+# if CRUDE_PROFILING
+ cp_enter ( bco );
+# endif
+
+
+ bciPtr = &(bcoInstr(bco,0));
+
+ LoopTopLabel
+
+ ASSERT((StgWord)(PC) < bco->n_instrs);
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"Sp = %p\tSu = %p\tpc = %d\t", xSp, xSu, PC);
+ SSS;
+ disInstr(bco,PC);
+ if (0) { int i;
+ fprintf(stderr,"\n");
+ for (i = 8; i >= 0; i--)
+ fprintf(stderr, "%d %p\n", i, (StgPtr)(*(gSp+i)));
+ }
+ fprintf(stderr,"\n");
+ LLL;
+ );
+
+# if CRUDE_PROFILING
+ SSS; cp_bill_insns(1); LLL;
+# endif
+
+ Dispatch
+
+ Case(i_INTERNAL_ERROR):
+ barf("INTERNAL_ERROR at %p:%d",bco,PC-1);
+ Case(i_PANIC):
+ barf("PANIC at %p:%d",bco,PC-1);
+ Case(i_STK_CHECK):
+ {
+ int n = BCO_INSTR_8;
+ if (xSp - n < xSpLim) {
+ xPushCPtr((StgClosure*)bco); /* code to restart with */
+ RETURN(StackOverflow);
+ }
+ Continue;
+ }
+ Case(i_STK_CHECK_big):
+ {
+ int n = BCO_INSTR_16;
+ if (xSp - n < xSpLim) {
+ xPushCPtr((StgClosure*)bco); /* code to restart with */
+ RETURN(StackOverflow);
+ }
+ Continue;
+ }
+ Case(i_ARG_CHECK):
+ {
+ nat n = BCO_INSTR_8;
+ if ((StgPtr*)(xSp + n) > (StgPtr*)xSu) {
+ StgWord words = (P_)xSu - xSp;
+
+ /* first build a PAP */
+ ASSERT((P_)xSu >= xSp); /* was (words >= 0) but that's always true */
+ if (words == 0) { /* optimisation */
+ /* Skip building the PAP and update with an indirection. */
+ } else {
+ /* Build the PAP. */
+ /* In the evaluator, we avoid the need to do
+ * a heap check here by including the size of
+ * the PAP in the heap check we performed
+ * when we entered the BCO.
+ */
+ StgInt i;
+ StgPAP* pap;
+ SSS; pap = (StgPAP*)grabHpNonUpd(PAP_sizeW(words)); LLL;
+ SET_HDR(pap,&PAP_info,CC_pap);
+ pap->n_args = words;
+ pap->fun = obj;
+ for (i = 0; i < (I_)words; ++i) {
+ payloadWord(pap,i) = xSp[i];
+ }
+ xSp += words;
+ obj = stgCast(StgClosure*,pap);
+ }
+
+ /* now deal with "update frame" */
+ /* as an optimisation, we process all on top of stack */
+ /* instead of just the top one */
+ ASSERT(xSp==(P_)xSu);
+ do {
+ switch (get_itbl(xSu)->type) {
+ case CATCH_FRAME:
+ /* Hit a catch frame during an arg satisfaction check,
+ * so the thing returning (1) has not thrown an
+ * exception, and (2) is of functional type. Just
+ * zap the catch frame and carry on down the stack
+ * (looking for more arguments, basically).
+ */
+ SSS; PopCatchFrame(); LLL;
+ break;
+ case UPDATE_FRAME:
+ xPopUpdateFrame(obj);
+ break;
+ case STOP_FRAME:
+ SSS; PopStopFrame(obj); LLL;
+ RETURN(ThreadFinished);
+ case SEQ_FRAME:
+ SSS; PopSeqFrame(); LLL;
+ ASSERT(xSp != (P_)xSu);
+ /* Hit a SEQ frame during an arg satisfaction check.
+ * So now return to bco_info which is under the
+ * SEQ frame. The following code is copied from a
+ * case RET_BCO further down. (The reason why we're
+ * here is that something of functional type has
+ * been seq-d on, and we're now returning to the
+ * algebraic-case-continuation which forced the
+ * evaluation in the first place.)
+ */
+ {
+ StgClosure* ret;
+ (void)xPopPtr();
+ ret = xPopCPtr();
+ xPushPtr((P_)obj);
+ obj = ret;
+ goto enterLoop;
+ }
+ break;
+ default:
+ barf("Invalid update frame during argcheck");
+ }
+ } while (xSp==(P_)xSu);
+ goto enterLoop;
+ }
+ Continue;
+ }
+ Case(i_ALLOC_AP):
+ {
+ StgPtr p;
+ int words = BCO_INSTR_8;
+ SSS; p = grabHpUpd(AP_sizeW(words)); LLL;
+ xPushPtr(p);
+ Continue;
+ }
+ Case(i_ALLOC_CONSTR):
+ {
+ StgPtr p;
+ StgInfoTable* info = bcoConstAddr(bco,BCO_INSTR_8);
+ SSS; p = grabHpNonUpd(sizeW_fromITBL(info)); LLL;
+ SET_HDR((StgClosure*)p,info,??);
+ xPushPtr(p);
+ Continue;
+ }
+ Case(i_ALLOC_CONSTR_big):
+ {
+ StgPtr p;
+ int x = BCO_INSTR_16;
+ StgInfoTable* info = bcoConstAddr(bco,x);
+ SSS; p = grabHpNonUpd(sizeW_fromITBL(info)); LLL;
