Merge branch 'master' into netgen-1.5

"*.GLOBAL" as equivalent to ".GLOBAL".  Corrected the property
matching to handle property combination when no "critical"
property is given.  Critical properties exist when one property
must remain constant and equal for other properties to combine,
such as transistor length.  But, for example, capacitors can
combine area without any restriction based on another property.
Also, corrected the property matching code to allow more than
one property to be additive (example:  capacitor area and
perimeter).  Corrected the equation for adding properties in
parallel combination.

VERSION

@@ -1 +1 @@
-1.5.294
+1.5.301

base/netcmp.c

@@ -5218,14 +5218,23 @@ int PropertyOptimize(struct objlist *ob, struct nlist *tp, int run, int series,
 
    if (comb == TRUE) {
       double pd;
+      int hascrit = FALSE;
       int mult, cidx = -1;
-      struct valuelist *avl, *cvl = NULL;
+      struct valuelist **avl, **cvl;
+      struct valuelist *cvlp;
+
       critval.type = PROP_ENDLIST;
       critval.value.dval = 0.0;
+
+      /* Track properties separately so that multiple properties can be
+       * added together (e.g., area and perimeter)
+       */
+      avl = (struct valuelist **)CALLOC(pcount, sizeof(struct valuelist *));
+      cvl = (struct valuelist **)CALLOC(pcount, sizeof(struct valuelist *));
+
       for (i = 0; i < run; i++) {
-         avl = NULL;
-	 // if (vlist[0][i] == NULL) continue;
-	 // mult = vlist[0][i]->value.ival;
+	 for (p = 0; p < pcount; p++) avl[p] = NULL;
+
 	 if (vlist[0][i] == NULL)
 	    mult = 1;
 	 else
@@ -5242,6 +5251,7 @@ int PropertyOptimize(struct objlist *ob, struct nlist *tp, int run, int series,
 
 	    /* critical properties never combine, but track them */
 	    if ((series == TRUE) && (ctype & MERGE_S_CRIT)) {
+		hascrit = TRUE;
 	        pd = 2 * fabs(vl->value.dval - critval.value.dval) /
 				(vl->value.dval + critval.value.dval);
 		if ((vl->type != critval.type) || (pd > kl->slop.dval))
@@ -5253,6 +5263,7 @@ int PropertyOptimize(struct objlist *ob, struct nlist *tp, int run, int series,
 		continue;
 	    }
 	    if ((series == FALSE) && (ctype & MERGE_P_CRIT)) {
+		hascrit = TRUE;
 	        pd = 2 * fabs(vl->value.dval - critval.value.dval) /
 				(vl->value.dval + critval.value.dval);
 		if ((vl->type != critval.type) || (pd > kl->slop.dval))
@@ -5286,19 +5297,30 @@ int PropertyOptimize(struct objlist *ob, struct nlist *tp, int run, int series,
 		}
 	    }
 	    if (ctype & (MERGE_S_ADD | MERGE_P_ADD | MERGE_S_PAR | MERGE_P_PAR))
-		avl = vl;
+		avl[p] = vl;
          }
-	 if (cidx == i) cvl = avl;
+	 if (hascrit == FALSE) cidx = 0;	/* No critical property */
+
+	 /* Each time a new critical value is found, set the location	*/
+	 /* of the property record that will collect the summation or	*/
+	 /* parallel combination of values.				*/
+	 if (cidx == i) {
+	    for (p = 1; p < pcount; p++) {
+	 	cvl[p] = avl[p];
+	    }
+	 }
 
 	 /* Sorting should have put all records with the same critical	*/
 	 /* value together sequentially.  So if there are still		*/
 	 /* multiple property records, then merge them into the first	*/
-	 /* record with the same critical property value.		*/
+	 /* record with the same critical property value.  If no 	*/
+	 /* critical value exists, then all records can be merged.	*/
 
 	 if ((i > 0) && (cidx >= 0) && (cidx < i)) {
 	    for (p = 1; p < pcount; p++) {
 		vl = vlist[p][i];
 		ctype = clist[p][i];
+		cvlp = cvl[p];
 
