inline void
Householder( Matrix<F>& A, Matrix<F>& t )
{
#ifndef RELEASE
    CallStackEntry entry("rq::Householder");
#endif
    t.ResizeTo( Min(A.Height(),A.Width()), 1 );

    // Matrix views
    Matrix<F>
        ATL, ATR,  A00, A01, A02,  ATopPan, 
        ABL, ABR,  A10, A11, A12,  ABottomPan,
                   A20, A21, A22;
    Matrix<F>
        tT,  t0,
        tB,  t1,
             t2;

    PartitionUpOffsetDiagonal
    ( A.Width()-A.Height(),
      A, ATL, ATR,
         ABL, ABR, 0 );
    PartitionUp
    ( t, tT,
         tB, 0 );
    while( ABR.Height() < A.Height() && ABR.Width() < A.Width() )
    {
        RepartitionUpDiagonal
        ( ATL, /**/ ATR,  A00, A01, /**/ A02,
               /**/       A10, A11, /**/ A12,
         /*************/ /******************/
          ABL, /**/ ABR,  A20, A21, /**/ A22 );

        RepartitionUp
        ( tT,  t0,
               t1,
         /**/ /**/
          tB,  t2 );

        View1x2( ATopPan, A00, A01 );
        View1x2( ABottomPan, A10, A11 );
        //--------------------------------------------------------------------//
        PanelHouseholder( ABottomPan, t1 );
        ApplyQ( RIGHT, ADJOINT, ABottomPan, t1, ATopPan );
        //--------------------------------------------------------------------//

        SlidePartitionUp
        ( tT,  t0,
         /**/ /**/
               t1,
          tB,  t2 );

        SlidePartitionUpDiagonal
        ( ATL, /**/ ATR,  A00, /**/ A01, A02,
         /*************/ /******************/
               /**/       A10, /**/ A11, A12,
          ABL, /**/ ABR,  A20, /**/ A21, A22 );
    }
}
Exemple #2
0
inline void
TrsvUN( UnitOrNonUnit diag, const DistMatrix<F>& U, DistMatrix<F>& x )
{
#ifndef RELEASE
    PushCallStack("internal::TrsvUN");
    if( U.Grid() != x.Grid() )
        throw std::logic_error("{U,x} must be distributed over the same grid");
    if( U.Height() != U.Width() )
        throw std::logic_error("U must be square");
    if( x.Width() != 1 && x.Height() != 1 )
        throw std::logic_error("x must be a vector");
    const int xLength = ( x.Width() == 1 ? x.Height() : x.Width() );
    if( U.Width() != xLength )
        throw std::logic_error("Nonconformal TrsvUN");
#endif
    const Grid& g = U.Grid();

    if( x.Width() == 1 )
    {
        // Matrix views 
        DistMatrix<F> U01(g),
                      U11(g);
        DistMatrix<F> 
            xT(g),  x0(g),
            xB(g),  x1(g),
                    x2(g);

        // Temporary distributions
        DistMatrix<F,STAR,STAR> U11_STAR_STAR(g);
        DistMatrix<F,STAR,STAR> x1_STAR_STAR(g);
        DistMatrix<F,MR,  STAR> x1_MR_STAR(g);
        DistMatrix<F,MC,  STAR> z_MC_STAR(g);

        // Views of z[MC,* ], which will store updates to x
        DistMatrix<F,MC,STAR> z0_MC_STAR(g),
                              z1_MC_STAR(g);

        z_MC_STAR.AlignWith( U );
        Zeros( x.Height(), 1, z_MC_STAR );

        // Start the algorithm
        PartitionUp
        ( x, xT,
             xB, 0 );
        while( xT.Height() > 0 )
        {
            RepartitionUp
            ( xT,  x0,
                   x1,
             /**/ /**/
              xB,  x2 );

            const int n0 = x0.Height();
            const int n1 = x1.Height();
            LockedView( U01, U, 0,  n0, n0, n1 );
            LockedView( U11, U, n0, n0, n1, n1 );
            View( z0_MC_STAR, z_MC_STAR, 0,  0, n0, 1 );
            View( z1_MC_STAR, z_MC_STAR, n0, 0, n1, 1 );

            x1_MR_STAR.AlignWith( U01 );
            //----------------------------------------------------------------//
            if( x2.Height() != 0 )
                x1.SumScatterUpdate( F(1), z1_MC_STAR );

            x1_STAR_STAR = x1;
            U11_STAR_STAR = U11;
            Trsv
            ( UPPER, NORMAL, diag,
              U11_STAR_STAR.LockedLocalMatrix(),
              x1_STAR_STAR.LocalMatrix() );
            x1 = x1_STAR_STAR;

            x1_MR_STAR = x1_STAR_STAR;
            Gemv
            ( NORMAL, F(-1), 
              U01.LockedLocalMatrix(), 
              x1_MR_STAR.LockedLocalMatrix(),
              F(1), z0_MC_STAR.LocalMatrix() );
            //----------------------------------------------------------------//
            x1_MR_STAR.FreeAlignments();

            SlidePartitionUp
            ( xT,  x0,
             /**/ /**/
                   x1,
              xB,  x2 );
        }
    }
    else
    {
        // Matrix views 
        DistMatrix<F> U01(g),
                      U11(g);
        DistMatrix<F> 
            xL(g), xR(g),
            x0(g), x1(g), x2(g);

        // Temporary distributions
        DistMatrix<F,STAR,STAR> U11_STAR_STAR(g);
        DistMatrix<F,STAR,STAR> x1_STAR_STAR(g);
        DistMatrix<F,STAR,MR  > x1_STAR_MR(g);
        DistMatrix<F,MC,  MR  > z1(g);
        DistMatrix<F,MR,  MC  > z1_MR_MC(g);
        DistMatrix<F,STAR,MC  > z_STAR_MC(g);

        // Views of z[* ,MC]
        DistMatrix<F,STAR,MC>  z0_STAR_MC(g),
                               z1_STAR_MC(g);

        z_STAR_MC.AlignWith( U );
        Zeros( 1, x.Width(), z_STAR_MC );

        // Start the algorithm
        PartitionLeft( x,  xL, xR, 0 );
        while( xL.Width() > 0 )
        {
            RepartitionLeft
            ( xL,     /**/ xR,
              x0, x1, /**/ x2 );

            const int n0 = x0.Width();
            const int n1 = x1.Width();
            LockedView( U01, U, 0,  n0, n0, n1 );
            LockedView( U11, U, n0, n0, n1, n1 );
            View( z0_STAR_MC, z_STAR_MC, 0, 0,  1, n0 );
            View( z1_STAR_MC, z_STAR_MC, 0, n0, 1, n1 );

            x1_STAR_MR.AlignWith( U01 );
            z1.AlignWith( x1 );
            //----------------------------------------------------------------//
            if( x2.Width() != 0 )
            {
                z1_MR_MC.SumScatterFrom( z1_STAR_MC );
                z1 = z1_MR_MC;
                Axpy( F(1), z1, x1 );
            }

            x1_STAR_STAR = x1;
            U11_STAR_STAR = U11;
            Trsv
            ( UPPER, NORMAL, diag,
              U11_STAR_STAR.LockedLocalMatrix(),
              x1_STAR_STAR.LocalMatrix() );
            x1 = x1_STAR_STAR;

            x1_STAR_MR = x1_STAR_STAR;
            Gemv
            ( NORMAL, F(-1), 
              U01.LockedLocalMatrix(), 
              x1_STAR_MR.LockedLocalMatrix(),
              F(1), z0_STAR_MC.LocalMatrix() );
            //----------------------------------------------------------------//
            x1_STAR_MR.FreeAlignments();
            z1.FreeAlignments(); 

