示例#1
0
extern "C" magma_int_t
magma_dsgesv_gpu(char trans, magma_int_t n, magma_int_t nrhs,
                 double *dA, magma_int_t ldda,
                 magma_int_t *ipiv,  magma_int_t *dipiv,
                 double *dB, magma_int_t lddb,
                 double *dX, magma_int_t lddx,
                 double *dworkd, float *dworks,
                 magma_int_t *iter, magma_int_t *info)
{
/*  -- MAGMA (version 1.4.0) --
       Univ. of Tennessee, Knoxville
       Univ. of California, Berkeley
       Univ. of Colorado, Denver
       August 2013

    Purpose
    =======
    DSGESV computes the solution to a real system of linear equations
       A * X = B or A' * X = B
    where A is an N-by-N matrix and X and B are N-by-NRHS matrices.

    DSGESV first attempts to factorize the matrix in real SINGLE PRECISION
    and use this factorization within an iterative refinement procedure
    to produce a solution with real DOUBLE PRECISION norm-wise backward error
    quality (see below). If the approach fails the method switches to a
    real DOUBLE PRECISION factorization and solve.

    The iterative refinement is not going to be a winning strategy if
    the ratio real SINGLE PRECISION performance over real DOUBLE PRECISION
    performance is too small. A reasonable strategy should take the
    number of right-hand sides and the size of the matrix into account.
    This might be done with a call to ILAENV in the future. Up to now, we
    always try iterative refinement.
    
    The iterative refinement process is stopped if
        ITER > ITERMAX
    or for all the RHS we have:
        RNRM < SQRT(N)*XNRM*ANRM*EPS*BWDMAX
    where
        o ITER is the number of the current iteration in the iterative
          refinement process
        o RNRM is the infinity-norm of the residual
        o XNRM is the infinity-norm of the solution
        o ANRM is the infinity-operator-norm of the matrix A
        o EPS is the machine epsilon returned by DLAMCH('Epsilon')
    The value ITERMAX and BWDMAX are fixed to 30 and 1.0D+00 respectively.

    Arguments
    =========
    TRANS   (input) CHARACTER*1
            Specifies the form of the system of equations:
            = 'N':  A * X = B  (No transpose)
            = 'T':  A'* X = B  (Transpose)
            = 'C':  A'* X = B  (Conjugate transpose = Transpose)

    N       (input) INTEGER
            The number of linear equations, i.e., the order of the
            matrix A.  N >= 0.

    NRHS    (input) INTEGER
            The number of right hand sides, i.e., the number of columns
            of the matrix B.  NRHS >= 0.

    dA      (input or input/output) DOUBLE PRECISION array on the GPU, dimension (ldda,N)
            On entry, the N-by-N coefficient matrix A.
            On exit, if iterative refinement has been successfully used
            (info.EQ.0 and ITER.GE.0, see description below), A is
            unchanged. If double precision factorization has been used
            (info.EQ.0 and ITER.LT.0, see description below), then the
            array dA contains the factors L and U from the factorization
            A = P*L*U; the unit diagonal elements of L are not stored.

    ldda    (input) INTEGER
            The leading dimension of the array dA.  ldda >= max(1,N).

    IPIV    (output) INTEGER array, dimension (N)
            The pivot indices that define the permutation matrix P;
            row i of the matrix was interchanged with row IPIV(i).
            Corresponds either to the single precision factorization
            (if info.EQ.0 and ITER.GE.0) or the double precision
            factorization (if info.EQ.0 and ITER.LT.0).

    dIPIV   (output) INTEGER array on the GPU, dimension (min(M,N))
            The pivot indices; for 1 <= i <= min(M,N), row i of the
            matrix was moved to row IPIV(i).

    dB      (input) DOUBLE PRECISION array on the GPU, dimension (lddb,NRHS)
            The N-by-NRHS right hand side matrix B.

    lddb    (input) INTEGER
            The leading dimension of the array dB.  lddb >= max(1,N).

    dX      (output) DOUBLE PRECISION array on the GPU, dimension (lddx,NRHS)
            If info = 0, the N-by-NRHS solution matrix X.

    lddx    (input) INTEGER
            The leading dimension of the array dX.  lddx >= max(1,N).

    dworkd  (workspace) DOUBLE PRECISION array on the GPU, dimension (N*NRHS)
            This array is used to hold the residual vectors.

    dworks  (workspace) SINGLE PRECISION array on the GPU, dimension (N*(N+NRHS))
            This array is used to store the real single precision matrix
            and the right-hand sides or solutions in single precision.

    iter    (output) INTEGER
            < 0: iterative refinement has failed, double precision
                 factorization has been performed
                 -1 : the routine fell back to full precision for
                      implementation- or machine-specific reasons
                 -2 : narrowing the precision induced an overflow,
                      the routine fell back to full precision
                 -3 : failure of SGETRF
                 -31: stop the iterative refinement after the 30th iteration
            > 0: iterative refinement has been successfully used.
                 Returns the number of iterations
 
    info   (output) INTEGER
            = 0:  successful exit
            < 0:  if info = -i, the i-th argument had an illegal value
            > 0:  if info = i, U(i,i) computed in DOUBLE PRECISION is
                  exactly zero.  The factorization has been completed,
                  but the factor U is exactly singular, so the solution
                  could not be computed.
    =====================================================================    */

    #define dB(i,j)     (dB + (i) + (j)*lddb)
    #define dX(i,j)     (dX + (i) + (j)*lddx)
    #define dR(i,j)     (dR + (i) + (j)*lddr)
    
    double c_neg_one = MAGMA_D_NEG_ONE;
    double c_one     = MAGMA_D_ONE;
    magma_int_t     ione  = 1;
    double *dR;
    float  *dSA, *dSX;
    double Xnrmv, Rnrmv;
    double          Anrm, Xnrm, Rnrm, cte, eps;
    magma_int_t     i, j, iiter, lddsa, lddr;
    
    /* Check arguments */
    *iter = 0;
    *info = 0;
    if ( n < 0 )
        *info = -1;
    else if ( nrhs < 0 )
        *info = -2;
    else if ( ldda < max(1,n))
        *info = -4;
    else if ( lddb < max(1,n))
        *info = -8;
    else if ( lddx < max(1,n))
        *info = -10;
    
    if (*info != 0) {
        magma_xerbla( __func__, -(*info) );
        return *info;
    }
    
    if ( n == 0 || nrhs == 0 )
        return *info;

    lddsa = n;
    lddr  = n;
    
    dSA = dworks;
    dSX = dSA + lddsa*n;
    dR  = dworkd;
    
    eps  = lapackf77_dlamch("Epsilon");
    Anrm = magmablas_dlange('I', n, n, dA, ldda, (double*)dworkd );
    cte  = Anrm * eps * pow((double)n, 0.5) * BWDMAX;
    
    /*
     * Convert to single precision
     */
    //magmablas_dlag2s( n, nrhs, dB, lddb, dSX, lddsx, info );  // done inside dsgetrs with pivots
    if (*info != 0) {
        *iter = -2;
        goto FALLBACK;
    }
    
    magmablas_dlag2s( n, n, dA, ldda, dSA, lddsa, info );
    if (*info != 0) {
        *iter = -2;
        goto FALLBACK;
    }
    
    // factor dSA in single precision
    magma_sgetrf_gpu( n, n, dSA, lddsa, ipiv, info );
    if (*info != 0) {
        *iter = -3;
        goto FALLBACK;
    }
    
    // Generate parallel pivots
    {
        magma_int_t *newipiv;
        magma_imalloc_cpu( &newipiv, n );
        if ( newipiv == NULL ) {
            *iter = -3;
            goto FALLBACK;
        }
        swp2pswp( trans, n, ipiv, newipiv );
        magma_setvector( n, sizeof(magma_int_t), newipiv, 1, dipiv, 1 );
        magma_free_cpu( newipiv );
    }
    
    // solve dSA*dSX = dB in single precision
    // converts dB to dSX and applies pivots, solves, then converts result back to dX
    magma_dsgetrs_gpu( trans, n, nrhs, dSA, lddsa, dipiv, dB, lddb, dX, lddx, dSX, info );
    
    // residual dR = dB - dA*dX in double precision
    magmablas_dlacpy( MagmaUpperLower, n, nrhs, dB, lddb, dR, lddr );
    if ( nrhs == 1 ) {
        magma_dgemv( trans, n, n,
                     c_neg_one, dA, ldda,
                                dX, 1,
                     c_one,     dR, 1 );
    }
    else {
        magma_dgemm( trans, MagmaNoTrans, n, nrhs, n,
                     c_neg_one, dA, ldda,
                                dX, lddx,
                     c_one,     dR, lddr );
    }
    
    // TODO: use MAGMA_D_ABS( dX(i,j) ) instead of dlange?
    for( j=0; j < nrhs; j++ ) {
        i = magma_idamax( n, dX(0,j), 1) - 1;
        magma_dgetmatrix( 1, 1, dX(i,j), 1, &Xnrmv, 1 );
        Xnrm = lapackf77_dlange( "F", &ione, &ione, &Xnrmv, &ione, NULL );
        
        i = magma_idamax ( n, dR(0,j), 1 ) - 1;
        magma_dgetmatrix( 1, 1, dR(i,j), 1, &Rnrmv, 1 );
        Rnrm = lapackf77_dlange( "F", &ione, &ione, &Rnrmv, &ione, NULL );
        
        if ( Rnrm >  Xnrm*cte ) {
            goto REFINEMENT;
        }
    }
    
    *iter = 0;
    return *info;

REFINEMENT:
    for( iiter=1; iiter < ITERMAX; ) {
        *info = 0;
        // convert residual dR to single precision dSX
        // solve dSA*dSX = R in single precision
        // convert result back to double precision dR
        // it's okay that dR is used for both dB input and dX output.
        magma_dsgetrs_gpu( trans, n, nrhs, dSA, lddsa, dipiv, dR, lddr, dR, lddr, dSX, info );
        if (*info != 0) {
            *iter = -3;
            goto FALLBACK;
        }
        
        // Add correction and setup residual
        // dX += dR  --and--
        // dR = dB
        // This saves going through dR a second time (if done with one more kernel).
        // -- not really: first time is read, second time is write.
        for( j=0; j < nrhs; j++ ) {
            magmablas_daxpycp( n, dR(0,j), dX(0,j), dB(0,j) );
        }
        
        // residual dR = dB - dA*dX in double precision
        if ( nrhs == 1 ) {
            magma_dgemv( trans, n, n,
                         c_neg_one, dA, ldda,
                                    dX, 1,
                         c_one,     dR, 1 );
        }
        else {
            magma_dgemm( trans, MagmaNoTrans, n, nrhs, n,
                         c_neg_one, dA, ldda,
                                    dX, lddx,
                         c_one,     dR, lddr );
        }
        
        /*  Check whether the nrhs normwise backward errors satisfy the
         *  stopping criterion. If yes, set ITER=IITER>0 and return. */
        for( j=0; j < nrhs; j++ ) {
            i = magma_idamax( n, dX(0,j), 1) - 1;
            magma_dgetmatrix( 1, 1, dX(i,j), 1, &Xnrmv, 1 );
            Xnrm = lapackf77_dlange( "F", &ione, &ione, &Xnrmv, &ione, NULL );
            
            i = magma_idamax ( n, dR(0,j), 1 ) - 1;
            magma_dgetmatrix( 1, 1, dR(i,j), 1, &Rnrmv, 1 );
            Rnrm = lapackf77_dlange( "F", &ione, &ione, &Rnrmv, &ione, NULL );
            
            if ( Rnrm >  Xnrm*cte ) {
                goto L20;
            }
        }
        
        /*  If we are here, the nrhs normwise backward errors satisfy
         *  the stopping criterion, we are good to exit. */
        *iter = iiter;
        return *info;
        
      L20:
        iiter++;
    }
    
    /* If we are at this place of the code, this is because we have
     * performed ITER=ITERMAX iterations and never satisified the
     * stopping criterion. Set up the ITER flag accordingly and follow
     * up on double precision routine. */
    *iter = -ITERMAX - 1;
    
FALLBACK:
    /* Single-precision iterative refinement failed to converge to a
     * satisfactory solution, so we resort to double precision. */
    magma_dgetrf_gpu( n, n, dA, ldda, ipiv, info );
    if (*info == 0) {
        magmablas_dlacpy( MagmaUpperLower, n, nrhs, dB, lddb, dX, lddx );
        magma_dgetrs_gpu( trans, n, nrhs, dA, ldda, ipiv, dX, lddx, info );
    }
    
    return *info;
}
示例#2
0
/**
    Purpose
    -------
    DLAHR2 reduces the first NB columns of a real general n-BY-(n-k+1)
    matrix A so that elements below the k-th subdiagonal are zero. The
    reduction is performed by an orthogonal similarity transformation
    Q' * A * Q. The routine returns the matrices V and T which determine
    Q as a block reflector I - V*T*V', and also the matrix Y = A * V.
    (Note this is different than LAPACK, which computes Y = A * V * T.)

    This is an auxiliary routine called by DGEHRD.

    Arguments
    ---------
    @param[in]
    n       INTEGER
            The order of the matrix A.

    @param[in]
    k       INTEGER
            The offset for the reduction. Elements below the k-th
            subdiagonal in the first NB columns are reduced to zero.
            K < N.

    @param[in]
    nb      INTEGER
            The number of columns to be reduced.

    @param[in,out]
    A       DOUBLE_PRECISION array, dimension (LDA,N-K+1)
            On entry, the n-by-(n-k+1) general matrix A.
            On exit, the elements on and above the k-th subdiagonal in
            the first NB columns are overwritten with the corresponding
            elements of the reduced matrix; the elements below the k-th
            subdiagonal, with the array TAU, represent the matrix Q as a
            product of elementary reflectors. The other columns of A are
            unchanged. See Further Details.

    @param[in]
    lda     INTEGER
            The leading dimension of the array A.  LDA >= max(1,N).

    @param[out]
    tau     DOUBLE_PRECISION array, dimension (NB)
            The scalar factors of the elementary reflectors. See Further
            Details.

    @param[out]
    T       DOUBLE_PRECISION array, dimension (LDT,NB)
            The upper triangular matrix T.

    @param[in]
    ldt     INTEGER
            The leading dimension of the array T.  LDT >= NB.

    @param[out]
    Y       DOUBLE_PRECISION array, dimension (LDY,NB)
            The n-by-nb matrix Y.

    @param[in]
    ldy     INTEGER
            The leading dimension of the array Y. LDY >= N.

    @param[in,out]
    data    Structure with pointers to dA, dT, dV, dW, dY
            which are distributed across multiple GPUs.

    Further Details
    ---------------
    The matrix Q is represented as a product of nb elementary reflectors

       Q = H(1) H(2) . . . H(nb).

    Each H(i) has the form

       H(i) = I - tau * v * v'

    where tau is a real scalar, and v is a real vector with
    v(1:i+k-1) = 0, v(i+k) = 1; v(i+k+1:n) is stored on exit in
    A(i+k+1:n,i), and tau in TAU(i).

    The elements of the vectors v together form the (n-k+1)-by-nb matrix
    V which is needed, with T and Y, to apply the transformation to the
    unreduced part of the matrix, using an update of the form:
    A := (I - V*T*V') * (A - Y*T*V').

    The contents of A on exit are illustrated by the following example
    with n = 7, k = 3 and nb = 2:

    @verbatim
       ( a   a   a   a   a )
       ( a   a   a   a   a )
       ( a   a   a   a   a )
       ( h   h   a   a   a )
       ( v1  h   a   a   a )
       ( v1  v2  a   a   a )
       ( v1  v2  a   a   a )
    @endverbatim

    where "a" denotes an element of the original matrix A, h denotes a
    modified element of the upper Hessenberg matrix H, and vi denotes an
    element of the vector defining H(i).

    This implementation follows the hybrid algorithm and notations described in

    S. Tomov and J. Dongarra, "Accelerating the reduction to upper Hessenberg
    form through hybrid GPU-based computing," University of Tennessee Computer
    Science Technical Report, UT-CS-09-642 (also LAPACK Working Note 219),
    May 24, 2009.

    @ingroup magma_dgeev_aux
    ********************************************************************/
extern "C" magma_int_t
magma_dlahr2_m(
    magma_int_t n, magma_int_t k, magma_int_t nb,
    double *A, magma_int_t lda,
    double *tau,
    double *T, magma_int_t ldt,
    double *Y, magma_int_t ldy,
    struct dgehrd_data* data )
{
    #define  A(  i, j ) ( A + (i) + (j)*lda)
    #define  Y(  i, j ) ( Y + (i) + (j)*ldy)
    #define  T(  i, j ) ( T + (i) + (j)*ldt)
    #define dA(  d, i, j ) (data->A [d] + (i) + (j)*ldda)
    #define dTi( d       ) (data->Ti[d])
    #define dV(  d, i, j ) (data->V [d] + (i) + (j)*ldv )
    #define dVd( d, i, j ) (data->Vd[d] + (i) + (j)*ldvd)
    #define dY(  d, i, j ) (data->Y [d] + (i) + (j)*ldda)

    double c_zero    = MAGMA_D_ZERO;
    double c_one     = MAGMA_D_ONE;
    double c_neg_one = MAGMA_D_NEG_ONE;
    double tmp;

    magma_int_t ngpu = data->ngpu;
    magma_int_t ldda = data->ldda;
    magma_int_t ldv  = data->ldv;
    magma_int_t ldvd = data->ldvd;
    
    magma_int_t ione = 1;
    
    magma_int_t d, dki1, dn, nblocks, gblock, lblock, lgid;
    magma_int_t n_k_i_1, n_k;
    double scale;

    magma_int_t i;
    double ei = MAGMA_D_ZERO;

    magma_int_t info_data = 0;
    magma_int_t *info = &info_data;
    if (n < 0) {
        *info = -1;
    } else if (k < 0 || k >= n) {
        *info = -2;
    } else if (nb < 1 || nb > n) {
        *info = -3;
    } else if (lda < max(1,n)) {
        *info = -5;
    } else if (ldt < nb) {
        *info = -8;
    } else if (ldy < max(1,n)) {
        *info = -10;
    }
    if (*info != 0) {
        magma_xerbla( __func__, -(*info) );
        return *info;
    }
    
    // adjust from 1-based indexing
    k -= 1;

    // Function Body
    if (n <= 1)
        return 0;
    
    // zero out current top block of V on all GPUs
    for( d = 0; d < ngpu; ++d ) {
        magma_setdevice( d );
        magmablasSetKernelStream( data->streams[d] );
        magmablas_dlaset( MagmaFull, nb, nb, c_zero, c_zero, dV(d,k,0), ldv );
    }
    
    // set all Y=0
    lapackf77_dlaset( "Full", &n, &nb, &c_zero, &c_zero, Y, &ldy );
    
    for (i = 0; i < nb; ++i) {
        n_k_i_1 = n - k - i - 1;
        n_k     = n - k;
        
        if (i > 0) {
            // Finish applying I - V * T * V' on right
            tmp = MAGMA_D_NEGATE( tau[i-1] );
            blasf77_daxpy( &n_k, &tmp, Y(k,i-1), &ione, A(k,i), &ione );
            
            // Apply I - V * T' * V' to this column (call it b) from the
            // left, using the last column of T as workspace, w.
            //
            // Let  V = ( V1 )   and   b = ( b1 )   (first i-1 rows)
            //          ( V2 )             ( b2 )
            // where V1 is unit lower triangular
            
            // w := b1 = A(k+1:k+i, i)
            blasf77_dcopy( &i,
                           A(k+1,i), &ione,
                           T(0,nb-1), &ione );
            
            // w := V1' * b1 = VA(k+1:k+i, 0:i-1)' * w
            blasf77_dtrmv( "Lower", "Conj", "Unit", &i,
                           A(k+1,0), &lda,
                           T(0,nb-1), &ione );
            
            // w := w + V2'*b2 = w + VA(k+i+1:n-1, 0:i-1)' * A(k+i+1:n-1, i)
            blasf77_dgemv( "Conj", &n_k_i_1, &i,
                           &c_one, A(k+i+1,0), &lda,
                                   A(k+i+1,i), &ione,
                           &c_one, T(0,nb-1), &ione );
            
            // w := T'*w = T(0:i-1, 0:i-1)' * w
            blasf77_dtrmv( "Upper", "Conj", "Non-unit", &i,
                           T(0,0), &ldt,
                           T(0,nb-1), &ione );
            
            // b2 := b2 - V2*w = A(k+i+1:n-1, i) - VA(k+i+1:n-1, 0:i-1) * w
            blasf77_dgemv( "No trans", &n_k_i_1, &i,
                           &c_neg_one, A(k+i+1,0), &lda,
                                       T(0,nb-1), &ione,
                           &c_one,     A(k+i+1,i), &ione );
            
            // w := V1*w = VA(k+1:k+i, 0:i-1) * w
            blasf77_dtrmv( "Lower", "No trans", "Unit", &i,
                           A(k+1,0), &lda,
                           T(0,nb-1), &ione );
            
            // b1 := b1 - w = A(k+1:k+i-1, i) - w
            blasf77_daxpy( &i,
                           &c_neg_one, T(0,nb-1), &ione,
                                       A(k+1,i), &ione );
            
            // Restore diagonal element, saved below during previous iteration
            *A(k+i,i-1) = ei;
        }
        
        // Generate the elementary reflector H(i) to annihilate A(k+i+1:n-1,i)
        lapackf77_dlarfg( &n_k_i_1,
                          A(k+i+1,i),
                          A(k+i+2,i), &ione, &tau[i] );
        // Save diagonal element and set to one, to simplify multiplying by V
        ei = *A(k+i+1,i);
        *A(k+i+1,i) = c_one;

        // compute yi = A vi = sum_g A{d} vi{d}
        nblocks = (n-1) / nb / ngpu + 1;
        for( d = 0; d < ngpu; ++d ) {
            magma_setdevice( d );
            magmablasSetKernelStream( data->streams[d] );
            
            // dV(k+i+1:n-1, i) = VA(k+i:n, i)
            magma_dsetvector_async( n_k_i_1,
                                    A(k+i+1,i), 1,
                                    dV(d, k+i+1, i), 1, data->streams[d] );
            
            // copy column of dV -> dVd, using block cyclic distribution.
            // This assumes V and Vd have been padded so that
            // a 2D matrix copy doesn't access them out-of-bounds
            gblock = k / nb;
            lblock = gblock / ngpu;
            lgid   = gblock % ngpu;
            if ( d < lgid ) {
                lblock += 1;
            }
            // treat V as (nb*ngpu) x nblock matrix, and Vd as nb x nblock matrix
            magmablas_dlacpy( MagmaFull, nb, nblocks-lblock,
                              dV (d, d*nb + lblock*nb*ngpu, i), nb*ngpu,
                              dVd(d, 0    + lblock*nb,      i), nb );
            
            // convert global indices (k) to local indices (dk)
            magma_indices_1D_bcyclic( nb, ngpu, d, k+i+1, n, &dki1, &dn );
            
            // dY(k:n, i) = dA(k:n, k+i+1:n) * dV(k+i+1:n, i)
            // skip if matrix is empty
            // each GPU copies to different temporary vector in Y,
            // which are summed in separate loop below
            if ( dn-dki1 > 0 ) {
                magma_dgemv( MagmaNoTrans, n-k, dn-dki1,
                             c_one,  dA (d, k,    dki1), ldda,
                                     dVd(d, dki1,    i), 1,
                             c_zero, dY (d, k,       i), 1 );
                
                // copy vector to host, storing in column nb+d of Y
                // as temporary space (Y has >= nb+ngpu columns)
                magma_dgetvector_async( n-k,
                                        dY(d, k, i), 1,
                                        Y(k, nb+d),  1, data->streams[d] );
            }
        }
        