 		if (ctype & (MERGE_S_ADD | MERGE_P_ADD)) {
 		    if (!vlist[0][i]) {
@@ -5307,21 +5329,21 @@ int PropertyOptimize(struct objlist *ob, struct nlist *tp, int run, int series,
 				sizeof(struct valuelist));
 		    }
 		    vlist[0][i]->value.ival = 0;	/* set M to 0 */
-		    if (cvl && (cvl->type == PROP_INTEGER))
+		    if (cvlp && (cvlp->type == PROP_INTEGER))
 		    {
 			if (vl->type == PROP_INTEGER)
-			    cvl->value.ival += vl->value.ival;
+			    cvlp->value.ival += vl->value.ival;
 			else {
-			    cvl->type = PROP_DOUBLE;
-			    cvl->value.dval = (double)cvl->value.ival + vl->value.dval;
+			    cvlp->type = PROP_DOUBLE;
+			    cvlp->value.dval = (double)cvlp->value.ival + vl->value.dval;
 			}
 		    }
-		    else if ((cvl && vl->type == PROP_DOUBLE))
+		    else if ((cvlp && vl->type == PROP_DOUBLE))
 		    {
 			if (vl->type == PROP_INTEGER)
-			    cvl->value.dval += (double)vl->value.ival;
+			    cvlp->value.dval += (double)vl->value.ival;
 			else
-			    cvl->value.dval += vl->value.dval;
+			    cvlp->value.dval += vl->value.dval;
 		    }
 		}
 		else if (ctype & (MERGE_S_PAR | MERGE_P_PAR)) {
@@ -5331,21 +5353,22 @@ int PropertyOptimize(struct objlist *ob, struct nlist *tp, int run, int series,
 				sizeof(struct valuelist));
 		    }
 		    vlist[0][i]->value.ival = 0;    /* set M to 0 */
-		    /* To do parallel combination, both types need to
+		    /* Parallel value combination: (X * Y) / (X + Y)
+		     * To do parallel combination, both types need to
 		     * be double, so recast them if they are integer.
 		     */
 		    if (vl->type == PROP_INTEGER) {
 			vl->type = PROP_DOUBLE;
 			vl->value.dval = (double)(vl->value.ival);
 		    }
-		    if (cvl && (cvl->type == PROP_INTEGER)) {
-			cvl->type = PROP_DOUBLE;
-			cvl->value.dval = (double)cvl->value.ival;
+		    if (cvlp && (cvlp->type == PROP_INTEGER)) {
+			cvlp->type = PROP_DOUBLE;
+			cvlp->value.dval = (double)cvlp->value.ival;
 		    }
-		    if ((cvl && (vl->type == PROP_DOUBLE))) {
-		        cvl->value.dval =
-				sqrt(cvl->value.dval * cvl->value.dval
-				+ vl->value.dval * vl->value.dval);
+		    if ((cvlp && (vl->type == PROP_DOUBLE))) {
+			cvlp->value.dval =
+				(vl->value.dval * cvlp->value.dval) /
+				(vl->value.dval + cvlp->value.dval);
 		    }
 		}
 	    }
@@ -5357,6 +5380,9 @@ int PropertyOptimize(struct objlist *ob, struct nlist *tp, int run, int series,
 		Printf("Combined %d parallel devices.\n", changed);
 	 }
       }
+
+      FREE(avl);
+      FREE(cvl);
    }
 
    // Remove entries with M (S) = 0
@@ -7530,6 +7556,12 @@ struct nlist *addproxies(struct hashlist *p, void *clientdata)
 	  else {
 	     lob = ob;
 	     ob->type = i++;
+	     if (ob->model.class == NULL) {
+		ob->model.class = strsave(tc->name);
+	     }
+	     if (ob->instance.name == NULL) {
+		ob->instance.name = strsave(firstpin->instance.name);
+	     }
 	     ob = ob->next;
 	  }
 	  tob = tob->next;
@@ -7595,6 +7627,7 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
    int hasproxy1 = 0, hasproxy2 = 0;
    int needclean1 = 0, needclean2 = 0;
    int nomatch = 0;
+   int P1, P2;
    int filenum = -1;
    int *correspond;
    char *ostr;
@@ -7627,6 +7660,7 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
       return 2;
    }
 
+   correspond = (int *)CALLOC((tc1->nodename_cache_maxnodenum + 1), sizeof(int));
    cover = (char *)CALLOC(numnodes, sizeof(char));
    numorig = numnodes;
 
