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diff --git a/SRC/cheev_2stage.f b/SRC/cheev_2stage.f new file mode 100644 index 00000000..b98dac76 --- /dev/null +++ b/SRC/cheev_2stage.f @@ -0,0 +1,355 @@ +*> \brief <b> CHEEV_2STAGE computes the eigenvalues and, optionally, the left and/or right eigenvectors for HE matrices</b> +* +* @generated from zheev_2stage.f, fortran z -> c, Sat Nov 5 23:18:06 2016 +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download CHEEV_2STAGE + dependencies +*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/cheev_2stage.f"> +*> [TGZ]</a> +*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/cheev_2stage.f"> +*> [ZIP]</a> +*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/cheev_2stage.f"> +*> [TXT]</a> +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE CHEEV_2STAGE( JOBZ, UPLO, N, A, LDA, W, WORK, LWORK, +* RWORK, INFO ) +* +* IMPLICIT NONE +* +* .. Scalar Arguments .. +* CHARACTER JOBZ, UPLO +* INTEGER INFO, LDA, LWORK, N +* .. +* .. Array Arguments .. +* REAL RWORK( * ), W( * ) +* COMPLEX A( LDA, * ), WORK( * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> CHEEV_2STAGE computes all eigenvalues and, optionally, eigenvectors of a +*> complex Hermitian matrix A using the 2stage technique for +*> the reduction to tridiagonal. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] JOBZ +*> \verbatim +*> JOBZ is CHARACTER*1 +*> = 'N': Compute eigenvalues only; +*> = 'V': Compute eigenvalues and eigenvectors. +*> Not available in this release. +*> \endverbatim +*> +*> \param[in] UPLO +*> \verbatim +*> UPLO is CHARACTER*1 +*> = 'U': Upper triangle of A is stored; +*> = 'L': Lower triangle of A is stored. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The order of the matrix A. N >= 0. +*> \endverbatim +*> +*> \param[in,out] A +*> \verbatim +*> A is COMPLEX array, dimension (LDA, N) +*> On entry, the Hermitian matrix A. If UPLO = 'U', the +*> leading N-by-N upper triangular part of A contains the +*> upper triangular part of the matrix A. If UPLO = 'L', +*> the leading N-by-N lower triangular part of A contains +*> the lower triangular part of the matrix A. +*> On exit, if JOBZ = 'V', then if INFO = 0, A contains the +*> orthonormal eigenvectors of the matrix A. +*> If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') +*> or the upper triangle (if UPLO='U') of A, including the +*> diagonal, is destroyed. +*> \endverbatim +*> +*> \param[in] LDA +*> \verbatim +*> LDA is INTEGER +*> The leading dimension of the array A. LDA >= max(1,N). +*> \endverbatim +*> +*> \param[out] W +*> \verbatim +*> W is REAL array, dimension (N) +*> If INFO = 0, the eigenvalues in ascending order. +*> \endverbatim +*> +*> \param[out] WORK +*> \verbatim +*> WORK is COMPLEX array, dimension (MAX(1,LWORK)) +*> On exit, if INFO = 0, WORK(1) returns the optimal LWORK. +*> \endverbatim +*> +*> \param[in] LWORK +*> \verbatim +*> LWORK is INTEGER +*> The length of the array WORK. LWORK >= 1, when N <= 1; +*> otherwise +*> If JOBZ = 'N' and N > 1, LWORK must be queried. +*> LWORK = MAX(1, dimension) where +*> dimension = max(stage1,stage2) + (KD+1)*N + N +*> = N*KD + N*max(KD+1,FACTOPTNB) +*> + max(2*KD*KD, KD*NTHREADS) +*> + (KD+1)*N + N +*> where KD is the blocking size of the reduction, +*> FACTOPTNB is the blocking used by the QR or LQ +*> algorithm, usually FACTOPTNB=128 is a good choice +*> NTHREADS is the number of threads used when +*> openMP compilation is enabled, otherwise =1. +*> If JOBZ = 'V' and N > 1, LWORK must be queried. Not yet available +*> +*> If LWORK = -1, then a workspace query is assumed; the routine +*> only calculates the optimal size of the WORK array, returns +*> this value as the first entry of the WORK array, and no error +*> message related to LWORK is issued by XERBLA. +*> \endverbatim +*> +*> \param[out] RWORK +*> \verbatim +*> RWORK is REAL array, dimension (max(1, 3*N-2)) +*> \endverbatim +*> +*> \param[out] INFO +*> \verbatim +*> INFO is INTEGER +*> = 0: successful exit +*> < 0: if INFO = -i, the i-th argument had an illegal value +*> > 0: if INFO = i, the algorithm failed to converge; i +*> off-diagonal elements of an intermediate tridiagonal +*> form did not converge to zero. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date November 2016 +* +*> \ingroup complexHEeigen +* +*> \par Further Details: +* ===================== +*> +*> \verbatim +*> +*> All details about the 2stage techniques are available in: +*> +*> Azzam Haidar, Hatem Ltaief, and Jack Dongarra. +*> Parallel reduction to condensed forms for symmetric eigenvalue problems +*> using aggregated fine-grained and memory-aware kernels. In Proceedings +*> of 2011 International Conference for High Performance Computing, +*> Networking, Storage and Analysis (SC '11), New York, NY, USA, +*> Article 8 , 11 pages. +*> http://doi.acm.org/10.1145/2063384.2063394 +*> +*> A. Haidar, J. Kurzak, P. Luszczek, 2013. +*> An improved parallel singular value algorithm and its implementation +*> for multicore hardware, In Proceedings of 2013 International Conference +*> for High Performance Computing, Networking, Storage and Analysis (SC '13). +*> Denver, Colorado, USA, 2013. +*> Article 90, 12 pages. +*> http://doi.acm.org/10.1145/2503210.2503292 +*> +*> A. Haidar, R. Solca, S. Tomov, T. Schulthess and J. Dongarra. +*> A novel hybrid CPU-GPU generalized eigensolver for electronic structure +*> calculations based on fine-grained memory aware tasks. +*> International Journal of High Performance Computing Applications. +*> Volume 28 Issue 2, Pages 196-209, May 2014. +*> http://hpc.sagepub.com/content/28/2/196 +*> +*> \endverbatim +* +* ===================================================================== + SUBROUTINE CHEEV_2STAGE( JOBZ, UPLO, N, A, LDA, W, WORK, LWORK, + $ RWORK, INFO ) +* + IMPLICIT NONE +* +* -- LAPACK driver routine (version 3.4.0) -- +* -- LAPACK is a software package provided by Univ. of Tennessee, -- +* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- +* November 2016 +* +* .. Scalar Arguments .. + CHARACTER JOBZ, UPLO + INTEGER INFO, LDA, LWORK, N +* .. +* .. Array Arguments .. + REAL RWORK( * ), W( * ) + COMPLEX A( LDA, * ), WORK( * ) +* .. +* +* ===================================================================== +* +* .. Parameters .. + REAL ZERO, ONE + PARAMETER ( ZERO = 0.0E0, ONE = 1.0E0 ) + COMPLEX CONE + PARAMETER ( CONE = ( 1.0E0, 0.0E0 ) ) +* .. +* .. Local