+ SET_HDR((StgClosure*)p,info,??);
+ xPushPtr(p);
+ Continue;
+ }
+ Case(i_MKAP):
+ {
+ int x = BCO_INSTR_8; /* ToDo: Word not Int! */
+ int y = BCO_INSTR_8;
+ StgAP_UPD* o = stgCast(StgAP_UPD*,xStackPtr(x));
+ SET_HDR(o,&AP_UPD_info,??);
+ o->n_args = y;
+ o->fun = stgCast(StgClosure*,xPopPtr());
+ for(x=0; x < y; ++x) {
+ payloadWord(o,x) = xPopWord();
+ }
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ Continue;
+ }
+ Case(i_MKAP_big):
+ {
+ int x, y;
+ StgAP_UPD* o;
+ x = BCO_INSTR_16;
+ y = BCO_INSTR_16;
+ o = stgCast(StgAP_UPD*,xStackPtr(x));
+ SET_HDR(o,&AP_UPD_info,??);
+ o->n_args = y;
+ o->fun = stgCast(StgClosure*,xPopPtr());
+ for(x=0; x < y; ++x) {
+ payloadWord(o,x) = xPopWord();
+ }
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ Continue;
+ }
+ Case(i_MKPAP):
+ {
+ int x = BCO_INSTR_8;
+ int y = BCO_INSTR_8;
+ StgPAP* o = stgCast(StgPAP*,xStackPtr(x));
+ SET_HDR(o,&PAP_info,??);
+ o->n_args = y;
+ o->fun = stgCast(StgClosure*,xPopPtr());
+ for(x=0; x < y; ++x) {
+ payloadWord(o,x) = xPopWord();
+ }
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ Continue;
+ }
+ Case(i_PACK):
+ {
+ int offset = BCO_INSTR_8;
+ StgClosure* o = stgCast(StgClosure*,xStackPtr(offset));
+ const StgInfoTable* info = get_itbl(o);
+ nat p = info->layout.payload.ptrs;
+ nat np = info->layout.payload.nptrs;
+ nat i;
+ for(i=0; i < p; ++i) {
+ o->payload[i] = xPopCPtr();
+ }
+ for(i=0; i < np; ++i) {
+ payloadWord(o,p+i) = 0xdeadbeef;
+ }
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ Continue;
+ }
+ Case(i_PACK_big):
+ {
+ int offset = BCO_INSTR_16;
+ StgClosure* o = stgCast(StgClosure*,xStackPtr(offset));
+ const StgInfoTable* info = get_itbl(o);
+ nat p = info->layout.payload.ptrs;
+ nat np = info->layout.payload.nptrs;
+ nat i;
+ for(i=0; i < p; ++i) {
+ o->payload[i] = xPopCPtr();
+ }
+ for(i=0; i < np; ++i) {
+ payloadWord(o,p+i) = 0xdeadbeef;
+ }
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ Continue;
+ }
+ Case(i_SLIDE):
+ {
+ int x = BCO_INSTR_8;
+ int y = BCO_INSTR_8;
+ ASSERT(xSp+x+y <= stgCast(StgPtr,xSu));
+ /* a_1, .. a_x, b_1, .. b_y, s => a_1, .. a_x, s */
+ while(--x >= 0) {
+ xSetStackWord(x+y,xStackWord(x));
+ }
+ xSp += y;
+ Continue;
+ }
+ Case(i_SLIDE_big):
+ {
+ int x, y;
+ x = BCO_INSTR_16;
+ y = BCO_INSTR_16;
+ ASSERT(xSp+x+y <= stgCast(StgPtr,xSu));
+ /* a_1, .. a_x, b_1, .. b_y, s => a_1, .. a_x, s */
+ while(--x >= 0) {
+ xSetStackWord(x+y,xStackWord(x));
+ }
+ xSp += y;
+ Continue;
+ }
+ Case(i_ENTER):
+ {
+ obj = xPopCPtr();
+ goto enterLoop;
+ }
+ Case(i_RETADDR):
+ {
+ xPushPtr(bcoConstPtr(bco,BCO_INSTR_8));
+ xPushPtr(stgCast(StgPtr,&ret_bco_info));
+ Continue;
+ }
+ Case(i_TEST):
+ {
+ int tag = BCO_INSTR_8;
+ StgWord offset = BCO_INSTR_16;
+ if (constrTag( (StgClosure*)xStackPtr(0) ) != tag) {
+ bciPtr += offset;
+ }
+ Continue;
+ }
+ Case(i_UNPACK):
+ {
+ StgClosure* o = stgCast(StgClosure*,xStackPtr(0));
+ const StgInfoTable* itbl = get_itbl(o);
+ int i = itbl->layout.payload.ptrs;
+ ASSERT( itbl->type == CONSTR
+ || itbl->type == CONSTR_STATIC
+ || itbl->type == CONSTR_NOCAF_STATIC
+ || itbl->type == CONSTR_1_0
+ || itbl->type == CONSTR_0_1
+ || itbl->type == CONSTR_2_0
+ || itbl->type == CONSTR_1_1
+ || itbl->type == CONSTR_0_2
+ );
+ while (--i>=0) {
+ xPushCPtr(o->payload[i]);
+ }
+ Continue;
+ }
+ Case(i_VAR_big):
+ {
+ int n = BCO_INSTR_16;
+ StgPtr p = xStackPtr(n);
+ xPushPtr(p);
+ Continue;
+ }
+ Case(i_VAR):
+ {
+ StgPtr p = xStackPtr(BCO_INSTR_8);
+ xPushPtr(p);
+ Continue;
+ }
+ Case(i_CONST):
+ {
+ xPushPtr(stgCast(StgPtr,bcoConstPtr(bco,BCO_INSTR_8)));
+ Continue;
+ }
+ Case(i_CONST_big):
+ {
+ int n = BCO_INSTR_16;
