Ejemplo n.º 1
0
void SUMMA_TNA
( Orientation orientA,
  T alpha,
  const AbstractDistMatrix<T>& APre,
  const AbstractDistMatrix<T>& BPre,
        AbstractDistMatrix<T>& CPre )
{
    DEBUG_CSE
    const Int n = CPre.Width();
    const Int bsize = Blocksize();
    const Grid& g = APre.Grid();

    DistMatrixReadProxy<T,T,MC,MR> AProx( APre );
    DistMatrixReadProxy<T,T,MC,MR> BProx( BPre );
    DistMatrixReadWriteProxy<T,T,MC,MR> CProx( CPre );
    auto& A = AProx.GetLocked();
    auto& B = BProx.GetLocked();
    auto& C = CProx.Get();

    // Temporary distributions
    DistMatrix<T,MC,STAR> B1_MC_STAR(g);
    DistMatrix<T,MR,STAR> D1_MR_STAR(g);
    DistMatrix<T,MR,MC  > D1_MR_MC(g);

    B1_MC_STAR.AlignWith( A );
    D1_MR_STAR.AlignWith( A );

    for( Int k=0; k<n; k+=bsize )
    {
        const Int nb = Min(bsize,n-k);
        auto B1 = B( ALL, IR(k,k+nb) );
        auto C1 = C( ALL, IR(k,k+nb) );

        // D1[MR,*] := alpha (A1[MC,MR])^T B1[MC,*]
        //           = alpha (A1^T)[MR,MC] B1[MC,*]
        B1_MC_STAR = B1; 
        LocalGemm( orientA, NORMAL, alpha, A, B1_MC_STAR, D1_MR_STAR );

        // C1[MC,MR] += scattered & transposed D1[MR,*] summed over grid cols
        Contract( D1_MR_STAR, D1_MR_MC );
        Axpy( T(1), D1_MR_MC, C1 );
    }
}
Ejemplo n.º 2
0
inline void
SymmLLA
( T alpha, const DistMatrix<T>& A, const DistMatrix<T>& B,
  T beta,        DistMatrix<T>& C )
{
#ifndef RELEASE
    PushCallStack("internal::SymmLLA");
    if( A.Grid() != B.Grid() || B.Grid() != C.Grid() )
        throw std::logic_error
        ("{A,B,C} must be distributed over the same grid");
#endif
    const Grid& g = A.Grid();

    DistMatrix<T> 
        BL(g), BR(g),
        B0(g), B1(g), B2(g);

    DistMatrix<T>
        CL(g), CR(g),
        C0(g), C1(g), C2(g);

    DistMatrix<T,MC,STAR> B1_MC_STAR(g);
    DistMatrix<T,VR,STAR> B1_VR_STAR(g);
    DistMatrix<T,STAR,MR> B1Trans_STAR_MR(g);
    DistMatrix<T> Z1(g);
    DistMatrix<T,MC,STAR> Z1_MC_STAR(g);
    DistMatrix<T,MR,STAR> Z1_MR_STAR(g);
    DistMatrix<T,MR,MC  > Z1_MR_MC(g);

    B1_MC_STAR.AlignWith( A );
    B1_VR_STAR.AlignWith( A );
    B1Trans_STAR_MR.AlignWith( A );
    Z1_MC_STAR.AlignWith( A );
    Z1_MR_STAR.AlignWith( A );

    Scale( beta, C );
    LockedPartitionRight
    ( B, BL, BR, 0 );
    PartitionRight
    ( C, CL, CR, 0 );
    while( CL.Width() < C.Width() )
    {
        LockedRepartitionRight 
        ( BL, /**/ BR,
          B0, /**/ B1, B2 );

        RepartitionRight
        ( CL, /**/ CR,
          C0, /**/ C1, C2 );

