Manage minimum area for VIAs in the P&R.

* New: In Hurricane::Layer, add support for a minimal area (given in
    microns). Exported in the Python interface.
* New: In Anabatic::AutoSegment::bloatStackedStrap(), method to
    enlarge too small vertically stacked VIAs. For now just create
    a square ensuring the minimal area. Potentially cause DRC error in
    some cases so needs to be refined.
* New: In Anabatic::_gutAnabatic(), check for too little stacked VIAs
    and display a report.

anabatic/src/AnabaticEngine.cpp

@@ -408,17 +408,20 @@ namespace Anabatic {
 
       size_t fixedSegments    = 0;
       size_t sameLayerDoglegs = 0;
+      size_t bloatedStraps    = 0;
       for ( auto isegment : _autoSegmentLut ) {
         if (isegment.second->isFixed()) ++fixedSegments;
         if (isegment.second->reduceDoglegLayer()) ++sameLayerDoglegs;
+        if (isegment.second->bloatStackedStrap()) ++bloatedStraps;
       }
 
       cmess1 << "  o  Driving Hurricane data-base." << endl;
-      cmess1 << Dots::asSizet("     - Active AutoSegments",AutoSegment::getAllocateds()-fixedSegments) << endl;
+      cmess1 << Dots::asSizet("     - Active AutoSegments"       ,AutoSegment::getAllocateds()-fixedSegments) << endl;
-      cmess1 << Dots::asSizet("     - Active AutoContacts",AutoContact::getAllocateds()-fixedSegments*2) << endl;
+      cmess1 << Dots::asSizet("     - Active AutoContacts"       ,AutoContact::getAllocateds()-fixedSegments*2) << endl;
-      cmess1 << Dots::asSizet("     - AutoSegments"       ,AutoSegment::getAllocateds()) << endl;
+      cmess1 << Dots::asSizet("     - AutoSegments"              ,AutoSegment::getAllocateds()) << endl;
-      cmess1 << Dots::asSizet("     - AutoContacts"       ,AutoContact::getAllocateds()) << endl;
+      cmess1 << Dots::asSizet("     - AutoContacts"              ,AutoContact::getAllocateds()) << endl;
-      cmess1 << Dots::asSizet("     - Same Layer doglegs" ,sameLayerDoglegs) << endl;
+      cmess1 << Dots::asSizet("     - Same Layer doglegs"        ,sameLayerDoglegs) << endl;
+      cmess1 << Dots::asSizet("     - Bloated straps (< minArea)",bloatedStraps   ) << endl;
 
     //for ( Net* net : _cell->getNets() ) _saveNet( net );
 

anabatic/src/AutoSegment.cpp

@@ -14,6 +14,7 @@
 // +-----------------------------------------------------------------+
 
 
+#include <cmath>
 #include "hurricane/DebugSession.h"
 #include "hurricane/Warning.h"
 #include "hurricane/Bug.h"
@@ -2000,7 +2001,7 @@ namespace Anabatic {
 
   bool  AutoSegment::reduceDoglegLayer ()
   {
-    if (not isReduced()) return true;
+    if (not isReduced()) return false;
 
     DebugSession::open( getNet(), 149, 160 );
     cdebug_log(159,1) << "AutoSegment::reduceDoglegLayer(): " << this << endl;
@@ -2085,6 +2086,23 @@ namespace Anabatic {
   }
 