        // while GPU is doing above Ag*v...
        // Compute T(0:i,i) = [ -tau T V' vi ]
        //                    [  tau         ]
        // T(0:i-1, i) = -tau VA(k+i+1:n-1, 0:i-1)' VA(k+i+1:n-1, i)
        scale = MAGMA_D_NEGATE( tau[i] );
        blasf77_dgemv( "Conj", &n_k_i_1, &i,
                       &scale,  A(k+i+1,0), &lda,
                                A(k+i+1,i), &ione,
                       &c_zero, T(0,i), &ione );
        // T(0:i-1, i) = T(0:i-1, 0:i-1) * T(0:i-1, i)
        blasf77_dtrmv( "Upper", "No trans", "Non-unit", &i,
                       T(0,0), &ldt,
                       T(0,i), &ione );
        *T(i,i) = tau[i];
        
        // apply reflectors to next column, A(i+1), on right only.
        // one axpy will be required to finish this, in the next iteration above
        if ( i > 0 && i+1 < nb ) {
            // Update next column, A(k:n,i+1), applying Q on right.
            // One axpy will be required to finish this, in the next iteration
            // above, after yi is computed.
            // This updates one more row than LAPACK does (row k),
            // making block above panel an even multiple of nb.
            // Use last column of T as workspace, w.
            magma_int_t i1 = i+1;
            
            // If real, conjugate row of V, and undo afterwards
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv( &i1,  A(k+i1,0), &lda );
            #endif
            // w = T(0:i, 0:i+1) * VA(k+i+1, 0:i+1)'
            // T is now rectangular, so we use gemv instead of trmv as in lapack.
            blasf77_dgemv( "No trans", &i, &i1,
                           &c_one,  T(0,0), &ldt,
                                    A(k+i1,0), &lda,
                           &c_zero, T(0,nb-1), &ione );
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv( &i1,  A(k+i1,0), &lda );
            #endif
            
            // A(k:n, i+1) -= Y(k:n, 0:i) * w
            blasf77_dgemv( "No trans", &n_k, &i,
                           &c_neg_one, Y(k,0), &ldy,
                                       T(0,nb-1), &ione,
                           &c_one,     A(k,i1), &ione );
        }
        
        // yi = sum_g yi{d}
        for( d = 0; d < ngpu; ++d ) {
            magma_setdevice( d );
            magma_queue_sync( data->streams[d] );
            magma_indices_1D_bcyclic( nb, ngpu, d, k+i+1, n, &dki1, &dn );
            if ( dn-dki1 > 0 ) {
                // yi = yi + yi{d}
                blasf77_daxpy( &n_k, &c_one, Y(k,nb+d), &ione, Y(k,i), &ione );
            }
        }
    }
    // Restore diagonal element
    *A(k+nb,nb-1) = ei;
    
    // compute Y = Am V = sum_g Am{d} V{d} --- top part, Y(0:k-1,:)
    for( d = 0; d < ngpu; ++d ) {
        magma_setdevice( d );
        magmablasSetKernelStream( data->streams[d] );
        
        // convert global indices (k) to local indices (dk)
        magma_indices_1D_bcyclic( nb, ngpu, d, k+1, n, &dki1, &dn );
        
        // dY(0:k, :) = dA(0:k, k+i+1:n-1) * dV(k+i+1:n-1, :)
        // skip if matrix is empty
        // each GPU copies to different temporary block in Y,
        // which are summed in separate loop below
        if ( dn-dki1 > 0 ) {
            magma_dgemm( MagmaNoTrans, MagmaNoTrans, k, nb, dn-dki1,
                         c_one,  dA (d, 0,    dki1), ldda,
                                 dVd(d, dki1,    0), ldvd,
                         c_zero, dY (d, 0,       0), ldda );
            
            // copy result to host, storing in columns [nb + nb*d : nb + nb*(d+1)] of Y
            // as temporary space (Y has nb + nb*ngpu columns)
            magma_dgetmatrix_async( k, nb,
                                    dY(d, 0, 0),  ldda,
                                    Y(0,nb+nb*d), ldy, data->streams[d] );
        }
    }
    
    // Y = sum_g Y{d}
    for( d = 0; d < ngpu; ++d ) {
        magma_setdevice( d );
        magma_queue_sync( 0 );
        magma_indices_1D_bcyclic( nb, ngpu, d, k+1, n, &dki1, &dn );
        if ( dn-dki1 > 0 ) {
            // Y = Y + Am V
            for( i = 0; i < nb; ++i ) {
                blasf77_daxpy( &k, &c_one, Y(0,nb+nb*d+i), &ione, Y(0,i), &ione );
            }
        }
    }
    
    // copy Y and T matrices to GPUs
    for( d = 0; d < ngpu; ++d ) {
        magma_setdevice( d );
        magma_dsetmatrix_async( n, nb, Y, ldy, dY(d, 0, 0), ldda, data->streams[d] );
        magma_dsetmatrix_async( nb, nb, T, nb, dTi(d),      nb,   data->streams[d] );
    }

    return 0;
} /* magma_dlahr2 */
示例#3
0
int main( int argc, char** argv )
{
    TESTING_INIT();
    
    real_Double_t   gflops, t1, t2;
    double c_neg_one = MAGMA_D_NEG_ONE;
    magma_int_t ione = 1;
    const char trans[] = { 'N', 'C', 'T' };
    const char uplo[]  = { 'L', 'U' };
    const char diag[]  = { 'U', 'N' };
    const char side[]  = { 'L', 'R' };
    
    double  *A,  *B,  *C,   *C2, *LU;
    double *dA, *dB, *dC1, *dC2;
    double alpha = MAGMA_D_MAKE( 0.5, 0.1 );
    double beta  = MAGMA_D_MAKE( 0.7, 0.2 );
    double dalpha = 0.6;
    double dbeta  = 0.8;
    double work[1], error, total_error;
    magma_int_t ISEED[4] = {0,0,0,1};
    magma_int_t m, n, k, size, maxn, ld, info;
    magma_int_t *piv;
    magma_err_t err;
    
    magma_opts opts;
    parse_opts( argc, argv, &opts );
    
    printf( "Compares magma wrapper function to cublas function; all diffs should be exactly 0.\n\n" );
    
    total_error = 0.;
    for( int i = 0; i < opts.ntest; ++i ) {
        m = opts.msize[i];
        n = opts.nsize[i];
        k = opts.ksize[i];
        printf("=========================================================================\n");
        printf( "M %d, N %d, K %d\n", (int) m, (int) n, (int) k );
        
        // allocate matrices
        // over-allocate so they can be any combination of {m,n,k} x {m,n,k}.
        maxn = max( max( m, n ), k );
        ld = maxn;
        size = maxn*maxn;
        err = magma_malloc_cpu( (void**) &piv, maxn*sizeof(magma_int_t) );  assert( err == 0 );
        err = magma_dmalloc_pinned( &A,  size );  assert( err == 0 );
        err = magma_dmalloc_pinned( &B,  size );  assert( err == 0 );
        err = magma_dmalloc_pinned( &C,  size );  assert( err == 0 );
        err = magma_dmalloc_pinned( &C2, size );  assert( err == 0 );
        err = magma_dmalloc_pinned( &LU, size );  assert( err == 0 );
        err = magma_dmalloc( &dA,  size );        assert( err == 0 );
        err = magma_dmalloc( &dB,  size );        assert( err == 0 );
        err = magma_dmalloc( &dC1, size );        assert( err == 0 );
        err = magma_dmalloc( &dC2, size );        assert( err == 0 );
        
        // initialize matrices
        size = maxn*maxn;
        lapackf77_dlarnv( &ione, ISEED, &size, A  );
        lapackf77_dlarnv( &ione, ISEED, &size, B  );
        lapackf77_dlarnv( &ione, ISEED, &size, C  );
        
        printf( "========== Level 1 BLAS ==========\n" );
        
        // ----- test DSWAP
        // swap 2nd and 3rd columns of dA, then copy to C2 and compare with A
        assert( n >= 4 );
        magma_dsetmatrix( m, n, A, ld, dA, ld );
        magma_dsetmatrix( m, n, A, ld, dB, ld );
        magma_dswap( m, dA(0,1), 1, dA(0,2), 1 );
        magma_dswap( m, dB(0,1), 1, dB(0,2), 1 );
        
        // check results, storing diff between magma and cuda calls in C2
        cublasDaxpy( ld*n, c_neg_one, dA, 1, dB, 1 );
        magma_dgetmatrix( m, n, dB, ld, C2, ld );
        error = lapackf77_dlange( "F", &m, &k, C2, &ld, work );
        total_error += error;
        printf( "dswap             diff %.2g\n", error );
        
        // ----- test IDAMAX
        // get argmax of column of A
        magma_dsetmatrix( m, k, A, ld, dA, ld );
        error = 0;
        for( int j = 0; j < k; ++j ) {
            magma_int_t i1 = magma_idamax( m, dA(0,j), 1 );
            magma_int_t i2 = cublasIdamax( m, dA(0,j), 1 );
            assert( i1 == i2 );
            error += abs( i1 - i2 );
        }
        total_error += error;
        gflops = (double)m * k / 1e9;
        printf( "idamax            diff %.2g\n", error );
        printf( "\n" );
        
        printf( "========== Level 2 BLAS ==========\n" );
        
        // ----- test DGEMV
        // c = alpha*A*b + beta*c,  with A m*n; b,c m or n-vectors
        // try no-trans/trans
        for( int ia = 0; ia < 3; ++ia ) {
            magma_dsetmatrix( m, n, A,  ld, dA,  ld );
            magma_dsetvector( maxn, B, 1, dB,  1 );
            magma_dsetvector( maxn, C, 1, dC1, 1 );
            magma_dsetvector( maxn, C, 1, dC2, 1 );
            t1 = magma_sync_wtime( 0 );
            magma_dgemv( trans[ia], m, n, alpha, dA, ld, dB, 1, beta, dC1, 1 );
            t1 = magma_sync_wtime( 0 ) - t1;
            t2 = magma_sync_wtime( 0 );
            cublasDgemv( trans[ia], m, n, alpha, dA, ld, dB, 1, beta, dC2, 1 );
            t2 = magma_sync_wtime( 0 ) - t2;
            
            // check results, storing diff between magma and cuda call in C2
            size = (trans[ia] == 'N' ? m : n);
            cublasDaxpy( size, c_neg_one, dC1, 1, dC2, 1 );
            magma_dgetvector( size, dC2, 1, C2, 1 );
            error = lapackf77_dlange( "F", &size, &ione, C2, &ld, work );
            total_error += error;
            gflops = FLOPS_DGEMV( m, n ) / 1e9;
            printf( "dgemv( %c )        diff %.2g,  Gflop/s %6.2f, %6.2f\n",
                    trans[ia], error, gflops/t1, gflops/t2 );
        }
        printf( "\n" );
        
        // ----- test DSYMV
        // c = alpha*A*b + beta*c,  with A m*m symmetric; b,c m-vectors
        // try upper/lower
        for( int iu = 0; iu < 2; ++iu ) {
            magma_dsetmatrix( m, m, A, ld, dA, ld );
            magma_dsetvector( m, B, 1, dB,  1 );
            magma_dsetvector( m, C, 1, dC1, 1 );
            magma_dsetvector( m, C, 1, dC2, 1 );
            t1 = magma_sync_wtime( 0 );
            magma_dsymv( uplo[iu], m, alpha, dA, ld, dB, 1, beta, dC1, 1 );
            t1 = magma_sync_wtime( 0 ) - t1;
            t2 = magma_sync_wtime( 0 );
            cublasDsymv( uplo[iu], m, alpha, dA, ld, dB, 1, beta, dC2, 1 );
            t2 = magma_sync_wtime( 0 ) - t2;
            
            // check results, storing diff between magma and cuda call in C2
            cublasDaxpy( m, c_neg_one, dC1, 1, dC2, 1 );
            magma_dgetvector( m, dC2, 1, C2, 1 );
            error = lapackf77_dlange( "F", &m, &ione, C2, &ld, work );
            total_error += error;
            gflops = FLOPS_DSYMV( m ) / 1e9;
            printf( "dsymv( %c )        diff %.2g,  Gflop/s %6.2f, %6.2f\n",
                    uplo[iu], error, gflops/t1, gflops/t2 );
        }
        printf( "\n" );
        
        // ----- test DTRSV
        // solve A*c = c,  with A m*m triangular; c m-vector
        // try upper/lower, no-trans/trans, unit/non-unit diag
        // Factor A into LU to get well-conditioned triangles, else solve yields garbage.
        // Still can give garbage if solves aren't consistent with LU factors,
        // e.g., using unit diag for U, so copy lower triangle to upper triangle.
        // Also used for trsm later.
        lapackf77_dlacpy( "Full", &maxn, &maxn, A, &ld, LU, &ld );
        lapackf77_dgetrf( &maxn, &maxn, LU, &ld, piv, &info );
        for( int j = 0; j < maxn; ++j ) {
            for( int i = 0; i < j; ++i ) {
                *LU(i,j) = *LU(j,i);
            }
        }
        for( int iu = 0; iu < 2; ++iu ) {
        for( int it = 0; it < 3; ++it ) {
        for( int id = 0; id < 2; ++id ) {
            magma_dsetmatrix( m, m, LU, ld, dA, ld );
            magma_dsetvector( m, C, 1, dC1, 1 );
            magma_dsetvector( m, C, 1, dC2, 1 );
            t1 = magma_sync_wtime( 0 );
            magma_dtrsv( uplo[iu], trans[it], diag[id], m, dA, ld, dC1, 1 );
            t1 = magma_sync_wtime( 0 ) - t1;
            t2 = magma_sync_wtime( 0 );
            cublasDtrsv( uplo[iu], trans[it], diag[id], m, dA, ld, dC2, 1 );
            t2 = magma_sync_wtime( 0 ) - t2;
            
            // check results, storing diff between magma and cuda call in C2
            cublasDaxpy( m, c_neg_one, dC1, 1, dC2, 1 );
            magma_dgetvector( m, dC2, 1, C2, 1 );
            error = lapackf77_dlange( "F", &m, &ione, C2, &ld, work );
            total_error += error;
            gflops = FLOPS_DTRSM( MagmaLeft, m, 1 ) / 1e9;
            printf( "dtrsv( %c, %c, %c )  diff %.2g,  Gflop/s %6.2f, %6.2f\n",
                    uplo[iu], trans[it], diag[id], error, gflops/t1, gflops/t2 );
        }}}
        printf( "\n" );
        
        printf( "========== Level 3 BLAS ==========\n" );
        
        // ----- test DGEMM
        // C = alpha*A*B + beta*C,  with A m*k or k*m; B k*n or n*k; C m*n
        // try combinations of no-trans/trans
        for( int ia = 0; ia < 3; ++ia ) {
        for( int ib = 0; ib < 3; ++ib ) {
            bool nta = (trans[ia] == 'N');
            bool ntb = (trans[ib] == 'N');
            magma_dsetmatrix( (nta ? m : k), (nta ? m : k), A, ld, dA,  ld );
            magma_dsetmatrix( (ntb ? k : n), (ntb ? n : k), B, ld, dB,  ld );
            magma_dsetmatrix( m, n, C, ld, dC1, ld );
            magma_dsetmatrix( m, n, C, ld, dC2, ld );
            t1 = magma_sync_wtime( 0 );
            magma_dgemm( trans[ia], trans[ib], m, n, k, alpha, dA, ld, dB, ld, beta, dC1, ld );
            t1 = magma_sync_wtime( 0 ) - t1;
            t2 = magma_sync_wtime( 0 );
            cublasDgemm( trans[ia], trans[ib], m, n, k, alpha, dA, ld, dB, ld, beta, dC2, ld );
            t2 = magma_sync_wtime( 0 ) - t2;
            
            // check results, storing diff between magma and cuda call in C2
            cublasDaxpy( ld*n, c_neg_one, dC1, 1, dC2, 1 );
            magma_dgetmatrix( m, n, dC2, ld, C2, ld );
            error = lapackf77_dlange( "F", &m, &n, C2, &ld, work );
            total_error += error;
            gflops = FLOPS_DGEMM( m, n, k ) / 1e9;
            printf( "dgemm( %c, %c )     diff %.2g,  Gflop/s %6.2f, %6.2f\n",
                    trans[ia], trans[ib], error, gflops/t1, gflops/t2 );
        }}
        printf( "\n" );
        
        // ----- test DSYMM
        // C = alpha*A*B + beta*C  (left)  with A m*m symmetric; B,C m*n; or
        // C = alpha*B*A + beta*C  (right) with A n*n symmetric; B,C m*n
        // try left/right, upper/lower
        for( int is = 0; is < 2; ++is ) {
        for( int iu = 0; iu < 2; ++iu ) {
            magma_dsetmatrix( m, m, A, ld, dA,  ld );
            magma_dsetmatrix( m, n, B, ld, dB,  ld );
            magma_dsetmatrix( m, n, C, ld, dC1, ld );
            magma_dsetmatrix( m, n, C, ld, dC2, ld );
            t1 = magma_sync_wtime( 0 );
            magma_dsymm( side[is], uplo[iu], m, n, alpha, dA, ld, dB, ld, beta, dC1, ld );
            t1 = magma_sync_wtime( 0 ) - t1;
            t2 = magma_sync_wtime( 0 );
            cublasDsymm( side[is], uplo[iu], m, n, alpha, dA, ld, dB, ld, beta, dC2, ld );
            t2 = magma_sync_wtime( 0 ) - t2;
            
            // check results, storing diff between magma and cuda call in C2
            cublasDaxpy( ld*n, c_neg_one, dC1, 1, dC2, 1 );
            magma_dgetmatrix( m, n, dC2, ld, C2, ld );
            error = lapackf77_dlange( "F", &m, &n, C2, &ld, work );
            total_error += error;
            gflops = FLOPS_DSYMM( side[is], m, n ) / 1e9;
            printf( "dsymm( %c, %c )     diff %.2g,  Gflop/s %6.2f, %6.2f\n",
                    side[is], uplo[iu], error, gflops/t1, gflops/t2 );
        }}
        printf( "\n" );
        
        // ----- test DSYRK
        // C = alpha*A*A^H + beta*C  (no-trans) with A m*k and C m*m symmetric; or
        // C = alpha*A^H*A + beta*C  (trans)    with A k*m and C m*m symmetric
        // try upper/lower, no-trans/trans
        for( int iu = 0; iu < 2; ++iu ) {
        for( int it = 0; it < 3; ++it ) {
            magma_dsetmatrix( n, k, A, ld, dA,  ld );
            magma_dsetmatrix( n, n, C, ld, dC1, ld );
            magma_dsetmatrix( n, n, C, ld, dC2, ld );
            t1 = magma_sync_wtime( 0 );
            magma_dsyrk( uplo[iu], trans[it], n, k, dalpha, dA, ld, dbeta, dC1, ld );
            t1 = magma_sync_wtime( 0 ) - t1;
            t2 = magma_sync_wtime( 0 );
            cublasDsyrk( uplo[iu], trans[it], n, k, dalpha, dA, ld, dbeta, dC2, ld );
            t2 = magma_sync_wtime( 0 ) - t2;
            
            // check results, storing diff between magma and cuda call in C2
            cublasDaxpy( ld*n, c_neg_one, dC1, 1, dC2, 1 );
            magma_dgetmatrix( n, n, dC2, ld, C2, ld );
            error = lapackf77_dlange( "F", &n, &n, C2, &ld, work );
            total_error += error;
            gflops = FLOPS_DSYRK( k, n ) / 1e9;
            printf( "dsyrk( %c, %c )     diff %.2g,  Gflop/s %6.2f, %6.2f\n",
                    uplo[iu], trans[it], error, gflops/t1, gflops/t2 );
        }}
        printf( "\n" );
        
        // ----- test DSYR2K
        // C = alpha*A*B^H + ^alpha*B*A^H + beta*C  (no-trans) with A,B n*k; C n*n symmetric; or
        // C = alpha*A^H*B + ^alpha*B^H*A + beta*C  (trans)    with A,B k*n; C n*n symmetric
        // try upper/lower, no-trans/trans
        for( int iu = 0; iu < 2; ++iu ) {
        for( int it = 0; it < 3; ++it ) {
            bool nt = (trans[it] == 'N');
            magma_dsetmatrix( (nt ? n : k), (nt ? n : k), A, ld, dA,  ld );
            magma_dsetmatrix( n, n, C, ld, dC1, ld );
            magma_dsetmatrix( n, n, C, ld, dC2, ld );
            t1 = magma_sync_wtime( 0 );
            magma_dsyr2k( uplo[iu], trans[it], n, k, alpha, dA, ld, dB, ld, dbeta, dC1, ld );
            t1 = magma_sync_wtime( 0 ) - t1;
            t2 = magma_sync_wtime( 0 );
            cublasDsyr2k( uplo[iu], trans[it], n, k, alpha, dA, ld, dB, ld, dbeta, dC2, ld );
            t2 = magma_sync_wtime( 0 ) - t2;
            
            // check results, storing diff between magma and cuda call in C2
            cublasDaxpy( ld*n, c_neg_one, dC1, 1, dC2, 1 );
            magma_dgetmatrix( n, n, dC2, ld, C2, ld );
            error = lapackf77_dlange( "F", &n, &n, C2, &ld, work );
            total_error += error;
            gflops = FLOPS_DSYR2K( k, n ) / 1e9;
            printf( "dsyr2k( %c, %c )    diff %.2g,  Gflop/s %6.2f, %6.2f\n",
                    uplo[iu], trans[it], error, gflops/t1, gflops/t2 );
        }}
        printf( "\n" );
        
        // ----- test DTRMM
        // C = alpha*A*C  (left)  with A m*m triangular; C m*n; or
        // C = alpha*C*A  (right) with A n*n triangular; C m*n
        // try left/right, upper/lower, no-trans/trans, unit/non-unit
        for( int is = 0; is < 2; ++is ) {
        for( int iu = 0; iu < 2; ++iu ) {
        for( int it = 0; it < 3; ++it ) {
        for( int id = 0; id < 2; ++id ) {
            bool left = (side[is] == 'L');
            magma_dsetmatrix( (left ? m : n), (left ? m : n), A, ld, dA,  ld );
            magma_dsetmatrix( m, n, C, ld, dC1, ld );
            magma_dsetmatrix( m, n, C, ld, dC2, ld );
            t1 = magma_sync_wtime( 0 );
            magma_dtrmm( side[is], uplo[iu], trans[it], diag[id], m, n, alpha, dA, ld, dC1, ld );
            t1 = magma_sync_wtime( 0 ) - t1;
            t2 = magma_sync_wtime( 0 );
            cublasDtrmm( side[is], uplo[iu], trans[it], diag[id], m, n, alpha, dA, ld, dC2, ld );
            t2 = magma_sync_wtime( 0 ) - t2;
            
            // check results, storing diff between magma and cuda call in C2
            cublasDaxpy( ld*n, c_neg_one, dC1, 1, dC2, 1 );
            magma_dgetmatrix( m, n, dC2, ld, C2, ld );
            error = lapackf77_dlange( "F", &n, &n, C2, &ld, work );
            total_error += error;
            gflops = FLOPS_DTRMM( side[is], m, n ) / 1e9;
            printf( "dtrmm( %c, %c )     diff %.2g,  Gflop/s %6.2f, %6.2f\n",
                    uplo[iu], trans[it], error, gflops/t1, gflops/t2 );
        }}}}
        printf( "\n" );
        