@@ -7845,8 +7879,6 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
 
    ob1 = tc1->cell;
 
-   correspond = (int *)CALLOC((tc1->nodename_cache_maxnodenum + 1), sizeof(int));
-  
    for (i = 0; i < numorig; i++) {
       bangptr1 = strrchr(ob1->name, '!');
       if (bangptr1 && (*(bangptr1 + 1) == '\0'))
@@ -7967,7 +7999,7 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
 	             if (bangptr2) *bangptr2 = '!';
 		     break;
 		  }
-		  else {
+		  else if (IsPort(ob1) && IsPort(ob2)) {
 		     struct Permutation *permute1, *permute2;
 		     struct objlist *ob1a = NULL, *ob2a = NULL;
 
@@ -7997,10 +8029,8 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
 		     }
 		     if (ob1a && ob2a) {
 			if ((ob1->node == ob1a->node) && (ob2->node == ob2a->node)) {
-			   /* This should be enough to prove equivalency */
-		           if ((correspond[ob1->node] == 0) || (correspond[ob1->node] == ob2->node)) {
-
-		              correspond[ob1->node] = ob2->node;	/* remember corresponding node */
+		           if ((correspond[ob1->node] == 0) ||
+					(correspond[ob1->node] == ob2->node)) {
 	                      ob2->model.port = i;			/* save order */
 	                      *(cover + i) = (char)1;
 
@@ -8263,6 +8293,38 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
    if (Debug == 0)
       output_string_print_divider(ostr, FALSE);
 
+   /* Catch errors where disconnected ports get effectively hidden by	*/
+   /* pin permutations.							*/
+
+   if (result == 1) {
+      int found = 0;
+      for (NC = NodeClasses; NC != NULL; NC = NC->next) {
+         P1 = P2 = 0;
+         for (N1 = NC->nodes; N1 != NULL; N1 = N1->next) {
+            if (N1->graph == Circuit2->file)
+	       if (IsPort(N1->object)) P2++;
+            if (N1->graph == Circuit1->file)
+	       if (IsPort(N1->object)) P1++;
+         }
+         if (P1 != P2) {
+	    if (found == 0)
+	       Fprintf(stdout, "\nPort connection errors found:\n");
+	    found = 1;
+            for (N1 = NC->nodes; N1 != NULL; N1 = N1->next) {
+	       obn = N1->object;
+
+	       if (IsPort(obn))
+	          Fprintf(stdout, "    %s (%d)\n", obn->name, N1->graph);
+	       else
+	          Fprintf(stdout, "    %s (%d) (no port)\n", obn->name, N1->graph);
+	       if (N1->graph == Circuit1->file)
+		   correspond[obn->node] = -1;
+	    }
+	 }
+      }
+      if (found == 1) Fprintf(stdout, "\n");
+   }
+
    /* Run cleanuppins on circuit 1 */
    if (needclean1)
       CleanupPins(tc1->name, tc1->file);
@@ -8475,6 +8537,182 @@ int EquivalentElement(char *name, struct nlist *circuit, struct objlist **retobj
   return retval;
 }
 