        Z1.AlignWith( C1 );
        Zeros( C1.Height(), C1.Width(), Z1_MC_STAR );
        Zeros( C1.Height(), C1.Width(), Z1_MR_STAR );
        //--------------------------------------------------------------------//
        B1_MC_STAR = B1;
        B1_VR_STAR = B1_MC_STAR;
        B1Trans_STAR_MR.TransposeFrom( B1_VR_STAR );
        LocalSymmetricAccumulateLL
        ( TRANSPOSE, 
          alpha, A, B1_MC_STAR, B1Trans_STAR_MR, Z1_MC_STAR, Z1_MR_STAR );

        Z1_MR_MC.SumScatterFrom( Z1_MR_STAR );
        Z1 = Z1_MR_MC;
        Z1.SumScatterUpdate( T(1), Z1_MC_STAR );
        Axpy( T(1), Z1, C1 );
        //--------------------------------------------------------------------//
        Z1.FreeAlignments();

        SlideLockedPartitionRight
        ( BL,     /**/ BR,
          B0, B1, /**/ B2 );

        SlidePartitionRight
        ( CL,     /**/ CR,
          C0, C1, /**/ C2 );
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
Ejemplo n.º 3
0
inline void
Her2kLN
( T alpha, const DistMatrix<T,MC,MR>& A,
           const DistMatrix<T,MC,MR>& B,
  T beta,        DistMatrix<T,MC,MR>& C )
{
#ifndef RELEASE
    PushCallStack("internal::Her2kLN");
    if( A.Grid() != B.Grid() || B.Grid() != C.Grid() )
        throw std::logic_error
        ("{A,B,C} must be distributed over the same grid");
    if( A.Height() != C.Height() || A.Height() != C.Width() ||
        B.Height() != C.Height() || B.Height() != C.Width() ||
        A.Width() != B.Width() )
    {
        std::ostringstream msg;
        msg << "Nonconformal Her2kLN:\n"
            << "  A ~ " << A.Height() << " x " << A.Width() << "\n"
            << "  B ~ " << B.Height() << " x " << B.Width() << "\n"
            << "  C ~ " << C.Height() << " x " << C.Width() << "\n";
        throw std::logic_error( msg.str() );
    }
#endif
    const Grid& g = A.Grid();

    // Matrix views 
    DistMatrix<T,MC,MR> AL(g), AR(g),
                        A0(g), A1(g), A2(g);
    DistMatrix<T,MC,MR> BL(g), BR(g),
                        B0(g), B1(g), B2(g);

    // Temporary distributions
    DistMatrix<T,MC,  STAR> A1_MC_STAR(g);
    DistMatrix<T,MC,  STAR> B1_MC_STAR(g);
    DistMatrix<T,VR,  STAR> A1_VR_STAR(g);
    DistMatrix<T,VR,  STAR> B1_VR_STAR(g);
    DistMatrix<T,STAR,MR  > A1Adj_STAR_MR(g);
    DistMatrix<T,STAR,MR  > B1Adj_STAR_MR(g);

    A1_MC_STAR.AlignWith( C );
    B1_MC_STAR.AlignWith( C );
    A1_VR_STAR.AlignWith( C );
    B1_VR_STAR.AlignWith( C );
    A1Adj_STAR_MR.AlignWith( C );
    B1Adj_STAR_MR.AlignWith( C );

    // Start the algorithm
    ScaleTrapezoid( beta, LEFT, LOWER, 0, C );
    LockedPartitionRight( A, AL, AR, 0 );
    LockedPartitionRight( B, BL, BR, 0 );
    while( AR.Width() > 0 )
    {
        LockedRepartitionRight
        ( AL, /**/ AR,
          A0, /**/ A1, A2 );

        LockedRepartitionRight
        ( BL, /**/ BR,
          B0, /**/ B1, B2 );

        //--------------------------------------------------------------------//
        A1_VR_STAR = A1_MC_STAR = A1;
        A1Adj_STAR_MR.AdjointFrom( A1_VR_STAR );

        B1_VR_STAR = B1_MC_STAR = B1;
        B1Adj_STAR_MR.AdjointFrom( B1_VR_STAR );

