Esempio n. 1
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/**
    Purpose
    -------
    ZPOTRI 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 ZPOTRF.

    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      COMPLEX_16 array on the GPU, 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
            ZPOTRF.
            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_zposv_comp
    ********************************************************************/
extern "C" magma_int_t
magma_zpotri_gpu(magma_uplo_t uplo, magma_int_t n,
              magmaDoubleComplex *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_ztrtri_gpu( uplo, MagmaNonUnit, n, dA, ldda, info );
    if ( *info == 0 ) {
        /* Form inv(U) * inv(U)**T or inv(L)**T * inv(L) */
        magma_zlauum_gpu( uplo, n, dA, ldda, info );
    }
    
    return *info;
} /* magma_zpotri */
extern "C" magma_int_t
magma_zpotri_gpu(magma_uplo_t uplo, magma_int_t n,
		magmaDoubleComplex_ptr a, size_t offset_a, magma_int_t lda, magma_int_t *info, magma_queue_t queue)
{
	/*  -- MAGMA (version 1.0.0) --
		Univ. of Tennessee, Knoxville
		Univ. of California, Berkeley
		Univ. of Colorado, Denver
		August 2012

		Purpose
		=======

		ZPOTRI 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 ZPOTRF.

		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) COMPLEX_16 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
		ZPOTRF.
		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_ztrtri_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_zlauum_gpu( uplo, n, a, offset_a, lda, info, queue );
	}

	return *info;
} /* magma_zpotri */