            SlidePartitionLeft
            ( xL, /**/ xR,
              x0, /**/ x1, x2 );
        }
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
Exemple #3
0
inline void
TrsmLLTSmall
( Orientation orientation, UnitOrNonUnit diag,
  F alpha, const DistMatrix<F,STAR,VR>& L, DistMatrix<F,VR,STAR>& X,
  bool checkIfSingular )
{
#ifndef RELEASE
    PushCallStack("internal::TrsmLLTSmall");
    if( L.Grid() != X.Grid() )
        throw std::logic_error
        ("L and X must be distributed over the same grid");
    if( orientation == NORMAL )
        throw std::logic_error("TrsmLLT expects a (Conjugate)Transpose option");
    if( L.Height() != L.Width() || L.Height() != X.Height() )
    {
        std::ostringstream msg;
        msg << "Nonconformal TrsmLLT: \n"
            << "  L ~ " << L.Height() << " x " << L.Width() << "\n"
            << "  X ~ " << X.Height() << " x " << X.Width() << "\n";
        throw std::logic_error( msg.str().c_str() );
    }
    if( L.RowAlignment() != X.ColAlignment() )
        throw std::logic_error("L and X must be aligned");
#endif
    const Grid& g = L.Grid();

    // Matrix views
    DistMatrix<F,STAR,VR> 
        LTL(g), LTR(g),  L00(g), L01(g), L02(g),
        LBL(g), LBR(g),  L10(g), L11(g), L12(g),
                         L20(g), L21(g), L22(g);

    DistMatrix<F,VR,STAR> XT(g),  X0(g),
                          XB(g),  X1(g),
                                  X2(g);

    // Temporary distributions
    DistMatrix<F,STAR,STAR> L11_STAR_STAR(g);
    DistMatrix<F,STAR,STAR> X1_STAR_STAR(g);

    // Start the algorithm
    Scale( alpha, X );
    LockedPartitionUpDiagonal
    ( L, LTL, LTR,
         LBL, LBR, 0 );
    PartitionUp
    ( X, XT,
         XB, 0 );
    while( XT.Height() > 0 )
    {
        LockedRepartitionUpDiagonal
        ( LTL, /**/ LTR,  L00, L01, /**/ L02,
               /**/       L10, L11, /**/ L12,
         /*************/ /******************/
          LBL, /**/ LBR,  L20, L21, /**/ L22 );

        RepartitionUp
        ( XT,  X0,
               X1,
         /**/ /**/
          XB,  X2 ); 

        //--------------------------------------------------------------------//
        L11_STAR_STAR = L11; // L11[* ,* ] <- L11[* ,VR]
        X1_STAR_STAR = X1;   // X1[* ,* ] <- X1[VR,* ]

        // X1[* ,* ] := L11^-[T/H][* ,* ] X1[* ,* ]
        LocalTrsm
        ( LEFT, LOWER, orientation, diag,
          F(1), L11_STAR_STAR, X1_STAR_STAR, checkIfSingular );

        X1 = X1_STAR_STAR;

        // X0[VR,* ] -= L10[* ,VR]^(T/H) X1[* ,* ]
        LocalGemm( orientation, NORMAL, F(-1), L10, X1_STAR_STAR, F(1), X0 );
        //--------------------------------------------------------------------//

        SlideLockedPartitionUpDiagonal
        ( LTL, /**/ LTR,  L00, /**/ L01, L02,
         /*************/ /******************/
               /**/       L10, /**/ L11, L12,
          LBL, /**/ LBR,  L20, /**/ L21, L22 );

        SlidePartitionUp
        ( XT,  X0,
         /**/ /**/
               X1,
          XB,  X2 );
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
Exemple #4
0
inline void
TrsmLLTLarge
( Orientation orientation, UnitOrNonUnit diag,
  F alpha, const DistMatrix<F>& L, DistMatrix<F>& X,
  bool checkIfSingular )
{
#ifndef RELEASE
    PushCallStack("internal::TrsmLLTLarge");
    if( orientation == NORMAL )
        throw std::logic_error("TrsmLLT expects a (Conjugate)Transpose option");
#endif
    const Grid& g = L.Grid();

    // Matrix views
    DistMatrix<F> 
        LTL(g), LTR(g),  L00(g), L01(g), L02(g),
        LBL(g), LBR(g),  L10(g), L11(g), L12(g),
                         L20(g), L21(g), L22(g);
    DistMatrix<F> XT(g),  X0(g),
                  XB(g),  X1(g),
                          X2(g);

    // Temporary distributions
    DistMatrix<F,STAR,MC  > L10_STAR_MC(g);
    DistMatrix<F,STAR,STAR> L11_STAR_STAR(g);
    DistMatrix<F,STAR,MR  > X1_STAR_MR(g);
    DistMatrix<F,STAR,VR  > X1_STAR_VR(g);

    // Start the algorithm
    Scale( alpha, X );
    LockedPartitionUpDiagonal
    ( L, LTL, LTR,
         LBL, LBR, 0 );
    PartitionUp
    ( X, XT,
         XB, 0 );
    while( XT.Height() > 0 )
    {
        LockedRepartitionUpDiagonal
        ( LTL, /**/ LTR,  L00, L01, /**/ L02,
               /**/       L10, L11, /**/ L12,
         /*************/ /******************/
          LBL, /**/ LBR,  L20, L21, /**/ L22 );

        RepartitionUp
        ( XT,  X0,
               X1,
         /**/ /**/
          XB,  X2 ); 

        L10_STAR_MC.AlignWith( X0 );
        X1_STAR_MR.AlignWith( X0 );
        //--------------------------------------------------------------------//
        L11_STAR_STAR = L11; // L11[* ,* ] <- L11[MC,MR]
        X1_STAR_VR    = X1;  // X1[* ,VR] <- X1[MC,MR]

        // X1[* ,VR] := L11^-[T/H][* ,* ] X1[* ,VR]
        LocalTrsm
        ( LEFT, LOWER, orientation, diag, F(1), L11_STAR_STAR, X1_STAR_VR,
          checkIfSingular );