+ xPushPtr(stgCast(StgPtr,bcoConstPtr(bco,n)));
+ Continue;
+ }
+ Case(i_VOID):
+ {
+ SSS; PushTaggedRealWorld(); LLL;
+ Continue;
+ }
+ Case(i_VAR_INT):
+ {
+ StgInt i = xTaggedStackInt(BCO_INSTR_8);
+ xPushTaggedInt(i);
+ Continue;
+ }
+ Case(i_CONST_INT):
+ {
+ xPushTaggedInt(bcoConstInt(bco,BCO_INSTR_8));
+ Continue;
+ }
+ Case(i_CONST_INT_big):
+ {
+ int n = BCO_INSTR_16;
+ xPushTaggedInt(bcoConstInt(bco,n));
+ Continue;
+ }
+ Case(i_PACK_INT):
+ {
+ StgClosure* o;
+ SSS; o = (StgClosure*)grabHpNonUpd(Izh_sizeW); LLL;
+ SET_HDR(o,Izh_con_info,??);
+ payloadWord(o,0) = xPopTaggedInt();
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ xPushPtr(stgCast(StgPtr,o));
+ Continue;
+ }
+ Case(i_UNPACK_INT):
+ {
+ StgClosure* con = stgCast(StgClosure*,xStackPtr(0));
+ /* ASSERT(isIntLike(con)); */
+ xPushTaggedInt(payloadWord(con,0));
+ Continue;
+ }
+ Case(i_TEST_INT):
+ {
+ StgWord offset = BCO_INSTR_16;
+ StgInt x = xPopTaggedInt();
+ StgInt y = xPopTaggedInt();
+ if (x != y) {
+ bciPtr += offset;
+ }
+ Continue;
+ }
+ Case(i_CONST_INTEGER):
+ {
+ StgPtr p;
+ int n;
+ char* s = bcoConstAddr(bco,BCO_INSTR_8);
+ SSS;
+ n = size_fromStr(s);
+ p = CreateByteArrayToHoldInteger(n);
+ do_fromStr ( s, n, IntegerInsideByteArray(p));
+ SloppifyIntegerEnd(p);
+ LLL;
+ xPushPtr(p);
+ Continue;
+ }
+ Case(i_VAR_WORD):
+ {
+ StgWord w = xTaggedStackWord(BCO_INSTR_8);
+ xPushTaggedWord(w);
+ Continue;
+ }
+ Case(i_CONST_WORD):
+ {
+ xPushTaggedWord(bcoConstWord(bco,BCO_INSTR_8));
+ Continue;
+ }
+ Case(i_PACK_WORD):
+ {
+ StgClosure* o;
+ SSS; o = (StgClosure*)grabHpNonUpd(Wzh_sizeW); LLL;
+ SET_HDR(o,Wzh_con_info,??);
+ payloadWord(o,0) = xPopTaggedWord();
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ xPushPtr(stgCast(StgPtr,o));
+ Continue;
+ }
+ Case(i_UNPACK_WORD):
+ {
+ StgClosure* con = stgCast(StgClosure*,xStackPtr(0));
+ /* ASSERT(isWordLike(con)); */
+ xPushTaggedWord(payloadWord(con,0));
+ Continue;
+ }
+ Case(i_VAR_ADDR):
+ {
+ StgAddr a = xTaggedStackAddr(BCO_INSTR_8);
+ xPushTaggedAddr(a);
+ Continue;
+ }
+ Case(i_CONST_ADDR):
+ {
+ xPushTaggedAddr(bcoConstAddr(bco,BCO_INSTR_8));
+ Continue;
+ }
+ Case(i_CONST_ADDR_big):
+ {
+ int n = BCO_INSTR_16;
+ xPushTaggedAddr(bcoConstAddr(bco,n));
+ Continue;
+ }
+ Case(i_PACK_ADDR):
+ {
+ StgClosure* o;
+ SSS; o = (StgClosure*)grabHpNonUpd(Azh_sizeW); LLL;
+ SET_HDR(o,Azh_con_info,??);
+ payloadPtr(o,0) = xPopTaggedAddr();
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ xPushPtr(stgCast(StgPtr,o));
+ Continue;
+ }
+ Case(i_UNPACK_ADDR):
+ {
+ StgClosure* con = (StgClosure*)xStackPtr(0);
+ /* ASSERT(isAddrLike(con)); */
+ xPushTaggedAddr(payloadPtr(con,0));
+ Continue;
+ }
+ Case(i_VAR_CHAR):
+ {
+ StgChar c = xTaggedStackChar(BCO_INSTR_8);
+ xPushTaggedChar(c);
+ Continue;
+ }
+ Case(i_CONST_CHAR):
+ {
+ xPushTaggedChar(bcoConstChar(bco,BCO_INSTR_8));
+ Continue;
+ }
+ Case(i_PACK_CHAR):
+ {
+ StgClosure* o;
+ SSS; o = (StgClosure*)grabHpNonUpd(Czh_sizeW); LLL;
+ SET_HDR(o,Czh_con_info,??);
+ payloadWord(o,0) = xPopTaggedChar();
+ xPushPtr(stgCast(StgPtr,o));
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ Continue;
+ }
+ Case(i_UNPACK_CHAR):
+ {
+ StgClosure* con = stgCast(StgClosure*,xStackPtr(0));
+ /* ASSERT(isCharLike(con)); */
+ xPushTaggedChar(payloadWord(con,0));
+ Continue;
+ }
+ Case(i_VAR_FLOAT):
+ {
+ StgFloat f = xTaggedStackFloat(BCO_INSTR_8);
+ xPushTaggedFloat(f);
+ Continue;
+ }
+ Case(i_CONST_FLOAT):
+ {
+ xPushTaggedFloat(bcoConstFloat(bco,BCO_INSTR_8));
+ Continue;
+ }
+ Case(i_PACK_FLOAT):
+ {
+ StgClosure* o;
+ SSS; o = (StgClosure*)grabHpNonUpd(Fzh_sizeW); LLL;
+ SET_HDR(o,Fzh_con_info,??);
