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-rw-r--r--rts/Interpreter.c1261
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diff --git a/rts/Interpreter.c b/rts/Interpreter.c
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--- /dev/null
+++ b/rts/Interpreter.c
@@ -0,0 +1,1261 @@
+/* -----------------------------------------------------------------------------
+ * Bytecode interpreter
+ *
+ * Copyright (c) The GHC Team, 1994-2002.
+ * ---------------------------------------------------------------------------*/
+
+#include "PosixSource.h"
+#include "Rts.h"
+#include "RtsAPI.h"
+#include "RtsUtils.h"
+#include "Closures.h"
+#include "TSO.h"
+#include "Schedule.h"
+#include "RtsFlags.h"
+#include "Storage.h"
+#include "LdvProfile.h"
+#include "Updates.h"
+#include "Sanity.h"
+#include "Liveness.h"
+
+#include "Bytecodes.h"
+#include "Printer.h"
+#include "Disassembler.h"
+#include "Interpreter.h"
+
+#include <string.h> /* for memcpy */
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+
+
+/* --------------------------------------------------------------------------
+ * The bytecode interpreter
+ * ------------------------------------------------------------------------*/
+
+/* Gather stats about entry, opcode, opcode-pair frequencies. For
+ tuning the interpreter. */
+
+/* #define INTERP_STATS */
+
+
+/* Sp points to the lowest live word on the stack. */
+
+#define BCO_NEXT instrs[bciPtr++]
+#define BCO_PTR(n) (W_)ptrs[n]
+#define BCO_LIT(n) literals[n]
+#define BCO_ITBL(n) itbls[n]
+
+#define LOAD_STACK_POINTERS \
+ Sp = cap->r.rCurrentTSO->sp; \
+ /* We don't change this ... */ \
+ SpLim = cap->r.rCurrentTSO->stack + RESERVED_STACK_WORDS;
+
+#define SAVE_STACK_POINTERS \
+ cap->r.rCurrentTSO->sp = Sp
+
+#define RETURN_TO_SCHEDULER(todo,retcode) \
+ SAVE_STACK_POINTERS; \
+ cap->r.rCurrentTSO->what_next = (todo); \
+ threadPaused(cap,cap->r.rCurrentTSO); \
+ cap->r.rRet = (retcode); \
+ return cap;
+
+#define RETURN_TO_SCHEDULER_NO_PAUSE(todo,retcode) \
+ SAVE_STACK_POINTERS; \
+ cap->r.rCurrentTSO->what_next = (todo); \
+ cap->r.rRet = (retcode); \
+ return cap;
+
+
+STATIC_INLINE StgPtr
+allocate_NONUPD (int n_words)
+{
+ return allocate(stg_max(sizeofW(StgHeader)+MIN_PAYLOAD_SIZE, n_words));
+}
+
+
+#ifdef INTERP_STATS
+
+/* Hacky stats, for tuning the interpreter ... */
+int it_unknown_entries[N_CLOSURE_TYPES];
+int it_total_unknown_entries;
+int it_total_entries;
+
+int it_retto_BCO;
+int it_retto_UPDATE;
+int it_retto_other;
+
+int it_slides;
+int it_insns;
+int it_BCO_entries;
+
+int it_ofreq[27];
+int it_oofreq[27][27];
+int it_lastopc;
+
+#define INTERP_TICK(n) (n)++
+
+void interp_startup ( void )
+{
+ int i, j;
+ it_retto_BCO = it_retto_UPDATE = it_retto_other = 0;
+ it_total_entries = it_total_unknown_entries = 0;
+ for (i = 0; i < N_CLOSURE_TYPES; i++)
+ it_unknown_entries[i] = 0;
+ it_slides = it_insns = it_BCO_entries = 0;
+ for (i = 0; i < 27; i++) it_ofreq[i] = 0;
+ for (i = 0; i < 27; i++)
+ for (j = 0; j < 27; j++)
+ it_oofreq[i][j] = 0;
+ it_lastopc = 0;
+}
+
+void interp_shutdown ( void )
+{
+ int i, j, k, o_max, i_max, j_max;
+ debugBelch("%d constrs entered -> (%d BCO, %d UPD, %d ??? )\n",
+ it_retto_BCO + it_retto_UPDATE + it_retto_other,
+ it_retto_BCO, it_retto_UPDATE, it_retto_other );
+ debugBelch("%d total entries, %d unknown entries \n",
+ it_total_entries, it_total_unknown_entries);
+ for (i = 0; i < N_CLOSURE_TYPES; i++) {
+ if (it_unknown_entries[i] == 0) continue;
+ debugBelch(" type %2d: unknown entries (%4.1f%%) == %d\n",
+ i, 100.0 * ((double)it_unknown_entries[i]) /
+ ((double)it_total_unknown_entries),
+ it_unknown_entries[i]);
+ }
+ debugBelch("%d insns, %d slides, %d BCO_entries\n",
+ it_insns, it_slides, it_BCO_entries);
+ for (i = 0; i < 27; i++)
+ debugBelch("opcode %2d got %d\n", i, it_ofreq[i] );
+
+ for (k = 1; k < 20; k++) {
+ o_max = 0;
+ i_max = j_max = 0;
+ for (i = 0; i < 27; i++) {
+ for (j = 0; j < 27; j++) {
+ if (it_oofreq[i][j] > o_max) {
+ o_max = it_oofreq[i][j];
+ i_max = i; j_max = j;
+ }
+ }
+ }
+
+ debugBelch("%d: count (%4.1f%%) %6d is %d then %d\n",
+ k, ((double)o_max) * 100.0 / ((double)it_insns), o_max,
+ i_max, j_max );
+ it_oofreq[i_max][j_max] = 0;
+
+ }
+}
+
+#else // !INTERP_STATS
+
+#define INTERP_TICK(n) /* nothing */
+
+#endif
+
+static StgWord app_ptrs_itbl[] = {
+ (W_)&stg_ap_p_info,
+ (W_)&stg_ap_pp_info,
+ (W_)&stg_ap_ppp_info,
+ (W_)&stg_ap_pppp_info,
+ (W_)&stg_ap_ppppp_info,
+ (W_)&stg_ap_pppppp_info,
+};
+
+Capability *
+interpretBCO (Capability* cap)
+{
+ // Use of register here is primarily to make it clear to compilers
+ // that these entities are non-aliasable.