+/*------------------------------------------------------*/
+/* Structure and definitins used by derivedprops()	*/
+/*------------------------------------------------------*/
+
+enum DerivedType {area_type, perimeter_type};
+
+typedef struct _derivedpropdata {
+    struct nlist *cell;
+    int fnum;
+    char *pwidth;
+    char *plength;
+    enum DerivedType type;
+} DerivedPropData;
+
+/*------------------------------------------------------*/
+/* derivedprops --- Callback function for a recursive	*/
+/* search over all cells with a pointer clientdata.	*/
+/* The pointer is a DerivedPropData structure that	*/
+/* contains the information needed to determine how to	*/
+/* generate an "area" or "perimeter" property based on	*/
+/* the device length and width.				*/
+/*------------------------------------------------------*/
+
+struct nlist *derivedprops(struct hashlist *p, void *clientdata)
+{
+    struct nlist *ptr;
+    struct objlist *ob;
+    struct valuelist *vl, *newvlist;
+    struct nlist *tc;
+    struct property *prop;
+    int i;
+    double valuew, valuel, valuea = 0.0, valuep = 0.0;
+    int haswidth = FALSE, haslength = FALSE;
+    int hasarea = FALSE, hasperimeter = FALSE;
+
+    DerivedPropData *dpd = (DerivedPropData *)clientdata;
+
+    tc = dpd->cell;
+    ptr = (struct nlist *)(p->ptr);
+    if (ptr->file != tc->file) return NULL;
+
+    /* Search all instances in the cell for properties, find those matching
+     * the cell class to be modified, and create a new derived property for
+     * area or perimeter for that instance.
+     */
+
+    for (ob = ptr->cell; ob; ob = ob->next) {
+       if (ob->type == PROPERTY) {
+	  if ((*matchfunc)(ob->model.class, tc->name)) {
+	     for (i = 0;; i++) {
+		vl = &(ob->instance.props[i]);
+		if (vl->type == PROP_ENDLIST) break;
+		prop = (struct property *)HashLookup(vl->key, &(tc->propdict));
+		if (prop != NULL) {
+		    if ((*matchfunc)(vl->key, dpd->pwidth)) {
+			haswidth = TRUE;
+			if (vl->type == PROP_DOUBLE)
+			    valuew = vl->value.dval;
+			else if (vl->type == PROP_INTEGER)
+			    valuew = (double)vl->value.ival;
+			else
+			   haswidth = FALSE;
+		    }
+		    else if ((*matchfunc)(vl->key, dpd->plength)) {
+			haslength = TRUE;
+			if (vl->type == PROP_DOUBLE)
+			    valuel = vl->value.dval;
+			else if (vl->type == PROP_INTEGER)
+			    valuel = (double)vl->value.ival;
+			else
+			    haslength = FALSE;
+		    }
+		    else if ((dpd->type == area_type)
+				&& ((*matchfunc)(vl->key, "area"))) {
+			hasarea = TRUE;
+		    }
+		    else if ((dpd->type == perimeter_type)
+				&& ((*matchfunc)(vl->key, "perimeter"))) {
+			hasperimeter = TRUE;
+		    }
+		}
+	     }
+	     if (haslength && haswidth) {
+
+		/* Once the property names for device width and length have
+		 * been found, and the values recorded, add the area or
+		 * perimeter value to the property list for the instance,
+		 * unless the instance already has the property.
+		 */
+		newvlist = (struct valuelist *)CALLOC(i + 1, sizeof(struct valuelist));
+		vl = &newvlist[i];
+		vl->key = NULL;
+		vl->type = PROP_ENDLIST;
+		vl->value.ival = 0;
+
+		vl = &newvlist[--i];
+		if ((dpd->type == area_type) && (!hasarea)) {
+		    valuea = valuew * valuel;
+		    vl->key = strsave("area");
+		    vl->type = PROP_DOUBLE;
+		    vl->value.dval = valuea;
+			
+		} else if ((dpd->type == perimeter_type) && (!hasperimeter)) {
+		    valuep = 2 * (valuew + valuel);
+		    vl->key = strsave("perimeter");
+		    vl->type = PROP_DOUBLE;
+		    vl->value.dval = valuep;
+		}
+		for (--i; i >= 0; i--) {
+		   vl = &newvlist[i];
+		   vl->key = ob->instance.props[i].key;
+		   vl->type = ob->instance.props[i].type;
+		   vl->value = ob->instance.props[i].value;
+		}
+		FREE(ob->instance.props);
+		ob->instance.props = newvlist;
+	     }
+	  }
+       }
+    }
+}
+
+/*------------------------------------------------------*/
+/* Create a new "area" or "perimeter" property in all	*/
+/* instances of a given device, based on the specified	*/
+/* names for the width and length parameters.		*/
+/*------------------------------------------------------*/
+
+void
+DeriveProperty(struct nlist *tc, int fnum, char *pwidth, char *plength, 
+	enum DerivedType type)
+{
+    DerivedPropData dpd;
+
+    dpd.pwidth = pwidth;
+    dpd.plength = plength;
+    dpd.fnum = fnum;
+    dpd.cell = tc;
+    dpd.type = type;
+
+    /* Create the new derived property in the cell. */
+    if (type == area_type)
+	PropertyDouble(tc->name, fnum, "area", 0.01, 0.0);    
+    else if (type == perimeter_type)
+	PropertyDouble(tc->name, fnum, "perimeter", 0.01, 0.0);    
+    else
+	return;
+
+    /* Find all instances of the cell and add the derived property */
+    RecurseCellHashTable2(derivedprops, (void *)(&dpd));
+}
+
+/*------------------------------------------------------*/
+/* Create a new "area" property in all instances of a	*/
+/* given device, based on the specified width and	*/
+/* length parameter names.				*/
+/*------------------------------------------------------*/
+
+void
+DeriveAreaProperty(struct nlist *tp, int fnum, char *pwidth, char *plength)
+{
+    DeriveProperty(tp, fnum, pwidth, plength, area_type);
+}
+
+/*------------------------------------------------------*/
+/* Create a new "perimeter" property in all instances	*/
+/* of a given device, based on the specified width and	*/
+/* length parameter names.				*/
+/*------------------------------------------------------*/
+
+void
+DerivePerimeterProperty(struct nlist *tp, int fnum, char *pwidth, char *plength)
+{
+    DeriveProperty(tp, fnum, pwidth, plength, perimeter_type);
+}
+
 /*------------------------------------------------------*/
 /* Flatten the two cells at the top of the compare	*/
 /* queue.						*/