        // ----- test DTRSM
        // solve A*X = alpha*B  (left)  with A m*m triangular; B m*n; or
        // solve X*A = alpha*B  (right) with A n*n triangular; B m*n
        // try left/right, upper/lower, no-trans/trans, unit/non-unit
        for( int is = 0; is < 2; ++is ) {
        for( int iu = 0; iu < 2; ++iu ) {
        for( int it = 0; it < 3; ++it ) {
        for( int id = 0; id < 2; ++id ) {
            bool left = (side[is] == 'L');
            magma_dsetmatrix( (left ? m : n), (left ? m : n), LU, ld, dA,  ld );
            magma_dsetmatrix( m, n, C, ld, dC1, ld );
            magma_dsetmatrix( m, n, C, ld, dC2, ld );
            t1 = magma_sync_wtime( 0 );
            magma_dtrsm( side[is], uplo[iu], trans[it], diag[id], m, n, alpha, dA, ld, dC1, ld );
            t1 = magma_sync_wtime( 0 ) - t1;
            t2 = magma_sync_wtime( 0 );
            cublasDtrsm( side[is], uplo[iu], trans[it], diag[id], m, n, alpha, dA, ld, dC2, ld );
            t2 = magma_sync_wtime( 0 ) - t2;
            
            // check results, storing diff between magma and cuda call in C2
            cublasDaxpy( ld*n, c_neg_one, dC1, 1, dC2, 1 );
            magma_dgetmatrix( m, n, dC2, ld, C2, ld );
            error = lapackf77_dlange( "F", &n, &n, C2, &ld, work );
            total_error += error;
            gflops = FLOPS_DTRSM( side[is], m, n ) / 1e9;
            printf( "dtrsm( %c, %c )     diff %.2g,  Gflop/s %6.2f, %6.2f\n",
                    uplo[iu], trans[it], error, gflops/t1, gflops/t2 );
        }}}}
        printf( "\n" );
        
        // cleanup
        magma_free_cpu( piv );
        magma_free_pinned( A  );
        magma_free_pinned( B  );
        magma_free_pinned( C  );
        magma_free_pinned( C2 );
        magma_free_pinned( LU );
        magma_free( dA  );
        magma_free( dB  );
        magma_free( dC1 );
        magma_free( dC2 );
    }
    
    if ( total_error != 0. ) {
        printf( "total error %.2g -- ought to be 0 -- some test failed (see above).\n",
                total_error );
    }
    else {
        printf( "all tests passed\n" );
    }
    
    TESTING_FINALIZE();
    return 0;
}
示例#4
0
magma_int_t
magma_dpgmres( magma_d_sparse_matrix A, magma_d_vector b, magma_d_vector *x,  
               magma_d_solver_par *solver_par, 
               magma_d_preconditioner *precond_par ){

    // prepare solver feedback
    solver_par->solver = Magma_PGMRES;
    solver_par->numiter = 0;
    solver_par->info = 0;

    // local variables
    double c_zero = MAGMA_D_ZERO, c_one = MAGMA_D_ONE, 
                                                c_mone = MAGMA_D_NEG_ONE;
    magma_int_t dofs = A.num_rows;
    magma_int_t i, j, k, m = 0;
    magma_int_t restart = min( dofs-1, solver_par->restart );
    magma_int_t ldh = restart+1;
    double nom, rNorm, RNorm, nom0, betanom, r0 = 0.;

    // CPU workspace
    magma_setdevice(0);
    double *H, *HH, *y, *h1;
    magma_dmalloc_pinned( &H, (ldh+1)*ldh );
    magma_dmalloc_pinned( &y, ldh );
    magma_dmalloc_pinned( &HH, ldh*ldh );
    magma_dmalloc_pinned( &h1, ldh );

    // GPU workspace
    magma_d_vector r, q, q_t, z, z_t, t;
    magma_d_vinit( &t, Magma_DEV, dofs, c_zero );
    magma_d_vinit( &r, Magma_DEV, dofs, c_zero );
    magma_d_vinit( &q, Magma_DEV, dofs*(ldh+1), c_zero );
    magma_d_vinit( &z, Magma_DEV, dofs*(ldh+1), c_zero );
    magma_d_vinit( &z_t, Magma_DEV, dofs, c_zero );
    q_t.memory_location = Magma_DEV; 
    q_t.val = NULL; 
    q_t.num_rows = q_t.nnz = dofs;

    double *dy, *dH = NULL;
    if (MAGMA_SUCCESS != magma_dmalloc( &dy, ldh )) 
        return MAGMA_ERR_DEVICE_ALLOC;
    if (MAGMA_SUCCESS != magma_dmalloc( &dH, (ldh+1)*ldh )) 
        return MAGMA_ERR_DEVICE_ALLOC;

    // GPU stream
    magma_queue_t stream[2];
    magma_event_t event[1];
    magma_queue_create( &stream[0] );
    magma_queue_create( &stream[1] );
    magma_event_create( &event[0] );
    magmablasSetKernelStream(stream[0]);

    magma_dscal( dofs, c_zero, x->val, 1 );              //  x = 0
    magma_dcopy( dofs, b.val, 1, r.val, 1 );             //  r = b
    nom0 = betanom = magma_dnrm2( dofs, r.val, 1 );     //  nom0= || r||
    nom = nom0  * nom0;
    solver_par->init_res = nom0;
    H(1,0) = MAGMA_D_MAKE( nom0, 0. ); 
    magma_dsetvector(1, &H(1,0), 1, &dH(1,0), 1);
    if ( (r0 = nom * solver_par->epsilon) < ATOLERANCE ) 
        r0 = ATOLERANCE;
    if ( nom < r0 )
        return MAGMA_SUCCESS;

    //Chronometry
    real_Double_t tempo1, tempo2;
    magma_device_sync(); tempo1=magma_wtime();
    if( solver_par->verbose > 0 ){
        solver_par->res_vec[0] = nom0;
        solver_par->timing[0] = 0.0;
    }
    // start iteration
    for( solver_par->numiter= 1; solver_par->numiter<solver_par->maxiter; 
                                                    solver_par->numiter++ ){
        magma_dcopy(dofs, r.val, 1, q(0), 1);       //  q[0] = 1.0/H(1,0) r
        magma_dscal(dofs, 1./H(1,0), q(0), 1);      //  (to be fused)

        for(k=1; k<=restart; k++) {
            q_t.val = q(k-1);
            magmablasSetKernelStream(stream[0]);
            // preconditioner
            //  z[k] = M^(-1) q(k)
            magma_d_applyprecond_left( A, q_t, &t, precond_par );      
            magma_d_applyprecond_right( A, t, &z_t, precond_par );     
  
            magma_dcopy(dofs, z_t.val, 1, z(k-1), 1);                  

            // r = A q[k] 
            magma_d_spmv( c_one, A, z_t, c_zero, r );


            if (solver_par->ortho == Magma_MGS ) {
                // modified Gram-Schmidt
                magmablasSetKernelStream(stream[0]);
                for (i=1; i<=k; i++) {
                    H(i,k) =magma_ddot(dofs, q(i-1), 1, r.val, 1);            
                        //  H(i,k) = q[i] . r
                    magma_daxpy(dofs,-H(i,k), q(i-1), 1, r.val, 1);            
                       //  r = r - H(i,k) q[i]
                }
                H(k+1,k) = MAGMA_D_MAKE( magma_dnrm2(dofs, r.val, 1), 0. );
                      //  H(k+1,k) = sqrt(r . r) 
                if (k < restart) {
                        magma_dcopy(dofs, r.val, 1, q(k), 1);                  
                      //  q[k] = 1.0/H[k][k-1] r
                        magma_dscal(dofs, 1./H(k+1,k), q(k), 1);               
                      //  (to be fused)   
                 }
            } else if (solver_par->ortho == Magma_FUSED_CGS ) {
                // fusing dgemv with dnrm2 in classical Gram-Schmidt
                magmablasSetKernelStream(stream[0]);
                magma_dcopy(dofs, r.val, 1, q(k), 1);  
                    // dH(1:k+1,k) = q[0:k] . r
                magmablas_dgemv(MagmaTrans, dofs, k+1, c_one, q(0), 
                                dofs, r.val, 1, c_zero, &dH(1,k), 1);
                    // r = r - q[0:k-1] dH(1:k,k)
                magmablas_dgemv(MagmaNoTrans, dofs, k, c_mone, q(0), 
                                dofs, &dH(1,k), 1, c_one, r.val, 1);
                   // 1) dH(k+1,k) = sqrt( dH(k+1,k) - dH(1:k,k) )
                magma_dcopyscale(  dofs, k, r.val, q(k), &dH(1,k) );  
                   // 2) q[k] = q[k] / dH(k+1,k) 

                magma_event_record( event[0], stream[0] );
                magma_queue_wait_event( stream[1], event[0] );
                magma_dgetvector_async(k+1, &dH(1,k), 1, &H(1,k), 1, stream[1]); 
                    // asynch copy dH(1:(k+1),k) to H(1:(k+1),k)
            } else {
                // classical Gram-Schmidt (default)
                // > explicitly calling magmabls
                magmablasSetKernelStream(stream[0]);                                                  
                magmablas_dgemv(MagmaTrans, dofs, k, c_one, q(0), 
                                dofs, r.val, 1, c_zero, &dH(1,k), 1); 
                                // dH(1:k,k) = q[0:k-1] . r
                #ifndef DNRM2SCALE 
                // start copying dH(1:k,k) to H(1:k,k)
                magma_event_record( event[0], stream[0] );
                magma_queue_wait_event( stream[1], event[0] );
                magma_dgetvector_async(k, &dH(1,k), 1, &H(1,k), 
                                                    1, stream[1]);
                #endif
                                  // r = r - q[0:k-1] dH(1:k,k)
                magmablas_dgemv(MagmaNoTrans, dofs, k, c_mone, q(0), 
                                    dofs, &dH(1,k), 1, c_one, r.val, 1);
                #ifdef DNRM2SCALE
                magma_dcopy(dofs, r.val, 1, q(k), 1);                 
                    //  q[k] = r / H(k,k-1) 
                magma_dnrm2scale(dofs, q(k), dofs, &dH(k+1,k) );     
                    //  dH(k+1,k) = sqrt(r . r) and r = r / dH(k+1,k)

                magma_event_record( event[0], stream[0] );            
                            // start sending dH(1:k,k) to H(1:k,k)
                magma_queue_wait_event( stream[1], event[0] );        
                            // can we keep H(k+1,k) on GPU and combine?
                magma_dgetvector_async(k+1, &dH(1,k), 1, &H(1,k), 1, stream[1]);
                #else
                H(k+1,k) = MAGMA_D_MAKE( magma_dnrm2(dofs, r.val, 1), 0. );   
                            //  H(k+1,k) = sqrt(r . r) 
                if( k<solver_par->restart ){
                        magmablasSetKernelStream(stream[0]);
                        magma_dcopy(dofs, r.val, 1, q(k), 1);                  
                            //  q[k]    = 1.0/H[k][k-1] r
                        magma_dscal(dofs, 1./H(k+1,k), q(k), 1);              
                            //  (to be fused)   
                 }
                #endif
            }
        }
        magma_queue_sync( stream[1] );
        for( k=1; k<=restart; k++ ){
            /*     Minimization of  || b-Ax ||  in H_k       */ 
            for (i=1; i<=k; i++) {
                #if defined(PRECISION_z) || defined(PRECISION_c)
                cblas_ddot_sub( i+1, &H(1,k), 1, &H(1,i), 1, &HH(k,i) );
                #else
                HH(k,i) = cblas_ddot(i+1, &H(1,k), 1, &H(1,i), 1);
                #endif
            }
            h1[k] = H(1,k)*H(1,0); 
            if (k != 1)
                for (i=1; i<k; i++) {
                    for (m=i+1; m<k; m++){
                        HH(k,m) -= HH(k,i) * HH(m,i);
                    }
                    HH(k,k) -= HH(k,i) * HH(k,i) / HH(i,i);
                    HH(k,i) = HH(k,i)/HH(i,i);
                    h1[k] -= h1[i] * HH(k,i);   
                }    
            y[k] = h1[k]/HH(k,k); 
            if (k != 1)  
                for (i=k-1; i>=1; i--) {
                    y[i] = h1[i]/HH(i,i);
                    for (j=i+1; j<=k; j++)
                        y[i] -= y[j] * HH(j,i);
                }                    
            m = k;
            rNorm = fabs(MAGMA_D_REAL(H(k+1,k)));
        }

        magma_dsetmatrix_async(m, 1, y+1, m, dy, m, stream[0]);
        magmablasSetKernelStream(stream[0]);
        magma_dgemv(MagmaNoTrans, dofs, m, c_one, z(0), dofs, dy, 1, 
                                                    c_one, x->val, 1); 
        magma_d_spmv( c_mone, A, *x, c_zero, r );      //  r = - A * x
        magma_daxpy(dofs, c_one, b.val, 1, r.val, 1);  //  r = r + b
        H(1,0) = MAGMA_D_MAKE( magma_dnrm2(dofs, r.val, 1), 0. ); 
                                            //  RNorm = H[1][0] = || r ||
        RNorm = MAGMA_D_REAL( H(1,0) );
        betanom = fabs(RNorm);  

        if( solver_par->verbose > 0 ){
            magma_device_sync(); tempo2=magma_wtime();
            if( (solver_par->numiter)%solver_par->verbose==0 ) {
                solver_par->res_vec[(solver_par->numiter)/solver_par->verbose] 
                        = (real_Double_t) betanom;
                solver_par->timing[(solver_par->numiter)/solver_par->verbose] 
                        = (real_Double_t) tempo2-tempo1;
            }
        }

        if (  betanom  < r0 ) {
            break;
        } 
    }

    magma_device_sync(); tempo2=magma_wtime();
    solver_par->runtime = (real_Double_t) tempo2-tempo1;
    double residual;
    magma_dresidual( A, b, *x, &residual );
    solver_par->iter_res = betanom;
    solver_par->final_res = residual;

    if( solver_par->numiter < solver_par->maxiter){
        solver_par->info = 0;
    }else if( solver_par->init_res > solver_par->final_res ){
        if( solver_par->verbose > 0 ){
            if( (solver_par->numiter)%solver_par->verbose==0 ) {
                solver_par->res_vec[(solver_par->numiter)/solver_par->verbose] 
                        = (real_Double_t) betanom;
                solver_par->timing[(solver_par->numiter)/solver_par->verbose] 
                        = (real_Double_t) tempo2-tempo1;
            }
        }
        solver_par->info = -2;
    }
    else{
        if( solver_par->verbose > 0 ){
            if( (solver_par->numiter)%solver_par->verbose==0 ) {
                solver_par->res_vec[(solver_par->numiter)/solver_par->verbose] 
                        = (real_Double_t) betanom;
                solver_par->timing[(solver_par->numiter)/solver_par->verbose] 
                        = (real_Double_t) tempo2-tempo1;
            }
        }
        solver_par->info = -1;
    }
    // free pinned memory
    magma_free_pinned( H );
    magma_free_pinned( y );
    magma_free_pinned( HH );
    magma_free_pinned( h1 );
    // free GPU memory
    magma_free(dy); 
    if (dH != NULL ) magma_free(dH); 
    magma_d_vfree(&t);
    magma_d_vfree(&r);
    magma_d_vfree(&q);
    magma_d_vfree(&z);
    magma_d_vfree(&z_t);

    // free GPU streams and events
    magma_queue_destroy( stream[0] );
    magma_queue_destroy( stream[1] );
    magma_event_destroy( event[0] );
    magmablasSetKernelStream(NULL);

    return MAGMA_SUCCESS;
}   /* magma_dgmres */
示例#5
0
/**
    Purpose
    -------
    DLABRD reduces the first NB rows and columns of a real general
    m by n matrix A to upper or lower bidiagonal form by an orthogonal
    transformation Q' * A * P, and returns the matrices X and Y which
    are needed to apply the transformation to the unreduced part of A.

    If m >= n, A is reduced to upper bidiagonal form; if m < n, to lower
    bidiagonal form.

    This is an auxiliary routine called by DGEBRD.

    Arguments
    ---------
    @param[in]
    m       INTEGER
            The number of rows in the matrix A.

    @param[in]
    n       INTEGER
            The number of columns in the matrix A.

    @param[in]
    nb      INTEGER
            The number of leading rows and columns of A to be reduced.

    @param[in,out]
    A       DOUBLE_PRECISION array, dimension (LDA,N)
            On entry, the m by n general matrix to be reduced.
            On exit, the first NB rows and columns of the matrix are
            overwritten; the rest of the array is unchanged.
            If m >= n, elements on and below the diagonal in the first NB
              columns, with the array TAUQ, represent the orthogonal
              matrix Q as a product of elementary reflectors; and
              elements above the diagonal in the first NB rows, with the
              array TAUP, represent the orthogonal matrix P as a product
              of elementary reflectors.
    \n
            If m < n, elements below the diagonal in the first NB
              columns, with the array TAUQ, represent the orthogonal
              matrix Q as a product of elementary reflectors, and
              elements on and above the diagonal in the first NB rows,
              with the array TAUP, represent the orthogonal matrix P as
              a product of elementary reflectors.
            See Further Details.

    @param[in]
    lda     INTEGER
            The leading dimension of the array A.  LDA >= max(1,M).

    @param[in,out]
    dA      DOUBLE_PRECISION array, dimension (LDDA,N)
            Copy of A on GPU.

    @param[in]
    ldda    INTEGER
            The leading dimension of the array dA.  LDDA >= max(1,M).

    @param[out]
    d       DOUBLE_PRECISION array, dimension (NB)
            The diagonal elements of the first NB rows and columns of
            the reduced matrix.  D(i) = A(i,i).

    @param[out]
    e       DOUBLE_PRECISION array, dimension (NB)
            The off-diagonal elements of the first NB rows and columns of
            the reduced matrix.

    @param[out]
    tauq    DOUBLE_PRECISION array dimension (NB)
            The scalar factors of the elementary reflectors which
            represent the orthogonal matrix Q. See Further Details.

    @param[out]
    taup    DOUBLE_PRECISION array, dimension (NB)
            The scalar factors of the elementary reflectors which
            represent the orthogonal matrix P. See Further Details.

    @param[out]
    X       DOUBLE_PRECISION array, dimension (LDX,NB)
            The m-by-nb matrix X required to update the unreduced part
            of A.

    @param[in]
    ldx     INTEGER
            The leading dimension of the array X. LDX >= M.

    @param[out]
    dX      DOUBLE_PRECISION array, dimension (LDDX,NB)
            Copy of X on GPU.

    @param[in]
    lddx    INTEGER
            The leading dimension of the array dX. LDDX >= M.

    @param[out]
    Y       DOUBLE_PRECISION array, dimension (LDY,NB)
            The n-by-nb matrix Y required to update the unreduced part
            of A.

    @param[in]
    ldy     INTEGER
            The leading dimension of the array Y. LDY >= N.

    @param[out]
    dY      DOUBLE_PRECISION array, dimension (LDDY,NB)
            Copy of Y on GPU.

    @param[in]
    lddy    INTEGER
            The leading dimension of the array dY. LDDY >= N.

    Further Details
    ---------------
    The matrices Q and P are represented as products of elementary
    reflectors:

       Q = H(1) H(2) . . . H(nb)  and  P = G(1) G(2) . . . G(nb)

    Each H(i) and G(i) has the form:

       H(i) = I - tauq * v * v'  and G(i) = I - taup * u * u'

    where tauq and taup are real scalars, and v and u are real vectors.

    If m >= n, v(1:i-1) = 0, v(i) = 1, and v(i:m) is stored on exit in
    A(i:m,i); u(1:i) = 0, u(i+1) = 1, and u(i+1:n) is stored on exit in
    A(i,i+1:n); tauq is stored in TAUQ(i) and taup in TAUP(i).

    If m < n, v(1:i) = 0, v(i+1) = 1, and v(i+1:m) is stored on exit in
    A(i+2:m,i); u(1:i-1) = 0, u(i) = 1, and u(i:n) is stored on exit in
    A(i,i+1:n); tauq is stored in TAUQ(i) and taup in TAUP(i).

    The elements of the vectors v and u together form the m-by-nb matrix
    V and the nb-by-n matrix U' which are needed, with X and Y, to apply
    the transformation to the unreduced part of the matrix, using a block
    update of the form:  A := A - V*Y' - X*U'.

    The contents of A on exit are illustrated by the following examples
    with nb = 2:

    @verbatim
    m = 6 and n = 5 (m > n):          m = 5 and n = 6 (m < n):

      (  1   1   u1  u1  u1 )           (  1   u1  u1  u1  u1  u1 )
      (  v1  1   1   u2  u2 )           (  1   1   u2  u2  u2  u2 )
      (  v1  v2  a   a   a  )           (  v1  1   a   a   a   a  )
      (  v1  v2  a   a   a  )           (  v1  v2  a   a   a   a  )
      (  v1  v2  a   a   a  )           (  v1  v2  a   a   a   a  )
      (  v1  v2  a   a   a  )
    @endverbatim

    where a denotes an element of the original matrix which is unchanged,
    vi denotes an element of the vector defining H(i), and ui an element
    of the vector defining G(i).

