Merge branch 'master' into work

misses a device if it has been already moved due to earlier
merging in the serial combine routine, and runs off the end of
the list;  the other if the pin check routine falls on the last
device in the list, leading to an incorrect check for a record
where there is only a NULL.

VERSION

@@ -1 +1 @@
-1.5.79
+1.5.87

base/flatten.c

@@ -1230,6 +1230,10 @@ int CleanupPins(char *name, int filenum)
       return 0;
    }
 
+   // If cell is type MODULE, this is a black-box circuit and
+   // pins are expected to be disconnected (so don't remove them).
+   if (ThisCell->class == CLASS_MODULE) return 0;
+
    // Avoid a loop through all cells unless we have to do it.
 
    for (ob = ThisCell->cell; ob != NULL; ob = ob->next) {

base/netcmp.c

@@ -6057,7 +6057,7 @@ int reorderpins(struct hashlist *p, int file)
     struct nlist *ptr;
     struct nlist *tc2 = Circuit2;
     struct objlist *ob, *ob2, *firstpin;
-    int i, numports, *nodes;
+    int i, numports, *nodes, unordered;
     char **names;
 
     ptr = (struct nlist *)(p->ptr);
@@ -6071,14 +6071,23 @@ int reorderpins(struct hashlist *p, int file)
     /* instances of both cells.					*/
 
     numports = 0;
+    unordered = 0;
     ob2 = tc2->cell;
     while (ob2 && ob2->type == PORT) {
+	if (ob2->model.port < 0) {
+	    ob2->model.port = numports;
+	    unordered = 1;
+	}
 	numports++;
 	ob2 = ob2->next;
     }
     nodes = (int *)CALLOC(numports, sizeof(int));
     names = (char **)CALLOC(numports, sizeof(char *));
 
+    if (unordered)
+	Fprintf(stderr, "Ports of %s are unordered.  "
+		"Ordering will be arbitrary.", tc2->name);
+
     for (ob = ptr->cell; ob != NULL; ) {
 	if (ob->type == FIRSTPIN) {
 	    if ((*matchfunc)(ob->model.class, tc2->name)) {
@@ -6274,6 +6283,7 @@ struct nlist *addproxies(struct hashlist *p, void *clientdata)
 int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
 {
    char *cover, *ctemp;
+   char *bangptr1, *bangptr2;
    struct objlist *ob1, *ob2, *obn, *obp, *ob1s, *ob2s, *obt;
    struct NodeClass *NC;
    struct Node *N1, *N2;
@@ -6486,13 +6496,25 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
 
    /* Do any unmatched pins have the same name? 		  */
    /* (This should not happen if unconnected pins are eliminated) */
+   /* (Semi-hack: Allow "!" global flag) */
 
    ob1 = tc1->cell;
+   bangptr1 = strrchr(ob1->name, '!');
+   if (bangptr1 && (*(bangptr1 + 1) == '\0'))
+      *bangptr1 = '\0';
+   else bangptr1 = NULL;
+  
    for (i = 0; i < numorig; i++) {
       if (*(cover + i) == (char)0) {
 	 j = 0;
          for (ob2 = tc2->cell; ob2 != NULL; ob2 = ob2->next) {
 	    if (!IsPort(ob2)) break;
+
+	    bangptr2 = strrchr(ob2->name, '!');
+	    if (bangptr2 && (*(bangptr2 + 1) == '\0'))
+	       *bangptr2 = '\0';
+	    else bangptr2 = NULL;
+
 	    if ((*matchfunc)(ob1->name, ob2->name)) {
 	       ob2->model.port = i;		/* save order */
 	       *(cover + i) = (char)1;
@@ -6521,11 +6543,13 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
 	       }
 #endif
 	    }
+	    if (bangptr2) *bangptr2 = '!';
 	    j++;
 	 }
       }
       ob1 = ob1->next;
    }
+   if (bangptr1) *bangptr1 = '!';
 
    /* Find the end of the pin list in tc1, for adding proxy pins */
 
@@ -6709,7 +6733,7 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
 
    /* Clean up "UNKNOWN" records from Circuit1 */
 
-   for (obn = tc1->cell; ; obn = obn->next) {
+   for (obn = tc1->cell; obn; obn = obn->next) {
       if (obn->type == UNKNOWN) obn->type = PORT;
       else if (obn->type != PORT) break;
    }
@@ -6728,13 +6752,13 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
 