        X1_STAR_MR  = X1_STAR_VR; // X1[* ,MR] <- X1[* ,VR]
        X1          = X1_STAR_MR; // X1[MC,MR] <- X1[* ,MR]
        L10_STAR_MC = L10;        // L10[* ,MC] <- L10[MC,MR]

        // X0[MC,MR] -= (L10[* ,MC])^(T/H) X1[* ,MR]
        //            = L10^[T/H][MC,* ] X1[* ,MR]
        LocalGemm
        ( orientation, NORMAL, F(-1), L10_STAR_MC, X1_STAR_MR, F(1), X0 );
        //--------------------------------------------------------------------//
        L10_STAR_MC.FreeAlignments();
        X1_STAR_MR.FreeAlignments();

        SlideLockedPartitionUpDiagonal
        ( LTL, /**/ LTR,  L00, /**/ L01, L02,
         /*************/ /******************/
               /**/       L10, /**/ L11, L12,
          LBL, /**/ LBR,  L20, /**/ L21, L22 );

        SlidePartitionUp
        ( XT,  X0,
         /**/ /**/
               X1,
          XB,  X2 );
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
Exemple #5
0
inline void
TrmmLLNC
( UnitOrNonUnit diag,
  T alpha, const DistMatrix<T>& L,
                 DistMatrix<T>& X )
{
#ifndef RELEASE
    CallStackEntry entry("internal::TrmmLLNC");
    if( L.Grid() != X.Grid() )
        throw std::logic_error
        ("L and X must be distributed over the same grid");
    if( L.Height() != L.Width() || L.Width() != X.Height() )
    {
        std::ostringstream msg;
        msg << "Nonconformal TrmmLLNC: \n"
            << "  L ~ " << L.Height() << " x " << L.Width() << "\n"
            << "  X ~ " << X.Height() << " x " << X.Width() << "\n";
        throw std::logic_error( msg.str().c_str() );
    }
#endif
    const Grid& g = L.Grid();

    // Matrix views
    DistMatrix<T> 
        LTL(g), LTR(g),  L00(g), L01(g), L02(g),
        LBL(g), LBR(g),  L10(g), L11(g), L12(g),
                         L20(g), L21(g), L22(g);
    DistMatrix<T> XT(g),  X0(g),
                  XB(g),  X1(g),
                          X2(g);

    // Temporary distributions
    DistMatrix<T,MC,  STAR> L21_MC_STAR(g);
    DistMatrix<T,STAR,STAR> L11_STAR_STAR(g);
    DistMatrix<T,STAR,VR  > X1_STAR_VR(g);
    DistMatrix<T,MR,  STAR> X1Trans_MR_STAR(g);

    // Start the algorithm
    Scale( alpha, X );
    LockedPartitionUpDiagonal
    ( L, LTL, LTR,
         LBL, LBR, 0 );
    PartitionUp
    ( X, XT,
         XB, 0 );
    while( XT.Height() > 0 )
    {
        LockedRepartitionUpDiagonal
        ( LTL, /**/ LTR,  L00, L01, /**/ L02,
               /**/       L10, L11, /**/ L12,
         /*************/ /******************/
          LBL, /**/ LBR,  L20, L21, /**/ L22 );

        RepartitionUp
        ( XT,  X0,
               X1,
         /**/ /**/
          XB,  X2 );

        L21_MC_STAR.AlignWith( X2 );
        X1Trans_MR_STAR.AlignWith( X2 );
        X1_STAR_VR.AlignWith( X1 );
        //--------------------------------------------------------------------//
        L21_MC_STAR = L21;
        X1Trans_MR_STAR.TransposeFrom( X1 );
        LocalGemm
        ( NORMAL, TRANSPOSE, T(1), L21_MC_STAR, X1Trans_MR_STAR, T(1), X2 );

        L11_STAR_STAR = L11;
        X1_STAR_VR.TransposeFrom( X1Trans_MR_STAR );
        LocalTrmm( LEFT, LOWER, NORMAL, diag, T(1), L11_STAR_STAR, X1_STAR_VR );
        X1 = X1_STAR_VR;
        //--------------------------------------------------------------------//
        L21_MC_STAR.FreeAlignments();
        X1Trans_MR_STAR.FreeAlignments();
        X1_STAR_VR.FreeAlignments();

        SlideLockedPartitionUpDiagonal
        ( LTL, /**/ LTR,  L00, /**/ L01, L02,
         /*************/ /******************/
               /**/       L10, /**/ L11, L12, 
          LBL, /**/ LBR,  L20, /**/ L21, L22 );

        SlidePartitionUp
        ( XT,  X0,
         /**/ /**/
               X1,
          XB,  X2 );
    }
}
Exemple #6
0
inline void
TrsmLUNSmall
( UnitOrNonUnit diag,
  F alpha, const DistMatrix<F,VC,STAR>& U, DistMatrix<F,VC,STAR>& X,
  bool checkIfSingular )
{
#ifndef RELEASE
    PushCallStack("internal::TrsmLUNSmall");
    if( U.Grid() != X.Grid() )
        throw std::logic_error
        ("U and X must be distributed over the same grid");
    if( U.Height() != U.Width() || U.Width() != X.Height() )
    {
        std::ostringstream msg;
        msg << "Nonconformal TrsmLUN: \n"
            << "  U ~ " << U.Height() << " x " << U.Width() << "\n"
            << "  X ~ " << X.Height() << " x " << X.Width() << "\n";
        throw std::logic_error( msg.str() );
    }
    if( U.ColAlignment() != X.ColAlignment() )
        throw std::logic_error("U and X are assumed to be aligned");
#endif
    const Grid& g = U.Grid();

    // Matrix views
    DistMatrix<F,VC,STAR> 
        UTL(g), UTR(g),  U00(g), U01(g), U02(g),
        UBL(g), UBR(g),  U10(g), U11(g), U12(g),
                         U20(g), U21(g), U22(g);
    DistMatrix<F,VC,STAR> XT(g),  X0(g),
                          XB(g),  X1(g),
                                  X2(g);

    // Temporary distributions
    DistMatrix<F,STAR,STAR> U11_STAR_STAR(g);
    DistMatrix<F,STAR,STAR> X1_STAR_STAR(g);

    // Start the algorithm
    Scale( alpha, X );
    LockedPartitionUpDiagonal
    ( U, UTL, UTR,
         UBL, UBR, 0 );
    PartitionUp
    ( X, XT,
         XB, 0 );
    while( XT.Height() > 0 )
    {
        LockedRepartitionUpDiagonal
        ( UTL, /**/ UTR,   U00, U01, /**/ U02,
               /**/        U10, U11, /**/ U12,
         /*************/  /******************/
          UBL, /**/ UBR,   U20, U21, /**/ U22 );

        RepartitionUp
        ( XT,  X0,
               X1,
         /**/ /**/
          XB,  X2 );

        //--------------------------------------------------------------------//
        U11_STAR_STAR = U11; // U11[* ,* ] <- U11[VC,* ]
        X1_STAR_STAR = X1;   // X1[* ,* ] <- X1[VC,* ]
        