base/netcmp.h

@@ -70,6 +70,8 @@ extern int remove_group_tags(struct objlist *ob);
 #ifdef TCL_NETGEN
 extern int EquivalentNode();
 extern int EquivalentElement();
+extern void DeriveAreaProperty();
+extern void DerivePerimeterProperty();
 
 extern void enable_interrupt();
 extern void disable_interrupt();

base/netfile.c

@@ -329,6 +329,11 @@ int GetNextLineNoNewline(char *delimiter)
 	    llen = strlen(line);
 	}
 	while (llen == linesize - 1) {
+	    /* Note that in the rare case where a newline is in the last buffer
+	     * position, we're done.
+	     */
+	    if (*(line + llen - 1) == '\n') break;
+
 	    newbuf = (char *)MALLOC(linesize + 501);
 	    strcpy(newbuf, line);
 	    FREE(line);
@@ -599,7 +604,7 @@ void SpiceTokNoNewline(void)
 {
     int contline;
 
-    if ((nexttok = strdtok(NULL, WHITESPACE_DELIMITER, NULL)) != NULL) return;
+    if ((nexttok = strdtok0(NULL, WHITESPACE_DELIMITER, NULL, FALSE)) != NULL) return;
 
     while (nexttok == NULL) {
 	contline = getc(infile);
@@ -701,7 +706,7 @@ void SpiceSkipNewLine(void)
 /* the boundary between two-character and one-character delimiters.	*/
 /*----------------------------------------------------------------------*/
 
-char *strdtok(char *pstring, char *delim1, char *delim2)
+char *strdtok0(char *pstring, char *delim1, char *delim2, char isverilog)
 {
     static char *stoken = NULL;
     static char *sstring = NULL;
@@ -746,7 +751,7 @@ char *strdtok(char *pstring, char *delim1, char *delim2)
     /* should know whether it is parsing SPICE or verilog and handle the syntax	*/
     /* accordingly (needs to be done).						*/
 
-    if (*s == '\\') {
+    if (isverilog && (*s == '\\')) {
         s++;
         while (*s != '\0') {
 	    if ((*s == ' ') || ((*s == '\\') && (*(s + 1) == '\0'))) {
@@ -817,6 +822,17 @@ char *strdtok(char *pstring, char *delim1, char *delim2)
     return sstring;
 }
 
+/*----------------------------------------------------------------------*/
+/* strdtok() is the original string tokenizer.  It calls strdtok0()	*/
+/* with isverilog=TRUE, so that tokens are parsed as (potentially)	*/
+/* verilog names, which includes verilog backslash notation.		*/
+/*----------------------------------------------------------------------*/
+
+char *strdtok(char *pstring, char *delim1, char *delim2)
+{
+   return strdtok0(pstring, delim1, delim2, TRUE);
+}
+
 /*----------------------------------------------------------------------*/
 
 void InputParseError(FILE *f)

base/netfile.h

@@ -36,6 +36,7 @@ extern struct hashdict *definitions;
 
 extern char *nexttok;
 #define SKIPTO(a) do {SkipTok(NULL);} while (!match(nexttok,a))
+extern char *strdtok0(char *pstring, char *delim1, char *delim2, char isverilog);
 extern char *strdtok(char *pstring, char *delim1, char *delim2);
 extern char *GetLineAtTok();
 extern void SkipTok(char *delimiter);

base/spice.c

@@ -532,8 +532,14 @@ void ReadSpiceFile(char *fname, int filenum, struct cellstack **CellStackPtr,
 
