In Katabatic, the layer assignment move up part of Net trunks.

* In Katabatic, in AutoSegment::canMoveUp(), adds the ability to reject
    the move up if the density of the depth we comes from is below 0.6
    in all the GCells, activated with the KbChecklowDensity flag.
* In Katabatic, In LayerAssign, new method moveUpNetTrunk2() which,
    unlike the previous one, move up only the part of the Net trunk
    which is connex to the seed segment. Use the canMoveUp with
    low density checking to avoid unbalancing higher metal layers.
* In Kite, in SegmentFsm, use the canMoveUp() with low density checking.

katabatic/src/AutoSegment.cpp

@@ -1501,8 +1501,9 @@ namespace Katabatic {
     ltrace(200) << "AutoSegment::canMoveUp() " << flags
                 << " (reserve:" << reserve << ")" << endl;
 
-    GCell* begin = NULL;
+    bool   lowDensity = true;
-    GCell* end   = NULL;
+    GCell* begin      = NULL;
+    GCell* end        = NULL;
 
     if ( isLayerChange() or isFixed() ) return false;
     if ( isStrongTerminal() and (not (flags & KbAllowTerminal)) ) return false;
@@ -1517,6 +1518,7 @@ namespace Katabatic {
     end   = *gcells.rbegin();
 
     for ( size_t i=0 ; i<gcells.size() ; i++ ) {
+      if ( lowDensity and (gcells[i]->getWDensity(depth-2) > 0.5) ) lowDensity = false;
       if (not gcells[i]->hasFreeTrack(depth,reserve)) {
         ltrace(200) << "Not enough free track in " << gcells[i] << endl;
         return false;
@@ -1542,6 +1544,7 @@ namespace Katabatic {
         if ( (*gcells.rbegin())->getIndex() > end  ->getIndex() ) end   = *gcells.rbegin(); 
 
         for ( size_t i=0 ; i<gcells.size() ; i++ ) {
+          if ( lowDensity and (gcells[i]->getWDensity(depth-2) > 0.6) ) lowDensity = false;
           if (not gcells[i]->hasFreeTrack(depth,reserve)) {
             ltrace(200) << "Not enough free track in " << gcells[i] << endl;
             return false;
@@ -1550,6 +1553,8 @@ namespace Katabatic {
       }
     }
 
+    if (lowDensity and (flags & KbCheckLowDensity)) return false;
+
     if ( (depth >= 4) and (flags & KbWithPerpands) ) {
       float fragmentation = begin->getFragmentation( depth-1 );
       ltrace(200) << "Check begin GCell perpandicular fragmentation: " << fragmentation << endl;

katabatic/src/GCell.cpp

@@ -1259,7 +1259,7 @@ namespace Katabatic {
 
       ltrace(500) << "Deter| Move up " << (*isegment) << endl;
 
-      if ( getGCellGrid()->getKatabatic()->moveUpNetTrunk(*isegment,globalNets,invalidateds) )
+      if ( getGCellGrid()->getKatabatic()->moveUpNetTrunk2(*isegment,globalNets,invalidateds) )
         return true;
     }
 