        // X1[* ,* ] := U11^-1[* ,* ] X1[* ,* ]
        LocalTrsm
        ( LEFT, UPPER, NORMAL, diag,
          F(1), U11_STAR_STAR, X1_STAR_STAR, checkIfSingular );
        X1 = X1_STAR_STAR;

        // X0[VC,* ] -= U01[VC,* ] X1[* ,* ]
        LocalGemm( NORMAL, NORMAL, F(-1), U01, X1_STAR_STAR, F(1), X0 );
        //--------------------------------------------------------------------//

        SlideLockedPartitionUpDiagonal
        ( UTL, /**/ UTR,  U00, /**/ U01, U02,
         /*************/ /******************/
               /**/       U10, /**/ U11, U12,
          UBL, /**/ UBR,  U20, /**/ U21, U22 );

        SlidePartitionUp
        ( XT,  X0,
         /**/ /**/
               X1,
          XB,  X2 );
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
Exemple #7
0
inline void
TrsmLUNLarge
( UnitOrNonUnit diag,
  F alpha, const DistMatrix<F>& U, DistMatrix<F>& X,
  bool checkIfSingular )
{
#ifndef RELEASE
    PushCallStack("internal::TrsmLUNLarge");
#endif
    const Grid& g = U.Grid();

    // Matrix views
    DistMatrix<F> 
        UTL(g), UTR(g),  U00(g), U01(g), U02(g),
        UBL(g), UBR(g),  U10(g), U11(g), U12(g),
                         U20(g), U21(g), U22(g);
    DistMatrix<F> XT(g),  X0(g),
                  XB(g),  X1(g),
                          X2(g);

    // Temporary distributions
    DistMatrix<F,MC,  STAR> U01_MC_STAR(g);
    DistMatrix<F,STAR,STAR> U11_STAR_STAR(g);
    DistMatrix<F,STAR,MR  > X1_STAR_MR(g);
    DistMatrix<F,STAR,VR  > X1_STAR_VR(g);

    // Start the algorithm
    Scale( alpha, X );
    LockedPartitionUpDiagonal
    ( U, UTL, UTR,
         UBL, UBR, 0 );
    PartitionUp
    ( X, XT,
         XB, 0 );
    while( XT.Height() > 0 )
    {
        LockedRepartitionUpDiagonal
        ( UTL, /**/ UTR,   U00, U01, /**/ U02,
               /**/        U10, U11, /**/ U12,
         /*************/  /******************/
          UBL, /**/ UBR,   U20, U21, /**/ U22 );

        RepartitionUp
        ( XT,  X0,
               X1,
         /**/ /**/
          XB,  X2 );

        U01_MC_STAR.AlignWith( X0 );
        X1_STAR_MR.AlignWith( X0 );
        //--------------------------------------------------------------------//
        U11_STAR_STAR = U11; // U11[* ,* ] <- U11[MC,MR]
        X1_STAR_VR    = X1;  // X1[* ,VR] <- X1[MC,MR]
        
        // X1[* ,VR] := U11^-1[* ,* ] X1[* ,VR]
        LocalTrsm
        ( LEFT, UPPER, NORMAL, diag, F(1), U11_STAR_STAR, X1_STAR_VR,
          checkIfSingular );

        X1_STAR_MR  = X1_STAR_VR; // X1[* ,MR]  <- X1[* ,VR]
        X1          = X1_STAR_MR; // X1[MC,MR] <- X1[* ,MR]
        U01_MC_STAR = U01;        // U01[MC,* ] <- U01[MC,MR]

        // X0[MC,MR] -= U01[MC,* ] X1[* ,MR]
        LocalGemm( NORMAL, NORMAL, F(-1), U01_MC_STAR, X1_STAR_MR, F(1), X0 );
        //--------------------------------------------------------------------//
        U01_MC_STAR.FreeAlignments();
        X1_STAR_MR.FreeAlignments();

        SlideLockedPartitionUpDiagonal
        ( UTL, /**/ UTR,  U00, /**/ U01, U02,
         /*************/ /******************/
               /**/       U10, /**/ U11, U12,
          UBL, /**/ UBR,  U20, /**/ U21, U22 );

        SlidePartitionUp
        ( XT,  X0,
         /**/ /**/
               X1,
          XB,  X2 );
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
Exemple #8
0
inline void
TrsmLUNMedium
( UnitOrNonUnit diag, F alpha, const DistMatrix<F>& U, DistMatrix<F>& X,
  bool checkIfSingular )
{
#ifndef RELEASE
    CallStackEntry entry("internal::TrsmLUNMedium");
#endif
    const Grid& g = U.Grid();

    // Matrix views
    DistMatrix<F> 
        UTL(g), UTR(g),  U00(g), U01(g), U02(g),
        UBL(g), UBR(g),  U10(g), U11(g), U12(g),
                         U20(g), U21(g), U22(g);
    DistMatrix<F> XT(g),  X0(g),
                  XB(g),  X1(g),
                          X2(g);

    // Temporary distributions
    DistMatrix<F,MC,  STAR> U01_MC_STAR(g);
    DistMatrix<F,STAR,STAR> U11_STAR_STAR(g);
    DistMatrix<F,MR,  STAR> X1Trans_MR_STAR(g);

    // Start the algorithm
    Scale( alpha, X );
    LockedPartitionUpDiagonal
    ( U, UTL, UTR,
         UBL, UBR, 0 );
    PartitionUp
    ( X, XT,
         XB, 0 );
    while( XT.Height() > 0 )
    {
        LockedRepartitionUpDiagonal
        ( UTL, /**/ UTR,   U00, U01, /**/ U02,
               /**/        U10, U11, /**/ U12,
         /*************/  /******************/
          UBL, /**/ UBR,   U20, U21, /**/ U22 );

        RepartitionUp
        ( XT,  X0,
               X1,
         /**/ /**/
          XB,  X2 );

        U01_MC_STAR.AlignWith( X0 );
        X1Trans_MR_STAR.AlignWith( X0 );
        //--------------------------------------------------------------------//
        U11_STAR_STAR = U11;                 // U11[* ,* ] <- U11[MC,MR]
        X1Trans_MR_STAR.TransposeFrom( X1 ); // X1[* ,MR] <- X1[MC,MR]
        
        // X1[* ,MR] := U11^-1[* ,* ] X1[* ,MR]
        //
        // X1^T[MR,* ] := X1^T[MR,* ] U11^-T[* ,* ]
        LocalTrsm
        ( RIGHT, UPPER, TRANSPOSE, diag, 
          F(1), U11_STAR_STAR, X1Trans_MR_STAR, checkIfSingular );
        X1.TransposeFrom( X1Trans_MR_STAR );

        U01_MC_STAR = U01;  // U01[MC,* ] <- U01[MC,MR]

