Change the way QuadTree.getLeafUnder() locate the leaf.

* Change: In cumulus/plugins.Block.getLeafUnder(): formerly, we where
    using the cut-lines (x/y) to locate which leaf a point is under.
    But in case of incomplete tree, it is difficult to manage.
      Now we chosse the leaf according to the distance to the center
    of the leaf area. Choose the shorter, of course.
      This solve the H-Tree DFF bad assignment around the PLL (top
    right corner) in LS180.

crlcore/src/ccore/alliance/vst/VstParserGrammar.yy

@@ -854,6 +854,12 @@ association_element
                       << "  Port map assignment discrepency "
                       << "instance:" << Vst::states->_instanceNets.size()
                       << " vs. model:"   << Vst::states->_masterNets.size();
+              message << "\nModel:";
+              for ( Net* net : Vst::states->_masterNets )
+	         message << " \"" << net->getName() << "\"";
+              message << "\nInstance:";
+              for ( Net* net : Vst::states->_instanceNets )
+	         message << " \"" << net->getName() << "\"";
               throw Error( message.str() );
             }
 	    

cumulus/src/plugins/alpha/block/block.py

@@ -383,8 +383,10 @@ class Block ( object ):
 
     @staticmethod
     def _instancesToPath ( cell, instances ):
-        instance = cell.getInstance( instances[0] )
-        return Block._rinstancesToPath( Path(instance), instances[1:] )
+        path = Path( cell.getInstance( instances[0] ))
+        if len(instances) == 1:
+            return path
+        return Block._rinstancesToPath( path, instances[1:] )
 
     def getFlattenedNet ( self, path ):
         """
@@ -398,9 +400,14 @@ class Block ( object ):
         elements = path.split('.')
         if len(elements) == 1:
             return None
-        path = Block._instancesToPath( self.conf.cellPnR, elements[:-1] )
-        net  = path.getTailInstance().getMasterCell().getNet( elements[-1] )
-        return Occurrence( net, path )
+        ipath = Block._instancesToPath( self.conf.cellPnR, elements[:-1] )
+        net   = ipath.getTailInstance().getMasterCell().getNet( elements[-1] )
+        if net is None:
+            raise ErrorMessage( 1, [ 'Block.getFlattenedNet(): On "{}" (deep)net,'.format( path )
+                                   , 'Tail {} has no net "{}".' \
+                                     .format( ipath.getTailInstance(), elements[-1] )
+                                   ] )
+        return Occurrence( net, ipath )
 
     def setUnexpandPins ( self, sides ):
         """

cumulus/src/plugins/alpha/block/spares.py

@@ -345,6 +345,10 @@ class QuadTree ( object ):
         if self.tr: self.tr.removeUnusedBuffers()
         self.pool._removeUnuseds()
 
+    def getDistance ( self, point ):
+        """Return the Manhattan distance between ``point`` and the area center."""
+        return self.area.getCenter().manhattanDistance( point )
+
     def rshowPoolUse ( self ):
         rused  = 0
         rtotal = 0
@@ -696,27 +700,27 @@ class QuadTree ( object ):
     def getLeafUnder ( self, position ):
         """Find the QuadTree leaf under ``position``."""
         if self.isLeaf(): return self
-        if self.isHBipart():
-            if position.getX() < self.xcut: return self.bl.getLeafUnder(position)
-            return self.br.getLeafUnder(position)
-        if self.isVBipart():
-            if position.getY() < self.ycut: return self.bl.getLeafUnder(position)
-            return self.tl.getLeafUnder(position)
-        leaf = None
-        if position.getX() < self.xcut:
-            if position.getY() < self.ycut: leaf = self.bl
-            else:                           leaf = self.tl
-        else:
-            if position.getY() < self.ycut: leaf = self.br
-            else:                           leaf = self.tr
-        if not leaf:
-            dx = abs( position.getX() - self.xcut )
-            dy = abs( position.getY() - self.ycut )
-            if self.tr and ((dx <  dy) or not leaf): leaf = self.tr
-            if self.tl and ((dx <  dy) or not leaf): leaf = self.tl
-            if self.br and ((dx >= dy) or not leaf): leaf = self.br
-            if self.bl and ((dx >= dy) or not leaf): leaf = self.bl
-        return leaf.getLeafUnder(position)
+        candidate = None
+        minDist   = None
+        if self.bl:
+            minDist   = self.bl.getDistance( position )
+            candidate = self.bl
+        if self.br:
+            distance = self.br.getDistance( position )
+            if (candidate is None) or (distance < minDist):
+                minDist   = distance
+                candidate = self.br
+        if self.tl:
+            distance = self.tl.getDistance( position )
+            if (candidate is None) or (distance < minDist):
+                minDist   = distance
+                candidate = self.tl
+        if self.tr:
+            distance = self.tr.getDistance( position )
+            if (candidate is None) or (distance < minDist):
+                minDist   = distance
+                candidate = self.tr
+        return candidate.getLeafUnder(position)
 
     def getFreeLeafUnder ( self, area, attractor=None ):
         """