        LocalTrr2k
        ( LOWER, 
          alpha, A1_MC_STAR, B1Adj_STAR_MR, 
                 B1_MC_STAR, A1Adj_STAR_MR,
          T(1),  C );
        //--------------------------------------------------------------------//

        SlideLockedPartitionRight
        ( AL,     /**/ AR,
          A0, A1, /**/ A2 );

        SlideLockedPartitionRight
        ( BL,     /**/ BR,
          B0, B1, /**/ B2 );
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
Ejemplo n.º 4
0
inline void
LocalSymmetricAccumulateLU
( Orientation orientation, T alpha,
  const DistMatrix<T>& A,
  const DistMatrix<T,MC,  STAR>& B_MC_STAR,
  const DistMatrix<T,STAR,MR  >& BAdjOrTrans_STAR_MR,
        DistMatrix<T,MC,  STAR>& Z_MC_STAR,
        DistMatrix<T,MR,  STAR>& Z_MR_STAR )
{
#ifndef RELEASE
    PushCallStack("internal::LocalSymmetricAccumulateLU");
    if( A.Grid() != B_MC_STAR.Grid() ||
        B_MC_STAR.Grid() != BAdjOrTrans_STAR_MR.Grid() ||
        BAdjOrTrans_STAR_MR.Grid() != Z_MC_STAR.Grid() ||
        Z_MC_STAR.Grid() != Z_MR_STAR.Grid() )
        throw std::logic_error
        ("{A,B,Z} must be distributed over the same grid");
    if( A.Height() != A.Width() ||
        A.Height() != B_MC_STAR.Height() ||
        A.Height() != BAdjOrTrans_STAR_MR.Width() ||
        A.Height() != Z_MC_STAR.Height() ||
        A.Height() != Z_MR_STAR.Height() ||
        B_MC_STAR.Width() != BAdjOrTrans_STAR_MR.Height() ||
        BAdjOrTrans_STAR_MR.Height() != Z_MC_STAR.Width() ||
        Z_MC_STAR.Width() != Z_MR_STAR.Width() )
    {
        std::ostringstream msg;
        msg << "Nonconformal LocalSymmetricAccumulateLU: \n"
            << "  A ~ " << A.Height() << " x " << A.Width() << "\n"
            << "  B[MC,* ] ~ " << B_MC_STAR.Height() << " x "
                               << B_MC_STAR.Width() << "\n"
            << "  B^H/T[* ,MR] ~ " << BAdjOrTrans_STAR_MR.Height() << " x "
                                   << BAdjOrTrans_STAR_MR.Width() << "\n"
            << "  Z[MC,* ] ~ " << Z_MC_STAR.Height() << " x "
                               << Z_MC_STAR.Width() << "\n"
            << "  Z[MR,* ] ` " << Z_MR_STAR.Height() << " x "
                               << Z_MR_STAR.Width() << "\n";
        throw std::logic_error( msg.str().c_str() );
    }
    if( B_MC_STAR.ColAlignment() != A.ColAlignment() ||
        BAdjOrTrans_STAR_MR.RowAlignment() != A.RowAlignment() ||
        Z_MC_STAR.ColAlignment() != A.ColAlignment() ||
        Z_MR_STAR.ColAlignment() != A.RowAlignment() )
        throw std::logic_error("Partial matrix distributions are misaligned");
#endif
    const Grid& g = A.Grid();

    DistMatrix<T>
        ATL(g), ATR(g),  A00(g), A01(g), A02(g),
        ABL(g), ABR(g),  A10(g), A11(g), A12(g),
                         A20(g), A21(g), A22(g);

    DistMatrix<T> D11(g);

    DistMatrix<T,MC,STAR>
        BT_MC_STAR(g),  B0_MC_STAR(g),
        BB_MC_STAR(g),  B1_MC_STAR(g),
                        B2_MC_STAR(g);

    DistMatrix<T,STAR,MR>
        BLAdjOrTrans_STAR_MR(g), BRAdjOrTrans_STAR_MR(g),
        B0AdjOrTrans_STAR_MR(g), B1AdjOrTrans_STAR_MR(g), 
        B2AdjOrTrans_STAR_MR(g);