    @ingroup magma_dgesvd_aux
    ********************************************************************/
extern "C" magma_int_t
magma_dlabrd_gpu( magma_int_t m, magma_int_t n, magma_int_t nb,
                  double *A,  magma_int_t lda,
                  double *dA, magma_int_t ldda,
                  double *d, double *e, double *tauq, double *taup,
                  double *X,  magma_int_t ldx,
                  double *dX, magma_int_t lddx,
                  double *Y,  magma_int_t ldy,
                  double *dY, magma_int_t lddy)
{
    #define A(i_,j_) (A + (i_) + (j_)*lda)
    #define X(i_,j_) (X + (i_) + (j_)*ldx)
    #define Y(i_,j_) (Y + (i_) + (j_)*ldy)
    #define dA(i_,j_) (dA + (i_) + (j_)*ldda)
    #define dY(i_,j_) (dY + (i_) + (j_)*lddy)
    #define dX(i_,j_) (dX + (i_) + (j_)*lddx)
    
    double c_neg_one = MAGMA_D_NEG_ONE;
    double c_one     = MAGMA_D_ONE;
    double c_zero    = MAGMA_D_ZERO;
    magma_int_t ione = 1;
    
    magma_int_t i__2, i__3;
    magma_int_t i;
    double alpha;

    A  -= 1 + lda;
    X  -= 1 + ldx;
    dX -= 1 + lddx;
    Y  -= 1 + ldy;
    dY -= 1 + lddy;
    --d;
    --e;
    --tauq;
    --taup;

    /* Quick return if possible */
    magma_int_t info = 0;
    if (m <= 0 || n <= 0) {
        return info;
    }

    double *f;
    magma_queue_t stream;
    magma_queue_create( &stream );
    magma_dmalloc_cpu( &f, max(n,m) );
    if ( f == NULL ) {
        info = MAGMA_ERR_HOST_ALLOC;
        return info;
    }
    
    if (m >= n) {
        /* Reduce to upper bidiagonal form */
        for (i = 1; i <= nb; ++i) {
            /*  Update A(i:m,i) */
            i__2 = m - i + 1;
            i__3 = i - 1;
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv( &i__3, Y(i,1), &ldy );
            #endif
            blasf77_dgemv( "No transpose", &i__2, &i__3, &c_neg_one,
                           A(i,1), &lda,
                           Y(i,1), &ldy, &c_one,
                           A(i,i), &ione );
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv( &i__3, Y(i,1), &ldy );
            #endif
            blasf77_dgemv( "No transpose", &i__2, &i__3, &c_neg_one,
                           X(i,1), &ldx,
                           A(1,i), &ione, &c_one,
                           A(i,i), &ione );
            
            /* Generate reflection Q(i) to annihilate A(i+1:m,i) */
            alpha = *A(i,i);
            i__2 = m - i + 1;
            i__3 = i + 1;
            lapackf77_dlarfg( &i__2, &alpha, A(min(i__3,m),i), &ione, &tauq[i] );
            d[i] = MAGMA_D_REAL( alpha );
            if (i < n) {
                *A(i,i) = c_one;

                /* Compute Y(i+1:n,i) */
                i__2 = m - i + 1;
                i__3 = n - i;

                // 1. Send the block reflector  A(i+1:m,i) to the GPU ------
                magma_dsetvector( i__2,
                                  A(i,i), 1,
                                  dA(i-1,i-1), 1 );
                // 2. Multiply ---------------------------------------------
                magma_dgemv( MagmaConjTrans, i__2, i__3, c_one,
                             dA(i-1,i),   ldda,
                             dA(i-1,i-1), ione, c_zero,
                             dY(i+1,i),   ione );
                
                // 3. Put the result back ----------------------------------
                magma_dgetmatrix_async( i__3, 1,
                                        dY(i+1,i), lddy,
                                        Y(i+1,i),  ldy, stream );
                i__2 = m - i + 1;
                i__3 = i - 1;
                blasf77_dgemv( MagmaConjTransStr, &i__2, &i__3, &c_one,
                               A(i,1), &lda,
                               A(i,i), &ione, &c_zero,
                               Y(1,i), &ione );

                i__2 = n - i;
                i__3 = i - 1;
                blasf77_dgemv( "N", &i__2, &i__3, &c_neg_one,
                               Y(i+1,1), &ldy,
                               Y(1,i),   &ione, &c_zero,
                               f,        &ione );
                i__2 = m - i + 1;
                i__3 = i - 1;
                blasf77_dgemv( MagmaConjTransStr, &i__2, &i__3, &c_one,
                               X(i,1), &ldx,
                               A(i,i), &ione, &c_zero,
                               Y(1,i), &ione );
                
                // 4. Sync to make sure the result is back ----------------
                magma_queue_sync( stream );

                if (i__3 != 0) {
                    i__2 = n - i;
                    blasf77_daxpy( &i__2, &c_one, f, &ione, Y(i+1,i), &ione );
                }

                i__2 = i - 1;
                i__3 = n - i;
                blasf77_dgemv( MagmaConjTransStr, &i__2, &i__3, &c_neg_one,
                               A(1,i+1), &lda,
                               Y(1,i),   &ione, &c_one,
                               Y(i+1,i), &ione );
                i__2 = n - i;
                blasf77_dscal( &i__2, &tauq[i], Y(i+1,i), &ione );

                /* Update A(i,i+1:n) */
                i__2 = n - i;
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv( &i__2, A(i,i+1), &lda );
                lapackf77_dlacgv( &i,  A(i,1), &lda );
                #endif
                blasf77_dgemv( "No transpose", &i__2, &i, &c_neg_one,
                               Y(i+1,1), &ldy,
                               A(i,1),   &lda, &c_one,
                               A(i,i+1), &lda );
                i__2 = i - 1;
                i__3 = n - i;
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv( &i,  A(i,1), &lda );
                lapackf77_dlacgv( &i__2, X(i,1), &ldx );
                #endif
                blasf77_dgemv( MagmaConjTransStr, &i__2, &i__3, &c_neg_one,
                               A(1,i+1), &lda,
                               X(i,1),   &ldx, &c_one,
                               A(i,i+1), &lda );
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv( &i__2, X(i,1), &ldx );
                #endif

                /* Generate reflection P(i) to annihilate A(i,i+2:n) */
                i__2 = n - i;
                i__3 = i + 2;
                alpha = *A(i,i+1);
                lapackf77_dlarfg( &i__2, &alpha, A(i,min(i__3,n)), &lda, &taup[i] );
                e[i] = MAGMA_D_REAL( alpha );
                *A(i,i+1) = c_one;

                /* Compute X(i+1:m,i) */
                i__2 = m - i;
                i__3 = n - i;
                // 1. Send the block reflector  A(i+1:m,i) to the GPU ------
                magma_dsetvector( i__3,
                                  A(i,i+1), lda,
                                  dA(i-1,i), ldda );
                // 2. Multiply ---------------------------------------------
                //magma_dcopy( i__3, dA(i-1,i), ldda, dY(1,1), 1 );
                magma_dgemv( MagmaNoTrans, i__2, i__3, c_one,
                             dA(i,i), ldda,
                             dA(i-1,i), ldda,
                             //dY(1,1), 1,
                             c_zero,
                             dX(i+1,i), ione );

                // 3. Put the result back ----------------------------------
                magma_dgetmatrix_async( i__2, 1,
                                        dX(i+1,i), lddx,
                                        X(i+1,i),  ldx, stream );

                i__2 = n - i;
                blasf77_dgemv( MagmaConjTransStr, &i__2, &i, &c_one,
                               Y(i+1,1), &ldy,
                               A(i,i+1), &lda, &c_zero,
                               X(1,i),   &ione );

                i__2 = m - i;
                blasf77_dgemv( "N", &i__2, &i, &c_neg_one,
                               A(i+1,1), &lda,
                               X(1,i),   &ione, &c_zero,
                               f,        &ione );
                i__2 = i - 1;
                i__3 = n - i;
                blasf77_dgemv( "N", &i__2, &i__3, &c_one,
                               A(1,i+1), &lda,
                               A(i,i+1), &lda, &c_zero,
                               X(1,i),   &ione );

                // 4. Sync to make sure the result is back ----------------
                magma_queue_sync( stream );
                if (i != 0) {
                    i__2 = m - i;
                    blasf77_daxpy( &i__2, &c_one, f, &ione, X(i+1,i), &ione );
                }


                i__2 = m - i;
                i__3 = i - 1;
                blasf77_dgemv( "No transpose", &i__2, &i__3, &c_neg_one,
                               X(i+1,1), &ldx,
                               X(1,i),   &ione, &c_one,
                               X(i+1,i), &ione );
                i__2 = m - i;
                blasf77_dscal( &i__2, &taup[i], X(i+1,i), &ione );

                #if defined(PRECISION_z) || defined(PRECISION_c)
                i__2 = n - i;
                lapackf77_dlacgv( &i__2,  A(i,i+1), &lda );
                // 4. Send the block reflector  A(i+1:m,i) to the GPU after DLACGV()
                magma_dsetvector( i__2,
                                  A(i,i+1),  lda,
                                  dA(i-1,i), ldda );
                #endif
            }
        }
    }
    else {
        /* Reduce to lower bidiagonal form */
        for (i = 1; i <= nb; ++i) {
        
            /* Update A(i,i:n) */
            i__2 = n - i + 1;
            i__3 = i - 1;
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv( &i__2, A(i,i), &lda );
            lapackf77_dlacgv( &i__3, A(i,1), &lda );
            #endif
            blasf77_dgemv( "No transpose", &i__2, &i__3, &c_neg_one,
                           Y(i,1), &ldy,
                           A(i,1), &lda, &c_one,
                           A(i,i), &lda );
            i__2 = i - 1;
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv( &i__3, A(i,1), &lda );
            lapackf77_dlacgv( &i__3, X(i,1), &ldx );
            #endif
            i__3 = n - i + 1;
            blasf77_dgemv( MagmaConjTransStr, &i__2, &i__3, &c_neg_one,
                           A(1,i), &lda,
                           X(i,1), &ldx, &c_one,
                           A(i,i), &lda );
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv( &i__2, X(i,1), &ldx );
            #endif
            
            /* Generate reflection P(i) to annihilate A(i,i+1:n) */
            i__2 = n - i + 1;
            i__3 = i + 1;
            alpha = *A(i,i);
            lapackf77_dlarfg( &i__2, &alpha, A(i,min(i__3,n)), &lda, &taup[i] );
            d[i] = MAGMA_D_REAL( alpha );
            if (i < m) {
                *A(i,i) = c_one;
                
                /* Compute X(i+1:m,i) */
                i__2 = m - i;
                i__3 = n - i + 1;
                
                // 1. Send the block reflector  A(i,i+1:n) to the GPU ------
                magma_dsetvector( i__3,
                                  A(i,i), lda,
                                  dA(i-1,i-1), ldda );
                
                // 2. Multiply ---------------------------------------------
                //magma_dcopy( i__3, dA(i-1,i-1), ldda, dY(1,1), 1 );
                magma_dgemv( MagmaNoTrans, i__2, i__3, c_one,
                             dA(i,i-1), ldda,
                             dA(i-1,i-1), ldda,
                             //dY(1,1), 1,
                             c_zero,
                             dX(i+1,i), ione );
                
                // 3. Put the result back ----------------------------------
                magma_dgetmatrix_async( i__2, 1,
                                        dX(i+1,i), lddx,
                                        X(i+1,i),  ldx, stream );
                
                i__2 = n - i + 1;
                i__3 = i - 1;
                blasf77_dgemv( MagmaConjTransStr, &i__2, &i__3, &c_one,
                               Y(i,1), &ldy,
                               A(i,i), &lda, &c_zero,
                               X(1,i), &ione );
                i__2 = m - i;
                i__3 = i - 1;
                blasf77_dgemv( "No transpose", &i__2, &i__3, &c_neg_one,
                               A(i+1,1), &lda,
                               X(1,i),   &ione, &c_zero,
                               f,        &ione );
                
                i__2 = i - 1;
                i__3 = n - i + 1;
                blasf77_dgemv( "No transpose", &i__2, &i__3, &c_one,
                               A(1,i), &lda,
                               A(i,i), &lda, &c_zero,
                               X(1,i), &ione );
                
                // 4. Sync to make sure the result is back ----------------
                magma_queue_sync( stream );
                if (i__2 != 0) {
                    i__3 = m - i;
                    blasf77_daxpy( &i__3, &c_one, f, &ione, X(i+1,i), &ione );
                }
                
                i__2 = m - i;
                i__3 = i - 1;
                blasf77_dgemv( "No transpose", &i__2, &i__3, &c_neg_one,
                               X(i+1,1), &ldx,
                               X(1,i),   &ione, &c_one,
                               X(i+1,i), &ione );
                i__2 = m - i;
                blasf77_dscal( &i__2, &taup[i], X(i+1,i), &ione );
                i__2 = n - i + 1;
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv( &i__2, A(i,i), &lda );
                magma_dsetvector( i__2,
                                  A(i,i), lda,
                                  dA(i-1,i-1), ldda );
                #endif
                
                /* Update A(i+1:m,i) */
                i__2 = m - i;
                i__3 = i - 1;
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv( &i__3, Y(i,1), &ldy );
                #endif
                blasf77_dgemv( "No transpose", &i__2, &i__3, &c_neg_one,
                               A(i+1,1), &lda,
                               Y(i,1),   &ldy, &c_one,
                               A(i+1,i), &ione );
                i__2 = m - i;
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv( &i__3, Y(i,1), &ldy );
                #endif
                blasf77_dgemv( "No transpose", &i__2, &i, &c_neg_one,
                               X(i+1,1), &ldx,
                               A(1,i),   &ione, &c_one,
                               A(i+1,i), &ione );
                
                /* Generate reflection Q(i) to annihilate A(i+2:m,i) */
                i__2 = m - i;
                i__3 = i + 2;
                alpha = *A(i+1,i);
                lapackf77_dlarfg( &i__2, &alpha, A(min(i__3,m),i), &ione, &tauq[i] );
                e[i] = MAGMA_D_REAL( alpha );
                *A(i+1,i) = c_one;
                
                /* Compute Y(i+1:n,i) */
                i__2 = m - i;
                i__3 = n - i;
                
                // 1. Send the block reflector  A(i+1:m,i) to the GPU ------
                magma_dsetvector( i__2,
                                  A(i+1,i), 1,
                                  dA(i,i-1), 1 );
                // 2. Multiply ---------------------------------------------
                magma_dgemv( MagmaConjTrans, i__2, i__3, c_one,
                             dA(i,i),   ldda,
                             dA(i,i-1), ione, c_zero,
                             dY(i+1,i), ione );
                
                // 3. Put the result back ----------------------------------
                magma_dgetmatrix_async( i__3, 1,
                                        dY(i+1,i), lddy,
                                        Y(i+1,i),  ldy, stream );
                
                i__2 = m - i;
                i__3 = i - 1;
                blasf77_dgemv( MagmaConjTransStr, &i__2, &i__3, &c_one,
                               A(i+1,1), &lda,
                               A(i+1,i), &ione, &c_zero,
                               Y(1,i),   &ione );
                i__2 = n - i;
                i__3 = i - 1;
                blasf77_dgemv( "No transpose", &i__2, &i__3, &c_neg_one,
                               Y(i+1,1), &ldy,
                               Y(1,i),   &ione, &c_zero,
                               f,        &ione );
                
                i__2 = m - i;
                blasf77_dgemv( MagmaConjTransStr, &i__2, &i, &c_one,
                               X(i+1,1), &ldx,
                               A(i+1,i), &ione, &c_zero,
                               Y(1,i),   &ione );
                
                // 4. Sync to make sure the result is back ----------------
                magma_queue_sync( stream );
                if (i__3 != 0) {
                    i__2 = n - i;
                    blasf77_daxpy( &i__2, &c_one, f, &ione, Y(i+1,i), &ione );
                }
                
                i__2 = n - i;
                blasf77_dgemv( MagmaConjTransStr, &i, &i__2, &c_neg_one,
                               A(1,i+1), &lda,
                               Y(1,i),   &ione, &c_one,
                               Y(i+1,i), &ione );
                i__2 = n - i;
                blasf77_dscal( &i__2, &tauq[i], Y(i+1,i), &ione );
            }
            #if defined(PRECISION_z) || defined(PRECISION_c)
            else {
                i__2 = n - i + 1;
                lapackf77_dlacgv( &i__2, A(i,i), &lda );
                magma_dsetvector( i__2,
                                  A(i,i), lda,
                                  dA(i-1,i-1), ldda );
            }
            #endif
        }
    }
    
    magma_queue_destroy( stream );
    magma_free_cpu( f );
    
    return info;
} /* magma_dlabrd_gpu */
示例#6
0
/**
    Purpose
    -------
    DLAHR2 reduces the first NB columns of a real general n-BY-(n-k+1)
    matrix A so that elements below the k-th subdiagonal are zero. The
    reduction is performed by an orthogonal similarity transformation
    Q' * A * Q. The routine returns the matrices V and T which determine
    Q as a block reflector I - V*T*V', and also the matrix Y = A * V.
    (Note this is different than LAPACK, which computes Y = A * V * T.)

    This is an auxiliary routine called by DGEHRD.

    Arguments
    ---------
    @param[in]
    n       INTEGER
            The order of the matrix A.

    @param[in]
    k       INTEGER
            The offset for the reduction. Elements below the k-th
            subdiagonal in the first NB columns are reduced to zero.
            K < N.

    @param[in]
    nb      INTEGER
            The number of columns to be reduced.

    @param[in,out]
    dA      DOUBLE PRECISION array on the GPU, dimension (LDDA,N-K+1)
            On entry, the n-by-(n-k+1) general matrix A.
            On exit, the elements in rows K:N of the first NB columns are
            overwritten with the matrix Y.

    @param[in]
    ldda    INTEGER
            The leading dimension of the array dA.  LDDA >= max(1,N).

    @param[out]
    dV      DOUBLE PRECISION array on the GPU, dimension (LDDV, NB)
            On exit this n-by-nb array contains the Householder vectors of the transformation.

    @param[in]
    lddv    INTEGER
            The leading dimension of the array dV.  LDDV >= max(1,N).

    @param[in,out]
    A       DOUBLE PRECISION array, dimension (LDA,N-K+1)
            On entry, the n-by-(n-k+1) general matrix A.
            On exit, the elements on and above the k-th subdiagonal in
            the first NB columns are overwritten with the corresponding
            elements of the reduced matrix; the elements below the k-th
            subdiagonal, with the array TAU, represent the matrix Q as a
            product of elementary reflectors. The other columns of A are
            unchanged. See Further Details.

    @param[in]
    lda     INTEGER
            The leading dimension of the array A.  LDA >= max(1,N).

    @param[out]
    tau     DOUBLE PRECISION array, dimension (NB)
            The scalar factors of the elementary reflectors. See Further
            Details.

    @param[out]
    T       DOUBLE PRECISION array, dimension (LDT,NB)
            The upper triangular matrix T.

    @param[in]
    ldt     INTEGER
            The leading dimension of the array T.  LDT >= NB.

    @param[out]
    Y       DOUBLE PRECISION array, dimension (LDY,NB)
            The n-by-nb matrix Y.

    @param[in]
    ldy     INTEGER
            The leading dimension of the array Y. LDY >= N.

    @param[in]
    queue   magma_queue_t
            Queue to execute in.

    Further Details
    ---------------
    The matrix Q is represented as a product of nb elementary reflectors

       Q = H(1) H(2) . . . H(nb).

    Each H(i) has the form

       H(i) = I - tau * v * v'

    where tau is a real scalar, and v is a real vector with
    v(1:i+k-1) = 0, v(i+k) = 1; v(i+k+1:n) is stored on exit in
    A(i+k+1:n,i), and tau in TAU(i).

    The elements of the vectors v together form the (n-k+1)-by-nb matrix
    V which is needed, with T and Y, to apply the transformation to the
    unreduced part of the matrix, using an update of the form:
    A := (I - V*T*V') * (A - Y*T*V').

    The contents of A on exit are illustrated by the following example
    with n = 7, k = 3 and nb = 2:

    @verbatim
       ( a   a   a   a   a )
       ( a   a   a   a   a )
       ( a   a   a   a   a )
       ( h   h   a   a   a )
       ( v1  h   a   a   a )
       ( v1  v2  a   a   a )
       ( v1  v2  a   a   a )
    @endverbatim

    where "a" denotes an element of the original matrix A, h denotes a
    modified element of the upper Hessenberg matrix H, and vi denotes an
    element of the vector defining H(i).

    This implementation follows the hybrid algorithm and notations described in

    S. Tomov and J. Dongarra, "Accelerating the reduction to upper Hessenberg
    form through hybrid GPU-based computing," University of Tennessee Computer
    Science Technical Report, UT-CS-09-642 (also LAPACK Working Note 219),
    May 24, 2009.

    @ingroup magma_dgeev_aux
    ********************************************************************/
extern "C" magma_int_t
magma_dlahr2(
    magma_int_t n, magma_int_t k, magma_int_t nb,
    magmaDouble_ptr dA, magma_int_t ldda,
    magmaDouble_ptr dV, magma_int_t lddv,
    double *A,     magma_int_t lda,
    double *tau,
    double *T,     magma_int_t ldt,
    double *Y,     magma_int_t ldy,
    magma_queue_t queue )
{
    #define  A(i_,j_) ( A + (i_) + (j_)*lda)
    #define  Y(i_,j_) ( Y + (i_) + (j_)*ldy)
    #define  T(i_,j_) ( T + (i_) + (j_)*ldt)
    #define dA(i_,j_) (dA + (i_) + (j_)*ldda)
    #define dV(i_,j_) (dV + (i_) + (j_)*lddv)
    
    double c_zero    = MAGMA_D_ZERO;
    double c_one     = MAGMA_D_ONE;
    double c_neg_one = MAGMA_D_NEG_ONE;

    magma_int_t ione = 1;
    
    magma_int_t n_k_i_1, n_k;
    double scale;

    magma_int_t i;
    double ei = MAGMA_D_ZERO;

    magma_int_t info = 0;
    if (n < 0) {
        info = -1;
    } else if (k < 0 || k > n) {
        info = -2;
    } else if (nb < 1 || nb > n) {
        info = -3;
    } else if (ldda < max(1,n)) {
        info = -5;
    } else if (lddv < max(1,n)) {
        info = -7;
    } else if (lda < max(1,n)) {
        info = -9;
    } else if (ldt < max(1,nb)) {
        info = -12;
    } else if (ldy < max(1,n)) {
        info = -13;
    }
    if (info != 0) {
        magma_xerbla( __func__, -(info) );
        return info;
    }

    // adjust from 1-based indexing
    k -= 1;

    if (n <= 1)
        return info;
    
    for (i = 0; i < nb; ++i) {
        n_k_i_1 = n - k - i - 1;
        n_k     = n - k;
        
        if (i > 0) {
            // Update A(k:n-1,i); Update i-th column of A - Y * T * V'
            // This updates one more row than LAPACK does (row k),
            // making the block above the panel an even multiple of nb.
            // Use last column of T as workspace, w.
            // w(0:i-1, nb-1) = VA(k+i, 0:i-1)'
            blasf77_dcopy( &i,
                           A(k+i,0),  &lda,
                           T(0,nb-1), &ione );
            #ifdef COMPLEX
            // If real, conjugate row of V.
            lapackf77_dlacgv(&i, T(0,nb-1), &ione);
            #endif
            
            // w = T(0:i-1, 0:i-1) * w
            blasf77_dtrmv( "Upper", "No trans", "No trans", &i,
                           T(0,0),    &ldt,
                           T(0,nb-1), &ione );
            
            // A(k:n-1, i) -= Y(k:n-1, 0:i-1) * w
            blasf77_dgemv( "No trans", &n_k, &i,
                           &c_neg_one, Y(k,0),    &ldy,
                                       T(0,nb-1), &ione,
                           &c_one,     A(k,i),    &ione );
            
            // Apply I - V * T' * V' to this column (call it b) from the
            // left, using the last column of T as workspace, w.
            //
            // Let  V = ( V1 )   and   b = ( b1 )   (first i-1 rows)
            //          ( V2 )             ( b2 )
            // where V1 is unit lower triangular
            
            // w := b1 = A(k+1:k+i, i)
            blasf77_dcopy( &i,
                           A(k+1,i),  &ione,
                           T(0,nb-1), &ione );
            
            // w := V1' * b1 = VA(k+1:k+i, 0:i-1)' * w
            blasf77_dtrmv( "Lower", "Conj", "Unit", &i,
                           A(k+1,0), &lda,
                           T(0,nb-1), &ione );
            
            // w := w + V2'*b2 = w + VA(k+i+1:n-1, 0:i-1)' * A(k+i+1:n-1, i)
            blasf77_dgemv( "Conj", &n_k_i_1, &i,
                           &c_one, A(k+i+1,0), &lda,
                                   A(k+i+1,i), &ione,
                           &c_one, T(0,nb-1),  &ione );
            
            // w := T'*w = T(0:i-1, 0:i-1)' * w
            blasf77_dtrmv( "Upper", "Conj", "Non-unit", &i,
                           T(0,0), &ldt,
                           T(0,nb-1), &ione );
            
            // b2 := b2 - V2*w = A(k+i+1:n-1, i) - VA(k+i+1:n-1, 0:i-1) * w
            blasf77_dgemv( "No trans", &n_k_i_1, &i,
                           &c_neg_one, A(k+i+1,0), &lda,
                                       T(0,nb-1),  &ione,
                           &c_one,     A(k+i+1,i), &ione );
            
            // w := V1*w = VA(k+1:k+i, 0:i-1) * w
            blasf77_dtrmv( "Lower", "No trans", "Unit", &i,
                           A(k+1,0), &lda,
                           T(0,nb-1), &ione );
            
            // b1 := b1 - w = A(k+1:k+i-1, i) - w
            blasf77_daxpy( &i,
                           &c_neg_one, T(0,nb-1), &ione,
                                       A(k+1,i),  &ione );
            
            // Restore diagonal element, saved below during previous iteration
            *A(k+i,i-1) = ei;
        }
        
        // Generate the elementary reflector H(i) to annihilate A(k+i+1:n-1,i)
        lapackf77_dlarfg( &n_k_i_1,
                          A(k+i+1,i),
                          A(k+i+2,i), &ione, &tau[i] );
        // Save diagonal element and set to one, to simplify multiplying by V
        ei = *A(k+i+1,i);
        *A(k+i+1,i) = c_one;

        // dV(i+1:n-k-1, i) = VA(k+i+1:n-1, i)
        magma_dsetvector( n_k_i_1,
                          A(k+i+1,i), 1,
                          dV(i+1,i),  1, queue );
        
        // Compute Y(k+1:n,i) = A vi
        // dA(k:n-1, i) = dA(k:n-1, i+1:n-k-1) * dV(i+1:n-k-1, i)
        magma_dgemv( MagmaNoTrans, n_k, n_k_i_1,
                     c_one,  dA(k,i+1), ldda,
                             dV(i+1,i), ione,
                     c_zero, dA(k,i),   ione, queue );
        
        // Compute T(0:i,i) = [ -tau T V' vi ]
        //                    [  tau         ]
        // T(0:i-1, i) = -tau VA(k+i+1:n-1, 0:i-1)' VA(k+i+1:n-1, i)
        scale = MAGMA_D_NEGATE( tau[i]);
        blasf77_dgemv( "Conj", &n_k_i_1, &i,
                       &scale,  A(k+i+1,0), &lda,
                                A(k+i+1,i), &ione,
                       &c_zero, T(0,i),     &ione );
        // T(0:i-1, i) = T(0:i-1, 0:i-1) * T(0:i-1, i)
        blasf77_dtrmv( "Upper", "No trans", "Non-unit", &i,
                       T(0,0), &ldt,
                       T(0,i), &ione );
        *T(i,i) = tau[i];

        // Y(k:n-1, i) = dA(k:n-1, i)
        magma_dgetvector( n-k,
                          dA(k,i), 1,
                          Y(k,i),  1, queue );
    }
    // Restore diagonal element
    *A(k+nb,nb-1) = ei;

    return info;
} /* magma_dlahr2 */
示例#7
0
extern "C" magma_int_t
magma_dlabrd_gpu( magma_int_t m, magma_int_t n, magma_int_t nb,
                  double *a, magma_int_t lda, double *da, magma_int_t ldda,
                  double *d, double *e, double *tauq, double *taup,
                  double *x, magma_int_t ldx, double *dx, magma_int_t lddx,
                  double *y, magma_int_t ldy, double *dy, magma_int_t lddy)
{
/*  -- MAGMA (version 1.4.0) --
       Univ. of Tennessee, Knoxville
       Univ. of California, Berkeley
       Univ. of Colorado, Denver
       August 2013

    Purpose
    =======
    DLABRD reduces the first NB rows and columns of a real general
    m by n matrix A to upper or lower bidiagonal form by an orthogonal
    transformation Q' * A * P, and returns the matrices X and Y which
    are needed to apply the transformation to the unreduced part of A.

