/** 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 */
/** Purpose ------- ZGETRI computes the inverse of a matrix using the LU factorization computed by ZGETRF. This method inverts U and then computes inv(A) by solving the system inv(A)*L = inv(U) for inv(A). Note that it is generally both faster and more accurate to use ZGESV, or ZGETRF and ZGETRS, to solve the system AX = B, rather than inverting the matrix and multiplying to form X = inv(A)*B. Only in special instances should an explicit inverse be computed with this routine. Arguments --------- @param[in] n INTEGER The order of the matrix A. N >= 0. @param[in,out] dA COMPLEX_16 array on the GPU, dimension (LDDA,N) On entry, the factors L and U from the factorization A = P*L*U as computed by ZGETRF_GPU. On exit, if INFO = 0, the inverse of the original matrix A. @param[in] ldda INTEGER The leading dimension of the array A. LDDA >= max(1,N). @param[in] ipiv INTEGER array, dimension (N) The pivot indices from ZGETRF; for 1 <= i <= N, row i of the matrix was interchanged with row IPIV(i). @param[out] dwork (workspace) COMPLEX_16 array on the GPU, dimension (MAX(1,LWORK)) @param[in] lwork INTEGER The dimension of the array DWORK. LWORK >= N*NB, where NB is the optimal blocksize returned by magma_get_zgetri_nb(n). \n Unlike LAPACK, this version does not currently support a workspace query, because the workspace is on the GPU. @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) is exactly zero; the matrix is singular and its cannot be computed. @ingroup magma_zgesv_comp ********************************************************************/ extern "C" magma_int_t magma_zgetri_gpu( magma_int_t n, magmaDoubleComplex *dA, magma_int_t ldda, magma_int_t *ipiv, magmaDoubleComplex *dwork, magma_int_t lwork, magma_int_t *info ) { #define dA(i, j) (dA + (i) + (j)*ldda) #define dL(i, j) (dL + (i) + (j)*lddl) /* Local variables */ magmaDoubleComplex c_zero = MAGMA_Z_ZERO; magmaDoubleComplex c_one = MAGMA_Z_ONE; magmaDoubleComplex c_neg_one = MAGMA_Z_NEG_ONE; magmaDoubleComplex *dL = dwork; magma_int_t lddl = n; magma_int_t nb = magma_get_zgetri_nb(n); magma_int_t j, jmax, jb, jp; *info = 0; if (n < 0) *info = -1; else if (ldda < max(1,n)) *info = -3; else if ( lwork < n*nb ) *info = -6; if (*info != 0) { magma_xerbla( __func__, -(*info) ); return *info; } /* Quick return if possible */ if ( n == 0 ) return *info; /* Invert the triangular factor U */ magma_ztrtri_gpu( MagmaUpper, MagmaNonUnit, n, dA, ldda, info ); if ( *info != 0 ) return *info; jmax = ((n-1) / nb)*nb; for( j = jmax; j >= 0; j -= nb ) { jb = min( nb, n-j ); // copy current block column of A to work space dL // (only needs lower trapezoid, but we also copy upper triangle), // then zero the strictly lower trapezoid block column of A. magmablas_zlacpy( MagmaFull, n-j, jb, dA(j,j), ldda, dL(j,0), lddl ); magmablas_zlaset( MagmaLower, n-j-1, jb, c_zero, c_zero, dA(j+1,j), ldda ); // compute current block column of Ainv // Ainv(:, j:j+jb-1) // = ( U(:, j:j+jb-1) - Ainv(:, j+jb:n) L(j+jb:n, j:j+jb-1) ) // * L(j:j+jb-1, j:j+jb-1)^{-1} // where L(:, j:j+jb-1) is stored in dL. if ( j+jb < n ) { magma_zgemm( MagmaNoTrans, MagmaNoTrans, n, jb, n-j-jb, c_neg_one, dA(0,j+jb), ldda, dL(j+jb,0), lddl, c_one, dA(0,j), ldda ); } // TODO use magmablas work interface magma_ztrsm( MagmaRight, MagmaLower, MagmaNoTrans, MagmaUnit, n, jb, c_one, dL(j,0), lddl, dA(0,j), ldda ); } // Apply column interchanges for( j = n-2; j >= 0; --j ) { jp = ipiv[j] - 1; if ( jp != j ) { magmablas_zswap( n, dA(0,j), 1, dA(0,jp), 1 ); } } return *info; }
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 */