    DistMatrix<T,MC,STAR>
        ZT_MC_STAR(g),  Z0_MC_STAR(g),
        ZB_MC_STAR(g),  Z1_MC_STAR(g),
                        Z2_MC_STAR(g);

    DistMatrix<T,MR,STAR>
        ZT_MR_STAR(g),  Z0_MR_STAR(g),
        ZB_MR_STAR(g),  Z1_MR_STAR(g),
                        Z2_MR_STAR(g);

    const int ratio = std::max( g.Height(), g.Width() );
    PushBlocksizeStack( ratio*Blocksize() );

    LockedPartitionDownDiagonal
    ( A, ATL, ATR,
         ABL, ABR, 0 );
    LockedPartitionDown
    ( B_MC_STAR, BT_MC_STAR,
                 BB_MC_STAR, 0 );
    LockedPartitionRight
    ( BAdjOrTrans_STAR_MR, BLAdjOrTrans_STAR_MR, BRAdjOrTrans_STAR_MR, 0 );
    PartitionDown
    ( Z_MC_STAR, ZT_MC_STAR,
                 ZB_MC_STAR, 0 );
    PartitionDown
    ( Z_MR_STAR, ZT_MR_STAR,
                 ZB_MR_STAR, 0 );
    while( ATL.Height() < A.Height() )
    {
        LockedRepartitionDownDiagonal
        ( ATL, /**/ ATR,  A00, /**/ A01, A02,
          /************/ /******************/
               /**/       A10, /**/ A11, A12,
          ABL, /**/ ABR,  A20, /**/ A21, A22 );

        LockedRepartitionDown
        ( BT_MC_STAR,  B0_MC_STAR,
         /**********/ /**********/
                       B1_MC_STAR,
          BB_MC_STAR,  B2_MC_STAR );

        LockedRepartitionRight
        ( BLAdjOrTrans_STAR_MR, /**/ BRAdjOrTrans_STAR_MR,
          B0AdjOrTrans_STAR_MR, /**/ B1AdjOrTrans_STAR_MR, 
                                     B2AdjOrTrans_STAR_MR );

        RepartitionDown
        ( ZT_MC_STAR,  Z0_MC_STAR,
         /**********/ /**********/
                       Z1_MC_STAR,
          ZB_MC_STAR,  Z2_MC_STAR );

        RepartitionDown
        ( ZT_MR_STAR,  Z0_MR_STAR,
         /**********/ /**********/
                       Z1_MR_STAR,
          ZB_MR_STAR,  Z2_MR_STAR );

        D11.AlignWith( A11 );
        //--------------------------------------------------------------------//
        D11 = A11;
        MakeTrapezoidal( LEFT, UPPER, 0, D11 );
        LocalGemm
        ( NORMAL, orientation, 
          alpha, D11, B1AdjOrTrans_STAR_MR, T(1), Z1_MC_STAR );
        MakeTrapezoidal( LEFT, UPPER, 1, D11 );

        LocalGemm
        ( orientation, NORMAL, alpha, D11, B1_MC_STAR, T(1), Z1_MR_STAR );

        LocalGemm
        ( NORMAL, orientation, 
          alpha, A12, B2AdjOrTrans_STAR_MR, T(1), Z1_MC_STAR );

        LocalGemm
        ( orientation, NORMAL, alpha, A12, B1_MC_STAR, T(1), Z2_MR_STAR );
        //--------------------------------------------------------------------//
        D11.FreeAlignments();

        SlideLockedPartitionDownDiagonal
        ( ATL, /**/ ATR,  A00, A01, /**/ A02,
               /**/       A10, A11, /**/ A12,
         /*************/ /******************/
          ABL, /**/ ABR,  A20, A21, /**/ A22 );

        SlideLockedPartitionDown
        ( BT_MC_STAR,  B0_MC_STAR,
                       B1_MC_STAR,
         /**********/ /**********/
          BB_MC_STAR,  B2_MC_STAR );