+ register StgPtr Sp; // local state -- stack pointer
+ register StgPtr SpLim; // local state -- stack lim pointer
+ register StgClosure* obj;
+ nat n, m;
+
+ LOAD_STACK_POINTERS;
+
+ // ------------------------------------------------------------------------
+ // Case 1:
+ //
+ // We have a closure to evaluate. Stack looks like:
+ //
+ // | XXXX_info |
+ // +---------------+
+ // Sp | -------------------> closure
+ // +---------------+
+ //
+ if (Sp[0] == (W_)&stg_enter_info) {
+ Sp++;
+ goto eval;
+ }
+
+ // ------------------------------------------------------------------------
+ // Case 2:
+ //
+ // We have a BCO application to perform. Stack looks like:
+ //
+ // | .... |
+ // +---------------+
+ // | arg1 |
+ // +---------------+
+ // | BCO |
+ // +---------------+
+ // Sp | RET_BCO |
+ // +---------------+
+ //
+ else if (Sp[0] == (W_)&stg_apply_interp_info) {
+ obj = (StgClosure *)Sp[1];
+ Sp += 2;
+ goto run_BCO_fun;
+ }
+
+ // ------------------------------------------------------------------------
+ // Case 3:
+ //
+ // We have an unboxed value to return. See comment before
+ // do_return_unboxed, below.
+ //
+ else {
+ goto do_return_unboxed;
+ }
+
+ // Evaluate the object on top of the stack.
+eval:
+ obj = (StgClosure*)Sp[0]; Sp++;
+
+eval_obj:
+ INTERP_TICK(it_total_evals);
+
+ IF_DEBUG(interpreter,
+ debugBelch(
+ "\n---------------------------------------------------------------\n");
+ debugBelch("Evaluating: "); printObj(obj);
+ debugBelch("Sp = %p\n", Sp);
+ debugBelch("\n" );
+
+ printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
+ debugBelch("\n\n");
+ );
+
+ IF_DEBUG(sanity,checkStackChunk(Sp, cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size));
+
+ switch ( get_itbl(obj)->type ) {
+
+ case IND:
+ case IND_OLDGEN:
+ case IND_PERM:
+ case IND_OLDGEN_PERM:
+ case IND_STATIC:
+ {
+ obj = ((StgInd*)obj)->indirectee;
+ goto eval_obj;
+ }
+
+ case CONSTR:
+ case CONSTR_1_0:
+ case CONSTR_0_1:
+ case CONSTR_2_0:
+ case CONSTR_1_1:
+ case CONSTR_0_2:
+ case CONSTR_INTLIKE:
+ case CONSTR_CHARLIKE:
+ case CONSTR_STATIC:
+ case CONSTR_NOCAF_STATIC:
+ case FUN:
+ case FUN_1_0:
+ case FUN_0_1:
+ case FUN_2_0:
+ case FUN_1_1:
+ case FUN_0_2:
+ case FUN_STATIC:
+ case PAP:
+ // already in WHNF
+ break;
+
+ case BCO:
+ ASSERT(((StgBCO *)obj)->arity > 0);
+ break;
+
+ case AP: /* Copied from stg_AP_entry. */
+ {
+ nat i, words;
+ StgAP *ap;
+
+ ap = (StgAP*)obj;
+ words = ap->n_args;
+
+ // Stack check
+ if (Sp - (words+sizeofW(StgUpdateFrame)) < SpLim) {
+ Sp -= 2;
+ Sp[1] = (W_)obj;
+ Sp[0] = (W_)&stg_enter_info;
+ RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
+ }
+
+ /* Ok; we're safe. Party on. Push an update frame. */
+ Sp -= sizeofW(StgUpdateFrame);
+ {
+ StgUpdateFrame *__frame;
+ __frame = (StgUpdateFrame *)Sp;
+ SET_INFO(__frame, (StgInfoTable *)&stg_upd_frame_info);
+ __frame->updatee = (StgClosure *)(ap);
+ }
+
+ /* Reload the stack */
+ Sp -= words;
+ for (i=0; i < words; i++) {
+ Sp[i] = (W_)ap->payload[i];
+ }
+
+ obj = (StgClosure*)ap->fun;
+ ASSERT(get_itbl(obj)->type == BCO);
+ goto run_BCO_fun;
+ }
+
+ default:
+#ifdef INTERP_STATS
+ {
+ int j;
+
+ j = get_itbl(obj)->type;
+ ASSERT(j >= 0 && j < N_CLOSURE_TYPES);
+ it_unknown_entries[j]++;
+ it_total_unknown_entries++;
+ }
+#endif
+ {
+ // Can't handle this object; yield to scheduler
+ IF_DEBUG(interpreter,
+ debugBelch("evaluating unknown closure -- yielding to sched\n");
+ printObj(obj);
+ );
+ Sp -= 2;
+ Sp[1] = (W_)obj;
+ Sp[0] = (W_)&stg_enter_info;
+ RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
+ }
+ }
+
+ // ------------------------------------------------------------------------
+ // We now have an evaluated object (obj). The next thing to
+ // do is return it to the stack frame on top of the stack.