+ ASSIGN_FLT(&payloadWord(o,0),xPopTaggedFloat());
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ xPushPtr(stgCast(StgPtr,o));
+ Continue;
+ }
+ Case(i_UNPACK_FLOAT):
+ {
+ StgClosure* con = stgCast(StgClosure*,xStackPtr(0));
+ /* ASSERT(isFloatLike(con)); */
+ xPushTaggedFloat(PK_FLT(&payloadWord(con,0)));
+ Continue;
+ }
+ Case(i_VAR_DOUBLE):
+ {
+ StgDouble d = xTaggedStackDouble(BCO_INSTR_8);
+ xPushTaggedDouble(d);
+ Continue;
+ }
+ Case(i_CONST_DOUBLE):
+ {
+ xPushTaggedDouble(bcoConstDouble(bco,BCO_INSTR_8));
+ Continue;
+ }
+ Case(i_CONST_DOUBLE_big):
+ {
+ int n = BCO_INSTR_16;
+ xPushTaggedDouble(bcoConstDouble(bco,n));
+ Continue;
+ }
+ Case(i_PACK_DOUBLE):
+ {
+ StgClosure* o;
+ SSS; o = (StgClosure*)grabHpNonUpd(Dzh_sizeW); LLL;
+ SET_HDR(o,Dzh_con_info,??);
+ ASSIGN_DBL(&payloadWord(o,0),xPopTaggedDouble());
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ printObj(stgCast(StgClosure*,o));
+ );
+ xPushPtr(stgCast(StgPtr,o));
+ Continue;
+ }
+ Case(i_UNPACK_DOUBLE):
+ {
+ StgClosure* con = stgCast(StgClosure*,xStackPtr(0));
+ /* ASSERT(isDoubleLike(con)); */
+ xPushTaggedDouble(PK_DBL(&payloadWord(con,0)));
+ Continue;
+ }
+ Case(i_VAR_STABLE):
+ {
+ StgStablePtr s = xTaggedStackStable(BCO_INSTR_8);
+ xPushTaggedStable(s);
+ Continue;
+ }
+ Case(i_PACK_STABLE):
+ {
+ StgClosure* o;
+ SSS; o = (StgClosure*)grabHpNonUpd(Stablezh_sizeW); LLL;
+ SET_HDR(o,StablePtr_con_info,??);
+ payloadWord(o,0) = xPopTaggedStable();
+ IF_DEBUG(evaluator,
+ fprintf(stderr,"\tBuilt ");
+ SSS;
+ printObj(stgCast(StgClosure*,o));
+ LLL;
+ );
+ xPushPtr(stgCast(StgPtr,o));
+ Continue;
+ }
+ Case(i_UNPACK_STABLE):
+ {
+ StgClosure* con = (StgClosure*)xStackPtr(0);
+ /* ASSERT(isStableLike(con)); */
+ xPushTaggedStable(payloadWord(con,0));
+ Continue;
+ }
+ Case(i_PRIMOP1):
+ {
+ int i;
+ void* p;
+ i = BCO_INSTR_8;
+ SSS; p = enterBCO_primop1 ( i ); LLL;
+ if (p) { obj = p; goto enterLoop; };
+ Continue;
+ }
+ Case(i_PRIMOP2):
+ {
+ int i, trc, pc_saved;
+ void* p;
+ StgBCO* bco_tmp;
+ trc = 12345678; /* Assume != any StgThreadReturnCode */
+ i = BCO_INSTR_8;
+ pc_saved = PC;
+ bco_tmp = bco;
+ SSS;
+ p = enterBCO_primop2 ( i, &trc, &bco_tmp, cap,
+ &hugsBlock );
+ LLL;
+ bco = bco_tmp;
+ bciPtr = &(bcoInstr(bco,pc_saved));
+ if (p) {
+ if (trc == 12345678) {
+ /* we want to enter p */
+ obj = p; goto enterLoop;
+ } else {
+ /* trc is the the StgThreadReturnCode for
+ * this thread */
+ RETURN((StgThreadReturnCode)trc);
+ };
+ }
+ Continue;
+ }
+
+ /* combined insns, created by peephole opt */
+ Case(i_SE):
+ {
+ int x = BCO_INSTR_8;
+ int y = BCO_INSTR_8;
+ ASSERT(xSp+x+y <= stgCast(StgPtr,xSu));
+ /* a_1, .. a_x, b_1, .. b_y, s => a_1, .. a_x, s */
+ if (x == 1) {
+ obj = xPopCPtr();
+ xSp += y;
+ goto enterLoop;
+ } else {
+ while(--x >= 0) {
+ xSetStackWord(x+y,xStackWord(x));
+ }
+ xSp += y;
+ obj = xPopCPtr();
+ }
+ goto enterLoop;
+ }
+ Case(i_VV):
+ {
+ StgPtr p;
+ p = xStackPtr(BCO_INSTR_8);
+ xPushPtr(p);
+ p = xStackPtr(BCO_INSTR_8);
+ xPushPtr(p);
+ Continue;
+ }
+ Case(i_RV):
+ {
+ StgPtr p;
+ xPushPtr(bcoConstPtr(bco,BCO_INSTR_8));
+ xPushPtr(stgCast(StgPtr,&ret_bco_info));
+ p = xStackPtr(BCO_INSTR_8);
+ xPushPtr(p);
+ Continue;
+ }
+ Case(i_RVE):
+ {
+ StgPtr retaddr = bcoConstPtr(bco,BCO_INSTR_8);
+ StgPtr ptr = xStackPtr(BCO_INSTR_8);
+
+ /* A shortcut. We're going to push the address of a
+ return continuation, and then enter a variable, so
+ that when the var is evaluated, we return to the
+ continuation. The shortcut is: if the var is a
+ constructor, don't bother to enter it. Instead,
+ push the variable on the stack (since this is what
+ the continuation expects) and jump directly to the
+ continuation.
