Fixed ILU preconditioners for distributed matrices

src/TNL/Solvers/Linear/Preconditioners/Diagonal_impl.h

@@ -96,9 +96,6 @@ solve( ConstVectorViewType b, VectorViewType x ) const
    const auto b_view = b.getConstLocalView();
    auto x_view = x.getLocalView();
 
-   // wait for pending synchronization
-   b.waitForSynchronization();
-
    // compute without ghosts (diagonal includes only local rows)
    x_view = b_view / diag_view;
 

src/TNL/Solvers/Linear/Preconditioners/ILU0.h

@@ -90,7 +90,12 @@ protected:
    template< typename M >
    static IndexType getMinColumn( const Matrices::DistributedMatrix< M >& m )
    {
-      return m.getLocalRowRange().getBegin();
+      if( m.getRows() == m.getColumns() )
+         // square matrix, assume global column indices
+         return m.getLocalRowRange().getBegin();
+      else
+         // non-square matrix, assume ghost indexing
+         return 0;
    }
 };
 

src/TNL/Solvers/Linear/Preconditioners/ILU0_impl.h

@@ -145,6 +145,9 @@ solve( ConstVectorViewType _b, VectorViewType _x ) const
 
    // Step 2: solve x from Ux = y
    triangularSolveUpper< true, true >( U, x, x );
+
+   // synchronize ghosts
+   Traits< Matrix >::startSynchronization( _x );
 }
 
 

src/TNL/Solvers/Linear/Preconditioners/ILUT.h

@@ -79,7 +79,12 @@ protected:
    template< typename M >
    static IndexType getMinColumn( const Matrices::DistributedMatrix< M >& m )
    {
-      return m.getLocalRowRange().getBegin();
+      if( m.getRows() == m.getColumns() )
+         // square matrix, assume global column indices
+         return m.getLocalRowRange().getBegin();
+      else
+         // non-square matrix, assume ghost indexing
+         return 0;
    }
 };
 

src/TNL/Solvers/Linear/Preconditioners/ILUT_impl.h

@@ -272,6 +272,9 @@ solve( ConstVectorViewType _b, VectorViewType _x ) const
 
    // Step 2: solve x from Ux = y
    triangularSolveUpper< true, false >( U, x, x );
+
+   // synchronize ghosts
+   Traits< Matrix >::startSynchronization( _x );
 }
 
 } // namespace Preconditioners

src/TNL/Solvers/Linear/Traits.h

@@ -52,6 +52,8 @@ struct Traits
    static LocalViewType getLocalView( VectorViewType v ) { return v; }
 
    static typename CommunicatorType::CommunicationGroup getCommunicationGroup( const Matrix& m ) { return CommunicatorType::AllGroup; }
+   static void startSynchronization( VectorViewType v ) {}
+   static void waitForSynchronization( VectorViewType v ) {}
 };
 
 template< typename Matrix, typename Communicator >
@@ -95,6 +97,8 @@ struct Traits< Matrices::DistributedMatrix< Matrix, Communicator > >
    static LocalViewType getLocalView( VectorViewType v ) { return v.getLocalView(); }
 
    static typename CommunicatorType::CommunicationGroup getCommunicationGroup( const Matrices::DistributedMatrix< Matrix, Communicator >& m ) { return m.getCommunicationGroup(); }
+   static void startSynchronization( VectorViewType v ) { v.startSynchronization(); }
+   static void waitForSynchronization( VectorViewType v ) { v.waitForSynchronization(); }
 };
 
 } // namespace Linear