Exemplo n.º 1
0
/***************************************************************************//**
    Purpose
    -------
    SPOTRI computes the inverse of a real symmetric positive definite
    matrix A using the Cholesky factorization A = U**T*U or A = L*L**T
    computed by SPOTRF.

    Arguments
    ---------
    @param[in]
    uplo    magma_uplo_t
      -     = MagmaUpper:  Upper triangle of A is stored;
      -     = MagmaLower:  Lower triangle of A is stored.

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

    @param[in,out]
    dA      REAL array on the GPU, dimension (LDDA,N)
            On entry, the triangular factor U or L from the Cholesky
            factorization A = U**T*U or A = L*L**T, as computed by
            SPOTRF.
            On exit, the upper or lower triangle of the (symmetric)
            inverse of A, overwriting the input factor U or L.

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

    @param[out]
    info    INTEGER
      -     = 0:  successful exit
      -     < 0:  if INFO = -i, the i-th argument had an illegal value
      -     > 0:  if INFO = i, the (i,i) element of the factor U or L is
                  zero, and the inverse could not be computed.

    @ingroup magma_potri
*******************************************************************************/
extern "C" magma_int_t
magma_spotri_gpu(
    magma_uplo_t uplo, magma_int_t n,
    magmaFloat_ptr dA, magma_int_t ldda,
    magma_int_t *info)
{
    /* Local variables */
    *info = 0;
    if ((uplo != MagmaUpper) && (uplo != MagmaLower))
        *info = -1;
    else if (n < 0)
        *info = -2;
    else if (ldda < max(1,n))
        *info = -4;

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

    /* Quick return if possible */
    if ( n == 0 )
        return *info;
    
    /* Invert the triangular Cholesky factor U or L */
    magma_strtri_gpu( uplo, MagmaNonUnit, n, dA, ldda, info );
    if ( *info == 0 ) {
        /* Form inv(U) * inv(U)**T or inv(L)**T * inv(L) */
        magma_slauum_gpu( uplo, n, dA, ldda, info );
    }
    
    return *info;
} /* magma_spotri */
Exemplo n.º 2
0
extern "C" magma_int_t
magma_spotri_gpu(magma_uplo_t uplo, magma_int_t n,
        magmaFloat_ptr a, size_t offset_a, magma_int_t lda, magma_int_t *info, magma_queue_t queue)
{
/*  -- MAGMA (version 1.1.0) --
    Univ. of Tennessee, Knoxville
    Univ. of California, Berkeley
    Univ. of Colorado, Denver
    @date January 2014

    Purpose
    =======

    SPOTRI computes the inverse of a real symmetric positive definite
    matrix A using the Cholesky factorization A = U**T*U or A = L*L**T
    computed by SPOTRF.

    Arguments
    =========

    UPLO    (input) CHARACTER*1
    = 'U':  Upper triangle of A is stored;
    = 'L':  Lower triangle of A is stored.

    N       (input) INTEGER
    The order of the matrix A.  N >= 0.

    A       (input/output) REAL array, dimension (LDA,N)
    On entry, the triangular factor U or L from the Cholesky
    factorization A = U**T*U or A = L*L**T, as computed by
    SPOTRF.
    On exit, the upper or lower triangle of the (symmetric)
    inverse of A, overwriting the input factor U or L.

    LDA     (input) INTEGER
    The leading dimension of the array A.  LDA >= max(1,N).
    INFO    (output) INTEGER
    = 0:  successful exit
    < 0:  if INFO = -i, the i-th argument had an illegal value
    > 0:  if INFO = i, the (i,i) element of the factor U or L is
    zero, and the inverse could not be computed.

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

    /* Local variables */
    magma_uplo_t uplo_ = uplo;

    *info = 0;
    if ((! lapackf77_lsame(lapack_const(uplo_), lapack_const(MagmaUpper))) && (! lapackf77_lsame(lapack_const(uplo_), lapack_const(MagmaLower))))
        *info = -1;
    else if (n < 0)
        *info = -2;
    else if (lda < max(1,n))
        *info = -4;

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

    /* Quick return if possible */
    if ( n == 0 )
        return *info;

    /* Invert the triangular Cholesky factor U or L */
    magma_strtri_gpu( uplo, MagmaNonUnit, n, a, offset_a, lda, info );
    
    if ( *info == 0 ) {
        /* Form inv(U) * inv(U)**T or inv(L)**T * inv(L) */
        magma_slauum_gpu( uplo, n, a, offset_a, lda, info, queue );
    }

    return *info;
} /* magma_spotri */