+do_return:
+ ASSERT(closure_HNF(obj));
+
+ IF_DEBUG(interpreter,
+ debugBelch(
+ "\n---------------------------------------------------------------\n");
+ debugBelch("Returning: "); printObj(obj);
+ debugBelch("Sp = %p\n", Sp);
+ debugBelch("\n" );
+ printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
+ debugBelch("\n\n");
+ );
+
+ IF_DEBUG(sanity,checkStackChunk(Sp, cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size));
+
+ switch (get_itbl((StgClosure *)Sp)->type) {
+
+ case RET_SMALL: {
+ const StgInfoTable *info;
+
+ // NOTE: not using get_itbl().
+ info = ((StgClosure *)Sp)->header.info;
+ if (info == (StgInfoTable *)&stg_ap_v_info) {
+ n = 1; m = 0; goto do_apply;
+ }
+ if (info == (StgInfoTable *)&stg_ap_f_info) {
+ n = 1; m = 1; goto do_apply;
+ }
+ if (info == (StgInfoTable *)&stg_ap_d_info) {
+ n = 1; m = sizeofW(StgDouble); goto do_apply;
+ }
+ if (info == (StgInfoTable *)&stg_ap_l_info) {
+ n = 1; m = sizeofW(StgInt64); goto do_apply;
+ }
+ if (info == (StgInfoTable *)&stg_ap_n_info) {
+ n = 1; m = 1; goto do_apply;
+ }
+ if (info == (StgInfoTable *)&stg_ap_p_info) {
+ n = 1; m = 1; goto do_apply;
+ }
+ if (info == (StgInfoTable *)&stg_ap_pp_info) {
+ n = 2; m = 2; goto do_apply;
+ }
+ if (info == (StgInfoTable *)&stg_ap_ppp_info) {
+ n = 3; m = 3; goto do_apply;
+ }
+ if (info == (StgInfoTable *)&stg_ap_pppp_info) {
+ n = 4; m = 4; goto do_apply;
+ }
+ if (info == (StgInfoTable *)&stg_ap_ppppp_info) {
+ n = 5; m = 5; goto do_apply;
+ }
+ if (info == (StgInfoTable *)&stg_ap_pppppp_info) {
+ n = 6; m = 6; goto do_apply;
+ }
+ goto do_return_unrecognised;
+ }
+
+ case UPDATE_FRAME:
+ // Returning to an update frame: do the update, pop the update
+ // frame, and continue with the next stack frame.
+ INTERP_TICK(it_retto_UPDATE);
+ UPD_IND(((StgUpdateFrame *)Sp)->updatee, obj);
+ Sp += sizeofW(StgUpdateFrame);
+ goto do_return;
+
+ case RET_BCO:
+ // Returning to an interpreted continuation: put the object on
+ // the stack, and start executing the BCO.
+ INTERP_TICK(it_retto_BCO);
+ Sp--;
+ Sp[0] = (W_)obj;
+ obj = (StgClosure*)Sp[2];
+ ASSERT(get_itbl(obj)->type == BCO);
+ goto run_BCO_return;
+
+ default:
+ do_return_unrecognised:
+ {
+ // Can't handle this return address; yield to scheduler
+ INTERP_TICK(it_retto_other);
+ IF_DEBUG(interpreter,
+ debugBelch("returning to unknown frame -- yielding to sched\n");
+ printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
+ );
+ Sp -= 2;
+ Sp[1] = (W_)obj;
+ Sp[0] = (W_)&stg_enter_info;
+ RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
+ }
+ }
+
+ // -------------------------------------------------------------------------
+ // Returning an unboxed value. The stack looks like this:
+ //
+ // | .... |
+ // +---------------+
+ // | fv2 |
+ // +---------------+
+ // | fv1 |
+ // +---------------+
+ // | BCO |
+ // +---------------+
+ // | stg_ctoi_ret_ |
+ // +---------------+
+ // | retval |
+ // +---------------+
+ // | XXXX_info |
+ // +---------------+
+ //
+ // where XXXX_info is one of the stg_gc_unbx_r1_info family.
+ //
+ // We're only interested in the case when the real return address
+ // is a BCO; otherwise we'll return to the scheduler.
+
+do_return_unboxed:
+ {
+ int offset;
+
+ ASSERT( Sp[0] == (W_)&stg_gc_unbx_r1_info
+ || Sp[0] == (W_)&stg_gc_unpt_r1_info
+ || Sp[0] == (W_)&stg_gc_f1_info
+ || Sp[0] == (W_)&stg_gc_d1_info
+ || Sp[0] == (W_)&stg_gc_l1_info
+ || Sp[0] == (W_)&stg_gc_void_info // VoidRep
+ );
+
+ // get the offset of the stg_ctoi_ret_XXX itbl
+ offset = stack_frame_sizeW((StgClosure *)Sp);
+
+ switch (get_itbl((StgClosure *)Sp+offset)->type) {
+
+ case RET_BCO:
+ // Returning to an interpreted continuation: put the object on
+ // the stack, and start executing the BCO.