    /* Clean up "UNKNOWN" records from Circuit2 */
 
-   for (obn = tc2->cell; ; obn = obn->next) {
+   for (obn = tc2->cell; obn; obn = obn->next) {
       if (obn->type == UNKNOWN) obn->type = PORT;
       else if (obn->type != PORT) break;
    }
 
    /* Check for ports that did not get ordered */
-   for (obn = tc2->cell; obn->type == PORT; obn = obn->next) {
+   for (obn = tc2->cell; obn && (obn->type == PORT); obn = obn->next) {
       if (obn->model.port == -1) {
 	 if (obn->node == -1) {
 	    // This only happens when pins have become separated from any net.

base/netgen.c

@@ -49,6 +49,7 @@ int NextNode;
 
 int Composition = NONE;
 int QuickSearch = 0;
+int GlobalParallelNone = FALSE;
 
 int AddToExistingDefinition = 0;  /* default: overwrite cell when reopened */
 
@@ -870,6 +871,32 @@ int ReduceExpressions(struct objlist *instprop, struct objlist *parprops,
     return 0;
 }
 
+/*----------------------------------------------------------------------*/
+/* Set/clear the flag bit COMB_NO_PARALLEL on all cells.  Note that the	*/
+/* function is called with value for enabling combine parallel, so	*/
+/* value TRUE means clear bit, value FALSE means set bit.		*/
+/*----------------------------------------------------------------------*/
+
+struct nlist *SetParallelCombineFlag(struct hashlist *p, void *clientdata)
+{
+  struct nlist *ptr;
+  int *value = (int *)clientdata;
+
+  ptr = (struct nlist *)(p->ptr);
+  if (*value == TRUE)
+     ptr->flags &= (~COMB_NO_PARALLEL);
+  else
+     ptr->flags |= COMB_NO_PARALLEL;
+
+  return NULL;	/* NULL keeps search alive */
+}
+
+void SetParallelCombine(int value)
+{
+  ClearDumpedList();
+  RecurseCellHashTable2(SetParallelCombineFlag, (void *)(&value));
+}
+
 /*----------------------------------------------------------------------*/
 /* Delete a property from the master cell record.			*/
 /*----------------------------------------------------------------------*/
@@ -1192,7 +1219,7 @@ void CellDef(char *name, int fnum)
 	np = InstallInCellHashTable(name, fnum);
 	CurrentCell = LookupCellFile(name, fnum);
 	CurrentCell->class = CLASS_SUBCKT;	/* default */
-	CurrentCell->flags = 0;
+	CurrentCell->flags = (GlobalParallelNone) ? COMB_NO_PARALLEL : 0;
 
 	LastPlaced = NULL;
 	CurrentTail = NULL;
@@ -3282,7 +3309,9 @@ int check_pin_nodes(struct objlist *ob1, struct objlist *ob2)
       pob = pob->next;
    }
 
-   if (nob->type > FIRSTPIN || pob->type > FIRSTPIN) return FALSE;
+   if (nob && pob && (nob->type > FIRSTPIN || pob->type > FIRSTPIN))
+      return FALSE;
+
    return TRUE;
 }
 
@@ -3459,7 +3488,13 @@ int CombineSerial(char *model, int file)
 	    /* only pointer to it.					*/
             for (obp = instlist[i][0]; obp->next->type > FIRSTPIN ||
 			obp->next->type == PROPERTY; obp = obp->next);
-            for (ob2 = obp; ob2->next != instlist[i][1]; ob2 = ob2->next);
+            for (ob2 = obp; ob2 && ob2->next != instlist[i][1]; ob2 = ob2->next);
+
+	    /* Device may have been moved by the above code.  If so, look for	*/
+	    /* it from the beginning of the list. */
+	    if (ob2 == NULL)
+               for (ob2 = tp->cell; ob2->next != instlist[i][1]; ob2 = ob2->next);
+
 	    for (obs = ob2->next; obs->next && (obs->next->type > FIRSTPIN
 			|| obs->next->type == PROPERTY); obs = obs->next);
 	    ob2->next = obs->next;

base/netgen.h

@@ -35,6 +35,7 @@ extern struct property *PropertyInteger(char *name, int fnum, char *key,
 extern struct property *PropertyString(char *name, int fnum, char *key,
 		double slop, char *pdefault);
 extern int  PropertyDelete(char *name, int fnum, char *key);
+extern void SetParallelCombine(int value);
 extern int  PropertyTolerance(char *name, int fnum, char *key, int ival,
 		double dval);
 extern int  PropertyMerge(char *name, int fnum, char *key, int merge_type);
@@ -53,6 +54,8 @@ extern void PortList(char *prefix, char *list_template);
 extern char *Cell(char *inststr, char *model, ...);
 extern int  IsIgnored(char *, int);
 