    If m >= n, A is reduced to upper bidiagonal form; if m < n, to lower
    bidiagonal form.

    This is an auxiliary routine called by SGEBRD

    Arguments
    =========
    M       (input) INTEGER
            The number of rows in the matrix A.

    N       (input) INTEGER
            The number of columns in the matrix A.

    NB      (input) INTEGER
            The number of leading rows and columns of A to be reduced.

    A       (input/output) DOUBLE_PRECISION array, dimension (LDA,N)
            On entry, the m by n general matrix to be reduced.
            On exit, the first NB rows and columns of the matrix are
            overwritten; the rest of the array is unchanged.
            If m >= n, elements on and below the diagonal in the first NB
              columns, with the array TAUQ, represent the orthogonal
              matrix Q as a product of elementary reflectors; and
              elements above the diagonal in the first NB rows, with the
              array TAUP, represent the orthogonal matrix P as a product
              of elementary reflectors.
            If m < n, elements below the diagonal in the first NB
              columns, with the array TAUQ, represent the orthogonal
              matrix Q as a product of elementary reflectors, and
              elements on and above the diagonal in the first NB rows,
              with the array TAUP, represent the orthogonal matrix P as
              a product of elementary reflectors.
            See Further Details.

    LDA     (input) INTEGER
            The leading dimension of the array A.  LDA >= max(1,M).

    D       (output) DOUBLE_PRECISION array, dimension (NB)
            The diagonal elements of the first NB rows and columns of
            the reduced matrix.  D(i) = A(i,i).

    E       (output) DOUBLE_PRECISION array, dimension (NB)
            The off-diagonal elements of the first NB rows and columns of
            the reduced matrix.

    TAUQ    (output) DOUBLE_PRECISION array dimension (NB)
            The scalar factors of the elementary reflectors which
            represent the orthogonal matrix Q. See Further Details.

    TAUP    (output) DOUBLE_PRECISION array, dimension (NB)
            The scalar factors of the elementary reflectors which
            represent the orthogonal matrix P. See Further Details.

    X       (output) DOUBLE_PRECISION array, dimension (LDX,NB)
            The m-by-nb matrix X required to update the unreduced part
            of A.

    LDX     (input) INTEGER
            The leading dimension of the array X. LDX >= M.

    Y       (output) DOUBLE_PRECISION array, dimension (LDY,NB)
            The n-by-nb matrix Y required to update the unreduced part
            of A.

    LDY     (input) INTEGER
            The leading dimension of the array Y. LDY >= N.

    Further Details
    ===============
    The matrices Q and P are represented as products of elementary
    reflectors:

       Q = H(1) H(2) . . . H(nb)  and  P = G(1) G(2) . . . G(nb)

    Each H(i) and G(i) has the form:

       H(i) = I - tauq * v * v'  and G(i) = I - taup * u * u'

    where tauq and taup are real scalars, and v and u are real vectors.

    If m >= n, v(1:i-1) = 0, v(i) = 1, and v(i:m) is stored on exit in
    A(i:m,i); u(1:i) = 0, u(i+1) = 1, and u(i+1:n) is stored on exit in
    A(i,i+1:n); tauq is stored in TAUQ(i) and taup in TAUP(i).

    If m < n, v(1:i) = 0, v(i+1) = 1, and v(i+1:m) is stored on exit in
    A(i+2:m,i); u(1:i-1) = 0, u(i) = 1, and u(i:n) is stored on exit in
    A(i,i+1:n); tauq is stored in TAUQ(i) and taup in TAUP(i).

    The elements of the vectors v and u together form the m-by-nb matrix
    V and the nb-by-n matrix U' which are needed, with X and Y, to apply
    the transformation to the unreduced part of the matrix, using a block
    update of the form:  A := A - V*Y' - X*U'.

    The contents of A on exit are illustrated by the following examples
    with nb = 2:

    m = 6 and n = 5 (m > n):          m = 5 and n = 6 (m < n):

      (  1   1   u1  u1  u1 )           (  1   u1  u1  u1  u1  u1 )
      (  v1  1   1   u2  u2 )           (  1   1   u2  u2  u2  u2 )
      (  v1  v2  a   a   a  )           (  v1  1   a   a   a   a  )
      (  v1  v2  a   a   a  )           (  v1  v2  a   a   a   a  )
      (  v1  v2  a   a   a  )           (  v1  v2  a   a   a   a  )
      (  v1  v2  a   a   a  )

    where a denotes an element of the original matrix which is unchanged,
    vi denotes an element of the vector defining H(i), and ui an element
    of the vector defining G(i).

    =====================================================================    */


    /* Table of constant values */
    double c_neg_one = MAGMA_D_NEG_ONE;
    double c_one = MAGMA_D_ONE;
    double c_zero = MAGMA_D_ZERO;
    magma_int_t c__1 = 1;
    
    /* System generated locals */
    magma_int_t a_dim1, a_offset, x_dim1, x_offset, y_dim1, y_offset, i__2, i__3;
    /* Local variables */
    magma_int_t i__;
    double alpha;

    a_dim1 = lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --d;
    --e;
    --tauq;
    --taup;

    x_dim1 = ldx;
    x_offset = 1 + x_dim1;
    x -= x_offset;
    dx-= 1 + lddx;

    y_dim1 = ldy;
    y_offset = 1 + y_dim1;
    y -= y_offset;
    dy-= 1 + lddy;

    /* Function Body */
    if (m <= 0 || n <= 0) {
        return 0;
    }

    double *f;
    magma_queue_t stream;
    magma_queue_create( &stream );
    magma_dmalloc_cpu( &f, max(n,m) );
    assert( f != NULL );  // TODO return error, or allocate outside dlatrd
    
    if (m >= n) {

        /* Reduce to upper bidiagonal form */

        for (i__ = 1; i__ <= nb; ++i__) {

            /*  Update A(i:m,i) */
            i__2 = m - i__ + 1;
            i__3 = i__ - 1;
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv( &i__3, &y[i__+y_dim1], &ldy );
            #endif
            blasf77_dgemv("No transpose", &i__2, &i__3, &c_neg_one, &a[i__ + a_dim1], &lda,
                   &y[i__+y_dim1], &ldy, &c_one, &a[i__ + i__ * a_dim1], &c__1);
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv( &i__3, &y[i__+y_dim1], &ldy );
            #endif
            blasf77_dgemv("No transpose", &i__2, &i__3, &c_neg_one, &x[i__ + x_dim1], &ldx,
                   &a[i__*a_dim1+1], &c__1, &c_one, &a[i__+i__*a_dim1], &c__1);
            
            /* Generate reflection Q(i) to annihilate A(i+1:m,i) */

            alpha = a[i__ + i__ * a_dim1];
            i__2 = m - i__ + 1;
            i__3 = i__ + 1;
            lapackf77_dlarfg(&i__2, &alpha,
                    &a[min(i__3,m) + i__ * a_dim1], &c__1, &tauq[i__]);
            d[i__] = MAGMA_D_REAL( alpha );
            if (i__ < n) {
                a[i__ + i__ * a_dim1] = c_one;

                /* Compute Y(i+1:n,i) */
                i__2 = m - i__ + 1;
                i__3 = n - i__;

                // 1. Send the block reflector  A(i+1:m,i) to the GPU ------
                magma_dsetvector( i__2,
                                  a + i__   + i__   * a_dim1, 1,
                                  da+(i__-1)+(i__-1)* (ldda), 1 );
                // 2. Multiply ---------------------------------------------
                magma_dgemv(MagmaTrans, i__2, i__3, c_one,
                            da + (i__-1) + ((i__-1) + 1) * (ldda), ldda,
                            da + (i__-1) + (i__-1) * (ldda), c__1, c_zero,
                            dy + i__ + 1 + i__ * y_dim1, c__1);
                
                // 3. Put the result back ----------------------------------
                magma_dgetmatrix_async( i__3, 1,
                                        dy+i__+1+i__*y_dim1, y_dim1,
                                        y+i__+1+i__*y_dim1,  y_dim1, stream );
                i__2 = m - i__ + 1;
                i__3 = i__ - 1;
                blasf77_dgemv(MagmaTransStr, &i__2, &i__3, &c_one, &a[i__ + a_dim1],
                        &lda, &a[i__ + i__ * a_dim1], &c__1, &c_zero,
                       &y[i__ * y_dim1 + 1], &c__1);

                i__2 = n - i__;
                i__3 = i__ - 1;
                blasf77_dgemv("N", &i__2, &i__3, &c_neg_one, &y[i__ + 1 +y_dim1], &ldy,
                       &y[i__ * y_dim1 + 1], &c__1,
                       &c_zero, f, &c__1);
                i__2 = m - i__ + 1;
                i__3 = i__ - 1;
                blasf77_dgemv(MagmaTransStr, &i__2, &i__3, &c_one, &x[i__ + x_dim1],
                       &ldx, &a[i__ + i__ * a_dim1], &c__1, &c_zero,
                       &y[i__ * y_dim1 + 1], &c__1);
                
                // 4. Synch to make sure the result is back ----------------
                magma_queue_sync( stream );

                if (i__3!=0){
                    i__2 = n - i__;
                    blasf77_daxpy(&i__2, &c_one, f,&c__1, &y[i__+1+i__*y_dim1],&c__1);
                }

                i__2 = i__ - 1;
                i__3 = n - i__;
                blasf77_dgemv(MagmaTransStr, &i__2, &i__3, &c_neg_one, &a[(i__ + 1) *
                        a_dim1 + 1], &lda, &y[i__ * y_dim1 + 1], &c__1, &c_one,
                        &y[i__ + 1 + i__ * y_dim1], &c__1);
                i__2 = n - i__;
                blasf77_dscal(&i__2, &tauq[i__], &y[i__ + 1 + i__ * y_dim1], &c__1);

                /* Update A(i,i+1:n) */
                i__2 = n - i__;
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv( &i__2, &a[i__+(i__+1)*a_dim1], &lda );
                lapackf77_dlacgv( &i__,  &a[i__+a_dim1], &lda );
                #endif
                blasf77_dgemv("No transpose", &i__2, &i__, &c_neg_one, &y[i__ + 1 +
                        y_dim1], &ldy, &a[i__ + a_dim1], &lda, &c_one, &a[i__ + (
                        i__ + 1) * a_dim1], &lda);
                i__2 = i__ - 1;
                i__3 = n - i__;
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv( &i__,  &a[i__+a_dim1], &lda );
                lapackf77_dlacgv( &i__2, &x[i__+x_dim1], &ldx );
                #endif
                blasf77_dgemv(MagmaTransStr, &i__2, &i__3, &c_neg_one, &a[(i__ + 1) *
                        a_dim1 + 1], &lda, &x[i__ + x_dim1], &ldx, &c_one, &a[
                        i__ + (i__ + 1) * a_dim1], &lda);
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv( &i__2, &x[i__+x_dim1], &ldx );
                #endif

                /* Generate reflection P(i) to annihilate A(i,i+2:n) */
                i__2 = n - i__;
                /* Computing MIN */
                i__3 = i__ + 2;
                alpha = a[i__ + (i__ + 1) * a_dim1];
                lapackf77_dlarfg(&i__2, &alpha, &a[i__ + min(
                        i__3,n) * a_dim1], &lda, &taup[i__]);
                e[i__] = MAGMA_D_REAL( alpha );
                a[i__ + (i__ + 1) * a_dim1] = c_one;

                /* Compute X(i+1:m,i) */
                i__2 = m - i__;
                i__3 = n - i__;
                // 1. Send the block reflector  A(i+1:m,i) to the GPU ------
                magma_dsetvector( i__3,
                                  a + i__   + (i__   +1)* a_dim1, lda,
                                  da+(i__-1)+((i__-1)+1)*(ldda),  ldda );
                // 2. Multiply ---------------------------------------------
                //magma_dcopy(i__3, da+(i__-1)+((i__-1)+1)*(ldda), ldda,
                //            dy + 1 + lddy, 1);
                magma_dgemv(MagmaNoTrans, i__2, i__3, c_one,
                            da + (i__-1)+1+ ((i__-1)+1) * (ldda), ldda,
                            da + (i__-1) +  ((i__-1)+1) * (ldda), ldda,
                            //dy + 1 + lddy, 1,
                            c_zero, dx + i__ + 1 + i__ * x_dim1, c__1);

                // 3. Put the result back ----------------------------------
                magma_dgetmatrix_async( i__2, 1,
                                        dx+i__+1+i__*x_dim1, x_dim1,
                                        x+i__+1+i__*x_dim1,  x_dim1, stream );

                i__2 = n - i__;
                blasf77_dgemv(MagmaTransStr, &i__2, &i__, &c_one, &y[i__ + 1 + y_dim1],
                        &ldy, &a[i__ + (i__ + 1) * a_dim1], &lda, &c_zero, &x[
                        i__ * x_dim1 + 1], &c__1);

                i__2 = m - i__;
                blasf77_dgemv("N", &i__2, &i__, &c_neg_one, &a[i__ + 1 + a_dim1], &lda,
                       &x[i__ * x_dim1 + 1], &c__1, &c_zero, f, &c__1);
                i__2 = i__ - 1;
                i__3 = n - i__;
                blasf77_dgemv("N", &i__2, &i__3, &c_one, &a[(i__ + 1) * a_dim1 + 1],
                       &lda, &a[i__ + (i__ + 1) * a_dim1], &lda,
                       &c_zero, &x[i__ * x_dim1 + 1], &c__1);

                // 4. Synch to make sure the result is back ----------------
                magma_queue_sync( stream );
                if (i__!=0){
                    i__2 = m - i__;
                    blasf77_daxpy(&i__2, &c_one, f,&c__1, &x[i__+1+i__*x_dim1],&c__1);
                }


                i__2 = m - i__;
                i__3 = i__ - 1;
                blasf77_dgemv("No transpose", &i__2, &i__3, &c_neg_one, &x[i__ + 1 +
                        x_dim1], &ldx, &x[i__ * x_dim1 + 1], &c__1, &c_one, &x[
                        i__ + 1 + i__ * x_dim1], &c__1);
                i__2 = m - i__;
                blasf77_dscal(&i__2, &taup[i__], &x[i__ + 1 + i__ * x_dim1], &c__1);

                #if defined(PRECISION_z) || defined(PRECISION_c)
                i__2 = n - i__;
                lapackf77_dlacgv( &i__2,  &a[i__+(i__+1)*a_dim1], &lda );
                // 4. Send the block reflector  A(i+1:m,i) to the GPU after DLACGV()
                magma_dsetvector( i__2,
                                  a + i__   + (i__   +1)* a_dim1, lda,
                                  da+(i__-1)+((i__-1)+1)*(ldda),  ldda );
                #endif
            }
        }
    }
    else {

        /* Reduce to lower bidiagonal form */
        
        for (i__ = 1; i__ <= nb; ++i__) {
        
            /* Update A(i,i:n) */
            i__2 = n - i__ + 1;
            i__3 = i__ - 1;
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv(&i__2, &a[i__ + i__ * a_dim1], &lda);
            lapackf77_dlacgv(&i__3, &a[i__ + a_dim1], &lda);
            #endif
            blasf77_dgemv("No transpose", &i__2, &i__3, &c_neg_one, &y[i__ + y_dim1], &ldy,
                   &a[i__ + a_dim1], &lda, &c_one, &a[i__ + i__ * a_dim1], &lda);
            i__2 = i__ - 1;
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv(&i__3, &a[i__ + a_dim1], &lda);
            lapackf77_dlacgv(&i__3, &x[i__ + x_dim1], &ldx);
            #endif
            i__3 = n - i__ + 1;
            blasf77_dgemv(MagmaTransStr, &i__2, &i__3, &c_neg_one, &a[i__ * a_dim1 + 1],
                   &lda, &x[i__ + x_dim1], &ldx, &c_one, &a[i__ + i__ * a_dim1], &lda);
            #if defined(PRECISION_z) || defined(PRECISION_c)
            lapackf77_dlacgv(&i__2, &x[i__ + x_dim1], &ldx);
            #endif
            
            /* Generate reflection P(i) to annihilate A(i,i+1:n) */
            i__2 = n - i__ + 1;
            /* Computing MIN */
            i__3 = i__ + 1;
            alpha = a[i__ + i__ * a_dim1];
            lapackf77_dlarfg(&i__2, &alpha,
                    &a[i__ + min(i__3,n) * a_dim1], &lda, &taup[i__]);
            d[i__] = MAGMA_D_REAL( alpha );
            if (i__ < m) {
                a[i__ + i__ * a_dim1] = c_one;
                
                /* Compute X(i+1:m,i) */
                i__2 = m - i__;
                i__3 = n - i__ + 1;
                
                // 1. Send the block reflector  A(i,i+1:n) to the GPU ------
                magma_dsetvector( i__3,
                                  a + i__   + i__   * a_dim1, lda,
                                  da+(i__-1)+(i__-1)* (ldda), ldda );
                
                // 2. Multiply ---------------------------------------------
                //magma_dcopy(i__3, da+(i__-1)+(i__-1)*(ldda), ldda,
                //            dy + 1 + lddy, 1);
                magma_dgemv(MagmaNoTrans, i__2, i__3, c_one,
                            da + (i__-1)+1 + (i__-1) * ldda, ldda,
                            da + (i__-1)   + (i__-1) * ldda, ldda,
                            // dy + 1 + lddy, 1,
                            c_zero,
                            dx + i__ + 1 + i__ * x_dim1, c__1);
                
                // 3. Put the result back ----------------------------------
                magma_dgetmatrix_async( i__2, 1,
                                        dx+i__+1+i__*x_dim1, x_dim1,
                                        x+i__+1+i__*x_dim1,  x_dim1, stream );
                
                i__2 = n - i__ + 1;
                i__3 = i__ - 1;
                blasf77_dgemv(MagmaTransStr, &i__2, &i__3, &c_one, &y[i__ + y_dim1],
                       &ldy, &a[i__ + i__ * a_dim1], &lda, &c_zero,
                       &x[i__ *  x_dim1 + 1], &c__1);
                i__2 = m - i__;
                i__3 = i__ - 1;
                blasf77_dgemv("No transpose", &i__2, &i__3, &c_neg_one,
                              &a[i__ + 1 + a_dim1], &lda, &x[i__ * x_dim1 + 1], &c__1, &c_zero,
                              f, &c__1);
                
                i__2 = i__ - 1;
                i__3 = n - i__ + 1;
                blasf77_dgemv("No transpose", &i__2, &i__3, &c_one,
                       &a[i__ * a_dim1 + 1], &lda, &a[i__ + i__ * a_dim1], &lda, &c_zero,
                       &x[i__ * x_dim1 + 1], &c__1);
                
                // 4. Synch to make sure the result is back ----------------
                magma_queue_sync( stream );
                if (i__2!=0){
                    i__3 = m - i__;
                    blasf77_daxpy(&i__3, &c_one, f,&c__1, &x[i__+1+i__*x_dim1],&c__1);
                }
                
                i__2 = m - i__;
                i__3 = i__ - 1;
                blasf77_dgemv("No transpose", &i__2, &i__3, &c_neg_one,
                       &x[i__ + 1 + x_dim1], &ldx, &x[i__ * x_dim1 + 1], &c__1, &c_one,
                       &x[i__ + 1 + i__ * x_dim1], &c__1);
                i__2 = m - i__;
                blasf77_dscal(&i__2, &taup[i__], &x[i__ + 1 + i__ * x_dim1], &c__1);
                i__2 = n - i__ + 1;
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv(&i__2, &a[i__ + i__ * a_dim1], &lda);
                magma_dsetvector( i__2,
                                  a + i__   + (i__  )* a_dim1, lda,
                                  da+(i__-1)+ (i__-1)*(ldda),  ldda );
                #endif
                
                /* Update A(i+1:m,i) */
                i__2 = m - i__;
                i__3 = i__ - 1;
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv(&i__3, &y[i__ + y_dim1], &ldy);
                #endif
                blasf77_dgemv("No transpose", &i__2, &i__3, &c_neg_one,
                       &a[i__ + 1 + a_dim1], &lda, &y[i__ + y_dim1], &ldy, &c_one,
                       &a[i__ + 1 + i__ * a_dim1], &c__1);
                i__2 = m - i__;
                #if defined(PRECISION_z) || defined(PRECISION_c)
                lapackf77_dlacgv(&i__3, &y[i__ + y_dim1], &ldy);
                #endif
                blasf77_dgemv("No transpose", &i__2, &i__, &c_neg_one,
                       &x[i__ + 1 + x_dim1], &ldx, &a[i__ * a_dim1 + 1], &c__1, &c_one,
                       &a[i__ + 1 + i__ * a_dim1], &c__1);
                
                /* Generate reflection Q(i) to annihilate A(i+2:m,i) */
                i__2 = m - i__;
                i__3 = i__ + 2;
                alpha = a[i__ + 1 + i__ * a_dim1];
                lapackf77_dlarfg(&i__2, &alpha,
                        &a[min(i__3,m) + i__ * a_dim1], &c__1, &tauq[i__]);
                e[i__] = MAGMA_D_REAL( alpha );
                a[i__ + 1 + i__ * a_dim1] = c_one;
                
                /* Compute Y(i+1:n,i) */
                i__2 = m - i__;
                i__3 = n - i__;
                
                // 1. Send the block reflector  A(i+1:m,i) to the GPU ------
                magma_dsetvector( i__2,
                                  a + i__   +1+  i__   * a_dim1, 1,
                                  da+(i__-1)+1+ (i__-1)*(ldda),  1 );
                // 2. Multiply ---------------------------------------------
                magma_dgemv(MagmaTrans, i__2, i__3, c_one,
                            da + (i__-1)+1+ ((i__-1)+1) * ldda, ldda,
                            da + (i__-1)+1+  (i__-1)    * ldda, c__1,
                            c_zero, dy + i__ + 1 + i__ * y_dim1, c__1);
                
                // 3. Put the result back ----------------------------------
                magma_dgetmatrix_async( i__3, 1,
                                        dy+i__+1+i__*y_dim1, y_dim1,
                                        y+i__+1+i__*y_dim1,  y_dim1, stream );
                
                i__2 = m - i__;
                i__3 = i__ - 1;
                blasf77_dgemv(MagmaTransStr, &i__2, &i__3, &c_one, &a[i__ + 1 + a_dim1],
                       &lda, &a[i__ + 1 + i__ * a_dim1], &c__1, &c_zero,
                       &y[ i__ * y_dim1 + 1], &c__1);
                i__2 = n - i__;
                i__3 = i__ - 1;
                blasf77_dgemv("No transpose", &i__2, &i__3, &c_neg_one,
                       &y[i__ + 1 + y_dim1], &ldy, &y[i__ * y_dim1 + 1], &c__1,
                       &c_zero, f, &c__1);
                
                i__2 = m - i__;
                blasf77_dgemv(MagmaTransStr, &i__2, &i__, &c_one, &x[i__ + 1 + x_dim1],
                       &ldx, &a[i__ + 1 + i__ * a_dim1], &c__1, &c_zero,
                       &y[i__ * y_dim1 + 1], &c__1);
                
                // 4. Synch to make sure the result is back ----------------
                magma_queue_sync( stream );
                if (i__3!=0){
                    i__2 = n - i__;
                    blasf77_daxpy(&i__2, &c_one, f,&c__1, &y[i__+1+i__*y_dim1],&c__1);
                }
                
                i__2 = n - i__;
                blasf77_dgemv(MagmaTransStr, &i__, &i__2, &c_neg_one,
                       &a[(i__ + 1) * a_dim1 + 1], &lda, &y[i__ * y_dim1 + 1],
                       &c__1, &c_one, &y[i__ + 1 + i__ * y_dim1], &c__1);
                i__2 = n - i__;
                blasf77_dscal(&i__2, &tauq[i__], &y[i__ + 1 + i__ * y_dim1], &c__1);
            }
            #if defined(PRECISION_z) || defined(PRECISION_c)
            else {
                i__2 = n - i__ + 1;
                lapackf77_dlacgv(&i__2, &a[i__ + i__ * a_dim1], &lda);
                magma_dsetvector( i__2,
                                  a + i__   + (i__  )* a_dim1, lda,
                                  da+(i__-1)+ (i__-1)*(ldda),  ldda );
            }
            #endif
        }
    }
    
    magma_queue_destroy( stream );
    magma_free_cpu(f);
    
    return MAGMA_SUCCESS;
} /* dlabrd */
示例#8
0
/**
    Purpose
    -------
    Solves the least squares problem
           min || A*X - C ||
    using the QR factorization A = Q*R computed by DGEQRF_GPU.