        // X0[MC,MR] -= U01[MC,* ] X1[* ,MR]
        LocalGemm
        ( NORMAL, TRANSPOSE, F(-1), U01_MC_STAR, X1Trans_MR_STAR, F(1), X0 );
        //--------------------------------------------------------------------//
        U01_MC_STAR.FreeAlignments();
        X1Trans_MR_STAR.FreeAlignments();

        SlideLockedPartitionUpDiagonal
        ( UTL, /**/ UTR,  U00, /**/ U01, U02,
         /*************/ /******************/
               /**/       U10, /**/ U11, U12,
          UBL, /**/ UBR,  U20, /**/ U21, U22 );

        SlidePartitionUp
        ( XT,  X0,
         /**/ /**/
               X1,
          XB,  X2 );
    }
}
inline void
internal::HermitianTridiagU
( DistMatrix<Complex<R>,MC,  MR  >& A,
  DistMatrix<Complex<R>,STAR,STAR>& t )
{
#ifndef RELEASE
    PushCallStack("internal::HermitianTridiagU");
    if( A.Grid() != t.Grid() )
        throw std::logic_error("{A,t} must be distributed over the same grid");
    if( A.Height() != A.Width() )
        throw std::logic_error("A must be square");
    if( t.Viewing() )
        throw std::logic_error("t must not be a view");
#endif
    typedef Complex<R> C;

    const Grid& g = A.Grid();
    DistMatrix<C,MD,STAR> tDiag(g);
    tDiag.AlignWithDiagonal( A, 1 );
    tDiag.ResizeTo( A.Height()-1, 1 );

    if( g.InGrid() )
    {
        // Matrix views
        DistMatrix<C,MC,MR>
        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<C,MD,STAR> tT(g),  t0(g),
                   tB(g),  t1(g),
                   t2(g);

        // Temporary distributions
        DistMatrix<C,MC,  MR  > WPan(g);
        DistMatrix<C,STAR,STAR> t1_STAR_STAR(g);
        DistMatrix<C,STAR,STAR> A11_STAR_STAR(g);
        DistMatrix<C,MC,  STAR> APan_MC_STAR(g),  A01_MC_STAR(g),
                   A11_MC_STAR(g);
        DistMatrix<C,MR,  STAR> APan_MR_STAR(g),  A01_MR_STAR(g),
                   A11_MR_STAR(g);
        DistMatrix<C,MC,  STAR> WPan_MC_STAR(g),  W01_MC_STAR(g),
                   W11_MC_STAR(g);
        DistMatrix<C,MR,  STAR> WPan_MR_STAR(g),  W01_MR_STAR(g),
                   W11_MR_STAR(g);

        PartitionUpDiagonal
        ( A, ATL, ATR,
          ABL, ABR, 0 );
        PartitionUp
        ( tDiag, tT,
          tB, 0 );
        while( ABR.Height() < A.Height() )
        {
            RepartitionUpDiagonal
            ( ATL, /**/ ATR,  A00, A01, /**/ A02,
              /**/       A10, A11, /**/ A12,
              /*************/ /******************/
              ABL, /**/ ABR,  A20, A21, /**/ A22 );

            RepartitionUp
            ( tT,  t0,
              t1,
              /**/ /**/
              tB,  t2 );

            if( A00.Height() > 0 )
            {
                WPan.AlignWith( A01 );
                APan_MC_STAR.AlignWith( A00 );
                WPan_MC_STAR.AlignWith( A00 );
                APan_MR_STAR.AlignWith( A00 );
                WPan_MR_STAR.AlignWith( A00 );
                //------------------------------------------------------------//
                WPan.ResizeTo( ATL.Height(), A11.Width() );
                APan_MC_STAR.ResizeTo( ATL.Height(), A11.Width() );
                WPan_MC_STAR.ResizeTo( ATL.Height(), A11.Width() );
                APan_MR_STAR.ResizeTo( ATL.Height(), A11.Width() );
                WPan_MR_STAR.ResizeTo( ATL.Height(), A11.Width() );

                internal::HermitianPanelTridiagU
                ( ATL, WPan, t1,
                  APan_MC_STAR, APan_MR_STAR, WPan_MC_STAR, WPan_MR_STAR );

                PartitionUp
                ( APan_MC_STAR, A01_MC_STAR,
                  A11_MC_STAR, A11.Height() );
                PartitionUp
                ( APan_MR_STAR, A01_MR_STAR,
                  A11_MR_STAR, A11.Height() );
                PartitionUp
                ( WPan_MC_STAR, W01_MC_STAR,
                  W11_MC_STAR, A11.Height() );
                PartitionUp
                ( WPan_MR_STAR, W01_MR_STAR,
                  W11_MR_STAR, A11.Height() );

                internal::LocalTrr2k
                ( UPPER, ADJOINT, ADJOINT,
                  (C)-1, A01_MC_STAR, W01_MR_STAR,
                  W01_MC_STAR, A01_MR_STAR,
                  (C)1,  A00 );
                //------------------------------------------------------------//
                WPan_MR_STAR.FreeAlignments();
                APan_MR_STAR.FreeAlignments();
                WPan_MC_STAR.FreeAlignments();
                APan_MC_STAR.FreeAlignments();
                WPan.FreeAlignments();
            }
            else
            {
                A11_STAR_STAR = A11;
                t1_STAR_STAR.ResizeTo( t1.Height(), 1 );

                HermitianTridiag
                ( UPPER, A11_STAR_STAR.LocalMatrix(),
                  t1_STAR_STAR.LocalMatrix() );

                A11 = A11_STAR_STAR;
                t1 = t1_STAR_STAR;
            }

            SlidePartitionUp
            ( tT,  t0,
              /**/ /**/
              t1,
              tB,  t2 );

            SlidePartitionUpDiagonal
            ( ATL, /**/ ATR,  A00, /**/ A01, A02,
              /*************/ /******************/
              /**/       A10, /**/ A11, A12,
              ABL, /**/ ABR,  A20, /**/ A21, A22 );
        }
    }
    // Redistribute from matrix-diagonal form to fully replicated
    t = tDiag;
#ifndef RELEASE
    PopCallStack();
#endif
}
Exemple #10
0
inline void
TrsvLT
( Orientation orientation, UnitOrNonUnit diag, 
  const DistMatrix<F>& L, DistMatrix<F>& x )
{
#ifndef RELEASE
    PushCallStack("internal::TrsvLT");
    if( L.Grid() != x.Grid() )
        throw std::logic_error("{L,x} must be distributed over the same grid");
    if( orientation == NORMAL )
        throw std::logic_error("TrsvLT expects a (conjugate-)transpose option");
    if( L.Height() != L.Width() )
        throw std::logic_error("L must be square");
    if( x.Width() != 1 && x.Height() != 1 )
        throw std::logic_error("x must be a vector");
    const int xLength = ( x.Width() == 1 ? x.Height() : x.Width() );
    if( L.Width() != xLength )
        throw std::logic_error("Nonconformal TrsvLT");
#endif
    const Grid& g = L.Grid();

    if( x.Width() == 1 )
    {
        // Matrix views 
        DistMatrix<F> L10(g), L11(g);
        DistMatrix<F> 
            xT(g),  x0(g),
            xB(g),  x1(g),
                    x2(g);