+ */
+ if (get_itbl((StgClosure*)ptr)->type == CONSTR) {
+ xPushPtr(ptr);
+ obj = (StgClosure*)retaddr;
+ IF_DEBUG(evaluator,
+ fprintf(stderr, "object to enter is a constructor -- "
+ "jumping directly to return continuation\n" );
+ );
+ goto bco_entry;
+ }
+
+ /* This is the normal, non-short-cut route */
+ xPushPtr(retaddr);
+ xPushPtr(stgCast(StgPtr,&ret_bco_info));
+ obj = (StgClosure*)ptr;
+ goto enterLoop;
+ }
+
+
+ Case(i_VAR_DOUBLE_big):
+ Case(i_CONST_FLOAT_big):
+ Case(i_VAR_FLOAT_big):
+ Case(i_CONST_CHAR_big):
+ Case(i_VAR_CHAR_big):
+ Case(i_VAR_ADDR_big):
+ Case(i_VAR_STABLE_big):
+ Case(i_CONST_INTEGER_big):
+ Case(i_VAR_INT_big):
+ Case(i_VAR_WORD_big):
+ Case(i_RETADDR_big):
+ Case(i_ALLOC_PAP):
+ bciPtr--;
+ printf ( "\n\n" );
+ disInstr ( bco, PC );
+ barf("\nUnrecognised instruction");
+
+ EndDispatch
+
+ barf("enterBCO: ran off end of loop");
+ break;
+ }
+
+# undef LoopTopLabel
+# undef Case
+# undef Continue
+# undef Dispatch
+# undef EndDispatch
+
+ /* ---------------------------------------------------- */
+ /* End of the bytecode evaluator */
+ /* ---------------------------------------------------- */
+
+ case CAF_UNENTERED:
+ {
+ StgBlockingQueue* bh;
+ StgCAF* caf = (StgCAF*)obj;
+ if (xSp - sizeofW(StgUpdateFrame) < xSpLim) {
+ xPushCPtr(obj); /* code to restart with */
+ RETURN(StackOverflow);
+ }
+ /* ToDo: look for xSp==xSu && stackInt(0) == UPD_FRAME
+ and insert an indirection immediately */
+ SSS; bh = (StgBlockingQueue*)grabHpUpd(BLACKHOLE_sizeW()); LLL;
+ SET_INFO(bh,&CAF_BLACKHOLE_info);
+ bh->blocking_queue = EndTSOQueue;
+ IF_DEBUG(gccafs,
+ fprintf(stderr,"Created CAF_BLACKHOLE %p for CAF %p in evaluator\n",bh,caf));
+ SET_INFO(caf,&CAF_ENTERED_info);
+ caf->value = (StgClosure*)bh;
+ if (caf->mut_link == NULL) {
+ SSS; recordOldToNewPtrs((StgMutClosure*)caf); LLL;
+ }
+ xPushUpdateFrame(bh,0);
+ xSp -= sizeofW(StgUpdateFrame);
+ caf->link = enteredCAFs;
+ enteredCAFs = caf;
+ obj = caf->body;
+ goto enterLoop;
+ }
+ case CAF_ENTERED:
+ {
+ StgCAF* caf = (StgCAF*)obj;
+ obj = caf->value; /* it's just a fancy indirection */
+ goto enterLoop;
+ }
+ case BLACKHOLE:
+ case SE_BLACKHOLE:
+ case CAF_BLACKHOLE:
+ case SE_CAF_BLACKHOLE:
+ {
+ /* Let the scheduler figure out what to do :-) */
+ cap->rCurrentTSO->what_next = ThreadEnterGHC;
+ xPushCPtr(obj);
+ RETURN(ThreadYielding);
+ }
+ case AP_UPD:
+ {
+ StgAP_UPD* ap = stgCast(StgAP_UPD*,obj);
+ int i = ap->n_args;
+ if (xSp - (i + sizeofW(StgUpdateFrame)) < xSpLim) {
+ xPushCPtr(obj); /* code to restart with */
+ RETURN(StackOverflow);
+ }
+ /* ToDo: look for xSp==xSu && stackInt(0) == UPD_FRAME
+ and insert an indirection immediately */
+ xPushUpdateFrame(ap,0);
+ xSp -= sizeofW(StgUpdateFrame);
+ while (--i >= 0) {
+ xPushWord(payloadWord(ap,i));
+ }
+ obj = ap->fun;
+#ifdef EAGER_BLACKHOLING
+#warn LAZY_BLACKHOLING is default for StgHugs
+#error Dont know if EAGER_BLACKHOLING works in StgHugs
+ {
+ /* superfluous - but makes debugging easier */
+ StgBlackHole* bh = stgCast(StgBlackHole*,ap);
+ SET_INFO(bh,&BLACKHOLE_info);
+ bh->blocking_queue = EndTSOQueue;
+ IF_DEBUG(gccafs,
+ fprintf(stderr,"Eagerly blackholed AP_UPD %p in evaluator\n",bh));
+ /* printObj(bh); */
+ }
+#endif /* EAGER_BLACKHOLING */
+ goto enterLoop;
+ }
+ case PAP:
+ {
+ StgPAP* pap = stgCast(StgPAP*,obj);
+ int i = pap->n_args; /* ToDo: stack check */
+ /* ToDo: if PAP is in whnf, we can update any update frames
+ * on top of stack.
+ */
+ while (--i >= 0) {
+ xPushWord(payloadWord(pap,i));
+ }
+ obj = pap->fun;
+ goto enterLoop;
+ }
+ case IND:
+ {
+ obj = stgCast(StgInd*,obj)->indirectee;
+ goto enterLoop;
+ }
+ case IND_OLDGEN:
+ {
+ obj = stgCast(StgIndOldGen*,obj)->indirectee;
+ goto enterLoop;
+ }
+ 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:
+ {
+ while (1) {
+ switch (get_itbl(stgCast(StgClosure*,xSp))->type) {
+ case CATCH_FRAME:
+ SSS; PopCatchFrame(); LLL;
+ break;
+ case UPDATE_FRAME:
+ xPopUpdateFrame(obj);
+ break;
+ case SEQ_FRAME:
+ SSS; PopSeqFrame(); LLL;
+ break;
+ case STOP_FRAME:
+ {
+ ASSERT(xSp==(P_)xSu);
+ IF_DEBUG(evaluator,
+ SSS;
+ fprintf(stderr, "hit a STOP_FRAME\n");
+ printObj(obj);
+ fprintf(stderr,"xSp = %p\txSu = %p\n", xSp, xSu);
+ printStack(xSp,cap->rCurrentTSO->stack
+ + cap->rCurrentTSO->stack_size,xSu);
+ LLL;
+ );
+ SSS; PopStopFrame(obj); LLL;
+ RETURN(ThreadFinished);
+ }
+ case RET_BCO:
+ {
+ StgClosure* ret;
+ (void)xPopPtr();
+ ret = xPopCPtr();
+ xPushPtr((P_)obj);
+ obj = ret;
+ goto bco_entry;
+ /* was: goto enterLoop;
+ But we know that obj must be a bco now, so jump directly.