     SkipTok(NULL); /* get the next token */
     if ((EndParseFile()) && (nexttok == NULL)) break;
+    if (nexttok == NULL) break;
 
-    if (nexttok[0] == '*') SkipNewLine(NULL);
+    /* Handle comment lines.  Note that some variants of CDL format
+     * use "*." for information that is transparent to SPICE simulators.
+     * Handle "*.GLOBAL" entries.  All others are ignored.
+     */
+    if ((nexttok[0] == '*') && (!matchnocase(nexttok, "*.GLOBAL")))
+	SkipNewLine(NULL);
 
     else if (matchnocase(nexttok, ".SUBCKT")) {
       SpiceTokNoNewline();
@@ -821,7 +827,10 @@ skip_ends:
 
     // Handle some commonly-used cards
 
-    else if (matchnocase(nexttok, ".GLOBAL")) {
+    /* .GLOBAL and *.GLOBAL.  Note that *.GLOBAL is excepted from comment-line
+     * handling, above, so any line starting with '*' is "*.GLOBAL".
+     */
+    else if (matchnocase(nexttok, ".GLOBAL") || (nexttok[0] == '*')) {
       while (nexttok != NULL) {
 	 int numnodes = 0;
          SpiceTokNoNewline();

tcltk/netgen.tcl.in

@@ -594,6 +594,9 @@ proc netgen::lvs { name1 name2 {setupfile setup.tcl} {logfile comp.out} args} {
 	    lappend properr [lindex $endval 0]
 	 } elseif {$uresult == -2} {	;# unmatched pins
 	    set doCheckFlatten 1
+	 } elseif {$uresult == -4} {	;# unmatched pins and properties
+	    lappend properr [lindex $endval 0]
+	    set doCheckFlatten 1
 	 }
       } else {
 	 # not equivalent

tcltk/tclnetgen.c

@@ -2572,6 +2572,7 @@ _netcmp_run(ClientData clientData,
 /*	 0: not verified				*/
 /*	-1: no elements or nodes			*/
 /*	-3: verified with property error		*/
+/*	-4: verified with property and port errors	*/
 /*   equiv option					*/
 /*	-2: pin mismatch				*/
 /*							*/
@@ -2673,8 +2674,12 @@ _netcmp_verify(ClientData clientData,
       else if (automorphisms == -2) {
 	 if (index == EQUIV_IDX)
 	    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(1));
-	 else if (index == UNIQUE_IDX)
-	    Tcl_SetObjResult(interp, Tcl_NewIntObj(-2));
+	 else if (index == UNIQUE_IDX) {
+	    if (PropertyErrorDetected == 0)
+	       Tcl_SetObjResult(interp, Tcl_NewIntObj(-2));
+	    else
+	       Tcl_SetObjResult(interp, Tcl_NewIntObj(-4));
+	 }
 	 else if (index > 0)
 	    Fprintf(stdout, "Circuits match uniquely with port errors.\n");
       }
@@ -3428,13 +3433,21 @@ _netcmp_property(ClientData clientData,
     double dval;
     int ival, argstart;
 
+    char *topoptions[] = {
+	"default", "series", "serial", "parallel", "topology", NULL
+    };
+    enum TopOptionIdx {
+	TOP_DEFAULT_IDX, TOP_SERIES_IDX, TOP_SERIAL_IDX, TOP_PARALLEL_IDX,
+	TOP_TOPOLOGY_IDX
+    };
+
     char *options[] = {
 	"add", "create", "remove", "delete", "tolerance", "merge", "serial",
-	"series", "parallel", "associate", "topology", NULL
+	"series", "parallel", "associate", "derive", NULL
     };
     enum OptionIdx {
 	ADD_IDX, CREATE_IDX, REMOVE_IDX, DELETE_IDX, TOLERANCE_IDX, MERGE_IDX,
-	SERIAL_IDX, SERIES_IDX, PARALLEL_IDX, ASSOCIATE_IDX, TOPOLOGY_IDX
+	SERIAL_IDX, SERIES_IDX, PARALLEL_IDX, ASSOCIATE_IDX, DERIVE_IDX
     };
     int result, index, idx2;
 