Scalars .. + LOGICAL LOWER, LQUERY, WANTZ + INTEGER IINFO, IMAX, INDE, INDTAU, INDWRK, ISCALE, + $ LLWORK, LWMIN, LHTRD, LWTRD, KD, IB, INDHOUS + REAL ANRM, BIGNUM, EPS, RMAX, RMIN, SAFMIN, SIGMA, + $ SMLNUM +* .. +* .. External Functions .. + LOGICAL LSAME + INTEGER ILAENV + REAL SLAMCH, CLANHE + EXTERNAL LSAME, ILAENV, SLAMCH, CLANHE +* .. +* .. External Subroutines .. + EXTERNAL SSCAL, SSTERF, XERBLA, CLASCL, CSTEQR, + $ CUNGTR, CHETRD_2STAGE +* .. +* .. Intrinsic Functions .. + INTRINSIC REAL, MAX, SQRT +* .. +* .. Executable Statements .. +* +* Test the input parameters. +* + WANTZ = LSAME( JOBZ, 'V' ) + LOWER = LSAME( UPLO, 'L' ) + LQUERY = ( LWORK.EQ.-1 ) +* + INFO = 0 + IF( .NOT.( LSAME( JOBZ, 'N' ) ) ) THEN + INFO = -1 + ELSE IF( .NOT.( LOWER .OR. LSAME( UPLO, 'U' ) ) ) THEN + INFO = -2 + ELSE IF( N.LT.0 ) THEN + INFO = -3 + ELSE IF( LDA.LT.MAX( 1, N ) ) THEN + INFO = -5 + END IF +* + IF( INFO.EQ.0 ) THEN + KD = ILAENV( 17, 'CHETRD_2STAGE', JOBZ, N, -1, -1, -1 ) + IB = ILAENV( 18, 'CHETRD_2STAGE', JOBZ, N, KD, -1, -1 ) + LHTRD = ILAENV( 19, 'CHETRD_2STAGE', JOBZ, N, KD, IB, -1 ) + LWTRD = ILAENV( 20, 'CHETRD_2STAGE', JOBZ, N, KD, IB, -1 ) + LWMIN = N + LHTRD + LWTRD + WORK( 1 ) = LWMIN +* + IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) + $ INFO = -8 + END IF +* + IF( INFO.NE.0 ) THEN + CALL XERBLA( 'CHEEV_2STAGE ', -INFO ) + RETURN + ELSE IF( LQUERY ) THEN + RETURN + END IF +* +* Quick return if possible +* + IF( N.EQ.0 ) THEN + RETURN + END IF +* + IF( N.EQ.1 ) THEN + W( 1 ) = REAL( A( 1, 1 ) ) + WORK( 1 ) = 1 + IF( WANTZ ) + $ A( 1, 1 ) = CONE + RETURN + END IF +* +* Get machine constants. +* + SAFMIN = SLAMCH( 'Safe minimum' ) + EPS = SLAMCH( 'Precision' ) + SMLNUM = SAFMIN / EPS + BIGNUM = ONE / SMLNUM + RMIN = SQRT( SMLNUM ) + RMAX = SQRT( BIGNUM ) +* +* Scale matrix to allowable range, if necessary. +* + ANRM = CLANHE( 'M', UPLO, N, A, LDA, RWORK ) + ISCALE = 0 + IF( ANRM.GT.ZERO .AND. ANRM.LT.RMIN ) THEN + ISCALE = 1 + SIGMA = RMIN / ANRM + ELSE IF( ANRM.GT.RMAX ) THEN + ISCALE = 1 + SIGMA = RMAX / ANRM + END IF + IF( ISCALE.EQ.1 ) + $ CALL CLASCL( UPLO, 0, 0, ONE, SIGMA, N, N, A, LDA, INFO ) +* +* Call CHETRD_2STAGE to reduce Hermitian matrix to tridiagonal form. +* + INDE = 1 + INDTAU = 1 + INDHOUS = INDTAU + N + INDWRK = INDHOUS + LHTRD + LLWORK = LWORK - INDWRK + 1 +* + CALL CHETRD_2STAGE( JOBZ, UPLO, N, A, LDA, W, RWORK( INDE ), + $ WORK( INDTAU ), WORK( INDHOUS ), LHTRD, + $ WORK( INDWRK ), LLWORK, IINFO ) +* +* For eigenvalues only, call SSTERF. For eigenvectors, first call +* CUNGTR to generate the unitary matrix, then call CSTEQR. +* + IF( .NOT.WANTZ ) THEN + CALL SSTERF( N, W, RWORK( INDE ), INFO ) + ELSE + CALL CUNGTR( UPLO, N, A, LDA, WORK( INDTAU ), WORK( INDWRK ), + $ LLWORK, IINFO ) + INDWRK = INDE + N + CALL CSTEQR( JOBZ, N, W, RWORK( INDE ), A, LDA, + $ RWORK( INDWRK ), INFO ) + END IF +* +* If matrix was scaled, then rescale eigenvalues appropriately. +* + IF( ISCALE.EQ.1 ) THEN + IF( INFO.EQ.0 ) THEN + IMAX = N + ELSE + IMAX = INFO - 1 + END IF + CALL SSCAL( IMAX, ONE / SIGMA, W, 1 ) + END IF +* +* Set WORK(1) to optimal complex workspace size. +* + WORK( 1 ) = LWMIN +* + RETURN +* +* End of CHEEV_2STAGE +* + END |