        SlideLockedPartitionRight
        ( BLAdjOrTrans_STAR_MR,                       /**/ BRAdjOrTrans_STAR_MR,
          B0AdjOrTrans_STAR_MR, B1AdjOrTrans_STAR_MR, /**/ B2AdjOrTrans_STAR_MR         );

        SlidePartitionDown
        ( ZT_MC_STAR,  Z0_MC_STAR,
                       Z1_MC_STAR,
         /**********/ /**********/
          ZB_MC_STAR,  Z2_MC_STAR );

        SlidePartitionDown
        ( ZT_MR_STAR,  Z0_MR_STAR,
                       Z1_MR_STAR,
         /**********/ /**********/
          ZB_MR_STAR,  Z2_MR_STAR );
    }
    PopBlocksizeStack();
#ifndef RELEASE
    PopCallStack();
#endif
}
Ejemplo n.º 5
0
inline void
HemmRUC
( T alpha, const DistMatrix<T>& A,
           const DistMatrix<T>& B,
  T beta,        DistMatrix<T>& C )
{
#ifndef RELEASE
    PushCallStack("internal::HemmRUC");
    if( A.Grid() != B.Grid() || B.Grid() != C.Grid() )
        throw std::logic_error("{A,B,C} must be distributed on the same grid");
#endif
    const Grid& g = A.Grid();

    // Matrix views
    DistMatrix<T> 
        ATL(g), ATR(g),  A00(g), A01(g), A02(g),  AColPan(g),
        ABL(g), ABR(g),  A10(g), A11(g), A12(g),  ARowPan(g),
                         A20(g), A21(g), A22(g);
    DistMatrix<T> BL(g), BR(g),
                  B0(g), B1(g), B2(g);
    DistMatrix<T> CL(g), CR(g),
                  C0(g), C1(g), C2(g),
                  CLeft(g), CRight(g);

    // Temporary distributions
    DistMatrix<T,MC,STAR> B1_MC_STAR(g);
    DistMatrix<T,VR,  STAR> AColPan_VR_STAR(g);
    DistMatrix<T,STAR,MR  > AColPanAdj_STAR_MR(g);
    DistMatrix<T,MR,  STAR> ARowPanAdj_MR_STAR(g);

    B1_MC_STAR.AlignWith( C );

    // Start the algorithm
    Scale( beta, C );
    LockedPartitionDownDiagonal
    ( A, ATL, ATR,
         ABL, ABR, 0 );
    LockedPartitionRight( B, BL, BR, 0 );
    PartitionRight( C, CL, CR, 0 );
    while( CR.Width() > 0 )
    {
        LockedRepartitionDownDiagonal
        ( ATL, /**/ ATR,  A00, /**/ A01, A02,
         /*************/ /******************/
               /**/       A10, /**/ A11, A12,
          ABL, /**/ ABR,  A20, /**/ A21, A22 );

        LockedRepartitionRight
        ( BL, /**/ BR,
          B0, /**/ B1, B2 );

        RepartitionRight
        ( CL, /**/ CR,
          C0, /**/ C1, C2 );

        ARowPan.LockedView1x2( A11, A12 );
        AColPan.LockedView2x1
        ( A01,
          A11 );

        CLeft.View1x2( C0, C1 );
        CRight.View1x2( C1, C2 );

        AColPan_VR_STAR.AlignWith( CLeft );
        AColPanAdj_STAR_MR.AlignWith( CLeft );
        ARowPanAdj_MR_STAR.AlignWith( CRight );
        //--------------------------------------------------------------------//
        B1_MC_STAR = B1;

        AColPan_VR_STAR = AColPan;
        AColPanAdj_STAR_MR.AdjointFrom( AColPan_VR_STAR );
        ARowPanAdj_MR_STAR.AdjointFrom( ARowPan );
        MakeTrapezoidal( LEFT,  LOWER,  0, ARowPanAdj_MR_STAR );
        MakeTrapezoidal( RIGHT, LOWER, -1, AColPanAdj_STAR_MR );