        // Temporary distributions
        DistMatrix<F,STAR,STAR> L11_STAR_STAR(g);
        DistMatrix<F,STAR,STAR> x1_STAR_STAR(g);
        DistMatrix<F,MC,  STAR> x1_MC_STAR(g);
        DistMatrix<F,MC,  MR  > z1(g);
        DistMatrix<F,MR,  MC  > z1_MR_MC(g);
        DistMatrix<F,MR,  STAR> z_MR_STAR(g);

        // Views of z[MR,* ]
        DistMatrix<F,MR,STAR> z0_MR_STAR(g),
                              z1_MR_STAR(g);

        z_MR_STAR.AlignWith( L );
        Zeros( x.Height(), 1, z_MR_STAR );

        // Start the algorithm
        PartitionUp
        ( x, xT,
             xB, 0 );
        while( xT.Height() > 0 )
        {
            RepartitionUp
            ( xT,  x0,
                   x1,
             /**/ /**/
              xB,  x2 );

            const int n0 = x0.Height();
            const int n1 = x1.Height();
            LockedView( L10, L, n0, 0,  n1, n0 );
            LockedView( L11, L, n0, n0, n1, n1 );
            View( z0_MR_STAR, z_MR_STAR, 0,  0, n0, 1 );
            View( z1_MR_STAR, z_MR_STAR, n0, 0, n1, 1 );

            x1_MC_STAR.AlignWith( L10 );
            z1.AlignWith( x1 );
            //----------------------------------------------------------------//
            if( x2.Height() != 0 )
            {
                z1_MR_MC.SumScatterFrom( z1_MR_STAR );
                z1 = z1_MR_MC;
                Axpy( F(1), z1, x1 );
            }

            x1_STAR_STAR = x1;
            L11_STAR_STAR = L11;
            Trsv
            ( LOWER, orientation, diag,
              L11_STAR_STAR.LockedMatrix(),
              x1_STAR_STAR.Matrix() );
            x1 = x1_STAR_STAR;

            x1_MC_STAR = x1_STAR_STAR;
            Gemv
            ( orientation, F(-1), 
              L10.LockedMatrix(), 
              x1_MC_STAR.LockedMatrix(),
              F(1), z0_MR_STAR.Matrix() );
            //----------------------------------------------------------------//
            x1_MC_STAR.FreeAlignments();
            z1.FreeAlignments();

            SlidePartitionUp
            ( xT,  x0,
             /**/ /**/
                   x1,
              xB,  x2 );
        }
    }
    else
    {
        // Matrix views 
        DistMatrix<F> L10(g), L11(g);
        DistMatrix<F> 
            xL(g), xR(g),
            x0(g), x1(g), x2(g);

        // Temporary distributions
        DistMatrix<F,STAR,STAR> L11_STAR_STAR(g);
        DistMatrix<F,STAR,STAR> x1_STAR_STAR(g);
        DistMatrix<F,STAR,MC  > x1_STAR_MC(g);
        DistMatrix<F,STAR,MR  > z_STAR_MR(g);

        // Views of z[* ,MR], which will store updates to x
        DistMatrix<F,STAR,MR> z0_STAR_MR(g),
                              z1_STAR_MR(g);

        z_STAR_MR.AlignWith( L );
        Zeros( 1, x.Width(), z_STAR_MR );

        // Start the algorithm
        PartitionLeft( x,  xL, xR, 0 );
        while( xL.Width() > 0 )
        {
            RepartitionLeft
            ( xL,     /**/ xR,
              x0, x1, /**/ x2 );

            const int n0 = x0.Width();
            const int n1 = x1.Width();
            LockedView( L10, L, n0, 0,  n1, n0 );
            LockedView( L11, L, n0, n0, n1, n1 );
            View( z0_STAR_MR, z_STAR_MR, 0, 0,  1, n0 );
            View( z1_STAR_MR, z_STAR_MR, 0, n0, 1, n1 );

            x1_STAR_MC.AlignWith( L10 );
            //----------------------------------------------------------------//
            if( x2.Width() != 0 )
                x1.SumScatterUpdate( F(1), z1_STAR_MR );

            x1_STAR_STAR = x1;
            L11_STAR_STAR = L11;
            Trsv
            ( LOWER, orientation, diag,
              L11_STAR_STAR.LockedMatrix(),
              x1_STAR_STAR.Matrix() );
            x1 = x1_STAR_STAR;

            x1_STAR_MC = x1_STAR_STAR;
            Gemv
            ( orientation, F(-1), 
              L10.LockedMatrix(), 
              x1_STAR_MC.LockedMatrix(),
              F(1), z0_STAR_MR.Matrix() );
            //----------------------------------------------------------------//
            x1_STAR_MC.FreeAlignments();

            SlidePartitionLeft
            ( xL, /**/ xR,
              x0, /**/ x1, x2 );
        }
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
Exemple #11
0
inline void
internal::TrsvUN
( UnitOrNonUnit diag, 
  const DistMatrix<F,MC,MR>& U, 
        DistMatrix<F,MC,MR>& x )
{
#ifndef RELEASE
    PushCallStack("internal::TrsvUN");
    if( U.Grid() != x.Grid() )
        throw std::logic_error("{U,x} must be distributed over the same grid");
    if( U.Height() != U.Width() )
        throw std::logic_error("U must be square");
    if( x.Width() != 1 && x.Height() != 1 )
        throw std::logic_error("x must be a vector");
    const int xLength = ( x.Width() == 1 ? x.Height() : x.Width() );
    if( U.Width() != xLength )
        throw std::logic_error("Nonconformal TrsvUN");
#endif
    const Grid& g = U.Grid();

    if( x.Width() == 1 )
    {
        // Matrix views 
        DistMatrix<F,MC,MR> 
            UTL(g), UTR(g),  U00(g), U01(g), U02(g),
            UBL(g), UBR(g),  U10(g), U11(g), U12(g),
                             U20(g), U21(g), U22(g);

        DistMatrix<F,MC,MR> 
            xT(g),  x0(g),
            xB(g),  x1(g),
                    x2(g);

        // Temporary distributions
        DistMatrix<F,STAR,STAR> U11_STAR_STAR(g);
        DistMatrix<F,STAR,STAR> x1_STAR_STAR(g);
        DistMatrix<F,MR,  STAR> x1_MR_STAR(g);
        DistMatrix<F,MC,  STAR> z0_MC_STAR(g);