+extern int auto_blackbox;	/* For handling empty subcircuits */
+
 /* netcmp.c */
 extern struct nlist *LookupClassEquivalent(char *model, int file1, int file2);
 extern void AssignCircuits(char *name1, int file1, char *name2, int file2);
@@ -132,6 +135,7 @@ extern int IgnoreRC;	  /* set this to 1 to ignore capacitance and resistance */
 extern int NoOutput;      /* set this to 1 to disable stdout output */
 extern int Composition;	  /* direction of composition */
 extern int UnixWildcards; /* TRUE if *,?,{},[] only; false if full REGEXP */
+extern int GlobalParallelNone;	/* If TRUE, don't parallel combine any cells */
 /* magic internal flag to restrict searches to recently placed cells */
 extern int QuickSearch;
 /* does re"CellDef"ing a cell add to it or overwrite it??? */

base/objlist.c

@@ -563,8 +563,11 @@ static int PrintCellHashTableElement(struct hashlist *p)
     /* only print primitive cells if Debug is enabled */
     if (Debug == 1)  Printf("Cell: %s (instanced %d times); Primitive\n",
 		       ptr->name, ptr->number);
+    else if (Debug == 3) {	/* list */
+       Tcl_AppendElement(netgeninterp, ptr->name);
+    }
   }
-  else if (Debug == 2) {	/* list only */
+  else if ((Debug == 2) || (Debug == 3)) {	/* list only */
 #ifdef TCL_NETGEN
      Tcl_AppendElement(netgeninterp, ptr->name);
 #else
@@ -595,7 +598,7 @@ void PrintCellHashTable(int full, int filenum)
 
   bins  = RecurseHashTable(&cell_dict, CountHashTableBinsUsed);
   total = RecurseHashTable(&cell_dict, CountHashTableEntries);
-  if (full != 2)
+  if (full < 2)
      Printf("Hash table: %d of %d bins used; %d cells total (%.2f per bin)\n",
 		bins, CELLHASHSIZE, total, (bins == 0) ? 0 :
 		(float)((float)total / (float)bins));
@@ -605,7 +608,7 @@ void PrintCellHashTable(int full, int filenum)
   RecurseHashTable(&cell_dict, PrintCellHashTableElement);
   Debug = OldDebug;
 #ifndef TCL_NETGEN
-  if (full == 2) Printf("\n");
+  if (full >= 2) Printf("\n");
 #endif
 }
 

base/spice.c

@@ -25,8 +25,10 @@ the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
 #include <stdarg.h>  /* what about varargs, like in pdutils.c ??? */
 #endif
 
-#ifdef IBMPC
-#include <stdlib.h>  /* for calloc(), free() */
+#include <stdlib.h>  /* for calloc(), free(), getenv() */
+#ifndef IBMPC
+#include <sys/types.h>	/* for getpwnam() tilde expansion */
+#include <pwd.h>
 #endif
 
 #ifdef TCL_NETGEN
@@ -42,6 +44,10 @@ the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
 // Global storage for parameters from .PARAM
 struct hashdict spiceparams;
 
+// Global setting for auto-detect of empty subcircuits as
+// black-box subcells.
+int auto_blackbox = FALSE;
+
 // Check if a token represents a numerical value (with
 // units) or an expression.  This is basically a hack
 // to see if it either passes StringIsValue() or is
@@ -398,6 +404,7 @@ int renamepins(struct hashlist *p, int file)
 
 void CleanupSubcell() {
    int maxnode = 0;
+   int has_devices = FALSE;
    struct objlist *sobj, *nobj, *lobj, *pobj;
 
    if (CurrentCell == NULL) return;
@@ -409,6 +416,8 @@ void CleanupSubcell() {
    lobj = NULL;
    for (sobj = CurrentCell->cell; sobj != NULL;) {
       nobj = sobj->next;
+      if (sobj->type == FIRSTPIN)
+	 has_devices = TRUE;
       if (sobj->node < 0) {
          if (IsGlobal(sobj)) {
  	    if (lobj != NULL)
@@ -437,6 +446,8 @@ void CleanupSubcell() {
          lobj = sobj;
       sobj = nobj;
    }
+   if ((has_devices == FALSE) && (auto_blackbox == TRUE))
+      SetClass(CLASS_MODULE);
 }
 