+ INTERP_TICK(it_retto_BCO);
+ obj = (StgClosure*)Sp[offset+1];
+ ASSERT(get_itbl(obj)->type == BCO);
+ goto run_BCO_return_unboxed;
+
+ default:
+ {
+ // Can't handle this return address; yield to scheduler
+ INTERP_TICK(it_retto_other);
+ IF_DEBUG(interpreter,
+ debugBelch("returning to unknown frame -- yielding to sched\n");
+ printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
+ );
+ RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
+ }
+ }
+ }
+ // not reached.
+
+
+ // -------------------------------------------------------------------------
+ // Application...
+
+do_apply:
+ // we have a function to apply (obj), and n arguments taking up m
+ // words on the stack. The info table (stg_ap_pp_info or whatever)
+ // is on top of the arguments on the stack.
+ {
+ switch (get_itbl(obj)->type) {
+
+ case PAP: {
+ StgPAP *pap;
+ nat i, arity;
+
+ pap = (StgPAP *)obj;
+
+ // we only cope with PAPs whose function is a BCO
+ if (get_itbl(pap->fun)->type != BCO) {
+ goto defer_apply_to_sched;
+ }
+
+ Sp++;
+ arity = pap->arity;
+ ASSERT(arity > 0);
+ if (arity < n) {
+ // n must be greater than 1, and the only kinds of
+ // application we support with more than one argument
+ // are all pointers...
+ //
+ // Shuffle the args for this function down, and put
+ // the appropriate info table in the gap.
+ for (i = 0; i < arity; i++) {
+ Sp[(int)i-1] = Sp[i];
+ // ^^^^^ careful, i-1 might be negative, but i in unsigned
+ }
+ Sp[arity-1] = app_ptrs_itbl[n-arity-1];
+ Sp--;
+ // unpack the PAP's arguments onto the stack
+ Sp -= pap->n_args;
+ for (i = 0; i < pap->n_args; i++) {
+ Sp[i] = (W_)pap->payload[i];
+ }
+ obj = pap->fun;
+ goto run_BCO_fun;
+ }
+ else if (arity == n) {
+ Sp -= pap->n_args;
+ for (i = 0; i < pap->n_args; i++) {
+ Sp[i] = (W_)pap->payload[i];
+ }
+ obj = pap->fun;
+ goto run_BCO_fun;
+ }
+ else /* arity > n */ {
+ // build a new PAP and return it.
+ StgPAP *new_pap;
+ new_pap = (StgPAP *)allocate(PAP_sizeW(pap->n_args + m));
+ SET_HDR(new_pap,&stg_PAP_info,CCCS);
+ new_pap->arity = pap->arity - n;
+ new_pap->n_args = pap->n_args + m;
+ new_pap->fun = pap->fun;
+ for (i = 0; i < pap->n_args; i++) {
+ new_pap->payload[i] = pap->payload[i];
+ }
+ for (i = 0; i < m; i++) {
+ new_pap->payload[pap->n_args + i] = (StgClosure *)Sp[i];
+ }
+ obj = (StgClosure *)new_pap;
+ Sp += m;
+ goto do_return;
+ }
+ }
+
+ case BCO: {
+ nat arity, i;
+
+ Sp++;
+ arity = ((StgBCO *)obj)->arity;
+ ASSERT(arity > 0);
+ if (arity < n) {
+ // n must be greater than 1, and the only kinds of
+ // application we support with more than one argument
+ // are all pointers...
+ //
+ // Shuffle the args for this function down, and put
+ // the appropriate info table in the gap.
+ for (i = 0; i < arity; i++) {
+ Sp[(int)i-1] = Sp[i];
+ // ^^^^^ careful, i-1 might be negative, but i in unsigned
+ }
+ Sp[arity-1] = app_ptrs_itbl[n-arity-1];
+ Sp--;
+ goto run_BCO_fun;
+ }
+ else if (arity == n) {
+ goto run_BCO_fun;
+ }
+ else /* arity > n */ {
+ // build a PAP and return it.
+ StgPAP *pap;
+ nat i;
+ pap = (StgPAP *)allocate(PAP_sizeW(m));
+ SET_HDR(pap, &stg_PAP_info,CCCS);
+ pap->arity = arity - n;
+ pap->fun = obj;
+ pap->n_args = m;
+ for (i = 0; i < m; i++) {
+ pap->payload[i] = (StgClosure *)Sp[i];
+ }
+ obj = (StgClosure *)pap;
+ Sp += m;
+ goto do_return;
+ }
+ }
+
+ // No point in us applying machine-code functions
+ default:
+ defer_apply_to_sched:
+ Sp -= 2;
+ Sp[1] = (W_)obj;
+ Sp[0] = (W_)&stg_enter_info;
+ RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
+ }
+
+ // ------------------------------------------------------------------------
+ // Ok, we now have a bco (obj), and its arguments are all on the
+ // stack. We can start executing the byte codes.
+ //
+ // The stack is in one of two states. First, if this BCO is a
+ // function:
+ //
+ // | .... |
+ // +---------------+
+ // | arg2 |
+ // +---------------+
+ // | arg1 |
+ // +---------------+
+ //
+ // Second, if this BCO is a continuation:
+ //
+ // | .... |
+ // +---------------+
+ // | fv2 |
+ // +---------------+
+ // | fv1 |
+ // +---------------+
+ // | BCO |
+ // +---------------+
+ // | stg_ctoi_ret_ |
+ // +---------------+
+ // | retval |
+ // +---------------+
+ //
+ // where retval is the value being returned to this continuation.
+ // In the event of a stack check, heap check, or context switch,
+ // we need to leave the stack in a sane state so the garbage
+ // collector can find all the pointers.