        // Start the algorithm
        LockedPartitionUpDiagonal
        ( U, UTL, UTR,
             UBL, UBR, 0 );
        PartitionUp
        ( x, xT,
             xB, 0 );
        while( xT.Height() > 0 )
        {
            LockedRepartitionUpDiagonal
            ( UTL, /**/ UTR,  U00, U01, /**/ U02,
                   /**/       U10, U11, /**/ U12,
             /*************/ /******************/
              UBL, /**/ UBR,  U20, U21, /**/ U22 );

            RepartitionUp
            ( xT,  x0,
                   x1,
             /**/ /**/
              xB,  x2 );

            x1_MR_STAR.AlignWith( U01 );
            z0_MC_STAR.AlignWith( U01 );
            z0_MC_STAR.ResizeTo( x0.Height(), 1 );
            //----------------------------------------------------------------//
            x1_STAR_STAR = x1;
            U11_STAR_STAR = U11;
            Trsv
            ( UPPER, NORMAL, diag,
              U11_STAR_STAR.LockedLocalMatrix(),
              x1_STAR_STAR.LocalMatrix() );
            x1 = x1_STAR_STAR;

            x1_MR_STAR = x1_STAR_STAR;
            Gemv
            ( NORMAL, (F)-1, 
              U01.LockedLocalMatrix(), 
              x1_MR_STAR.LockedLocalMatrix(),
              (F)0, z0_MC_STAR.LocalMatrix() );
            x0.SumScatterUpdate( (F)1, z0_MC_STAR );
            //----------------------------------------------------------------//
            x1_MR_STAR.FreeAlignments();
            z0_MC_STAR.FreeAlignments();

            SlideLockedPartitionUpDiagonal
            ( UTL, /**/ UTR,  U00, /**/ U01, U02,
             /*************/ /******************/
                   /**/       U10, /**/ U11, U12,
              UBL, /**/ UBR,  U20, /**/ U21, U22 );

            SlidePartitionUp
            ( xT,  x0,
             /**/ /**/
                   x1,
              xB,  x2 );
        }
    }
    else
    {
        // Matrix views 
        DistMatrix<F,MC,MR> 
            UTL(g), UTR(g),  U00(g), U01(g), U02(g),
            UBL(g), UBR(g),  U10(g), U11(g), U12(g),
                             U20(g), U21(g), U22(g);

        DistMatrix<F,MC,MR> 
            xL(g), xR(g),
            x0(g), x1(g), x2(g);

        // Temporary distributions
        DistMatrix<F,STAR,STAR> U11_STAR_STAR(g);
        DistMatrix<F,STAR,STAR> x1_STAR_STAR(g);
        DistMatrix<F,STAR,MR  > x1_STAR_MR(g);
        DistMatrix<F,STAR,MC  > z0_STAR_MC(g);
        DistMatrix<F,MR,  MC  > z0_MR_MC(g);
        DistMatrix<F,MC,  MR  > z0(g);

        // Start the algorithm
        LockedPartitionUpDiagonal
        ( U, UTL, UTR,
             UBL, UBR, 0 );
        PartitionLeft( x,  xL, xR, 0 );
        while( xL.Width() > 0 )
        {
            LockedRepartitionUpDiagonal
            ( UTL, /**/ UTR,  U00, U01, /**/ U02,
                   /**/       U10, U11, /**/ U12,
             /*************/ /******************/
              UBL, /**/ UBR,  U20, U21, /**/ U22 );

            RepartitionLeft
            ( xL,     /**/ xR,
              x0, x1, /**/ x2 );

            x1_STAR_MR.AlignWith( U01 );
            z0_STAR_MC.AlignWith( U01 );
            z0.AlignWith( x0 );
            z0_STAR_MC.ResizeTo( 1, x0.Width() );
            //----------------------------------------------------------------//
            x1_STAR_STAR = x1;
            U11_STAR_STAR = U11;
            Trsv
            ( UPPER, NORMAL, diag,
              U11_STAR_STAR.LockedLocalMatrix(),
              x1_STAR_STAR.LocalMatrix() );
            x1 = x1_STAR_STAR;

            x1_STAR_MR = x1_STAR_STAR;
            Gemv
            ( NORMAL, (F)-1, 
              U01.LockedLocalMatrix(), 
              x1_STAR_MR.LockedLocalMatrix(),
              (F)0, z0_STAR_MC.LocalMatrix() );
            z0_MR_MC.SumScatterFrom( z0_STAR_MC );
            z0 = z0_MR_MC;
            Axpy( (F)1, z0, x0 );
            //----------------------------------------------------------------//
            x1_STAR_MR.FreeAlignments();
            z0_STAR_MC.FreeAlignments();
            z0.FreeAlignments(); 

            SlideLockedPartitionUpDiagonal
            ( UTL, /**/ UTR,  U00, /**/ U01, U02,
             /*************/ /******************/
                   /**/       U10, /**/ U11, U12,
              UBL, /**/ UBR,  U20, /**/ U21, U22 );

            SlidePartitionLeft
            ( xL, /**/ xR,
              x0, /**/ x1, x2 );
        }
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
Exemple #12
0
inline void
internal::TrsvLT
( Orientation orientation,
  UnitOrNonUnit diag, 
  const DistMatrix<F,MC,MR>& L, 
        DistMatrix<F,MC,MR>& x )
{
#ifndef RELEASE
    PushCallStack("internal::TrsvLT");
    if( L.Grid() != x.Grid() )
        throw std::logic_error("{L,x} must be distributed over the same grid");
    if( orientation == NORMAL )
        throw std::logic_error("TrsvLT expects a (conjugate-)transpose option");
    if( L.Height() != L.Width() )
        throw std::logic_error("L must be square");
    if( x.Width() != 1 && x.Height() != 1 )
        throw std::logic_error("x must be a vector");
    const int xLength = ( x.Width() == 1 ? x.Height() : x.Width() );
    if( L.Width() != xLength )
        throw std::logic_error("Nonconformal TrsvLT");
#endif
    const Grid& g = L.Grid();

    if( x.Width() == 1 )
    {
        // Matrix views 
        DistMatrix<F,MC,MR> 
            LTL(g), LTR(g),  L00(g), L01(g), L02(g),
            LBL(g), LBR(g),  L10(g), L11(g), L12(g),
                             L20(g), L21(g), L22(g);

        DistMatrix<F,MC,MR> 
            xT(g),  x0(g),
            xB(g),  x1(g),
                    x2(g);

        // Temporary distributions
        DistMatrix<F,STAR,STAR> L11_STAR_STAR(g);
        DistMatrix<F,STAR,STAR> x1_STAR_STAR(g);
        DistMatrix<F,MC,  STAR> x1_MC_STAR(g);
        DistMatrix<F,MR,  STAR> z0_MR_STAR(g);
        DistMatrix<F,MR,  MC  > z0_MR_MC(g);
        DistMatrix<F,MC,  MR  > z0(g);