 /*------------------------------------------------------*/
@@ -615,7 +626,7 @@ void ReadSpiceFile(char *fname, int filenum, struct cellstack **CellStackPtr,
 	    }
 	    SpiceTokNoNewline();
          }
-         SetClass((blackbox) ? CLASS_MODULE : CLASS_SUBCKT);
+	 SetClass((blackbox) ? CLASS_MODULE : CLASS_SUBCKT);
 
 	 if (hasports == 0) {
 	    // If the cell defines no ports, then create a proxy
@@ -743,7 +754,7 @@ skip_ends:
       SpiceSkipNewLine();
     }
     else if (matchnocase(nexttok, ".INCLUDE")) {
-      char *iname, *iptr, *quotptr, *pathend;
+      char *iname, *iptr, *quotptr, *pathend, *userpath = NULL;
 
       SpiceTokNoNewline();
       if (nexttok == NULL) continue;	/* Ignore if no filename */
@@ -755,12 +766,44 @@ skip_ends:
       pathend = strrchr(fname, '/');
       iptr = nexttok;
       while (*iptr == '\'' || *iptr == '\"' || *iptr == '`') iptr++;
-      if ((pathend != NULL) && (*iptr != '/')) {
+      if ((pathend != NULL) && (*iptr != '/') && (*iptr != '~')) {
 	 *pathend = '\0';
 	 iname = (char *)MALLOC(strlen(fname) + strlen(iptr) + 2);
 	 sprintf(iname, "%s/%s", fname, iptr);
 	 *pathend = '/';
       }
+#ifndef IBMPC
+      else if ((*iptr == '~') && (*(iptr + 1) == '/')) {
+	 /* For ~/<path>, substitute tilde from $HOME */
+	 userpath = getenv("HOME");
+	 iname = (char *)MALLOC(strlen(userpath) + strlen(iptr));
+	 sprintf(iname, "%s%s", userpath, iptr + 1);
+      }
+      else if (*iptr == '~') {
+	 /* For ~<user>/<path>, substitute tilde from getpwnam() */
+	 struct passwd *passwd;
+	 char *pathstart;
+         pathstart = strchr(iptr, '/');
+	 if (pathstart) *pathstart = '\0';
+	 passwd = getpwnam(iptr + 1);
+	 if (passwd != NULL) {
+	    userpath = passwd->pw_dir;
+	    if (pathstart) {
+	       *pathstart = '/';
+	       iname = (char *)MALLOC(strlen(userpath) + strlen(pathstart) + 1);
+	       sprintf(iname, "%s%s", userpath, pathstart);
+	    }
+	    else {
+	       /* Almost certainly an error, but make the substitution anyway */
+	       iname = STRDUP(userpath);
+	    }
+	 }
+	 else {
+	    /* Probably an error, but copy the filename verbatim */
+	    iname = STRDUP(iptr);
+	 }
+      }
+#endif
       else
 	 iname = STRDUP(iptr);
 

tcltk/netgen.tcl.in

@@ -370,7 +370,6 @@ proc netgen::convert_to_json {filename lvs_final} {
 proc netgen::lvs { name1 name2 {setupfile setup.tcl} {logfile comp.out} args} {
    set dolist 0
    set dojson 0
-   puts stdout "Diagnostic version"
    foreach arg $args {
       if {$arg == "-list"} {
 	 puts stdout "Generating list result"
@@ -381,6 +380,9 @@ proc netgen::lvs { name1 name2 {setupfile setup.tcl} {logfile comp.out} args} {
 	 set dolist 1
 	 set dojson 1
 	 set lvs_final {}
+      } elseif {$arg == "-blackbox"} {
+	 puts stdout "Treating empty subcircuits as black-box cells"
+	 netgen::model blackbox on
       }
    }
 

tcltk/tclnetgen.c

@@ -1437,9 +1437,9 @@ _netgen_cells(ClientData clientData,
    char *optstart;
    int filenum = -1;
    struct nlist *np = NULL;
-   int result, dolist = 0;
+   int result, printopt, dolist = 0, doall = 0, dotop = 0;
 