katabatic/src/LayerAssign.cpp

@@ -273,6 +273,100 @@ namespace Katabatic {
   }
 
 
+  bool  KatabaticEngine::moveUpNetTrunk2 ( AutoSegment* seed, set<Net*>& globalNets, GCell::SetIndex& invalidateds )
+  {
+    Net*         net       = seed->getNet();
+    unsigned int seedDepth = Session::getRoutingGauge()->getLayerDepth(seed->getLayer());
+
+    DebugSession::open( net, 90 );
+    ltrace(500) << "Deter| moveUpNetTrunk() depth:" << seedDepth << " " << seed << endl;
+
+    if (not seed->canMoveUp( 1.0, KbPropagate|KbAllowTerminal|KbNoCheckLayer) ) {
+      ltrace(500) << "Deter| Reject seed move up, cannot move up." << endl;
+      DebugSession::close();
+      return false;
+    }
+    ltracein(400);
+
+    globalNets.insert( net );
+
+    vector< pair<AutoContact*,AutoSegment*> > stack;
+    vector<AutoSegment*> globals;
+    vector<AutoSegment*> locals;
+
+    stack.push_back( pair<AutoContact*,AutoSegment*>(NULL,seed) );
+    while ( not stack.empty() ) {
+      AutoContact* from    = stack.back().first;
+      AutoSegment* segment = stack.back().second;
+      stack.pop_back();
+
+      if (segment->isLocal()) {
+        if (not segment->isStrongTerminal()) locals.push_back( segment );
+        continue;
+      }
+      if ( (segment->getLength() < 3*Session::getSliceHeight()) and (segment != seed) ) {
+        locals.push_back( segment );
+        continue;
+      }
+
+    // Do something here.
+      if (not segment->canMoveUp(1.0,KbPropagate|KbAllowTerminal|KbNoCheckLayer|KbCheckLowDensity) )
+        continue;
+
+      globals.push_back( segment );
+
+      AutoContact* source = segment->getAutoSource();
+      if (source != from) {
+        for ( AutoSegment* connected : source->getAutoSegments() ) {
+          if (connected != segment) { stack.push_back( make_pair(source,connected) ); }
+        }
+      }
+      AutoContact* target = segment->getAutoTarget();
+      if (target != from) {
+        for ( AutoSegment* connected : target->getAutoSegments() ) {
+          if (connected != segment) { stack.push_back( make_pair(target,connected) ); }
+        }
+      }
+    }
+
+    for ( size_t i=0 ; i<globals.size() ; ++i ) {
+    //ltrace(500) << "Deter| Looking up G:" << globals[i] << endl;
+      unsigned int depth = Session::getRoutingGauge()->getLayerDepth( globals[i]->getLayer() );
+      globals[i]->changeDepth( depth+2, KbWithNeighbors );
+
+      vector<GCell*> gcells;
+      globals[i]->getGCells( gcells );
+      for ( size_t j=0 ; j<gcells.size() ; j++ ) {
+        invalidateds.insert( gcells[j] );
+      }
+    }
+
+    for ( size_t i=0 ; i<locals.size() ; ++i ) {
+    //ltrace(500) << "Deter| Looking up L:" << locals[i] << endl;
+
+      unsigned int depth = Session::getRoutingGauge()->getLayerDepth(locals[i]->getLayer());
+      if (depth > seedDepth+1) continue;
+
+      if (locals[i]->canPivotUp(2.0,KbPropagate|KbNoCheckLayer)) {
+        locals[i]->changeDepth( depth+2, KbWithNeighbors );
+
+      //ltrace(500) << "Deter| Trunk move up L:" << locals[i] << endl;
+
+        vector<GCell*> gcells;
+        locals[i]->getGCells( gcells );
+        for ( size_t j=0 ; j<gcells.size() ; j++ ) {
+          invalidateds.insert( gcells[j] );
+        }
+      }
+    }
+
+    ltraceout(400);
+    DebugSession::close();
+
+    return true;
+  }
+
+
   bool  KatabaticEngine::moveUpNetTrunk ( AutoSegment* seed, set<Net*>& globalNets, GCell::SetIndex& invalidateds )
   {
     Net*         net       = seed->getNet();

katabatic/src/katabatic/Constants.h

@@ -47,6 +47,7 @@ namespace Katabatic {
                        , KbNoGCellShrink     = 0x01000000
                        , KbCParanoid         = 0x02000000
                        , KbCreate            = 0x04000000
+                       , KbCheckLowDensity   = 0x08000000
                        , KbDirectionMask     = KbHorizontal|KbVertical
                        };
 

katabatic/src/katabatic/KatabaticEngine.h

@@ -146,6 +146,7 @@ namespace Katabatic {
               void                    slackenBorder             ( Box bb, Layer::Mask, unsigned int flags );
               void                    slackenBlockIos           ( Instance* core );
               bool                    moveUpNetTrunk            ( AutoSegment*, set<Net*>& globalNets, GCell::SetIndex& invalidateds );
+              bool                    moveUpNetTrunk2           ( AutoSegment*, set<Net*>& globalNets, GCell::SetIndex& invalidateds );
               void                    moveULeft                 ( AutoSegment*, set<Net*>& globalNets, GCell::SetIndex& invalidateds );
               void                    moveURight                ( AutoSegment*, set<Net*>& globalNets, GCell::SetIndex& invalidateds );
               void                    balanceGlobalDensity      ();

kite/src/SegmentFsm.cpp

@@ -725,7 +725,7 @@ namespace Kite {
     Interval              constraints;
     vector<Cs1Candidate>  candidates;
     TrackElement*         segment    = _event->getSegment();
-    bool                  canMoveUp  = (segment->isLocal()) ? segment->canPivotUp(0.5) : segment->canMoveUp(1.0); // MARK 1
+    bool                  canMoveUp  = (segment->isLocal()) ? segment->canPivotUp(0.5) : segment->canMoveUp(1.0,Katabatic::KbCheckLowDensity); // MARK 1
     unsigned int          relaxFlags = Manipulator::NoDoglegReuse
                                      | ((_data and (_data->getStateCount() < 2)) ? Manipulator::AllowExpand
                                                                                  : Manipulator::NoExpand);
@@ -1151,7 +1151,7 @@ namespace Kite {
       case DataNegociate::ConflictSolveByPlaceds:
         ltrace(200) << "Global, SegmentFsm: ConflictSolveByHistory or ConflictSolveByPlaceds." << endl;
         if ((success = conflictSolveByPlaceds())) {
-          if (segment->canMoveUp(1.0))
+          if (segment->canMoveUp(1.0,Katabatic::KbCheckLowDensity))
             nextState = DataNegociate::MoveUp;
           else {
             if (data->getStateCount() > 3)