    Arguments
    ---------
    @param[in]
    m       INTEGER
            The number of rows of the matrix A. M >= 0.

    @param[in]
    n       INTEGER
            The number of columns of the matrix A. M >= N >= 0.

    @param[in]
    nrhs    INTEGER
            The number of columns of the matrix C. NRHS >= 0.

    @param[in]
    dA      DOUBLE_PRECISION array on the GPU, dimension (LDDA,N)
            The i-th column must contain the vector which defines the
            elementary reflector H(i), for i = 1,2,...,n, as returned by
            DGEQRF_GPU in the first n columns of its array argument A.

    @param[in]
    ldda    INTEGER
            The leading dimension of the array A, LDDA >= M.

    @param[in]
    tau     DOUBLE_PRECISION array, dimension (N)
            TAU(i) must contain the scalar factor of the elementary
            reflector H(i), as returned by MAGMA_DGEQRF_GPU.

    @param[in,out]
    dB      DOUBLE_PRECISION array on the GPU, dimension (LDDB,NRHS)
            On entry, the M-by-NRHS matrix C.
            On exit, the N-by-NRHS solution matrix X.

    @param[in]
    dT      DOUBLE_PRECISION array that is the output (the 6th argument)
            of magma_dgeqrf_gpu of size
            2*MIN(M, N)*NB + ((N+31)/32*32 )* MAX(NB, NRHS).
            The array starts with a block of size MIN(M,N)*NB that stores
            the triangular T matrices used in the QR factorization,
            followed by MIN(M,N)*NB block storing the diagonal block
            inverses for the R matrix, followed by work space of size
            ((N+31)/32*32 )* MAX(NB, NRHS).

    @param[in]
    lddb    INTEGER
            The leading dimension of the array dB. LDDB >= M.

    @param[out]
    hwork   (workspace) DOUBLE_PRECISION array, dimension (LWORK)
            On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

    @param[in]
    lwork   INTEGER
            The dimension of the array WORK,
            LWORK >= (M - N + NB)*(NRHS + NB) + NRHS*NB,
            where NB is the blocksize given by magma_get_dgeqrf_nb( M ).
    \n
            If LWORK = -1, then a workspace query is assumed; the routine
            only calculates the optimal size of the HWORK array, returns
            this value as the first entry of the WORK array.

    @param[out]
    info    INTEGER
      -     = 0:  successful exit
      -     < 0:  if INFO = -i, the i-th argument had an illegal value

    @ingroup magma_dgels_comp
    ********************************************************************/
extern "C" magma_int_t
magma_dgeqrs_gpu(magma_int_t m, magma_int_t n, magma_int_t nrhs,
                 double *dA,    magma_int_t ldda,
                 double *tau,   double *dT,
                 double *dB,    magma_int_t lddb,
                 double *hwork, magma_int_t lwork,
                 magma_int_t *info)
{
    #define dA(a_1,a_2) (dA + (a_2)*(ldda) + (a_1))
    #define dT(a_1)     (dT + (lddwork+(a_1))*nb)

    double c_zero    = MAGMA_D_ZERO;
    double c_one     = MAGMA_D_ONE;
    double c_neg_one = MAGMA_D_NEG_ONE;
    double *dwork;
    magma_int_t i, k, lddwork, rows, ib;
    magma_int_t ione = 1;

    magma_int_t nb     = magma_get_dgeqrf_nb(m);
    magma_int_t lwkopt = (m - n + nb)*(nrhs + nb) + nrhs*nb;
    int lquery = (lwork == -1);

    hwork[0] = MAGMA_D_MAKE( (double)lwkopt, 0. );

    *info = 0;
    if (m < 0)
        *info = -1;
    else if (n < 0 || m < n)
        *info = -2;
    else if (nrhs < 0)
        *info = -3;
    else if (ldda < max(1,m))
        *info = -5;
    else if (lddb < max(1,m))
        *info = -9;
    else if (lwork < lwkopt && ! lquery)
        *info = -11;

    if (*info != 0) {
        magma_xerbla( __func__, -(*info) );
        return *info;
    }
    else if (lquery)
        return *info;

    k = min(m,n);
    if (k == 0) {
        hwork[0] = c_one;
        return *info;
    }

    /* B := Q' * B */
    magma_dormqr_gpu( MagmaLeft, MagmaTrans,
                      m, nrhs, n,
                      dA(0,0), ldda, tau,
                      dB, lddb, hwork, lwork, dT, nb, info );
    if ( *info != 0 ) {
        return *info;
    }

    /* Solve R*X = B(1:n,:) */
    lddwork= k;
    if (nb < k)
        dwork = dT+2*lddwork*nb;
    else
        dwork = dT;
    // To do: Why did we have this line originally; seems to be a bug (Stan)?
    // dwork = dT;

    i    = (k-1)/nb * nb;
    ib   = n-i;
    rows = m-i;

    // TODO: this assumes that, on exit from magma_dormqr_gpu, hwork contains
    // the last block of A and B (i.e., C in dormqr). This should be fixed.
    // Seems this data should already be on the GPU, so could switch to
    // magma_dtrsm and drop the dsetmatrix.
    if ( nrhs == 1 ) {
        blasf77_dtrsv( MagmaUpperStr, MagmaNoTransStr, MagmaNonUnitStr,
                       &ib, hwork,         &rows,
                            hwork+rows*ib, &ione);
    } else {
        blasf77_dtrsm( MagmaLeftStr, MagmaUpperStr, MagmaNoTransStr, MagmaNonUnitStr,
                       &ib, &nrhs,
                       &c_one, hwork,         &rows,
                               hwork+rows*ib, &rows);
    }
    
    // update the solution vector
    magma_dsetmatrix( ib, nrhs, hwork+rows*ib, rows, dwork+i, lddwork );

    // update c
    if (nrhs == 1)
        magma_dgemv( MagmaNoTrans, i, ib,
                     c_neg_one, dA(0, i), ldda,
                                dwork + i,   1,
                     c_one,     dB,           1);
    else
        magma_dgemm( MagmaNoTrans, MagmaNoTrans,
                     i, nrhs, ib,
                     c_neg_one, dA(0, i), ldda,
                                dwork + i,   lddwork,
                     c_one,     dB,           lddb);

    int start = i-nb;
    if (nb < k) {
        for (i = start; i >= 0; i -= nb) {
            ib = min(k-i, nb);
            rows = m -i;

            if (i + ib < n) {
                if (nrhs == 1) {
                    magma_dgemv( MagmaNoTrans, ib, ib,
                                 c_one,  dT(i), ib,
                                         dB+i,      1,
                                 c_zero, dwork+i,  1);
                    magma_dgemv( MagmaNoTrans, i, ib,
                                 c_neg_one, dA(0, i), ldda,
                                            dwork + i,   1,
                                 c_one,     dB,           1);
                }
                else {
                    magma_dgemm( MagmaNoTrans, MagmaNoTrans,
                                 ib, nrhs, ib,
                                 c_one,  dT(i), ib,
                                         dB+i,      lddb,
                                 c_zero, dwork+i,  lddwork);
                    magma_dgemm( MagmaNoTrans, MagmaNoTrans,
                                 i, nrhs, ib,
                                 c_neg_one, dA(0, i), ldda,
                                            dwork + i,   lddwork,
                                 c_one,     dB,          lddb);
                }
            }
        }
    }

    magma_dcopymatrix( (n), nrhs,
                       dwork, lddwork,
                       dB,    lddb );
    
    return *info;
}
示例#9
0
extern "C" magma_int_t
magma_dgeqrs_gpu(
    magma_int_t m, magma_int_t n, magma_int_t nrhs,
    magmaDouble_ptr dA, size_t dA_offset, magma_int_t ldda,
    double *tau,   magmaDouble_ptr dT, size_t dT_offset,
    magmaDouble_ptr dB, size_t dB_offset, magma_int_t lddb,
    double *hwork, magma_int_t lwork,
    magma_queue_t queue,
    magma_int_t *info)
{
/*  -- clMagma (version 0.1) --
       Univ. of Tennessee, Knoxville
       Univ. of California, Berkeley
       Univ. of Colorado, Denver
       @date November 2014

    Purpose
    =======
    Solves the least squares problem
           min || A*X - C ||
    using the QR factorization A = Q*R computed by DGEQRF_GPU.

    Arguments
    =========
    M       (input) INTEGER
            The number of rows of the matrix A. M >= 0.

    N       (input) INTEGER
            The number of columns of the matrix A. M >= N >= 0.

    NRHS    (input) INTEGER
            The number of columns of the matrix C. NRHS >= 0.

    A       (input) DOUBLE_PRECISION array on the GPU, dimension (LDDA,N)
            The i-th column must contain the vector which defines the
            elementary reflector H(i), for i = 1,2,...,n, as returned by
            DGEQRF_GPU in the first n columns of its array argument A.

    LDDA    (input) INTEGER
            The leading dimension of the array A, LDDA >= M.

    TAU     (input) DOUBLE_PRECISION array, dimension (N)
            TAU(i) must contain the scalar factor of the elementary
            reflector H(i), as returned by MAGMA_DGEQRF_GPU.

    DB      (input/output) DOUBLE_PRECISION array on the GPU, dimension (LDDB,NRHS)
            On entry, the M-by-NRHS matrix C.
            On exit, the N-by-NRHS solution matrix X.

    DT      (input) DOUBLE_PRECISION array that is the output (the 6th argument)
            of magma_dgeqrf_gpu of size
            2*MIN(M, N)*NB + ((N+31)/32*32 )* MAX(NB, NRHS).
            The array starts with a block of size MIN(M,N)*NB that stores
            the triangular T matrices used in the QR factorization,
            followed by MIN(M,N)*NB block storing the diagonal block
            inverses for the R matrix, followed by work space of size
            ((N+31)/32*32 )* MAX(NB, NRHS).

    LDDB    (input) INTEGER
            The leading dimension of the array DB. LDDB >= M.

    HWORK   (workspace/output) DOUBLE_PRECISION array, dimension (LWORK)
            On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

    LWORK   (input) INTEGER
            The dimension of the array WORK,
            LWORK >= (M - N + NB)*(NRHS + NB) + NRHS*NB,
            where NB is the blocksize given by magma_get_dgeqrf_nb( M ).

            If LWORK = -1, then a workspace query is assumed; the routine
            only calculates the optimal size of the HWORK array, returns
            this value as the first entry of the WORK array.

    INFO    (output) INTEGER
            = 0:  successful exit
            < 0:  if INFO = -i, the i-th argument had an illegal value
    =====================================================================    */

   #define a_ref(a_1,a_2)  dA, (dA_offset + (a_1) + (a_2)*(ldda))
   #define d_ref(a_1)      dT, (dT_offset + (lddwork+(a_1))*nb)

    double c_zero    = MAGMA_D_ZERO;
    double c_one     = MAGMA_D_ONE;
    double c_neg_one = MAGMA_D_NEG_ONE;
    magmaDouble_ptr dwork;
    magma_int_t i, k, lddwork, rows, ib;
    magma_int_t ione = 1;

    magma_int_t nb     = magma_get_dgeqrf_nb(m);
    magma_int_t lwkopt = (m - n + nb)*(nrhs + nb) + nrhs*nb;
    int lquery = (lwork == -1);

    hwork[0] = MAGMA_D_MAKE( (double)lwkopt, 0. );

    *info = 0;
    if (m < 0)
        *info = -1;
    else if (n < 0 || m < n)
        *info = -2;
    else if (nrhs < 0)
        *info = -3;
    else if (ldda < max(1,m))
        *info = -5;
    else if (lddb < max(1,m))
        *info = -8;
    else if (lwork < lwkopt && ! lquery)
        *info = -10;

    if (*info != 0) {
        magma_xerbla( __func__, -(*info) );
        return *info;
    }
    else if (lquery)
        return *info;

    k = min(m,n);
    if (k == 0) {
        hwork[0] = c_one;
        return *info;
    }

    /* B := Q' * B */
    magma_dormqr_gpu( MagmaLeft, MagmaConjTrans,
                      m, nrhs, n,
                      a_ref(0,0), ldda, tau,
                      dB, dB_offset, lddb, hwork, lwork, dT, dT_offset, nb, queue, info );
    if ( *info != 0 ) {
        return *info;
    }

    /* Solve R*X = B(1:n,:) */
    lddwork= k;

    int ldtwork;
    size_t dwork_offset = 0;
    if (nb < k) {
        dwork = dT;
        dwork_offset = dT_offset+2*lddwork*nb;
    }
    else {
        ldtwork = ( 2*k + ((n+31)/32)*32 )*nb;
        magma_dmalloc( &dwork, ldtwork );
    }
    // To do: Why did we have this line originally; seems to be a bug (Stan)?
    //dwork = dT;

    i    = (k-1)/nb * nb;
    ib   = n-i;
    rows = m-i;

    // TODO: this assumes that, on exit from magma_dormqr_gpu, hwork contains
    // the last block of A and B (i.e., C in dormqr). This should be fixed.
    // Seems this data should already be on the GPU, so could switch to
    // magma_dtrsm and drop the dsetmatrix.
    if ( nrhs == 1 ) {
        blasf77_dtrsv( MagmaUpperStr, MagmaNoTransStr, MagmaNonUnitStr,
                       &ib, hwork,         &rows,
                            hwork+rows*ib, &ione);
    } else {
        blasf77_dtrsm( MagmaLeftStr, MagmaUpperStr, MagmaNoTransStr, MagmaNonUnitStr,
                       &ib, &nrhs,
                       &c_one, hwork,         &rows,
                               hwork+rows*ib, &rows);
    }
      
    // update the solution vector
    magma_dsetmatrix( ib, nrhs, hwork+rows*ib, rows, dwork, dwork_offset+i, lddwork, queue );

    // update c
    if (nrhs == 1)
        magma_dgemv( MagmaNoTrans, i, ib,
                     c_neg_one, a_ref(0, i), ldda,
                                         dwork, dwork_offset+i, 1,
                     c_one,     dB, dB_offset, 1, queue );
    else
        magma_dgemm( MagmaNoTrans, MagmaNoTrans,
                     i, nrhs, ib,
                     c_neg_one, a_ref(0, i), ldda,
                                dwork, dwork_offset + i,   lddwork,
                     c_one,     dB, dB_offset, lddb, queue );

    int start = i-nb;
    if (nb < k) {
        for (i = start; i >=0; i -= nb) {
            ib = min(k-i, nb);
            rows = m -i;

            if (i + ib < n) {
                if (nrhs == 1) {
                    magma_dgemv( MagmaNoTrans, ib, ib,
                                 c_one,  d_ref(i), ib,
                                 dB, dB_offset+i,      1,
                                 c_zero, dwork, dwork_offset+i,  1, queue );
                    magma_dgemv( MagmaNoTrans, i, ib,
                                 c_neg_one, a_ref(0, i), ldda,
                                 dwork, dwork_offset+i,   1,
                                 c_one,     dB, dB_offset, 1, queue );
                }
                else {
                    magma_dgemm( MagmaNoTrans, MagmaNoTrans,
                                 ib, nrhs, ib,
                                 c_one,  d_ref(i), ib,
                                 dB, dB_offset+i, lddb,
                                 c_zero, dwork, dwork_offset+i,  lddwork, queue );
                    magma_dgemm( MagmaNoTrans, MagmaNoTrans,
                                 i, nrhs, ib,
                                 c_neg_one, a_ref(0, i), ldda,
                                 dwork, dwork_offset+i, lddwork,
                                 c_one,     dB, dB_offset, lddb, queue );
                }
            }
        }
    }

    magma_dcopymatrix( (n), nrhs,
                       dwork, dwork_offset, lddwork,
                       dB, dB_offset,   lddb, queue );

    if (nb >= k)
      magma_free(dwork);

    magma_queue_sync( queue );

    return *info;
}
示例#10
0
/**
    Purpose
    -------
    DSGEQRSV solves the least squares problem
       min || A*X - B ||,
    where A is an M-by-N matrix and X and B are M-by-NRHS matrices.

    DSGEQRSV first attempts to factorize the matrix in real SINGLE PRECISION
    and use this factorization within an iterative refinement procedure
    to produce a solution with real DOUBLE PRECISION norm-wise backward error
    quality (see below). If the approach fails the method switches to a
    real DOUBLE PRECISION factorization and solve.

    The iterative refinement is not going to be a winning strategy if
    the ratio real SINGLE PRECISION performance over real DOUBLE PRECISION
    performance is too small. A reasonable strategy should take the
    number of right-hand sides and the size of the matrix into account.
    This might be done with a call to ILAENV in the future. Up to now, we
    always try iterative refinement.
    
    The iterative refinement process is stopped if
        ITER > ITERMAX
    or for all the RHS we have:
        RNRM < SQRT(N)*XNRM*ANRM*EPS*BWDMAX
    where
        o ITER is the number of the current iteration in the iterative
          refinement process
        o RNRM is the infinity-norm of the residual
        o XNRM is the infinity-norm of the solution
        o ANRM is the infinity-operator-norm of the matrix A
        o EPS is the machine epsilon returned by DLAMCH('Epsilon')
    The value ITERMAX and BWDMAX are fixed to 30 and 1.0D+00 respectively.

    Arguments
    ---------
    @param[in]
    m       INTEGER
            The number of rows of the matrix A. M >= 0.

    @param[in]
    n       INTEGER
            The number of columns of the matrix A. M >= N >= 0.

    @param[in]
    nrhs    INTEGER
            The number of right hand sides, i.e., the number of columns
            of the matrix B.  NRHS >= 0.

    @param[in,out]
    dA      DOUBLE PRECISION array on the GPU, dimension (LDDA,N)
            On entry, the M-by-N coefficient matrix A.
            On exit, if iterative refinement has been successfully used
            (info.EQ.0 and ITER.GE.0, see description below), A is
            unchanged. If double precision factorization has been used
            (info.EQ.0 and ITER.LT.0, see description below), then the
            array dA contains the QR factorization of A as returned by
            function DGEQRF_GPU.

    @param[in]
    ldda    INTEGER
            The leading dimension of the array dA.  LDDA >= max(1,M).

    @param[in,out]
    dB      DOUBLE PRECISION array on the GPU, dimension (LDDB,NRHS)
            The M-by-NRHS right hand side matrix B.
            May be overwritten (e.g., if refinement fails).

    @param[in]
    lddb    INTEGER
            The leading dimension of the array dB.  LDDB >= max(1,M).

    @param[out]
    dX      DOUBLE PRECISION array on the GPU, dimension (LDDX,NRHS)
            If info = 0, the N-by-NRHS solution matrix X.

    @param[in]
    lddx    INTEGER
            The leading dimension of the array dX.  LDDX >= max(1,N).