 
+  bool  AutoSegment::bloatStackedStrap ()
+  {
+    if (getLength() or isReduced()) return false;
+    if (   ((_flags & (SegSourceBottom|SegTargetTop)) != (SegSourceBottom|SegTargetTop))
+       and ((_flags & (SegTargetBottom|SegSourceTop)) != (SegTargetBottom|SegSourceTop)) ) return false;
+
+    double minArea = getLayer()->getMinimalArea();
+    if (minArea == 0.0) return false;
+
+    DbU::Unit side = DbU::fromPhysical( std::sqrt(minArea) , DbU::UnitPower::Micro );
+    setWidth( side );
+    setDuSource( -side/2 );
+    setDuTarget(  side/2 );
+    return true;
+  }
+
+
 #if THIS_IS_DISABLED
   bool  AutoSegment::shearUp ( GCell* upGCell, AutoSegment*& movedUp, float reserve, Flags flags )
   {

anabatic/src/anabatic/AutoSegment.h

@@ -205,6 +205,7 @@ namespace Anabatic {
       inline         bool                isSourceTerminal           () const;
       inline         bool                isTargetTerminal           () const;
       inline         bool                isLayerChange              () const;
+      inline         bool                isStackedStrap             () const;
       inline         bool                isSpinTop                  () const;
       inline         bool                isSpinBottom               () const;
       inline         bool                isSpinTopOrBottom          () const;
@@ -325,6 +326,7 @@ namespace Anabatic {
                      bool                moveUp                     ( Flags flags=Flags::NoFlags );
                      bool                moveDown                   ( Flags flags=Flags::NoFlags );
                      bool                reduceDoglegLayer          ();
+                     bool                bloatStackedStrap          ();
                      bool                reduce                     ();
                      bool                raise                      ();
     // Canonical Modifiers.                                            
@@ -559,7 +561,6 @@ namespace Anabatic {
 //inline  void            AutoSegment::mergeUserConstraints   ( const Interval& constraints ) { _userConstraints.intersection(constraints); }
   inline  void            AutoSegment::resetUserConstraints   () { _userConstraints = Interval(false); }
 
-
   inline  void  AutoSegment::setLayer ( size_t depth )
   {
     RoutingLayerGauge* layerGauge = Session::getLayerGauge( depth );
@@ -570,7 +571,6 @@ namespace Anabatic {
     _flags|=SegInvalidatedLayer;
   }
 
-
   inline  DbU::Unit  AutoSegment::getContactWidth () const
   { return getWidth() + Session::getViaWidth(getLayer()) - Session::getWireWidth(getLayer()); }
 

hurricane/src/hurricane/Layer.cpp

@@ -58,6 +58,7 @@ namespace Hurricane {
                  , _nextOfTechnologyLayerMap(NULL)
                  , _symbolic(false)
                  , _blockage(false)
+                 , _minimalArea(0.0)
   {
     if ( !_technology )
       throw Error ( "Can't create " + _TName("Layer") + " : null technology" );
@@ -138,6 +139,10 @@ namespace Hurricane {
   { return 0; }
 
 
+  double  Layer::getMinimalArea () const
+  { return _minimalArea; }
+
+
   bool Layer::contains ( const Layer* layer ) const
   {
     return ( layer && ((_mask & layer->getMask()) == layer->getMask()) );
@@ -184,6 +189,10 @@ namespace Hurricane {
   }
 
 
+  void Layer::setMinimalArea ( double area )
+  { _minimalArea = area; }
+
+
   void  Layer::setEnclosure ( const BasicLayer*, DbU::Unit, uint32_t )
   {
     cerr << "[WARNING] Layer::setEnclosure() musn't be called on "

hurricane/src/hurricane/hurricane/Layer.h

@@ -88,6 +88,7 @@ namespace Hurricane {
       virtual DbU::Unit         getExtentionWidth            ( const BasicLayer* layer ) const;
       virtual DbU::Unit         getTopEnclosure              ( uint32_t flags ) const;
       virtual DbU::Unit         getBottomEnclosure           ( uint32_t flags ) const;
+      virtual double            getMinimalArea               () const;
     // Predicates
       inline  bool              above                        ( const Layer* layer ) const;
       inline  bool              below                        ( const Layer* layer ) const;
@@ -104,6 +105,7 @@ namespace Hurricane {
       virtual void              setEnclosure                 ( const BasicLayer* layer, DbU::Unit, uint32_t flags );
       virtual void              setExtentionCap              ( const BasicLayer* layer, DbU::Unit );
       virtual void              setExtentionWidth            ( const BasicLayer* layer, DbU::Unit );
+      virtual void              setMinimalArea               ( double );
     // Hurricane Managment.
       virtual void              _toJson                      ( JsonWriter* ) const;
       virtual string            _getString                   () const;
@@ -126,6 +128,7 @@ namespace Hurricane {
               Layer*            _nextOfTechnologyLayerMap;
               bool              _symbolic;
               bool              _blockage;
+              double            _minimalArea;
 