+ //
+ // (1) BCO is a function: the BCO's bitmap describes the
+ // pointerhood of the arguments.
+ //
+ // (2) BCO is a continuation: BCO's bitmap describes the
+ // pointerhood of the free variables.
+ //
+ // Sadly we have three different kinds of stack/heap/cswitch check
+ // to do:
+
+run_BCO_return:
+ // Heap check
+ if (doYouWantToGC()) {
+ Sp--; Sp[0] = (W_)&stg_enter_info;
+ RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
+ }
+ // Stack checks aren't necessary at return points, the stack use
+ // is aggregated into the enclosing function entry point.
+ goto run_BCO;
+
+run_BCO_return_unboxed:
+ // Heap check
+ if (doYouWantToGC()) {
+ RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
+ }
+ // Stack checks aren't necessary at return points, the stack use
+ // is aggregated into the enclosing function entry point.
+ goto run_BCO;
+
+run_BCO_fun:
+ IF_DEBUG(sanity,
+ Sp -= 2;
+ Sp[1] = (W_)obj;
+ Sp[0] = (W_)&stg_apply_interp_info;
+ checkStackChunk(Sp,SpLim);
+ Sp += 2;
+ );
+
+ // Heap check
+ if (doYouWantToGC()) {
+ Sp -= 2;
+ Sp[1] = (W_)obj;
+ Sp[0] = (W_)&stg_apply_interp_info; // placeholder, really
+ RETURN_TO_SCHEDULER(ThreadInterpret, HeapOverflow);
+ }
+
+ // Stack check
+ if (Sp - INTERP_STACK_CHECK_THRESH < SpLim) {
+ Sp -= 2;
+ Sp[1] = (W_)obj;
+ Sp[0] = (W_)&stg_apply_interp_info; // placeholder, really
+ RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
+ }
+ goto run_BCO;
+
+ // Now, actually interpret the BCO... (no returning to the
+ // scheduler again until the stack is in an orderly state).
+run_BCO:
+ INTERP_TICK(it_BCO_entries);
+ {
+ register int bciPtr = 1; /* instruction pointer */
+ register StgBCO* bco = (StgBCO*)obj;
+ register StgWord16* instrs = (StgWord16*)(bco->instrs->payload);
+ register StgWord* literals = (StgWord*)(&bco->literals->payload[0]);
+ register StgPtr* ptrs = (StgPtr*)(&bco->ptrs->payload[0]);
+ register StgInfoTable** itbls = (StgInfoTable**)
+ (&bco->itbls->payload[0]);
+
+#ifdef INTERP_STATS
+ it_lastopc = 0; /* no opcode */
+#endif
+
+ nextInsn:
+ ASSERT(bciPtr <= instrs[0]);
+ IF_DEBUG(interpreter,
+ //if (do_print_stack) {
+ //debugBelch("\n-- BEGIN stack\n");
+ //printStack(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size,iSu);
+ //debugBelch("-- END stack\n\n");
+ //}
+ debugBelch("Sp = %p pc = %d ", Sp, bciPtr);
+ disInstr(bco,bciPtr);
+ if (0) { int i;
+ debugBelch("\n");
+ for (i = 8; i >= 0; i--) {
+ debugBelch("%d %p\n", i, (StgPtr)(*(Sp+i)));
+ }
+ debugBelch("\n");
+ }
+ //if (do_print_stack) checkStack(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size,iSu);
+ );
+
+ INTERP_TICK(it_insns);
+
+#ifdef INTERP_STATS
+ ASSERT( (int)instrs[bciPtr] >= 0 && (int)instrs[bciPtr] < 27 );
+ it_ofreq[ (int)instrs[bciPtr] ] ++;
+ it_oofreq[ it_lastopc ][ (int)instrs[bciPtr] ] ++;
+ it_lastopc = (int)instrs[bciPtr];
+#endif
+
+ switch (BCO_NEXT) {
+
+ case bci_STKCHECK: {
+ // Explicit stack check at the beginning of a function
+ // *only* (stack checks in case alternatives are
+ // propagated to the enclosing function).