        LocalGemm
        ( NORMAL, ADJOINT, 
          alpha, B1_MC_STAR, ARowPanAdj_MR_STAR, T(1), CRight );

        LocalGemm
        ( NORMAL, NORMAL,
          alpha, B1_MC_STAR, AColPanAdj_STAR_MR, T(1), CLeft );
        //--------------------------------------------------------------------//
        AColPan_VR_STAR.FreeAlignments();
        AColPanAdj_STAR_MR.FreeAlignments();
        ARowPanAdj_MR_STAR.FreeAlignments();

        SlideLockedPartitionDownDiagonal
        ( ATL, /**/ ATR,  A00, A01, /**/ A02,
               /**/       A10, A11, /**/ A12,
         /*************/ /******************/
          ABL, /**/ ABR,  A20, A21, /**/ A22 );

        SlideLockedPartitionRight
        ( BL,     /**/ BR,
          B0, B1, /**/ B2 );

        SlidePartitionRight
        ( CL,     /**/ CR,
          C0, C1, /**/ C2 );
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
Ejemplo n.º 6
0
inline void
Syr2kUN
( T alpha, const DistMatrix<T>& A, const DistMatrix<T>& B,
  T beta,        DistMatrix<T>& C,
  bool conjugate=false )
{
#ifndef RELEASE
    CallStackEntry entry("internal::Syr2kUN");
    if( A.Grid() != B.Grid() || B.Grid() != C.Grid() )
        throw std::logic_error
        ("{A,B,C} must be distributed over the same grid");
    if( A.Height() != C.Height() || A.Height() != C.Width() ||
        B.Height() != C.Height() || B.Height() != C.Width() ||
        A.Width() != B.Width() )
    {
        std::ostringstream msg;
        msg << "Nonconformal Syr2kUN:\n"
            << "  A ~ " << A.Height() << " x " << A.Width() << "\n"
            << "  B ~ " << B.Height() << " x " << B.Width() << "\n"
            << "  C ~ " << C.Height() << " x " << C.Width() << "\n";
        throw std::logic_error( msg.str().c_str() );
    }
#endif
    const Grid& g = C.Grid();

    // Matrix views 
    DistMatrix<T> AL(g), AR(g),
                  A0(g), A1(g), A2(g);
    DistMatrix<T> BL(g), BR(g),
                  B0(g), B1(g), B2(g);

    // Temporary distributions
    DistMatrix<T,MC,  STAR> A1_MC_STAR(g);
    DistMatrix<T,MC,  STAR> B1_MC_STAR(g);
    DistMatrix<T,VR,  STAR> A1_VR_STAR(g);
    DistMatrix<T,VR,  STAR> B1_VR_STAR(g);
    DistMatrix<T,STAR,MR  > A1Trans_STAR_MR(g);
    DistMatrix<T,STAR,MR  > B1Trans_STAR_MR(g);

    A1_MC_STAR.AlignWith( C );
    B1_MC_STAR.AlignWith( C );
    A1_VR_STAR.AlignWith( C );
    B1_VR_STAR.AlignWith( C );
    A1Trans_STAR_MR.AlignWith( C );
    B1Trans_STAR_MR.AlignWith( C );

    // Start the algorithm
    ScaleTrapezoid( beta, LEFT, UPPER, 0, C );
    LockedPartitionRight( A, AL, AR, 0 );
    LockedPartitionRight( B, BL, BR, 0 );
    while( AR.Width() > 0 )
    {
        LockedRepartitionRight
        ( AL, /**/ AR,
          A0, /**/ A1, A2 );

        LockedRepartitionRight
        ( BL, /**/ BR,
          B0, /**/ B1, B2 );

        //--------------------------------------------------------------------//
        A1_VR_STAR = A1_MC_STAR = A1;
        A1Trans_STAR_MR.TransposeFrom( A1_VR_STAR, conjugate );

        B1_VR_STAR = B1_MC_STAR = B1;
        B1Trans_STAR_MR.TransposeFrom( B1_VR_STAR, conjugate );