    @param[out]
    iter    INTEGER
      -     < 0: iterative refinement has failed, double precision
                 factorization has been performed
        +        -1 : the routine fell back to full precision for
                      implementation- or machine-specific reasons
        +        -2 : narrowing the precision induced an overflow,
                      the routine fell back to full precision
        +        -3 : failure of SGEQRF
        +        -31: stop the iterative refinement after the 30th iteration
      -     > 0: iterative refinement has been successfully used.
                 Returns the number of iterations

    @param[out]
    info    INTEGER
      -     = 0:  successful exit
      -     < 0:  if info = -i, the i-th argument had an illegal value

    @ingroup magma_dgels_driver
    ********************************************************************/
extern "C" magma_int_t
magma_dsgeqrsv_gpu(
    magma_int_t m, magma_int_t n, magma_int_t nrhs,
    magmaDouble_ptr dA,  magma_int_t ldda,
    magmaDouble_ptr dB,  magma_int_t lddb,
    magmaDouble_ptr dX,  magma_int_t lddx,
    magma_int_t *iter,
    magma_int_t *info)
{
    #define dB(i,j)     (dB + (i) + (j)*lddb)
    #define dX(i,j)     (dX + (i) + (j)*lddx)
    #define dR(i,j)     (dR + (i) + (j)*lddr)
    #define dSX(i,j)    (dSX + (i) + (j)*lddsx)
    
    double c_neg_one = MAGMA_D_NEG_ONE;
    double c_one     = MAGMA_D_ONE;
    magma_int_t     ione  = 1;
    double *hworkd;
    float  *hworks;
    double *tau;
    float  *stau;
    magmaDouble_ptr dworkd;
    magmaFloat_ptr  dworks;
    magmaDouble_ptr dR, dT;
    magmaFloat_ptr  dSA, dSX, dST;
    double Xnrmv, Rnrmv;
    double          Anrm, Xnrm, Rnrm, cte, eps;
    magma_int_t     i, j, iiter, lddsa, lddsx, lddr, nb, lhwork, minmn, size, ldworkd;

    /* Check arguments */
    *iter = 0;
    *info = 0;
    if ( m < 0 )
        *info = -1;
    else if ( n < 0 || n > m )
        *info = -2;
    else if ( nrhs < 0 )
        *info = -3;
    else if ( ldda < max(1,m))
        *info = -5;
    else if ( lddb < max(1,m))
        *info = -7;
    else if ( lddx < max(1,n))
        *info = -9;

    if (*info != 0) {
        magma_xerbla( __func__, -(*info) );
        return *info;
    }

    if ( m == 0 || n == 0 || nrhs == 0 )
        return *info;

    nb   = magma_get_sgeqrf_nb(m);
    minmn= min(m, n);
    
    /* dSX contains both B and X, so must be max(m or lddb,n). */
    lddsa = ldda;
    lddsx = max(lddb,n);
    lddr  = lddb;
    
    /*
     * Allocate temporary buffers
     */
    /* dworks(dSA + dSX + dST) */
    size = lddsa*n + lddsx*nrhs + ( 2*minmn + ((n+31)/32)*32 )*nb;
    if (MAGMA_SUCCESS != magma_smalloc( &dworks, size )) {
        fprintf(stderr, "Allocation of dworks failed (%d)\n", (int) size);
        *info = MAGMA_ERR_DEVICE_ALLOC;
        return *info;
    }
    dSA = dworks;
    dSX = dSA + lddsa*n;
    dST = dSX + lddsx*nrhs;

    /* dworkd(dR) = lddr*nrhs */
    ldworkd = lddr*nrhs;
    if (MAGMA_SUCCESS != magma_dmalloc( &dworkd, ldworkd )) {
        magma_free( dworks );
        fprintf(stderr, "Allocation of dworkd failed\n");
        *info = MAGMA_ERR_DEVICE_ALLOC;
        return *info;
    }
    dR = dworkd;

    /* hworks(workspace for cgeqrs + stau) = min(m,n) + lhworks */
    lhwork = (m - n + nb)*(nrhs + nb) + nrhs*nb;
    size = lhwork + minmn;
    magma_smalloc_cpu( &hworks, size );
    if ( hworks == NULL ) {
        magma_free( dworks );
        magma_free( dworkd );
        fprintf(stderr, "Allocation of hworks failed\n");
        *info = MAGMA_ERR_HOST_ALLOC;
        return *info;
    }
    stau = hworks + lhwork;

    eps  = lapackf77_dlamch("Epsilon");
    Anrm = magmablas_dlange(MagmaInfNorm, m, n, dA, ldda, (double*)dworkd );
    cte  = Anrm * eps * pow((double)n, 0.5) * BWDMAX;

    /*
     * Convert to single precision
     */
    magmablas_dlag2s( m, nrhs, dB, lddb, dSX, lddsx, info );
    if (*info != 0) {
        *iter = -2;
        goto FALLBACK;
    }

    magmablas_dlag2s( m, n, dA, ldda, dSA, lddsa, info );
    if (*info != 0) {
        *iter = -2;
        goto FALLBACK;
    }

    // factor dSA in single precision
    magma_sgeqrf_gpu( m, n, dSA, lddsa, stau, dST, info );
    if (*info != 0) {
        *iter = -3;
        goto FALLBACK;
    }

    // solve dSA*dSX = dB in single precision
    magma_sgeqrs_gpu( m, n, nrhs, dSA, lddsa, stau, dST, dSX, lddsx, hworks, lhwork, info );
    if (*info != 0) {
        *iter = -3;
        goto FALLBACK;
    }

    // residual dR = dB - dA*dX in double precision
    magmablas_slag2d( n, nrhs, dSX, lddsx, dX, lddx, info );
    magmablas_dlacpy( MagmaUpperLower, m, nrhs, dB, lddb, dR, lddr );
    if ( nrhs == 1 ) {
        magma_dgemv( MagmaNoTrans, m, n,
                     c_neg_one, dA, ldda,
                                dX, 1,
                     c_one,     dR, 1 );
    }
    else {
        magma_dgemm( MagmaNoTrans, MagmaNoTrans, m, nrhs, n,
                     c_neg_one, dA, ldda,
                                dX, lddx,
                     c_one,     dR, lddr );
    }

    // TODO: use MAGMA_D_ABS( dX(i,j) ) instead of dlange?
    for( j=0; j < nrhs; j++ ) {
        i = magma_idamax( n, dX(0,j), 1) - 1;
        magma_dgetmatrix( 1, 1, dX(i,j), 1, &Xnrmv, 1 );
        Xnrm = lapackf77_dlange( "F", &ione, &ione, &Xnrmv, &ione, NULL );

        i = magma_idamax ( m, dR(0,j), 1 ) - 1;
        magma_dgetmatrix( 1, 1, dR(i,j), 1, &Rnrmv, 1 );
        Rnrm = lapackf77_dlange( "F", &ione, &ione, &Rnrmv, &ione, NULL );

        if ( Rnrm >  Xnrm*cte ) {
            goto REFINEMENT;
        }
    }

    *iter = 0;

    /* Free workspaces */
    magma_free( dworks );
    magma_free( dworkd );
    magma_free_cpu( hworks );
    return *info;

REFINEMENT:
    /* TODO: this iterative refinement algorithm works only for compatibile
     * systems (B in colspan of A).
     * See Matrix Computations (3rd ed) p. 267 for correct algorithm. */
    for( iiter=1; iiter < ITERMAX; ) {
        *info = 0;
        // convert residual dR to single precision dSX
        magmablas_dlag2s( m, nrhs, dR, lddr, dSX, lddsx, info );
        if (*info != 0) {
            *iter = -2;
            goto FALLBACK;
        }
        // solve dSA*dSX = R in single precision
        magma_sgeqrs_gpu( m, n, nrhs, dSA, lddsa, stau, dST, dSX, lddsx, hworks, lhwork, info );
        if (*info != 0) {
            *iter = -3;
            goto FALLBACK;
        }

        // Add correction and setup residual
        // dX += dSX [including conversion]  --and--
        // dR[1:n] = dB[1:n]   (only n rows, not whole m rows! -- useless if m > n)
        for( j=0; j < nrhs; j++ ) {
            magmablas_dsaxpycp( n, dSX(0,j), dX(0,j), dB(0,j), dR(0,j) );
        }
        // dR = dB  (whole m rows)
        magmablas_dlacpy( MagmaUpperLower, m, nrhs, dB, lddb, dR, lddr );
        
        // residual dR = dB - dA*dX in double precision
        if ( nrhs == 1 ) {
            magma_dgemv( MagmaNoTrans, m, n,
                         c_neg_one, dA, ldda,
                                    dX, 1,
                         c_one,     dR, 1 );
        }
        else {
            magma_dgemm( MagmaNoTrans, MagmaNoTrans, m, nrhs, n,
                         c_neg_one, dA, ldda,
                                    dX, lddx,
                         c_one,     dR, lddr );
        }

        /*  Check whether the nrhs normwise backward errors satisfy the
         *  stopping criterion. If yes, set ITER=IITER > 0 and return. */
        for( j=0; j < nrhs; j++ ) {
            i = magma_idamax( n, dX(0,j), 1) - 1;
            magma_dgetmatrix( 1, 1, dX(i,j), 1, &Xnrmv, 1 );
            Xnrm = lapackf77_dlange( "F", &ione, &ione, &Xnrmv, &ione, NULL );

            i = magma_idamax ( m, dR(0,j), 1 ) - 1;
            magma_dgetmatrix( 1, 1, dR(i,j), 1, &Rnrmv, 1 );
            Rnrm = lapackf77_dlange( "F", &ione, &ione, &Rnrmv, &ione, NULL );

            if ( Rnrm >  Xnrm*cte ) {
                goto L20;
            }
        }

        /*  If we are here, the nrhs normwise backward errors satisfy
         *  the stopping criterion, we are good to exit. */
        *iter = iiter;

        /* Free workspaces */
        magma_free( dworks );
        magma_free( dworkd );
        magma_free_cpu( hworks );
        return *info;
        
      L20:
        iiter++;
    }

    /* If we are at this place of the code, this is because we have
     * performed ITER=ITERMAX iterations and never satisified the
     * stopping criterion. Set up the ITER flag accordingly and follow
     * up on double precision routine. */
    *iter = -ITERMAX - 1;
    
FALLBACK:
    /* Single-precision iterative refinement failed to converge to a
     * satisfactory solution, so we resort to double precision. */
    magma_free( dworks );
    magma_free_cpu( hworks );

    /*
     * Allocate temporary buffers
     */
    /* dworkd = dT for dgeqrf */
    nb   = magma_get_dgeqrf_nb( m );
    size = (2*min(m, n) + (n+31)/32*32 )*nb;
    if ( size > ldworkd ) {
        magma_free( dworkd );
        if (MAGMA_SUCCESS != magma_dmalloc( &dworkd, size )) {
            fprintf(stderr, "Allocation of dworkd2 failed\n");
            *info = MAGMA_ERR_DEVICE_ALLOC;
            return *info;
        }
    }
    dT = dworkd;

    /* hworkd(dtau + workspace for dgeqrs) = min(m,n) + lhwork */
    size = lhwork + minmn;
    magma_dmalloc_cpu( &hworkd, size );
    if ( hworkd == NULL ) {
        magma_free( dworkd );
        fprintf(stderr, "Allocation of hworkd2 failed\n");
        *info = MAGMA_ERR_HOST_ALLOC;
        return *info;
    }
    tau = hworkd + lhwork;

    magma_dgeqrf_gpu( m, n, dA, ldda, tau, dT, info );
    if (*info == 0) {
        // if m > n, then dB won't fit in dX, so solve with dB and copy n rows to dX
        magma_dgeqrs_gpu( m, n, nrhs, dA, ldda, tau, dT, dB, lddb, hworkd, lhwork, info );
        magmablas_dlacpy( MagmaUpperLower, n, nrhs, dB, lddb, dX, lddx );
    }

    magma_free( dworkd );
    magma_free_cpu( hworkd );
    return *info;
}
示例#11
0
extern "C" magma_int_t
magmablas_dsymv_mgpu( magma_int_t num_gpus, magma_int_t k, magma_uplo_t uplo,
                      magma_int_t n, magma_int_t nb,
                      double alpha,
                      double **dA, magma_int_t ldda, magma_int_t offset,
                      double **dx, magma_int_t incx,
                      double beta,
                      double **dy, magma_int_t incy,
                      double **dwork, magma_int_t ldwork,
                      double *work, double *W,
                      magma_queue_t stream[][10] )
{
#define dX(id, i)    (dx[(id)]+incx*(i))
#define dY(id, i, j) (dy[(id)]+incy*(i)+n*(j))

    magma_int_t id;

#ifdef MAGMABLAS_DSYMV_MGPU
    for( id=0; id < num_gpus; id++ ) {
        magma_setdevice(id);
        magmablasSetKernelStream(stream[id][0]);
        trace_gpu_start( id, 0, "memset", "memset" );
        cudaMemset( dwork[id], 0, ldwork*sizeof(double) );
        trace_gpu_end( id, 0 );
        trace_gpu_start( id, 0, "symv", "symv" );
    }

    if ( nb == 32 ) {
        magmablas_dsymv_mgpu_32_offset( uplo, offset+n, alpha, dA, ldda,
                                        dx, incx,
                                        beta,
                                        dy, incy,
                                        dwork, ldwork,
                                        num_gpus, nb, offset,
                                        stream );
    } else {
        magmablas_dsymv_mgpu_offset( uplo, offset+n, alpha, dA, ldda,
                                     dx, incx,
                                     beta,
                                     dy, incy,
                                     dwork, ldwork,
                                     num_gpus, nb, offset,
                                     stream );
    }
    for( id=0; id < num_gpus; id++ ) {
        magma_setdevice(id);
        trace_gpu_end( id, 0 );
        magmablasSetKernelStream(NULL);
    }
    //magma_setdevice(0);
    //magmablasSetKernelStream(stream[0][0]);
    //magma_dsymv(MagmaLower, n, alpha, &dA[0][offset+offset*ldda], ldda, &dx[0][offset], incx, beta, &dy[0][offset], incy );
    //magmablasSetKernelStream(NULL);

    /* send to CPU */
    magma_setdevice(0);
    trace_gpu_start( 0, 0, "comm", "comm" );
    magma_dgetvector_async( n, dY(0, offset, 0), 1, W, 1, stream[0][0] );
    trace_gpu_end( 0, 0 );
    magmablasSetKernelStream(NULL);

    for( id=1; id < num_gpus; id++ ) {
        magma_setdevice(id);
        trace_gpu_start(  id, 0, "comm", "comm" );
        magma_dgetvector_async( n, dY(id, offset, 0), 1, &work[id*n], 1, stream[id][0] );
        trace_gpu_end( id, 0 );
        magmablasSetKernelStream(NULL);
    }
#else
    double c_one = MAGMA_D_ONE;
    const char* uplo_  = lapack_uplo_const( uplo  );
    magma_int_t i, ii, j, kk, ib, ib0, i_1, i_local, idw;
    magma_int_t i_0=n;
    magma_int_t loffset0 = nb*(offset/(nb*num_gpus));
    magma_int_t loffset1 = offset%nb;
    magma_int_t loffset;
    
    //magma_dsymv(uplo, n, alpha, dA, ldda, dx, incx, beta, dy, incy );

    idw = (offset/nb)%num_gpus;

    for( id=0; id < num_gpus; id++ ) {
        magma_setdevice(id);
        magmablasSetKernelStream(stream[id][0]);
        cudaMemset( dy[id], 0, n*k*sizeof(double) );
    }

    if (uplo == MagmaLower) {
        /* the first block */
        if ( loffset1 > 0 ) {
            id = idw;
            kk = 0;

            magma_setdevice(id);
            magmablasSetKernelStream(stream[id][kk]);

            loffset = loffset0+loffset1;
            ib0 = min(nb-loffset1,n);
            // diagonal
            magma_dsymv(MagmaLower, ib0, c_one, dA(id, 0, 0 ), ldda,
                        dX(id, 0), incx, c_one, dY(id, 0, kk), incy);
            // off-diagonl
            if ( ib0 < n ) {
                for( j=ib0; j < n; j += i_0 ) {
                    i_1 = min(i_0, n-j);
                    magma_dgemv(MagmaNoTrans, i_1, ib0, c_one, dA(id, j, 0), ldda,
                                dX(id, 0), incx, c_one, dY(id, j, kk), incy);
                    magma_dgemv(MagmaTrans, i_1, ib0, c_one, dA(id, j, 0), ldda,
                                dX(id, j), incx, c_one, dY(id, 0, kk), incy);
                }
            }
        }
        else {
            ib0 = 0;
        }

        /* diagonal */
        for( i=ib0; i < n; i += nb ) {
            id = ((i+offset)/nb)%num_gpus;
            kk = ((i+loffset1)/(nb*num_gpus))%k;

            magma_setdevice(id);
            magmablasSetKernelStream(stream[id][kk]);

            i_local = (i+loffset1)/(nb*num_gpus);
            ib = min(nb,n-i);

            ii = nb*i_local;

            loffset = loffset0;
            if ( id < idw )
                loffset += nb;
            magma_dsymv(MagmaLower,  ib, c_one, dA(id, i, ii), ldda,
                        dX(id, i), incx, c_one, dY(id, i, kk), incy);
        }

        /* off-diagonal */
        for( i=ib0; i < n-nb; i += nb ) {
            id = ((i+offset)/nb)%num_gpus;
            kk = ((i+loffset1)/(nb*num_gpus))%k;
            magma_setdevice(id);
            magmablasSetKernelStream(stream[id][kk]);

            i_local = ((i+loffset1)/nb)/num_gpus;
            ii = nb*i_local;
            ib = min(nb,n-i);
            loffset = loffset0;
            if ( id < idw )
                loffset += nb;

            for( j=i+ib; j < n; j += i_0 ) {
                i_1 = min(i_0, n-j);
                magma_dgemv(MagmaNoTrans, i_1, ib, c_one, dA(id, j, ii), ldda,
                            dX(id, i), incx, c_one, dY(id, j, kk), incy);
                magma_dgemv(MagmaTrans, i_1, ib, c_one, dA(id, j, ii), ldda,
                            dX(id, j), incx, c_one, dY(id, i, kk), incy);
            }
        }
    } else { /* upper-triangular storage */
        loffset = 0;
        /* diagonal */
        for( i=0; i < n; i += nb ) {
            id = (i/nb)%num_gpus;
            kk = (i/(nb*num_gpus))%k;
            ib = min(nb,n-i);

            magma_setdevice(id);
            magmablasSetKernelStream(stream[id][kk]);

            i_local = i/(nb*num_gpus);
            ii = nb*i_local;

            magma_dsymv(MagmaUpper, ib, c_one, dA(id, i, ii), ldda,
                        dX(id, i), incx, c_one, dY(id, i, kk), incy);
        }

        /* off-diagonal */
        for( i=nb; i < n; i += nb ) {
            id = (i/nb)%num_gpus;
            kk = (i/(nb*num_gpus))%k;
            magma_setdevice(id);
            magmablasSetKernelStream(stream[id][kk]);

            i_local = (i/nb)/num_gpus;
            ii = nb*i_local;
            ib = min(nb,n-i);

            magma_dgemv(MagmaNoTrans, i, ib, c_one, dA(id, 0, ii), ldda,
                        dX(id, i), incx, c_one, dY(id, 0, kk), incy);
            magma_dgemv(MagmaTrans, i, ib, c_one, dA(id, 0, ii), ldda,
                        dX(id, 0), incx, c_one, dY(id, i, kk), incy);
        }
    }
    /* send to CPU */
    magma_setdevice(0);
    magma_dgetvector_async( n, dY(0, 0, 0), 1, W, 1, stream[0][0] );
    for( kk=1; kk < k; kk++ ) {
        magma_dgetvector_async( n, dY(0, 0, kk), 1, &work[kk*n], 1, stream[0][kk] );
    }
    magmablasSetKernelStream(NULL);

    for( id=1; id < num_gpus; id++ ) {
        magma_setdevice(id);
        for( kk=0; kk < k; kk++ ) {
            magma_dgetvector_async( n, dY(id, 0, kk), 1, &work[id*k*n + kk*n], 1, stream[id][kk] );
        }
        magmablasSetKernelStream(NULL);
    }
#endif
    return 0;
}
示例#12
0
/**
    Purpose
    -------
    DSGESV computes the solution to a real system of linear equations
       A * X = B,  A**T * X = B,  or  A**H * X = B,
    where A is an N-by-N matrix and X and B are N-by-NRHS matrices.

    DSGESV first attempts to factorize the matrix in real SINGLE PRECISION
    and use this factorization within an iterative refinement procedure
    to produce a solution with real DOUBLE PRECISION norm-wise backward error
    quality (see below). If the approach fails the method switches to a
    real DOUBLE PRECISION factorization and solve.

    The iterative refinement is not going to be a winning strategy if
    the ratio real SINGLE PRECISION performance over real DOUBLE PRECISION
    performance is too small. A reasonable strategy should take the
    number of right-hand sides and the size of the matrix into account.
    This might be done with a call to ILAENV in the future. Up to now, we
    always try iterative refinement.
    
    The iterative refinement process is stopped if
        ITER > ITERMAX
    or for all the RHS we have:
        RNRM < SQRT(N)*XNRM*ANRM*EPS*BWDMAX
    where
        o ITER is the number of the current iteration in the iterative
          refinement process
        o RNRM is the infinity-norm of the residual
        o XNRM is the infinity-norm of the solution
        o ANRM is the infinity-operator-norm of the matrix A
        o EPS is the machine epsilon returned by DLAMCH('Epsilon')
    The value ITERMAX and BWDMAX are fixed to 30 and 1.0D+00 respectively.

    Arguments
    ---------
    @param[in]
    trans   magma_trans_t
            Specifies the form of the system of equations:
      -     = MagmaNoTrans:    A    * X = B  (No transpose)
      -     = MagmaTrans:      A**T * X = B  (Transpose)
      -     = MagmaConjTrans:  A**H * X = B  (Conjugate transpose)

    @param[in]
    n       INTEGER
            The number of linear equations, i.e., the order of the
            matrix A.  N >= 0.

    @param[in]
    nrhs    INTEGER
            The number of right hand sides, i.e., the number of columns
            of the matrix B.  NRHS >= 0.

    @param[in,out]
    dA      DOUBLE PRECISION array on the GPU, dimension (ldda,N)
            On entry, the N-by-N coefficient matrix A.
            On exit, if iterative refinement has been successfully used
            (info.EQ.0 and ITER.GE.0, see description below), A is
            unchanged. If double precision factorization has been used
            (info.EQ.0 and ITER.LT.0, see description below), then the
            array dA contains the factors L and U from the factorization
            A = P*L*U; the unit diagonal elements of L are not stored.

    @param[in]
    ldda    INTEGER
            The leading dimension of the array dA.  ldda >= max(1,N).

    @param[out]
    ipiv    INTEGER array, dimension (N)
            The pivot indices that define the permutation matrix P;
            row i of the matrix was interchanged with row IPIV(i).
            Corresponds either to the single precision factorization
            (if info.EQ.0 and ITER.GE.0) or the double precision
            factorization (if info.EQ.0 and ITER.LT.0).

    @param[out]
    dipiv   INTEGER array on the GPU, dimension (N)
            The pivot indices; for 1 <= i <= N, after permuting, row i of the
            matrix was moved to row dIPIV(i).
            Note this is different than IPIV, where interchanges
            are applied one-after-another.

    @param[in]
    dB      DOUBLE PRECISION array on the GPU, dimension (lddb,NRHS)
            The N-by-NRHS right hand side matrix B.

    @param[in]
    lddb    INTEGER
            The leading dimension of the array dB.  lddb >= max(1,N).

    @param[out]
    dX      DOUBLE PRECISION array on the GPU, dimension (lddx,NRHS)
            If info = 0, the N-by-NRHS solution matrix X.

    @param[in]
    lddx    INTEGER
            The leading dimension of the array dX.  lddx >= max(1,N).

    @param
    dworkd  (workspace) DOUBLE PRECISION array on the GPU, dimension (N*NRHS)
            This array is used to hold the residual vectors.

    @param
    dworks  (workspace) SINGLE PRECISION array on the GPU, dimension (N*(N+NRHS))
            This array is used to store the real single precision matrix
            and the right-hand sides or solutions in single precision.

    @param[out]
    iter    INTEGER
      -     < 0: iterative refinement has failed, double precision
                 factorization has been performed
        +        -1 : the routine fell back to full precision for
                      implementation- or machine-specific reasons
        +        -2 : narrowing the precision induced an overflow,
                      the routine fell back to full precision
        +        -3 : failure of SGETRF
        +        -31: stop the iterative refinement after the 30th iteration
      -     > 0: iterative refinement has been successfully used.
                 Returns the number of iterations
 
    @param[out]
    info   INTEGER
      -     = 0:  successful exit
      -     < 0:  if info = -i, the i-th argument had an illegal value
      -     > 0:  if info = i, U(i,i) computed in DOUBLE PRECISION is
                  exactly zero.  The factorization has been completed,
                  but the factor U is exactly singular, so the solution
                  could not be computed.