+ int stk_words_reqd = BCO_NEXT + 1;
+ if (Sp - stk_words_reqd < SpLim) {
+ Sp -= 2;
+ Sp[1] = (W_)obj;
+ Sp[0] = (W_)&stg_apply_interp_info;
+ RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
+ } else {
+ goto nextInsn;
+ }
+ }
+
+ case bci_PUSH_L: {
+ int o1 = BCO_NEXT;
+ Sp[-1] = Sp[o1];
+ Sp--;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_LL: {
+ int o1 = BCO_NEXT;
+ int o2 = BCO_NEXT;
+ Sp[-1] = Sp[o1];
+ Sp[-2] = Sp[o2];
+ Sp -= 2;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_LLL: {
+ int o1 = BCO_NEXT;
+ int o2 = BCO_NEXT;
+ int o3 = BCO_NEXT;
+ Sp[-1] = Sp[o1];
+ Sp[-2] = Sp[o2];
+ Sp[-3] = Sp[o3];
+ Sp -= 3;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_G: {
+ int o1 = BCO_NEXT;
+ Sp[-1] = BCO_PTR(o1);
+ Sp -= 1;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_ALTS: {
+ int o_bco = BCO_NEXT;
+ Sp[-2] = (W_)&stg_ctoi_R1p_info;
+ Sp[-1] = BCO_PTR(o_bco);
+ Sp -= 2;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_ALTS_P: {
+ int o_bco = BCO_NEXT;
+ Sp[-2] = (W_)&stg_ctoi_R1unpt_info;
+ Sp[-1] = BCO_PTR(o_bco);
+ Sp -= 2;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_ALTS_N: {
+ int o_bco = BCO_NEXT;
+ Sp[-2] = (W_)&stg_ctoi_R1n_info;
+ Sp[-1] = BCO_PTR(o_bco);
+ Sp -= 2;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_ALTS_F: {
+ int o_bco = BCO_NEXT;
+ Sp[-2] = (W_)&stg_ctoi_F1_info;
+ Sp[-1] = BCO_PTR(o_bco);
+ Sp -= 2;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_ALTS_D: {
+ int o_bco = BCO_NEXT;
+ Sp[-2] = (W_)&stg_ctoi_D1_info;
+ Sp[-1] = BCO_PTR(o_bco);
+ Sp -= 2;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_ALTS_L: {
+ int o_bco = BCO_NEXT;
+ Sp[-2] = (W_)&stg_ctoi_L1_info;
+ Sp[-1] = BCO_PTR(o_bco);
+ Sp -= 2;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_ALTS_V: {
+ int o_bco = BCO_NEXT;
+ Sp[-2] = (W_)&stg_ctoi_V_info;
+ Sp[-1] = BCO_PTR(o_bco);
+ Sp -= 2;
+ goto nextInsn;
+ }
+
+ case bci_PUSH_APPLY_N:
+ Sp--; Sp[0] = (W_)&stg_ap_n_info;
+ goto nextInsn;
+ case bci_PUSH_APPLY_V:
+ Sp--; Sp[0] = (W_)&stg_ap_v_info;
+ goto nextInsn;
+ case bci_PUSH_APPLY_F:
+ Sp--; Sp[0] = (W_)&stg_ap_f_info;
+ goto nextInsn;
+ case bci_PUSH_APPLY_D:
+ Sp--; Sp[0] = (W_)&stg_ap_d_info;
+ goto nextInsn;
+ case bci_PUSH_APPLY_L:
+ Sp--; Sp[0] = (W_)&stg_ap_l_info;
+ goto nextInsn;
+ case bci_PUSH_APPLY_P:
+ Sp--; Sp[0] = (W_)&stg_ap_p_info;
+ goto nextInsn;
+ case bci_PUSH_APPLY_PP:
+ Sp--; Sp[0] = (W_)&stg_ap_pp_info;
+ goto nextInsn;
+ case bci_PUSH_APPLY_PPP:
+ Sp--; Sp[0] = (W_)&stg_ap_ppp_info;
+ goto nextInsn;
+ case bci_PUSH_APPLY_PPPP:
+ Sp--; Sp[0] = (W_)&stg_ap_pppp_info;
+ goto nextInsn;
+ case bci_PUSH_APPLY_PPPPP:
+ Sp--; Sp[0] = (W_)&stg_ap_ppppp_info;
+ goto nextInsn;
+ case bci_PUSH_APPLY_PPPPPP:
+ Sp--; Sp[0] = (W_)&stg_ap_pppppp_info;
+ goto nextInsn;
+
+ case bci_PUSH_UBX: {
+ int i;
+ int o_lits = BCO_NEXT;
+ int n_words = BCO_NEXT;
+ Sp -= n_words;
+ for (i = 0; i < n_words; i++) {
+ Sp[i] = (W_)BCO_LIT(o_lits+i);
+ }
+ goto nextInsn;
+ }
+
+ case bci_SLIDE: {
+ int n = BCO_NEXT;
+ int by = BCO_NEXT;
+ /* a_1, .. a_n, b_1, .. b_by, s => a_1, .. a_n, s */
+ while(--n >= 0) {
+ Sp[n+by] = Sp[n];
+ }
+ Sp += by;
+ INTERP_TICK(it_slides);
+ goto nextInsn;
+ }
+
+ case bci_ALLOC_AP: {
+ StgAP* ap;
+ int n_payload = BCO_NEXT;
+ ap = (StgAP*)allocate(AP_sizeW(n_payload));
+ Sp[-1] = (W_)ap;
+ ap->n_args = n_payload;
+ SET_HDR(ap, &stg_AP_info, CCS_SYSTEM/*ToDo*/)
+ Sp --;
+ goto nextInsn;
+ }
+
+ case bci_ALLOC_PAP: {
+ StgPAP* pap;
+ int arity = BCO_NEXT;
+ int n_payload = BCO_NEXT;
+ pap = (StgPAP*)allocate(PAP_sizeW(n_payload));
+ Sp[-1] = (W_)pap;
+ pap->n_args = n_payload;
+ pap->arity = arity;
+ SET_HDR(pap, &stg_PAP_info, CCS_SYSTEM/*ToDo*/)
+ Sp --;
+ goto nextInsn;
+ }
+
+ case bci_MKAP: {
+ int i;
+ int stkoff = BCO_NEXT;
+ int n_payload = BCO_NEXT;
+ StgAP* ap = (StgAP*)Sp[stkoff];
+ ASSERT((int)ap->n_args == n_payload);
+ ap->fun = (StgClosure*)Sp[0];
+
+ // The function should be a BCO, and its bitmap should
+ // cover the payload of the AP correctly.