        LocalTrr2k
        ( UPPER, 
          alpha, A1_MC_STAR, B1Trans_STAR_MR,
                 B1_MC_STAR, A1Trans_STAR_MR,
          T(1),  C );
        //--------------------------------------------------------------------//

        SlideLockedPartitionRight
        ( AL,     /**/ AR,
          A0, A1, /**/ A2 );

        SlideLockedPartitionRight
        ( BL,     /**/ BR,
          B0, B1, /**/ B2 );
    }
}
Ejemplo n.º 7
0
inline void
internal::GemmTNA
( Orientation orientationOfA,
  T alpha, const DistMatrix<T,MC,MR>& A,
           const DistMatrix<T,MC,MR>& B,
  T beta,        DistMatrix<T,MC,MR>& C )
{
#ifndef RELEASE
    PushCallStack("internal::GemmTNA");    
    if( A.Grid() != B.Grid() || B.Grid() != C.Grid() )
        throw std::logic_error
        ("{A,B,C} must be distributed over the same grid");
    if( orientationOfA == NORMAL )
        throw std::logic_error("GemmTNA assumes A is (Conjugate)Transposed");
    if( A.Width()  != C.Height() ||
        B.Width()  != C.Width()  ||
        A.Height() != B.Height()   )
    {
        std::ostringstream msg;
        msg << "Nonconformal GemmTNA: \n"
            << "  A ~ " << A.Height() << " x " << A.Width() << "\n"
            << "  B ~ " << B.Height() << " x " << B.Width() << "\n"
            << "  C ~ " << C.Height() << " x " << C.Width() << "\n";
        throw std::logic_error( msg.str().c_str() );
    }
#endif
    const Grid& g = A.Grid();

    // Matrix views
    DistMatrix<T,MC,MR> BL(g), BR(g),
                        B0(g), B1(g), B2(g);

    DistMatrix<T,MC,MR> CL(g), CR(g),
                        C0(g), C1(g), C2(g);

    // Temporary distributions
    DistMatrix<T,MC,STAR> B1_MC_STAR(g);
    DistMatrix<T,MR,STAR> D1_MR_STAR(g);
    DistMatrix<T,MR,MC  > D1_MR_MC(g);
    DistMatrix<T,MC,MR  > D1(g);

    // Start the algorithm
    Scal( beta, C );
    LockedPartitionRight( B, BL, BR, 0 );
    PartitionRight( C, CL, CR, 0 );
    while( BR.Width() > 0 )
    {
        LockedRepartitionRight
        ( BL, /**/     BR,
          B0, /**/ B1, B2 );
 
        RepartitionRight
        ( CL, /**/     CR,
          C0, /**/ C1, C2 );

        B1_MC_STAR.AlignWith( A );
        D1_MR_STAR.AlignWith( A );
        D1_MR_STAR.ResizeTo( C1.Height(), C1.Width() );
        D1.AlignWith( C1 );
        //--------------------------------------------------------------------//
        B1_MC_STAR = B1; // B1[MC,*] <- B1[MC,MR]

        // D1[MR,*] := alpha (A1[MC,MR])^T B1[MC,*]
        //           = alpha (A1^T)[MR,MC] B1[MC,*]
        internal::LocalGemm
        ( orientationOfA, NORMAL, alpha, A, B1_MC_STAR, (T)0, D1_MR_STAR );

        // C1[MC,MR] += scattered & transposed D1[MR,*] summed over grid cols
        D1_MR_MC.SumScatterFrom( D1_MR_STAR );
        D1 = D1_MR_MC; 
        Axpy( (T)1, D1, C1 );
        //--------------------------------------------------------------------//
        B1_MC_STAR.FreeAlignments();
        D1_MR_STAR.FreeAlignments();
        D1.FreeAlignments();

        SlideLockedPartitionRight
        ( BL,     /**/ BR,
          B0, B1, /**/ B2 );

        SlidePartitionRight
        ( CL,     /**/ CR,
          C0, C1, /**/ C2 );
    }
#ifndef RELEASE
    PopCallStack();
#endif
}