One more change to the extraction method to avoid extracting the

substrate more than once for the same subcell, since the substrate
extraction method scans the entire plane area;  this was making
large standard cell layouts extract very slowly, as every component
cell was causing the substrate search to be repeated.

calma/CalmaRdcl.c

@@ -345,6 +345,7 @@ calmaParseStructure(filename)
 	}
     }
     cifReadCellDef = calmaFindCell(strname, &was_called);
+    def->cd_flags &= ~CDDEREFERENCE;
     DBCellClearDef(cifReadCellDef);
     DBCellSetAvail(cifReadCellDef);
     HashSetValue(he, cifReadCellDef);
@@ -664,6 +665,10 @@ calmaElementSref(filename)
 	    TxPrintf("Cell definition %s does not exist!\n", sname);
 	    fseek(calmaInputFile, originalFilePos, SEEK_SET);
 	    def = calmaFindCell(sname, NULL);
+	    /* Cell flags set to "dereferenced" in case there is no	*/
+	    /* definition in the GDS file.  If there is a definition	*/
+	    /* made after the instance, then the flag will be cleared.	*/
+	    def->cd_flags |= CDDEREFERENCE;
 	}
     }
 

database/database.h.in

@@ -498,6 +498,11 @@ typedef struct celluse
  */  
 #define CU_SELECT_NET	0x02
 #define CU_SELECT_CHUNK	0x04
+/* CU_SUB_EXTRACTED is a temporary flag indicating that the substrate
+ *		    of the use has been extracted and the extraction
+ *		    does not need to be repeated for this use.
+ */
+#define CU_SUB_EXTRACTED 0x08
 
 /* Character prefix used to denote a locked cell use in a .mag file */
 #define CULOCKCHAR	'*'

extract/ExtHier.c

@@ -91,6 +91,10 @@ extHierSubstrate(ha, use, x, y)
     /* define a substrate plane or substrate connections. */
     if (glob_subsnode == NULL) return;
 
+    /* If the substrate has already been extracted for this use	*/
+    /* then there is no need to do it again.			*/
+    if (use->cu_flags & CU_SUB_EXTRACTED) return;
+
     def = (CellDef *)ha->ha_parentUse->cu_def;
 
     /* Register the name of the parent's substrate */

extract/ExtSubtree.c

@@ -93,6 +93,26 @@ void extSubtreeAdjustInit();
 void extSubtreeOutputCoupling();
 void extSubtreeHardSearch();
 
+/*
+ * ----------------------------------------------------------------------------
+ *
+ * extClearUseFlags --
+ *
+ *  Callback function to clear the CU_SUB_EXTRACTED flag from each child
+ *  use of a CellDef.
+ *
+ * ----------------------------------------------------------------------------
+ */
+
+int
+extClearUseFlags(use, clientData)
+    CellUse *use;
+    ClientData clientData;
+{
+    use->cu_flags &= ~CU_SUB_EXTRACTED;
+    return 0;
+}
+
 
 /*
  * ----------------------------------------------------------------------------
@@ -292,6 +312,9 @@ done:
     /* Output connections and node adjustments */
     extOutputConns(&ha.ha_connHash, f);
     HashKill(&ha.ha_connHash);
+
+    /* Clear the CU_SUB_EXTRACTED flag from all children instances */
+    DBCellEnum(def, extClearUseFlags, (ClientData)NULL);
 }
 
 #ifdef	exactinteractions
@@ -800,6 +823,8 @@ extSubtreeFunc(scx, ha)
 	    for (y = use->cu_ylo; y <= use->cu_yhi; y++)
 		extHierSubstrate(ha, use, x, y);
     }
+    /* Mark substrate as having been extracted for this use. */
+    use->cu_flags |= CU_SUB_EXTRACTED;
 
     /* Free the cumulative node list we extracted above */
     if (ha->ha_cumFlat.et_nodes)