    @ingroup magma_dgesv_driver
    ********************************************************************/
extern "C" magma_int_t
magma_dsgesv_gpu(magma_trans_t trans, magma_int_t n, magma_int_t nrhs,
                 double *dA, magma_int_t ldda,
                 magma_int_t *ipiv,  magma_int_t *dipiv,
                 double *dB, magma_int_t lddb,
                 double *dX, magma_int_t lddx,
                 double *dworkd, float *dworks,
                 magma_int_t *iter, magma_int_t *info)
{
    #define dB(i,j)     (dB + (i) + (j)*lddb)
    #define dX(i,j)     (dX + (i) + (j)*lddx)
    #define dR(i,j)     (dR + (i) + (j)*lddr)
    
    double c_neg_one = MAGMA_D_NEG_ONE;
    double c_one     = MAGMA_D_ONE;
    magma_int_t     ione  = 1;
    double *dR;
    float  *dSA, *dSX;
    double Xnrmv, Rnrmv;
    double          Anrm, Xnrm, Rnrm, cte, eps;
    magma_int_t     i, j, iiter, lddsa, lddr;
    
    /* Check arguments */
    *iter = 0;
    *info = 0;
    if ( n < 0 )
        *info = -1;
    else if ( nrhs < 0 )
        *info = -2;
    else if ( ldda < max(1,n))
        *info = -4;
    else if ( lddb < max(1,n))
        *info = -8;
    else if ( lddx < max(1,n))
        *info = -10;
    
    if (*info != 0) {
        magma_xerbla( __func__, -(*info) );
        return *info;
    }
    
    if ( n == 0 || nrhs == 0 )
        return *info;

    lddsa = n;
    lddr  = n;
    
    dSA = dworks;
    dSX = dSA + lddsa*n;
    dR  = dworkd;
    
    eps  = lapackf77_dlamch("Epsilon");
    Anrm = magmablas_dlange(MagmaInfNorm, n, n, dA, ldda, (double*)dworkd );
    cte  = Anrm * eps * pow((double)n, 0.5) * BWDMAX;
    
    /*
     * Convert to single precision
     */
    //magmablas_dlag2s( n, nrhs, dB, lddb, dSX, lddsx, info );  // done inside dsgetrs with pivots
    if (*info != 0) {
        *iter = -2;
        goto FALLBACK;
    }
    
    magmablas_dlag2s( n, n, dA, ldda, dSA, lddsa, info );
    if (*info != 0) {
        *iter = -2;
        goto FALLBACK;
    }
    
    // factor dSA in single precision
    magma_sgetrf_gpu( n, n, dSA, lddsa, ipiv, info );
    if (*info != 0) {
        *iter = -3;
        goto FALLBACK;
    }
    
    // Generate parallel pivots
    {
        magma_int_t *newipiv;
        magma_imalloc_cpu( &newipiv, n );
        if ( newipiv == NULL ) {
            *iter = -3;
            goto FALLBACK;
        }
        swp2pswp( trans, n, ipiv, newipiv );
        magma_setvector( n, sizeof(magma_int_t), newipiv, 1, dipiv, 1 );
        magma_free_cpu( newipiv );
    }
    
    // solve dSA*dSX = dB in single precision
    // converts dB to dSX and applies pivots, solves, then converts result back to dX
    magma_dsgetrs_gpu( trans, n, nrhs, dSA, lddsa, dipiv, dB, lddb, dX, lddx, dSX, info );
    
    // residual dR = dB - dA*dX in double precision
    magmablas_dlacpy( MagmaUpperLower, n, nrhs, dB, lddb, dR, lddr );
    if ( nrhs == 1 ) {
        magma_dgemv( trans, n, n,
                     c_neg_one, dA, ldda,
                                dX, 1,
                     c_one,     dR, 1 );
    }
    else {
        magma_dgemm( trans, MagmaNoTrans, n, nrhs, n,
                     c_neg_one, dA, ldda,
                                dX, lddx,
                     c_one,     dR, lddr );
    }
    
    // TODO: use MAGMA_D_ABS( dX(i,j) ) instead of dlange?
    for( j=0; j < nrhs; j++ ) {
        i = magma_idamax( n, dX(0,j), 1) - 1;
        magma_dgetmatrix( 1, 1, dX(i,j), 1, &Xnrmv, 1 );
        Xnrm = lapackf77_dlange( "F", &ione, &ione, &Xnrmv, &ione, NULL );
        
        i = magma_idamax ( n, dR(0,j), 1 ) - 1;
        magma_dgetmatrix( 1, 1, dR(i,j), 1, &Rnrmv, 1 );
        Rnrm = lapackf77_dlange( "F", &ione, &ione, &Rnrmv, &ione, NULL );
        
        if ( Rnrm >  Xnrm*cte ) {
            goto REFINEMENT;
        }
    }
    
    *iter = 0;
    return *info;

REFINEMENT:
    for( iiter=1; iiter < ITERMAX; ) {
        *info = 0;
        // convert residual dR to single precision dSX
        // solve dSA*dSX = R in single precision
        // convert result back to double precision dR
        // it's okay that dR is used for both dB input and dX output.
        magma_dsgetrs_gpu( trans, n, nrhs, dSA, lddsa, dipiv, dR, lddr, dR, lddr, dSX, info );
        if (*info != 0) {
            *iter = -3;
            goto FALLBACK;
        }
        
        // Add correction and setup residual
        // dX += dR  --and--
        // dR = dB
        // This saves going through dR a second time (if done with one more kernel).
        // -- not really: first time is read, second time is write.
        for( j=0; j < nrhs; j++ ) {
            magmablas_daxpycp( n, dR(0,j), dX(0,j), dB(0,j) );
        }
        
        // residual dR = dB - dA*dX in double precision
        if ( nrhs == 1 ) {
            magma_dgemv( trans, n, n,
                         c_neg_one, dA, ldda,
                                    dX, 1,
                         c_one,     dR, 1 );
        }
        else {
            magma_dgemm( trans, MagmaNoTrans, n, nrhs, n,
                         c_neg_one, dA, ldda,
                                    dX, lddx,
                         c_one,     dR, lddr );
        }
        
        /*  Check whether the nrhs normwise backward errors satisfy the
         *  stopping criterion. If yes, set ITER=IITER > 0 and return. */
        for( j=0; j < nrhs; j++ ) {
            i = magma_idamax( n, dX(0,j), 1) - 1;
            magma_dgetmatrix( 1, 1, dX(i,j), 1, &Xnrmv, 1 );
            Xnrm = lapackf77_dlange( "F", &ione, &ione, &Xnrmv, &ione, NULL );
            
            i = magma_idamax ( n, dR(0,j), 1 ) - 1;
            magma_dgetmatrix( 1, 1, dR(i,j), 1, &Rnrmv, 1 );
            Rnrm = lapackf77_dlange( "F", &ione, &ione, &Rnrmv, &ione, NULL );
            
            if ( Rnrm >  Xnrm*cte ) {
                goto L20;
            }
        }
        
        /*  If we are here, the nrhs normwise backward errors satisfy
         *  the stopping criterion, we are good to exit. */
        *iter = iiter;
        return *info;
        
      L20:
        iiter++;
    }
    
    /* If we are at this place of the code, this is because we have
     * performed ITER=ITERMAX iterations and never satisified the
     * stopping criterion. Set up the ITER flag accordingly and follow
     * up on double precision routine. */
    *iter = -ITERMAX - 1;
    
FALLBACK:
    /* Single-precision iterative refinement failed to converge to a
     * satisfactory solution, so we resort to double precision. */
    magma_dgetrf_gpu( n, n, dA, ldda, ipiv, info );
    if (*info == 0) {
        magmablas_dlacpy( MagmaUpperLower, n, nrhs, dB, lddb, dX, lddx );
        magma_dgetrs_gpu( trans, n, nrhs, dA, ldda, ipiv, dX, lddx, info );
    }
    
    return *info;
}
示例#13
0
/* ////////////////////////////////////////////////////////////////////////////
   -- testing zdot
*/
int main(  int argc, char** argv )
{
    magma_int_t info = 0;
    magma_queue_t queue=NULL;
    magma_queue_create( 0, &queue );

    const double one  = MAGMA_D_MAKE(1.0, 0.0);
    const double zero = MAGMA_D_MAKE(0.0, 0.0);
    double alpha;

    TESTING_INIT();

    magma_d_matrix a={Magma_CSR}, b={Magma_CSR}, x={Magma_CSR}, y={Magma_CSR}, skp={Magma_CSR};

    printf("%%=======================================================================================================================================================================\n");
    printf("\n");
    printf("            |                            runtime                                            |                              GFLOPS\n");
    printf("%% n num_vecs |  CUDOT       CUGEMV       MAGMAGEMV       MDOT       MDGM    MDGM_SHFL      |      CUDOT       CUGEMV      MAGMAGEMV       MDOT       MDGM      MDGM_SHFL\n");
    printf("%%------------------------------------------------------------------------------------------------------------------------------------------------------------------------\n");
    printf("\n");

    for( magma_int_t num_vecs=1; num_vecs <= 32; num_vecs += 1 ) {
        for( magma_int_t n=500000; n < 500001; n += 10000 ) {
            int iters = 10;
            double computations = (2.* n * iters * num_vecs);

            #define ENABLE_TIMER
            #ifdef ENABLE_TIMER
            real_Double_t mdot1, mdot2, mdgm1, mdgm2, magmagemv1, magmagemv2, cugemv1, cugemv2, cudot1, cudot2;
            real_Double_t mdot_time, mdgm_time, mdgmshf_time, magmagemv_time, cugemv_time, cudot_time;
            #endif

            CHECK( magma_dvinit( &a, Magma_DEV, n, num_vecs, one, queue ));
            CHECK( magma_dvinit( &b, Magma_DEV, n, 1, one, queue ));
            CHECK( magma_dvinit( &x, Magma_DEV, n, 8, one, queue ));
            CHECK( magma_dvinit( &y, Magma_DEV, n, 8, one, queue ));
            CHECK( magma_dvinit( &skp, Magma_DEV, 1, num_vecs, zero, queue ));

            // warm up
            CHECK( magma_dgemvmdot( n, num_vecs, a.dval, b.dval, x.dval, y.dval, skp.dval, queue ));

            // CUDOT
            #ifdef ENABLE_TIMER
            cudot1 = magma_sync_wtime( queue );
            #endif
            for( int h=0; h < iters; h++) {
                for( int l=0; l<num_vecs; l++){
                    alpha = magma_ddot( n, a.dval+l*a.num_rows, 1, b.dval, 1, queue );
                    //cudaDeviceSynchronize();    
                }
                //cudaDeviceSynchronize();   
            }
            #ifdef ENABLE_TIMER
            cudot2 = magma_sync_wtime( queue );
            cudot_time=cudot2-cudot1;
            #endif
            // CUGeMV
            #ifdef ENABLE_TIMER
            cugemv1 = magma_sync_wtime( queue );
            #endif
            for( int h=0; h < iters; h++) {
                magma_dgemv( MagmaTrans, n, num_vecs, one, a.dval, n, b.dval, 1, zero, skp.dval, 1, queue );
            }
            #ifdef ENABLE_TIMER
            cugemv2 = magma_sync_wtime( queue );
            cugemv_time=cugemv2-cugemv1;
            #endif
            // MAGMAGeMV
            #ifdef ENABLE_TIMER
            magmagemv1 = magma_sync_wtime( queue );
            #endif
            for( int h=0; h < iters; h++) {
                magmablas_dgemv( MagmaTrans, n, num_vecs, one, a.dval, n, b.dval, 1, zero, skp.dval, 1, queue );
            }
            #ifdef ENABLE_TIMER
            magmagemv2 = magma_sync_wtime( queue );
            magmagemv_time=magmagemv2-magmagemv1;
            #endif
            // MDOT
            #ifdef ENABLE_TIMER
            mdot1 = magma_sync_wtime( queue );
            #endif
            for( int h=0; h < iters; h++) {
                for( int c = 0; c<num_vecs/2; c++ ){
                    CHECK( magma_dmdotc( n, 2, a.dval, b.dval, x.dval, y.dval, skp.dval, queue ));
                }
                for( int c = 0; c<num_vecs%2; c++ ){
                    CHECK( magma_dmdotc( n, 1, a.dval, b.dval, x.dval, y.dval, skp.dval, queue ));
                }
                //h++;
            }
            #ifdef ENABLE_TIMER
            mdot2 = magma_sync_wtime( queue );
            mdot_time=mdot2-mdot1;
            #endif
            // MDGM
            #ifdef ENABLE_TIMER
            mdgm1 = magma_sync_wtime( queue );
            #endif
            for( int h=0; h < iters; h++) {
                CHECK( magma_dgemvmdot( n, num_vecs, a.dval, b.dval, x.dval, y.dval, skp.dval, queue ));
                //h++;
            }
            #ifdef ENABLE_TIMER
            mdgm2 = magma_sync_wtime( queue );
            mdgm_time=mdgm2-mdgm1;
            #endif
            // MDGM_shfl
            
            #ifdef ENABLE_TIMER
            mdgm1 = magma_sync_wtime( queue );
            #endif
            for( int h=0; h < iters; h++) {
                CHECK( magma_dgemvmdot_shfl( n, num_vecs, a.dval, b.dval, x.dval, y.dval, skp.dval, queue ));
            }
            #ifdef ENABLE_TIMER
            mdgm2 = magma_sync_wtime( queue );
            mdgmshf_time=mdgm2-mdgm1;
            #endif
                
                
            //magma_dprint_gpu(num_vecs,1,skp.dval,num_vecs);

            //Chronometry
            #ifdef ENABLE_TIMER
            printf("%d  %d  %e  %e  %e  %e  %e  %e  || %e  %e  %e  %e  %e  %e\n",
                    int(n), int(num_vecs),
                    cudot_time/iters,
                    (cugemv_time)/iters,
                    (magmagemv_time)/iters,
                    (mdot_time)/iters,
                    (mdgm_time)/iters,
                    (mdgmshf_time)/iters,
                    computations/(cudot_time*1e9),
                    computations/(cugemv_time*1e9),
                    computations/(magmagemv_time*1e9),
                    computations/(mdot_time*1e9),
                    computations/(mdgm_time*1e9),
                    computations/(mdgmshf_time*1e9) );
            #endif

            magma_dmfree(&a, queue );
            magma_dmfree(&b, queue );
            magma_dmfree(&x, queue );
            magma_dmfree(&y, queue );
            magma_dmfree(&skp, queue );
        }

        //printf("%%================================================================================================================================================\n");
        //printf("\n");
        //printf("\n");
    }
    
    // use alpha to silence compiler warnings
    if ( isnan( real( alpha ))) {
        info = -1;
    }

cleanup:
    magma_queue_destroy( queue );
    TESTING_FINALIZE();
    return info;
}
示例#14
0
extern "C" magma_int_t 
magma_dlahr2(magma_int_t n, magma_int_t k, magma_int_t nb,
             double *da, double *dv, 
             double *a, magma_int_t lda,
             double *tau, double *t, magma_int_t ldt, 
             double *y, magma_int_t ldy)
{
/*  -- MAGMA auxiliary routine (version 1.0) --
       Univ. of Tennessee, Knoxville
       Univ. of California, Berkeley
       Univ. of Colorado, Denver
       November 2012

    Purpose   
    =======   

    DLAHR2 reduces the first NB columns of a real general n-BY-(n-k+1)   
    matrix A so that elements below the k-th subdiagonal are zero. The   
    reduction is performed by an orthogonal similarity transformation   
    Q' * A * Q. The routine returns the matrices V and T which determine   
    Q as a block reflector I - V*T*V', and also the matrix Y = A * V.   

    This is an auxiliary routine called by DGEHRD.   

    Arguments   
    =========   

    N       (input) INTEGER   
            The order of the matrix A.   

    K       (input) INTEGER   
            The offset for the reduction. Elements below the k-th   
            subdiagonal in the first NB columns are reduced to zero.   
            K < N.   

    NB      (input) INTEGER   
            The number of columns to be reduced.

    DA      (input/output) DOUBLE_PRECISION array on the GPU, dimension (LDA,N-K+1)   
            On entry, the n-by-(n-k+1) general matrix A.   
            On exit, the elements on and above the k-th subdiagonal in   
            the first NB columns are overwritten with the corresponding   
            elements of the reduced matrix; the elements below the k-th   
            subdiagonal, with the array TAU, represent the matrix Q as a   
            product of elementary reflectors. The other columns of A are   
            unchanged. See Further Details.   

    DV      (output) DOUBLE_PRECISION array on the GPU, dimension (N, NB)
            On exit this contains the Householder vectors of the transformation.

    LDA     (input) INTEGER   
            The leading dimension of the array A.  LDA >= max(1,N).   

    TAU     (output) DOUBLE_PRECISION array, dimension (NB)   
            The scalar factors of the elementary reflectors. See Further   
            Details.   

    T       (output) DOUBLE_PRECISION array, dimension (LDT,NB)   
            The upper triangular matrix T.   

    LDT     (input) INTEGER   
            The leading dimension of the array T.  LDT >= NB.   

    Y       (output) DOUBLE_PRECISION array, dimension (LDY,NB)   
            The n-by-nb matrix Y.   

    LDY     (input) INTEGER   
            The leading dimension of the array Y. LDY >= N.   

    Further Details   
    ===============   
    The matrix Q is represented as a product of nb elementary reflectors   

       Q = H(1) H(2) . . . H(nb).   

    Each H(i) has the form   

       H(i) = I - tau * v * v'   

    where tau is a real scalar, and v is a real vector with   
    v(1:i+k-1) = 0, v(i+k) = 1; v(i+k+1:n) is stored on exit in   
    A(i+k+1:n,i), and tau in TAU(i).   

    The elements of the vectors v together form the (n-k+1)-by-nb matrix   
    V which is needed, with T and Y, to apply the transformation to the   
    unreduced part of the matrix, using an update of the form:   
    A := (I - V*T*V') * (A - Y*T*V').   

    The contents of A on exit are illustrated by the following example   
    with n = 7, k = 3 and nb = 2:   

       ( a   a   a   a   a )   
       ( a   a   a   a   a )   
       ( a   a   a   a   a )   
       ( h   h   a   a   a )   
       ( v1  h   a   a   a )   
       ( v1  v2  a   a   a )   
       ( v1  v2  a   a   a )   

    where a denotes an element of the original matrix A, h denotes a   
    modified element of the upper Hessenberg matrix H, and vi denotes an   
    element of the vector defining H(i).

    This implementation follows the hybrid algorithm and notations described in

    S. Tomov and J. Dongarra, "Accelerating the reduction to upper Hessenberg
    form through hybrid GPU-based computing," University of Tennessee Computer
    Science Technical Report, UT-CS-09-642 (also LAPACK Working Note 219),
    May 24, 2009.
    =====================================================================    */


    double c_zero    = MAGMA_D_ZERO;
    double c_one     = MAGMA_D_ONE;
    double c_neg_one = MAGMA_D_NEG_ONE;

    magma_int_t ldda = lda;
    magma_int_t c__1 = 1;
    
    magma_int_t a_dim1, a_offset, t_dim1, t_offset, y_dim1, y_offset, i__2, i__3;
    double d__1;

    magma_int_t i__;
    double ei;

    --tau;
    a_dim1 = lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    t_dim1 = ldt;
    t_offset = 1 + t_dim1;
    t -= t_offset;
    y_dim1 = ldy;
    y_offset = 1 + y_dim1;
    y -= y_offset;

    /* Function Body */
    if (n <= 1)
      return 0;
    
    for (i__ = 1; i__ <= nb; ++i__) {
        if (i__ > 1) {

          /* Update A(K+1:N,I); Update I-th column of A - Y * V' */
          i__2 = n - k + 1;
          i__3 = i__ - 1;
          #if defined(PRECISION_z) || defined(PRECISION_c)
             lapackf77_dlacgv(&i__3, &a[k+i__-1+a_dim1], &lda);
          #endif
          blasf77_dcopy(&i__3, &a[k+i__-1+a_dim1], &lda, &t[nb*t_dim1+1], &c__1);
          blasf77_dtrmv("u","n","n",&i__3,&t[t_offset], &ldt, &t[nb*t_dim1+1], &c__1);

          blasf77_dgemv("NO TRANSPOSE", &i__2, &i__3, &c_neg_one, &y[k + y_dim1],
                        &ldy, &t[nb*t_dim1+1], &c__1, &c_one, &a[k+i__*a_dim1],&c__1);

          #if defined(PRECISION_z) || defined(PRECISION_c)
             lapackf77_dlacgv(&i__3, &a[k+i__-1+a_dim1], &lda);
          #endif

          /* Apply I - V * T' * V' to this column (call it b) from the   
             left, using the last column of T as workspace   

             Let  V = ( V1 )   and   b = ( b1 )   (first I-1 rows)   
                      ( V2 )             ( b2 )   
             where V1 is unit lower triangular   
             w := V1' * b1                                                 */
          
          i__2 = i__ - 1;
          blasf77_dcopy(&i__2, &a[k+1+i__*a_dim1], &c__1, &t[nb*t_dim1+1], &c__1);
          blasf77_dtrmv("Lower", MagmaTransStr, "UNIT", &i__2, 
                        &a[k + 1 + a_dim1], &lda, &t[nb * t_dim1 + 1], &c__1);

          /* w := w + V2'*b2 */
          i__2 = n - k - i__ + 1;
          i__3 = i__ - 1;
          blasf77_dgemv(MagmaTransStr, &i__2, &i__3, &c_one, 
                        &a[k + i__ + a_dim1], &lda, &a[k+i__+i__*a_dim1], &c__1, 
                        &c_one, &t[nb*t_dim1+1], &c__1);

          /* w := T'*w */
          i__2 = i__ - 1;
          blasf77_dtrmv("U", MagmaTransStr, "N", &i__2, &t[t_offset], &ldt, 
                        &t[nb*t_dim1+1], &c__1);
          
          /* b2 := b2 - V2*w */
          i__2 = n - k - i__ + 1;
          i__3 = i__ - 1;
          blasf77_dgemv("N", &i__2, &i__3, &c_neg_one, &a[k + i__ + a_dim1], &lda, 
                 &t[nb*t_dim1+1], &c__1, &c_one, &a[k+i__+i__*a_dim1], &c__1);

          /* b1 := b1 - V1*w */
          i__2 = i__ - 1;
          blasf77_dtrmv("L","N","U",&i__2,&a[k+1+a_dim1],&lda,&t[nb*t_dim1+1],&c__1);
          blasf77_daxpy(&i__2, &c_neg_one, &t[nb * t_dim1 + 1], &c__1, 
                 &a[k + 1 + i__ * a_dim1], &c__1);
          
          a[k + i__ - 1 + (i__ - 1) * a_dim1] = ei;
        }
        
        /* Generate the elementary reflector H(I) to annihilate A(K+I+1:N,I) */
        i__2 = n - k - i__ + 1;
        i__3 = k + i__ + 1;
        lapackf77_dlarfg(&i__2, &a[k + i__ + i__ * a_dim1], 
                         &a[min(i__3,n) + i__ * a_dim1], &c__1, &tau[i__]);
        ei = a[k + i__ + i__ * a_dim1];
        a[k + i__ + i__ * a_dim1] = c_one;

        /* Compute  Y(K+1:N,I) */
        i__2 = n - k;
        i__3 = n - k - i__ + 1;
        magma_dsetvector( i__3,
                          &a[k + i__ + i__*a_dim1], 1,
                          dv+(i__-1)*(ldda+1),      1 );

        magma_dgemv(MagmaNoTrans, i__2+1, i__3, c_one, 
                    da -1 + k + i__ * ldda, ldda, 
                    dv+(i__-1)*(ldda+1), c__1, c_zero, 
                    da-1 + k + (i__-1)*ldda, c__1);     
        
        i__2 = n - k - i__ + 1;
        i__3 = i__ - 1;
        blasf77_dgemv(MagmaTransStr, &i__2, &i__3, &c_one, 
                      &a[k + i__ + a_dim1], &lda, &a[k+i__+i__*a_dim1], &c__1, 
                      &c_zero, &t[i__*t_dim1+1], &c__1);

        /* Compute T(1:I,I) */
        i__2 = i__ - 1;
        d__1 = MAGMA_D_NEGATE( tau[i__] );
        blasf77_dscal(&i__2, &d__1, &t[i__ * t_dim1 + 1], &c__1);
        blasf77_dtrmv("U","N","N", &i__2, &t[t_offset], &ldt, &t[i__*t_dim1+1], &c__1);
        t[i__ + i__ * t_dim1] = tau[i__];

        magma_dgetvector( n - k + 1,
                          da-1+ k+(i__-1)*ldda, 1,
                          y+ k + i__*y_dim1,    1 );
    }
    a[k + nb + nb * a_dim1] = ei;

    return 0;
} /* magma_dlahr2 */