+ */
+ }
+ case RET_SMALL: /* return to GHC */
+ case RET_VEC_SMALL:
+ case RET_BIG:
+ case RET_VEC_BIG:
+ cap->rCurrentTSO->what_next = ThreadEnterGHC;
+ xPushCPtr(obj);
+ RETURN(ThreadYielding);
+ default:
+ belch("entered CONSTR with invalid continuation on stack");
+ IF_DEBUG(evaluator,
+ SSS;
+ printObj(stgCast(StgClosure*,xSp));
+ LLL;
+ );
+ barf("bailing out");
+ }
+ }
+ }
+ default:
+ {
+ //SSS;
+ //fprintf(stderr, "enterCountI = %d\n", enterCountI);
+ //fprintf(stderr, "entering unknown closure -- yielding to sched\n");
+ //printObj(obj);
+ //LLL;
+ cap->rCurrentTSO->what_next = ThreadEnterGHC;
+ xPushCPtr(obj); /* code to restart with */
+ RETURN(ThreadYielding);
+ }
+ }
+ barf("Ran off the end of enter - yoiks");
+ assert(0);
+}
+
+#undef RETURN
+#undef BCO_INSTR_8
+#undef BCO_INSTR_16
+#undef SSS
+#undef LLL
+#undef PC
+#undef xPushPtr
+#undef xPopPtr
+#undef xPushCPtr
+#undef xPopCPtr
+#undef xPopWord
+#undef xStackPtr
+#undef xStackWord
+#undef xSetStackWord
+#undef xPushTag
+#undef xPopTag
+#undef xPushTaggedInt
+#undef xPopTaggedInt
+#undef xTaggedStackInt
+#undef xPushTaggedWord
+#undef xPopTaggedWord
+#undef xTaggedStackWord
+#undef xPushTaggedAddr
+#undef xTaggedStackAddr
+#undef xPopTaggedAddr
+#undef xPushTaggedStable
+#undef xTaggedStackStable
+#undef xPopTaggedStable
+#undef xPushTaggedChar
+#undef xTaggedStackChar
+#undef xPopTaggedChar
+#undef xPushTaggedFloat
+#undef xTaggedStackFloat
+#undef xPopTaggedFloat
+#undef xPushTaggedDouble
+#undef xTaggedStackDouble
+#undef xPopTaggedDouble
+#undef xPopUpdateFrame
+#undef xPushUpdateFrame
+
+
+/* --------------------------------------------------------------------------
+ * Supporting routines for primops
+ * ------------------------------------------------------------------------*/
+
+static inline void PushTag ( StackTag t )
+ { *(--gSp) = t; }
+ inline void PushPtr ( StgPtr x )
+ { *(--stgCast(StgPtr*,gSp)) = x; }
+static inline void PushCPtr ( StgClosure* x )
+ { *(--stgCast(StgClosure**,gSp)) = x; }
+static inline void PushInt ( StgInt x )
+ { *(--stgCast(StgInt*,gSp)) = x; }
+static inline void PushWord ( StgWord x )
+ { *(--stgCast(StgWord*,gSp)) = x; }
+
+
+static inline void checkTag ( StackTag t1, StackTag t2 )
+ { ASSERT(t1 == t2);}
+static inline void PopTag ( StackTag t )
+ { checkTag(t,*(gSp++)); }
+ inline StgPtr PopPtr ( void )
+ { return *stgCast(StgPtr*,gSp)++; }
+static inline StgClosure* PopCPtr ( void )
+ { return *stgCast(StgClosure**,gSp)++; }
+static inline StgInt PopInt ( void )
+ { return *stgCast(StgInt*,gSp)++; }
+static inline StgWord PopWord ( void )
+ { return *stgCast(StgWord*,gSp)++; }
+
+static inline StgPtr stackPtr ( StgStackOffset i )
+ { return *stgCast(StgPtr*, gSp+i); }
+static inline StgInt stackInt ( StgStackOffset i )
+ { return *stgCast(StgInt*, gSp+i); }
+static inline StgWord stackWord ( StgStackOffset i )
+ { return *stgCast(StgWord*,gSp+i); }
+
+static inline void setStackWord ( StgStackOffset i, StgWord w )
+ { gSp[i] = w; }
+
+static inline void PushTaggedRealWorld( void )
+ { PushTag(REALWORLD_TAG); }
+ inline void PushTaggedInt ( StgInt x )
+ { gSp -= sizeofW(StgInt); *gSp = x; PushTag(INT_TAG); }
+ inline void PushTaggedWord ( StgWord x )
+ { gSp -= sizeofW(StgWord); *gSp = x; PushTag(WORD_TAG); }
+ inline void PushTaggedAddr ( StgAddr x )
+ { gSp -= sizeofW(StgAddr); *gSp = (W_)x; PushTag(ADDR_TAG); }
+ inline void PushTaggedChar ( StgChar x )
+ { gSp -= sizeofW(StgChar); *gSp = stgCast(StgWord,x); PushTag(CHAR_TAG); }
+ inline void PushTaggedFloat ( StgFloat x )
+ { gSp -= sizeofW(StgFloat); ASSIGN_FLT(gSp,x); PushTag(FLOAT_TAG); }
+ inline void PushTaggedDouble ( StgDouble x )
+ { gSp -= sizeofW(StgDouble); ASSIGN_DBL(gSp,x); PushTag(DOUBLE_TAG); }
+ inline void PushTaggedStablePtr ( StgStablePtr x )
+ { gSp -= sizeofW(StgStablePtr); *gSp = x; PushTag(STABLE_TAG); }
+static inline void PushTaggedBool ( int x )
+ { PushTaggedInt(x); }
+
+
+
+static inline void PopTaggedRealWorld ( void )
+ { PopTag(REALWORLD_TAG); }
+ inline StgInt PopTaggedInt ( void )
+ { StgInt r; PopTag(INT_TAG); r = *stgCast(StgInt*, gSp);