@@ -3469,6 +3482,14 @@ _netcmp_property(ClientData clientData,
 	COMB_NONE_IDX, COMB_PAR_IDX, COMB_ADD_IDX, COMB_CRITICAL_IDX
     };
 
+    char *deriveoptions[] = {
+	"area", "perimeter", NULL
+    };
+
+    enum DeriveOptionIdx {
+	AREA_IDX, PERIMETER_IDX
+    };
+
     char *yesno[] = {
 	"on", "yes", "true", "enable", "allow",
 	"off", "no", "false", "disable", "prohibit", NULL
@@ -3483,8 +3504,13 @@ _netcmp_property(ClientData clientData,
 	"strict", "relaxed", NULL
     };
 
+    /* Don't need to check return value */
+    index = -1;
+    Tcl_GetIndexFromObj(interp, objv[1], (CONST84 char **)topoptions,
+		"option", 0, &index);
+
     /* Check for special command "property default" */
-    if ((objc == 2) && (!strcmp(Tcl_GetString(objv[1]), "default"))) {
+    if ((objc == 2) && (index == TOP_DEFAULT_IDX)) {
 
 	/* For each FET device, do "merge {w add_critical}" and	*/
 	/* "remove as ad ps pd".  This allows parallel devices	*/
@@ -3531,7 +3557,7 @@ _netcmp_property(ClientData clientData,
 	}
 	return TCL_OK;
     }
-    else if ((objc == 3) && (!strcmp(Tcl_GetString(objv[1]), "parallel"))) {
+    else if ((objc == 3) && (index == TOP_PARALLEL_IDX)) {
 	if (!strcmp(Tcl_GetString(objv[2]), "none")) {
 	    GlobalParallelNone = TRUE;
 	    SetParallelCombine(FALSE);
@@ -3553,8 +3579,7 @@ _netcmp_property(ClientData clientData,
 	}
 	return TCL_OK;
     }
-    else if ((objc == 3) && ((!strcmp(Tcl_GetString(objv[1]), "series")) ||
-		(!strcmp(Tcl_GetString(objv[1]), "serial")))) {
+    else if ((objc == 3) && ((index == TOP_SERIES_IDX) || (index == TOP_SERIAL_IDX))) {
 	if (!strcmp(Tcl_GetString(objv[2]), "none")) {
 	    SetSeriesCombine(FALSE);
 	}
@@ -3568,7 +3593,7 @@ _netcmp_property(ClientData clientData,
 	}
 	return TCL_OK;
     }
-    else if ((objc > 1) && (!strcmp(Tcl_GetString(objv[1]), "topology"))) {
+    else if ((objc > 1) && (index == TOP_TOPOLOGY_IDX)) {
 	if (objc == 2) {
 	    if (ExactTopology)
 		Tcl_SetResult(interp, "Strict topology property matching.",
@@ -4014,6 +4039,32 @@ _netcmp_property(ClientData clientData,
 		}
 		break;
 
+	    case DERIVE_IDX:
+		/* Create a derived property.  For now, this just creates
+		 * "area" or "perimeter" properties.  There may not (?)
+		 * be enough cause to make other ones.  Unlike other
+		 * "property" options, this option causes the whole circuit
+		 * database to be searched for the device in question, and
+		 * the new property is added.
+		 */
+		if (objc < 6) {
+		    Tcl_WrongNumArgs(interp, 2, objv, "{area|perimeter width length}");
+		    return TCL_ERROR;
+		}
+		result = Tcl_GetIndexFromObj(interp, objv[3],
+			(CONST84 char **)deriveoptions,
+			"area|perimeter", 0, &idx2);
+		if (result != TCL_OK) return result;
+		switch (idx2) {
+		    case AREA_IDX:
+			DeriveAreaProperty(tp, fnum, Tcl_GetString(objv[4]),
+				Tcl_GetString(objv[5]));
+			break;
+		    case PERIMETER_IDX:
+			DerivePerimeterProperty(tp, fnum, Tcl_GetString(objv[4]),
+				Tcl_GetString(objv[5]));
+			break;
+		}
 	}
     }
     return TCL_OK;