-   if (objc > 1) {
+   while (objc > 1) {
       optstart = Tcl_GetString(objv[1]);
       if (*optstart == '-') optstart++;
       if (!strcmp(optstart, "list")) {
@@ -1447,27 +1447,41 @@ _netgen_cells(ClientData clientData,
 	 objv++;
 	 objc--;
       }
+      else if (!strcmp(optstart, "all")) {
+	 doall = 1;
+	 objv++;
+	 objc--;
+      }
+      else if (!strcmp(optstart, "top")) {
+	 dotop = 1;
+	 objv++;
+	 objc--;
+      }
+      else {
+	 result = CommonParseCell(interp, objv[1], &np, &filenum);
+	 if (result != TCL_OK) return result;
+	 objv++;
+	 objc--;
+      }
    }
 
-   if (objc == 1) {
-      PrintCellHashTable((dolist) ? 2 : 0, -1);
-   }
-   else if (objc != 2) {
-      Tcl_WrongNumArgs(interp, 1, objv, "[list] [-all|-top|valid_filename]");
+   if (objc != 1) {
+      Tcl_WrongNumArgs(interp, 1, objv, "[list] [-top] [-all] [valid_filename]");
       return TCL_ERROR;
    }
    else {
       Tcl_Obj *lobj;
 
-      repstr = Tcl_GetString(objv[1]);
-      if (!strncmp(repstr, "-top", 4)) {
+      if (dotop) {
 	 if (dolist)
 	     lobj = Tcl_NewListObj(0, NULL);
 	 else
 	     Fprintf(stdout, "Top level cells: ");
 	 np = FirstCell();
 	 while (np != NULL) {
-	    if (np->flags & CELL_TOP) {
+	    if ((np->flags & CELL_TOP) && ((filenum == -1) ||
+			(np->file == filenum))) {
+		
 		if (dolist)
 		    Tcl_ListObjAppendElement(interp, lobj,
 			Tcl_NewStringObj(np->name, -1));
@@ -1483,11 +1497,13 @@ _netgen_cells(ClientData clientData,
 
 	 return TCL_OK;
       }
-      else if (strncmp(repstr, "-all", 4)) {
-	 result = CommonParseCell(interp, objv[1], &np, &filenum);
-	 if (result != TCL_OK) return result;
+      else {
+	 if (dolist)
+	    printopt = (doall) ? 3 : 2;
+	 else
+	    printopt = (doall) ? 1 : 0;
+         PrintCellHashTable(printopt, filenum);
       }
-      PrintCellHashTable((dolist) ? 2 : 1, filenum);
    }
    return TCL_OK;
 }
@@ -1528,8 +1544,27 @@ _netgen_model(ClientData clientData,
       return TCL_ERROR;
    }
 
+   /* Check for "model blackbox on|off"	*/
+   /* Behavior is to treat empty subcircuits as blackbox cells */
+
+   if ((objc > 1) && !strcmp(Tcl_GetString(objv[1]), "blackbox")) {
+      if ((objc > 2) && !strcmp(Tcl_GetString(objv[2]), "on")) {
+	 auto_blackbox = TRUE;
+	 return TCL_OK;
+      }
+      else if ((objc > 2) && !strcmp(Tcl_GetString(objv[2]), "off")) {
+	 auto_blackbox = FALSE;
+	 return TCL_OK;
+      }
+      else if (objc == 2) {
+	 Tcl_SetObjResult(interp, Tcl_NewBooleanObj(auto_blackbox));
+	 return TCL_OK;
+      }
+   }
+
    result = CommonParseCell(interp, objv[1], &tp, &fnum);
-   if (result != TCL_OK) return result;
+   if (result != TCL_OK)
+      return result;
 
    if (objc == 3) {
       model = Tcl_GetString(objv[2]);
@@ -1641,6 +1676,13 @@ _netgen_model(ClientData clientData,
 	    retclass = modelclasses[SUBCKT_IDX];
 	    break;
 