     protected:
     // Internal: Constructors & Destructors.

hurricane/src/isobar/PyLayer.cpp

@@ -374,14 +374,16 @@ extern "C" {
   accessorDbuFromUInt         (                          getBottomEnclosure,PyLayer,Layer)
   DirectGetLongAttribute      (PyLayer_getMinimalSize   ,getMinimalSize    ,PyLayer,Layer)
   DirectGetLongAttribute      (PyLayer_getMinimalSpacing,getMinimalSpacing ,PyLayer,Layer)
+  DirectGetDoubleAttribute    (PyLayer_getMinimalArea   ,getMinimalArea    ,PyLayer,Layer)
 
   SetNameMethod(Layer, layer)
   updatorFromDbu          (setMinimalSize   ,PyLayer,Layer)
   updatorFromDbu          (setMinimalSpacing,PyLayer,Layer)
   updatorFromBasicLayerDbu(setExtentionCap  ,PyLayer,Layer)
   updatorFromBasicLayerDbu(setExtentionWidth,PyLayer,Layer)
-  DirectSetBoolAttribute  (PyLayer_setSymbolic,setSymbolic,PyLayer,Layer)
+  DirectSetBoolAttribute  (PyLayer_setSymbolic   ,setSymbolic   ,PyLayer,Layer)
-  DirectSetBoolAttribute  (PyLayer_setBlockage,setBlockage,PyLayer,Layer)
+  DirectSetBoolAttribute  (PyLayer_setBlockage   ,setBlockage   ,PyLayer,Layer)
+  DirectSetDoubleAttribute(PyLayer_setMinimalArea,setMinimalArea,PyLayer,Layer)
 
   // Standart destroy (Attribute).
   DBoDestroyAttribute(PyLayer_destroy, PyLayer)
@@ -398,6 +400,8 @@ extern "C" {
                               , "Returns the extract mask of the layer (for GDSII)." }
     , { "getMinimalSize"      , (PyCFunction)PyLayer_getMinimalSize      , METH_NOARGS
                               , "Returns the minimum width allowed for the layer." }
+    , { "getMinimalArea"      , (PyCFunction)PyLayer_getMinimalArea      , METH_NOARGS
+                              , "Returns the minimum area allowed for the layer." }
     , { "getMinimalSpacing"   , (PyCFunction)PyLayer_getMinimalSpacing   , METH_NOARGS
                               , "Returns the spacing allowed for the layer (edge to edge)." }
     , { "getBasicLayers"      , (PyCFunction)PyLayer_getBasicLayers      , METH_NOARGS
@@ -458,6 +462,8 @@ extern "C" {
                               , "Sets the extention cap for the given BasiLayer sub-component." }
     , { "setExtentionWidth"   , (PyCFunction)PyLayer_setExtentionWidth   , METH_VARARGS
                               , "Sets the extention width for the given BasiLayer sub-component." }
+    , { "setMinimalArea"      , (PyCFunction)PyLayer_setMinimalArea      , METH_VARARGS
+                              , "Sets the minimum area allowed for the layer." }
     , { "destroy"             , (PyCFunction)PyLayer_destroy             , METH_NOARGS
                               , "Destroy associated hurricane object The python object remains." }
     , {NULL, NULL, 0, NULL}   /* sentinel */