+ ASSERT(get_itbl(ap->fun)->type == BCO
+ && BCO_BITMAP_SIZE(ap->fun) == ap->n_args);
+
+ for (i = 0; i < n_payload; i++)
+ ap->payload[i] = (StgClosure*)Sp[i+1];
+ Sp += n_payload+1;
+ IF_DEBUG(interpreter,
+ debugBelch("\tBuilt ");
+ printObj((StgClosure*)ap);
+ );
+ goto nextInsn;
+ }
+
+ case bci_MKPAP: {
+ int i;
+ int stkoff = BCO_NEXT;
+ int n_payload = BCO_NEXT;
+ StgPAP* pap = (StgPAP*)Sp[stkoff];
+ ASSERT((int)pap->n_args == n_payload);
+ pap->fun = (StgClosure*)Sp[0];
+
+ // The function should be a BCO
+ ASSERT(get_itbl(pap->fun)->type == BCO);
+
+ for (i = 0; i < n_payload; i++)
+ pap->payload[i] = (StgClosure*)Sp[i+1];
+ Sp += n_payload+1;
+ IF_DEBUG(interpreter,
+ debugBelch("\tBuilt ");
+ printObj((StgClosure*)pap);
+ );
+ goto nextInsn;
+ }
+
+ case bci_UNPACK: {
+ /* Unpack N ptr words from t.o.s constructor */
+ int i;
+ int n_words = BCO_NEXT;
+ StgClosure* con = (StgClosure*)Sp[0];
+ Sp -= n_words;
+ for (i = 0; i < n_words; i++) {
+ Sp[i] = (W_)con->payload[i];
+ }
+ goto nextInsn;
+ }
+
+ case bci_PACK: {
+ int i;
+ int o_itbl = BCO_NEXT;
+ int n_words = BCO_NEXT;
+ StgInfoTable* itbl = INFO_PTR_TO_STRUCT(BCO_ITBL(o_itbl));
+ int request = CONSTR_sizeW( itbl->layout.payload.ptrs,
+ itbl->layout.payload.nptrs );
+ StgClosure* con = (StgClosure*)allocate_NONUPD(request);
+ ASSERT( itbl->layout.payload.ptrs + itbl->layout.payload.nptrs > 0);
+ SET_HDR(con, BCO_ITBL(o_itbl), CCS_SYSTEM/*ToDo*/);
+ for (i = 0; i < n_words; i++) {
+ con->payload[i] = (StgClosure*)Sp[i];
+ }
+ Sp += n_words;
+ Sp --;
+ Sp[0] = (W_)con;
+ IF_DEBUG(interpreter,
+ debugBelch("\tBuilt ");
+ printObj((StgClosure*)con);
+ );
+ goto nextInsn;
+ }
+
+ case bci_TESTLT_P: {
+ unsigned int discr = BCO_NEXT;
+ int failto = BCO_NEXT;
+ StgClosure* con = (StgClosure*)Sp[0];
+ if (GET_TAG(con) >= discr) {
+ bciPtr = failto;
+ }
+ goto nextInsn;
+ }
+
+ case bci_TESTEQ_P: {
+ unsigned int discr = BCO_NEXT;
+ int failto = BCO_NEXT;
+ StgClosure* con = (StgClosure*)Sp[0];
+ if (GET_TAG(con) != discr) {
+ bciPtr = failto;
+ }
+ goto nextInsn;
+ }
+
+ case bci_TESTLT_I: {
+ // There should be an Int at Sp[1], and an info table at Sp[0].
+ int discr = BCO_NEXT;
+ int failto = BCO_NEXT;
+ I_ stackInt = (I_)Sp[1];
+ if (stackInt >= (I_)BCO_LIT(discr))
+ bciPtr = failto;
+ goto nextInsn;
+ }
+
+ case bci_TESTEQ_I: {
+ // There should be an Int at Sp[1], and an info table at Sp[0].
+ int discr = BCO_NEXT;
+ int failto = BCO_NEXT;
+ I_ stackInt = (I_)Sp[1];
+ if (stackInt != (I_)BCO_LIT(discr)) {
+ bciPtr = failto;
+ }
+ goto nextInsn;
+ }
+
+ case bci_TESTLT_D: {
+ // There should be a Double at Sp[1], and an info table at Sp[0].
+ int discr = BCO_NEXT;
+ int failto = BCO_NEXT;
+ StgDouble stackDbl, discrDbl;
+ stackDbl = PK_DBL( & Sp[1] );
+ discrDbl = PK_DBL( & BCO_LIT(discr) );
+ if (stackDbl >= discrDbl) {
+ bciPtr = failto;
+ }
+ goto nextInsn;
+ }
+
+ case bci_TESTEQ_D: {
+ // There should be a Double at Sp[1], and an info table at Sp[0].
+ int discr = BCO_NEXT;
+ int failto = BCO_NEXT;
+ StgDouble stackDbl, discrDbl;
+ stackDbl = PK_DBL( & Sp[1] );
+ discrDbl = PK_DBL( & BCO_LIT(discr) );
+ if (stackDbl != discrDbl) {
+ bciPtr = failto;
+ }
+ goto nextInsn;
+ }
+
+ case bci_TESTLT_F: {
+ // There should be a Float at Sp[1], and an info table at Sp[0].
+ int discr = BCO_NEXT;
+ int failto = BCO_NEXT;
+ StgFloat stackFlt, discrFlt;
+ stackFlt = PK_FLT( & Sp[1] );
+ discrFlt = PK_FLT( & BCO_LIT(discr) );
+ if (stackFlt >= discrFlt) {
+ bciPtr = failto;
+ }
+ goto nextInsn;
+ }
+
+ case bci_TESTEQ_F: {
+ // There should be a Float at Sp[1], and an info table at Sp[0].