+ gSp += sizeofW(StgInt); return r;}
+ inline StgWord PopTaggedWord ( void )
+ { StgWord r; PopTag(WORD_TAG); r = *stgCast(StgWord*, gSp);
+ gSp += sizeofW(StgWord); return r;}
+ inline StgAddr PopTaggedAddr ( void )
+ { StgAddr r; PopTag(ADDR_TAG); r = *stgCast(StgAddr*, gSp);
+ gSp += sizeofW(StgAddr); return r;}
+ inline StgChar PopTaggedChar ( void )
+ { StgChar r; PopTag(CHAR_TAG); r = stgCast(StgChar, *gSp);
+ gSp += sizeofW(StgChar); return r;}
+ inline StgFloat PopTaggedFloat ( void )
+ { StgFloat r; PopTag(FLOAT_TAG); r = PK_FLT(gSp);
+ gSp += sizeofW(StgFloat); return r;}
+ inline StgDouble PopTaggedDouble ( void )
+ { StgDouble r; PopTag(DOUBLE_TAG); r = PK_DBL(gSp);
+ gSp += sizeofW(StgDouble); return r;}
+ inline StgStablePtr PopTaggedStablePtr ( void )
+ { StgInt r; PopTag(STABLE_TAG); r = *stgCast(StgStablePtr*, gSp);
+ gSp += sizeofW(StgStablePtr); return r;}
+
+
+
+static inline StgInt taggedStackInt ( StgStackOffset i )
+ { checkTag(INT_TAG,gSp[i]); return *stgCast(StgInt*, gSp+1+i); }
+static inline StgWord taggedStackWord ( StgStackOffset i )
+ { checkTag(WORD_TAG,gSp[i]); return *stgCast(StgWord*, gSp+1+i); }
+static inline StgAddr taggedStackAddr ( StgStackOffset i )
+ { checkTag(ADDR_TAG,gSp[i]); return *stgCast(StgAddr*, gSp+1+i); }
+static inline StgChar taggedStackChar ( StgStackOffset i )
+ { checkTag(CHAR_TAG,gSp[i]); return stgCast(StgChar, *(gSp+1+i)) ; }
+static inline StgFloat taggedStackFloat ( StgStackOffset i )
+ { checkTag(FLOAT_TAG,gSp[i]); return PK_FLT(gSp+1+i); }
+static inline StgDouble taggedStackDouble ( StgStackOffset i )
+ { checkTag(DOUBLE_TAG,gSp[i]); return PK_DBL(gSp+1+i); }
+static inline StgStablePtr taggedStackStable ( StgStackOffset i )
+ { checkTag(STABLE_TAG,gSp[i]); return *stgCast(StgStablePtr*, gSp+1+i); }
+
+
+/* --------------------------------------------------------------------------
+ * Heap allocation
+ *
+ * Should we allocate from a nursery or use the
+ * doYouWantToGC/allocate interface? We'd already implemented a
+ * nursery-style scheme when the doYouWantToGC/allocate interface
+ * was implemented.
+ * One reason to prefer the doYouWantToGC/allocate interface is to
+ * support operations which allocate an unknown amount in the heap
+ * (array ops, gmp ops, etc)
+ * ------------------------------------------------------------------------*/
+
+static inline StgPtr grabHpUpd( nat size )
+{
+ ASSERT( size >= MIN_UPD_SIZE + sizeofW(StgHeader) );
+#ifdef CRUDE_PROFILING
+ cp_bill_words ( size );
+#endif
+ return allocate(size);
+}
+
+static inline StgPtr grabHpNonUpd( nat size )
+{
+ ASSERT( size >= MIN_NONUPD_SIZE + sizeofW(StgHeader) );
+#ifdef CRUDE_PROFILING
+ cp_bill_words ( size );
+#endif
+ return allocate(size);
+}
+
+/* --------------------------------------------------------------------------
+ * Manipulate "update frame" list:
+ * o Update frames (based on stg_do_update and friends in Updates.hc)
+ * o Error handling/catching (based on catchzh_fast and friends in Prims.hc)
+ * o Seq frames (based on seq_frame_entry in Prims.hc)
+ * o Stop frames
+ * ------------------------------------------------------------------------*/
+
+static inline void PopUpdateFrame ( StgClosure* obj )
+{
+ /* NB: doesn't assume that gSp == gSu */
+ IF_DEBUG(evaluator,
+ fprintf(stderr, "Updating ");
+ printPtr(stgCast(StgPtr,gSu->updatee));
+ fprintf(stderr, " with ");
+ printObj(obj);
+ fprintf(stderr,"gSp = %p\tgSu = %p\n\n", gSp, gSu);
+ );
+#ifdef EAGER_BLACKHOLING
+#warn LAZY_BLACKHOLING is default for StgHugs
+#error Dont know if EAGER_BLACKHOLING works in StgHugs
+ ASSERT(get_itbl(gSu->updatee)->type == BLACKHOLE
+ || get_itbl(gSu->updatee)->type == SE_BLACKHOLE
+ || get_itbl(gSu->updatee)->type == CAF_BLACKHOLE
+ || get_itbl(gSu->updatee)->type == SE_CAF_BLACKHOLE
+ );
+#endif /* EAGER_BLACKHOLING */
+ UPD_IND(gSu->updatee,obj);
+ gSp = stgCast(StgStackPtr,gSu) + sizeofW(StgUpdateFrame);
+ gSu = gSu->link;
+}
+
+static inline void PopStopFrame ( StgClosure* obj )
+{
+ /* Move gSu just off the end of the stack, we're about to gSpam the
+ * STOP_FRAME with the return value.