+	 case CLASS_MODULE:
+	    if (auto_blackbox)
+		retclass = modelclasses[BLACKBOX_IDX];
+	    else
+		retclass = modelclasses[MODULE_IDX];
+	    break;
+
 	 default: /* (includes case CLASS_UNDEF) */
 	    retclass = modelclasses[UNDEF_IDX];
 	    break;
@@ -2678,10 +2720,10 @@ _netcmp_equate(ClientData clientData,
    };
    int result, index;
    char *name1 = NULL, *name2 = NULL, *optstart;
-   struct nlist *tp1, *tp2;
+   struct nlist *tp1, *tp2, *SaveC1, *SaveC2;
    struct objlist *ob1, *ob2;
    int file1, file2;
-   int i, l1, l2, ltest, lent, dolist;
+   int i, l1, l2, ltest, lent, dolist = 0;
    Tcl_Obj *tobj1, *tobj2, *tobj3;
 
    if (objc > 1) {
@@ -2849,7 +2891,7 @@ _netcmp_equate(ClientData clientData,
 	 break;
 
       case PINS_IDX:
-	 if (ElementClasses == NULL) {
+	 if ((ElementClasses == NULL) && (auto_blackbox == FALSE)) {
 	    if (CurrentCell == NULL)
 		Fprintf(stderr, "Equate elements:  no current cell.\n");
 	    Fprintf(stderr, "Equate pins:  cell %s and/or %s has no elements.\n",
@@ -2857,20 +2899,30 @@ _netcmp_equate(ClientData clientData,
 	    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(0));
 	    return TCL_OK;
 	 }
-	 if (tp1 == Circuit1 && tp2 == Circuit2) {
-	    int result;
-	    if (MatchPins(tp1, tp2, dolist)) {
-	       Fprintf(stdout, "Cell pin lists are equivalent.\n");
-	       Tcl_SetObjResult(interp, Tcl_NewBooleanObj(1));
-	    }
-	    else {
-	       Fprintf(stdout, "Cell pin lists for %s and %s altered to match.\n",
-			name1, name2);
-	       Tcl_SetObjResult(interp, Tcl_NewBooleanObj(0));
-	    }
+	 else if (ElementClasses == NULL) {
+	    /* This has been called outside of a netlist compare,	*/
+	    /* probably to force name matching of pins on black-box	*/
+	    /* devices.  But MatchPins only works if tp1 == Circuit1	*/
+	    /* and tp2 == Circuit2, so preserve these values and 	*/
+	    /* recover afterward (what a hack).				*/
+	    SaveC1 = Circuit1;
+	    SaveC2 = Circuit2;
+	    Circuit1 = tp1;
+	    Circuit2 = tp2;
+	 }
+	 if (MatchPins(tp1, tp2, dolist)) {
+	    Fprintf(stdout, "Cell pin lists are equivalent.\n");
+	    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(1));
 	 }
 	 else {
-	    Fprintf(stderr, "Function not defined outside of LVS scope.\n");
+	    Fprintf(stdout, "Cell pin lists for %s and %s altered to match.\n",
+			name1, name2);
+	    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(0));
+	 }
+	 if (ElementClasses == NULL) {
+	    /* Recover temporarily set global variables (see above) */
+	    Circuit1 = SaveC1;
+	    Circuit2 = SaveC2;
 	 }
 	 break;
 
@@ -3093,8 +3145,12 @@ _netcmp_equate(ClientData clientData,
 /*	netgen::property <device>|<model> <option>	*/
 /*		yes|no					*/
 /* Where <option> is one of:				*/
-/*     serial	 --- allow/prohibit serial combination	*/
+/*     serial	--- allow/prohibit serial combination	*/
 /*     parallel --- allow/prohibit parallel combination	*/
+/* or							*/
+/*	netgen::property parallel none			*/
+/*		--- prohibit parallel combinations by	*/
+/*		    default.				*/
 /*							*/
 /* Formerly: (none)					*/
 /* Results:						*/
@@ -3188,6 +3244,22 @@ _netcmp_property(ClientData clientData,
 	}
 	return TCL_OK;
     }
+    else if ((objc == 3) && (!strcmp(Tcl_GetString(objv[1]), "parallel"))) {
+	if (!strcmp(Tcl_GetString(objv[2]), "none")) {
+	    GlobalParallelNone = TRUE;
+	    SetParallelCombine(FALSE);
+	}
+	else if (!strcmp(Tcl_GetString(objv[2]), "all")) {
+	    GlobalParallelNone = FALSE;
+	    SetParallelCombine(TRUE);
+	}
+	else {
+	    Tcl_SetResult(interp, "Bad option, should be property parallel none|all",
+			NONE);
+	    return TCL_ERROR;
+	}
+	return TCL_OK;
+    }
 
     result = CommonParseCell(interp, objv[1], &tp, &fnum);
     if (result != TCL_OK) return result;