", which might include a return value,
1383 // back to the TSO stack. It would of course be enough to
1384 // just copy the return value, but we don't know the offset.
1385 memcpy(Sp, arguments, sizeof(W_) * stk_offset);
1392 /* BCO_NEXT modifies bciPtr, so be conservative. */
1393 int nextpc = BCO_NEXT;
1399 barf("interpretBCO: hit a CASEFAIL");
1403 barf("interpretBCO: unknown or unimplemented opcode %d",
1406 } /* switch on opcode */
1410 barf("interpretBCO: fell off end of the interpreter");