+ int discr = BCO_NEXT;
+ int failto = BCO_NEXT;
+ StgFloat stackFlt, discrFlt;
+ stackFlt = PK_FLT( & Sp[1] );
+ discrFlt = PK_FLT( & BCO_LIT(discr) );
+ if (stackFlt != discrFlt) {
+ bciPtr = failto;
+ }
+ goto nextInsn;
+ }
+
+ // Control-flow ish things
+ case bci_ENTER:
+ // Context-switch check. We put it here to ensure that
+ // the interpreter has done at least *some* work before
+ // context switching: sometimes the scheduler can invoke
+ // the interpreter with context_switch == 1, particularly
+ // if the -C0 flag has been given on the cmd line.
+ if (context_switch) {
+ Sp--; Sp[0] = (W_)&stg_enter_info;
+ RETURN_TO_SCHEDULER(ThreadInterpret, ThreadYielding);
+ }
+ goto eval;
+
+ case bci_RETURN:
+ obj = (StgClosure *)Sp[0];
+ Sp++;
+ goto do_return;
+
+ case bci_RETURN_P:
+ Sp--;
+ Sp[0] = (W_)&stg_gc_unpt_r1_info;
+ goto do_return_unboxed;
+ case bci_RETURN_N:
+ Sp--;
+ Sp[0] = (W_)&stg_gc_unbx_r1_info;
+ goto do_return_unboxed;
+ case bci_RETURN_F:
+ Sp--;
+ Sp[0] = (W_)&stg_gc_f1_info;
+ goto do_return_unboxed;
+ case bci_RETURN_D:
+ Sp--;
+ Sp[0] = (W_)&stg_gc_d1_info;
+ goto do_return_unboxed;
+ case bci_RETURN_L:
+ Sp--;
+ Sp[0] = (W_)&stg_gc_l1_info;
+ goto do_return_unboxed;
+ case bci_RETURN_V:
+ Sp--;
+ Sp[0] = (W_)&stg_gc_void_info;
+ goto do_return_unboxed;
+
+ case bci_SWIZZLE: {
+ int stkoff = BCO_NEXT;
+ signed short n = (signed short)(BCO_NEXT);
+ Sp[stkoff] += (W_)n;
+ goto nextInsn;
+ }
+
+ case bci_CCALL: {
+ void *tok;
+ int stk_offset = BCO_NEXT;
+ int o_itbl = BCO_NEXT;
+ void(*marshall_fn)(void*) = (void (*)(void*))BCO_LIT(o_itbl);
+ int ret_dyn_size =
+ RET_DYN_BITMAP_SIZE + RET_DYN_NONPTR_REGS_SIZE
+ + sizeofW(StgRetDyn);
+
+#ifdef THREADED_RTS
+ // Threaded RTS:
+ // Arguments on the TSO stack are not good, because garbage
+ // collection might move the TSO as soon as we call
+ // suspendThread below.
+
+ W_ arguments[stk_offset];
+
+ memcpy(arguments, Sp, sizeof(W_) * stk_offset);
+#endif
+
+ // Restore the Haskell thread's current value of errno
+ errno = cap->r.rCurrentTSO->saved_errno;
+
+ // There are a bunch of non-ptr words on the stack (the
+ // ccall args, the ccall fun address and space for the
+ // result), which we need to cover with an info table
+ // since we might GC during this call.
+ //
+ // We know how many (non-ptr) words there are before the
+ // next valid stack frame: it is the stk_offset arg to the
+ // CCALL instruction. So we build a RET_DYN stack frame
+ // on the stack frame to describe this chunk of stack.
+ //
+ Sp -= ret_dyn_size;
+ ((StgRetDyn *)Sp)->liveness = NO_PTRS | N_NONPTRS(stk_offset);
+ ((StgRetDyn *)Sp)->info = (StgInfoTable *)&stg_gc_gen_info;
+
+ SAVE_STACK_POINTERS;
+ tok = suspendThread(&cap->r);
+
+#ifndef THREADED_RTS
+ // Careful:
+ // suspendThread might have shifted the stack
+ // around (stack squeezing), so we have to grab the real
+ // Sp out of the TSO to find the ccall args again.
+
+ marshall_fn ( (void*)(cap->r.rCurrentTSO->sp + ret_dyn_size) );
+#else
+ // Threaded RTS:
+ // We already made a copy of the arguments above.
+
+ marshall_fn ( arguments );
+#endif
+
+ // And restart the thread again, popping the RET_DYN frame.
+ cap = (Capability *)((void *)((unsigned char*)resumeThread(tok) - sizeof(StgFunTable)));
+ LOAD_STACK_POINTERS;
+ Sp += ret_dyn_size;
+
+ // Save the Haskell thread's current value of errno
+ cap->r.rCurrentTSO->saved_errno = errno;
+
+#ifdef THREADED_RTS
+ // Threaded RTS:
+ // Copy the "arguments", which might include a return value,
+ // back to the TSO stack. It would of course be enough to
+ // just copy the return value, but we don't know the offset.
+ memcpy(Sp, arguments, sizeof(W_) * stk_offset);
+#endif
+
+ goto nextInsn;
+ }
+
+ case bci_JMP: {
+ /* BCO_NEXT modifies bciPtr, so be conservative. */
+ int nextpc = BCO_NEXT;
+ bciPtr = nextpc;
+ goto nextInsn;
+ }
+
+ case bci_CASEFAIL:
+ barf("interpretBCO: hit a CASEFAIL");
+
+ // Errors
+ default:
+ barf("interpretBCO: unknown or unimplemented opcode");
+
+ } /* switch on opcode */
+ }
+ }
+
+ barf("interpretBCO: fell off end of the interpreter");
+}
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