        // Start the algorithm
        LockedPartitionUpDiagonal
        ( L, LTL, LTR,
             LBL, LBR, 0 );
        PartitionUp
        ( x, xT,
             xB, 0 );
        while( xT.Height() > 0 )
        {
            LockedRepartitionUpDiagonal
            ( LTL, /**/ LTR,  L00, L01, /**/ L02,
                   /**/       L10, L11, /**/ L12,
             /*************/ /******************/
              LBL, /**/ LBR,  L20, L21, /**/ L22 );

            RepartitionUp
            ( xT,  x0,
                   x1,
             /**/ /**/
              xB,  x2 );

            x1_MC_STAR.AlignWith( L10 );
            z0_MR_STAR.AlignWith( L10 );
            z0_MR_STAR.ResizeTo( x0.Height(), 1 );
            z0.AlignWith( x0 );
            //----------------------------------------------------------------//
            x1_STAR_STAR = x1;
            L11_STAR_STAR = L11;
            Trsv
            ( LOWER, orientation, diag,
              L11_STAR_STAR.LockedLocalMatrix(),
              x1_STAR_STAR.LocalMatrix() );
            x1 = x1_STAR_STAR;

            x1_MC_STAR = x1_STAR_STAR;
            Gemv
            ( orientation, (F)-1, 
              L10.LockedLocalMatrix(), 
              x1_MC_STAR.LockedLocalMatrix(),
              (F)0, z0_MR_STAR.LocalMatrix() );
            z0_MR_MC.SumScatterFrom( z0_MR_STAR );
            z0 = z0_MR_MC;
            Axpy( (F)1, z0, x0 );
            //----------------------------------------------------------------//
            x1_MC_STAR.FreeAlignments();
            z0_MR_STAR.FreeAlignments();
            z0.FreeAlignments();

            SlideLockedPartitionUpDiagonal
            ( LTL, /**/ LTR,  L00, /**/ L01, L02,
             /*************/ /******************/
                   /**/       L10, /**/ L11, L12,
              LBL, /**/ LBR,  L20, /**/ L21, L22 );

            SlidePartitionUp
            ( xT,  x0,
             /**/ /**/
                   x1,
              xB,  x2 );
        }
    }
    else
    {
        // Matrix views 
        DistMatrix<F,MC,MR> 
            LTL(g), LTR(g),  L00(g), L01(g), L02(g),
            LBL(g), LBR(g),  L10(g), L11(g), L12(g),
                             L20(g), L21(g), L22(g);

        DistMatrix<F,MC,MR> 
            xL(g), xR(g),
            x0(g), x1(g), x2(g);

        // Temporary distributions
        DistMatrix<F,STAR,STAR> L11_STAR_STAR(g);
        DistMatrix<F,STAR,STAR> x1_STAR_STAR(g);
        DistMatrix<F,STAR,MC  > x1_STAR_MC(g);
        DistMatrix<F,STAR,MR  > z0_STAR_MR(g);

        // Start the algorithm
        LockedPartitionUpDiagonal
        ( L, LTL, LTR,
             LBL, LBR, 0 );
        PartitionLeft( x,  xL, xR, 0 );
        while( xL.Width() > 0 )
        {
            LockedRepartitionUpDiagonal
            ( LTL, /**/ LTR,  L00, L01, /**/ L02,
                   /**/       L10, L11, /**/ L12,
             /*************/ /******************/
              LBL, /**/ LBR,  L20, L21, /**/ L22 );

            RepartitionLeft
            ( xL,     /**/ xR,
              x0, x1, /**/ x2 );

            x1_STAR_MC.AlignWith( L10 );
            z0_STAR_MR.AlignWith( L10 );
            //----------------------------------------------------------------//
            x1_STAR_STAR = x1;
            L11_STAR_STAR = L11;
            Trsv
            ( LOWER, orientation, diag,
              L11_STAR_STAR.LockedLocalMatrix(),
              x1_STAR_STAR.LocalMatrix() );
            x1 = x1_STAR_STAR;

            x1_STAR_MC = x1_STAR_STAR;
            Gemv
            ( orientation, (F)-1, 
              L10.LockedLocalMatrix(), 
              x1_STAR_MC.LockedLocalMatrix(),
              (F)0, z0_STAR_MR.LocalMatrix() );
            x0.SumScatterUpdate( (F)1, z0_STAR_MR );
            //----------------------------------------------------------------//
            x1_STAR_MC.FreeAlignments();
            z0_STAR_MR.FreeAlignments();

            SlideLockedPartitionUpDiagonal
            ( LTL, /**/ LTR,  L00, /**/ L01, L02,
             /*************/ /******************/
                   /**/       L10, /**/ L11, L12,
              LBL, /**/ LBR,  L20, /**/ L21, L22 );

            SlidePartitionLeft
            ( xL, /**/ xR,
              x0, /**/ x1, x2 );
        }
    }
#ifndef RELEASE
    PopCallStack();
#endif
}
inline void
Householder( DistMatrix<F>& A, DistMatrix<F,MD,STAR>& t )
{
#ifndef RELEASE
    CallStackEntry entry("rq::Householder");
    if( A.Grid() != t.Grid() )
        LogicError("{A,s} must be distributed over the same grid");
#endif
    const Int offset = A.Width()-A.Height();
    if( t.Viewing() )
    {
        if( !t.AlignedWithDiagonal( A, offset ) ) 
            LogicError("t was not aligned with A");
    }
    else
    {
        t.AlignWithDiagonal( A, offset );
    }
    t.ResizeTo( Min(A.Height(),A.Width()), 1 );

    // Matrix views
    const Grid& g = A.Grid();
    DistMatrix<F>
        ATL(g), ATR(g),  A00(g), A01(g), A02(g),  ATopPan(g), 
        ABL(g), ABR(g),  A10(g), A11(g), A12(g),  ABottomPan(g),
                         A20(g), A21(g), A22(g);
    DistMatrix<F,MD,STAR>
        tT(g),  t0(g),
        tB(g),  t1(g),
                t2(g);

    PartitionUpOffsetDiagonal
    ( offset,
      A, ATL, ATR,
         ABL, ABR, 0 );
    PartitionUp
    ( t, tT,
         tB, 0 );
    while( ABR.Height() < A.Height() && ABR.Width() < A.Width() )
    {
        RepartitionUpDiagonal
        ( ATL, /**/ ATR,  A00, A01, /**/ A02,
               /**/       A10, A11, /**/ A12,
         /*************/ /******************/
          ABL, /**/ ABR,  A20, A21, /**/ A22 );

        RepartitionUp
        ( tT,  t0,
               t1,
         /**/ /**/
          tB,  t2 );

        View1x2( ATopPan, A00, A01 );
        View1x2( ABottomPan, A10, A11 );
        //--------------------------------------------------------------------//
        PanelHouseholder( ABottomPan, t1 );
        ApplyQ( RIGHT, ADJOINT, ABottomPan, t1, ATopPan );
        //--------------------------------------------------------------------//

        SlidePartitionUp
        ( tT,  t0,
         /**/ /**/
               t1,
          tB,  t2 );

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