+ */
+ gSu = stgCast(StgUpdateFrame*,gSp+1);
+ *stgCast(StgClosure**,gSp) = obj;
+}
+
+static inline void PushCatchFrame ( StgClosure* handler )
+{
+ StgCatchFrame* fp;
+ /* ToDo: stack check! */
+ gSp -= sizeofW(StgCatchFrame);
+ fp = stgCast(StgCatchFrame*,gSp);
+ SET_HDR(fp,(StgInfoTable*)&catch_frame_info,CCCS);
+ fp->handler = handler;
+ fp->link = gSu;
+ gSu = stgCast(StgUpdateFrame*,fp);
+}
+
+static inline void PopCatchFrame ( void )
+{
+ /* NB: doesn't assume that gSp == gSu */
+ /* fprintf(stderr,"Popping catch frame\n"); */
+ gSp = stgCast(StgStackPtr,gSu) + sizeofW(StgCatchFrame);
+ gSu = stgCast(StgCatchFrame*,gSu)->link;
+}
+
+static inline void PushSeqFrame ( void )
+{
+ StgSeqFrame* fp;
+ /* ToDo: stack check! */
+ gSp -= sizeofW(StgSeqFrame);
+ fp = stgCast(StgSeqFrame*,gSp);
+ SET_HDR(fp,(StgInfoTable*)&seq_frame_info,CCCS);
+ fp->link = gSu;
+ gSu = stgCast(StgUpdateFrame*,fp);
+}
+
+static inline void PopSeqFrame ( void )
+{
+ /* NB: doesn't assume that gSp == gSu */
+ gSp = stgCast(StgStackPtr,gSu) + sizeofW(StgSeqFrame);
+ gSu = stgCast(StgSeqFrame*,gSu)->link;
+}
+
+static inline StgClosure* raiseAnError ( StgClosure* exception )
+{
+ /* This closure represents the expression 'primRaise E' where E
+ * is the exception raised (:: Exception).
+ * It is used to overwrite all the
+ * thunks which are currently under evaluation.
+ */
+ HaskellObj primRaiseClosure
+ = asmClosureOfObject(getHugs_AsmObject_for("primRaise"));
+ HaskellObj reraiseClosure
+ = rts_apply ( primRaiseClosure, exception );
+
+ while (1) {
+ switch (get_itbl(gSu)->type) {
+ case UPDATE_FRAME:
+ UPD_IND(gSu->updatee,reraiseClosure);
+ gSp = stgCast(StgStackPtr,gSu) + sizeofW(StgUpdateFrame);
+ gSu = gSu->link;
+ break;
+ case SEQ_FRAME:
+ PopSeqFrame();
+ break;
+ case CATCH_FRAME: /* found it! */
+ {
+ StgCatchFrame* fp = stgCast(StgCatchFrame*,gSu);
+ StgClosure *handler = fp->handler;
+ gSu = fp->link;
+ gSp += sizeofW(StgCatchFrame); /* Pop */
+ PushCPtr(exception);
+ return handler;
+ }
+ case STOP_FRAME:
+ barf("raiseError: uncaught exception: STOP_FRAME");
+ default:
+ barf("raiseError: weird activation record");
+ }
+ }
+}
+
+
+static StgClosure* makeErrorCall ( const char* msg )
+{
+ /* Note! the msg string should be allocated in a
+ place which will not get freed -- preferably
+ read-only data of the program. That's because
+ the thunk we build here may linger indefinitely.
+ (thinks: probably not so, but anyway ...)
+ */
+ HaskellObj error
+ = asmClosureOfObject(getHugs_AsmObject_for("error"));
+ HaskellObj unpack
+ = asmClosureOfObject(getHugs_AsmObject_for("hugsprimUnpackString"));
+ HaskellObj thunk
+ = rts_apply ( unpack, rts_mkAddr ( (void*)msg ) );
+ thunk
+ = rts_apply ( error, thunk );
+ return
+ (StgClosure*) thunk;
+}
+
+#define raiseIndex(where) makeErrorCall("Array index out of range in " where)
+#define raiseDiv0(where) makeErrorCall("Division by zero in " where)
+
+/* --------------------------------------------------------------------------
+ * Evaluator
+ * ------------------------------------------------------------------------*/
+
+#define OP_CC_B(e) \
+{ \
+ unsigned char x = PopTaggedChar(); \
+ unsigned char y = PopTaggedChar(); \
+ PushTaggedBool(e); \
+}
+
+#define OP_C_I(e) \
+{ \
+ unsigned char x = PopTaggedChar(); \
+ PushTaggedInt(e); \
+}
+
+#define OP__I(e) \
+{ \
+ PushTaggedInt(e); \
+}
+
+#define OP_IW_I(e) \
+{ \
+ StgInt x = PopTaggedInt(); \
+ StgWord y = PopTaggedWord(); \
+ PushTaggedInt(e); \
+}
+
+#define OP_II_I(e) \
+{ \
+ StgInt x = PopTaggedInt(); \
+ StgInt y = PopTaggedInt(); \
+ PushTaggedInt(e); \
+}
+
+#define OP_II_B(e) \
+{ \
+ StgInt x = PopTaggedInt(); \
+ StgInt y = PopTaggedInt(); \
+ PushTaggedBool(e); \
+}
+
+#define OP__A(e) \
+{ \
+ PushTaggedAddr(e); \
+}
+
+#define OP_I_A(e) \
+{ \
+ StgInt x = PopTaggedInt(); \
+ PushTaggedAddr(e); \
+}
+
+#define OP_I_I(e) \
+{ \
+ StgInt x = PopTaggedInt(); \
+ PushTaggedInt(e); \
+}
+
+#define OP__C(e) \
+{ \
+ PushTaggedChar(e); \
+}
+
+#define OP_I_C(e) \
+{ \
+ StgInt x = PopTaggedInt(); \
+ PushTaggedChar(e); \
+}
+
+#define OP__W(e) \
+{ \
+ PushTaggedWord(e); \
+}
+
+#define OP_I_W(e) \
+{ \
+ StgInt x = PopTaggedInt(); \
+ PushTaggedWord(e); \
+}
+
+#define OP_I_s(e) \
+{ \
+ StgInt x = PopTaggedInt(); \
+ PushTaggedStablePtr(e); \
+}
+
+#define OP__F(e) \
+{ \
+ PushTaggedFloat(e); \
+}
+
+#define OP_I_F(e) \
+{ \
+ StgInt x = PopTaggedInt(); \
+ PushTaggedFloat(e); \
+}
+
+#define OP__D(e) \
+{ \
+ PushTaggedDouble(e); \
+}
+
+#define OP_I_D(e) \
+{ \
+ StgInt x = PopTaggedInt(); \
+ PushTaggedDouble(e); \
+}
+
+#define OP_WW_B(e) \
+{ \
+ StgWord x = PopTaggedWord(); \