*> \brief \b XLAENV * * =========== DOCUMENTATION =========== * * Online html documentation available at * http://www.netlib.org/lapack/explore-html/ * * Definition: * =========== * * SUBROUTINE XLAENV( ISPEC, NVALUE ) * * .. Scalar Arguments .. * INTEGER ISPEC, NVALUE * .. * * *> \par Purpose: * ============= *> *> \verbatim *> *> XLAENV sets certain machine- and problem-dependent quantities *> which will later be retrieved by ILAENV. *> \endverbatim * * Arguments: * ========== * *> \param[in] ISPEC *> \verbatim *> ISPEC is INTEGER *> Specifies the parameter to be set in the COMMON array IPARMS. *> = 1: the optimal blocksize; if this value is 1, an unblocked *> algorithm will give the best performance. *> = 2: the minimum block size for which the block routine *> should be used; if the usable block size is less than *> this value, an unblocked routine should be used. *> = 3: the crossover point (in a block routine, for N less *> than this value, an unblocked routine should be used) *> = 4: the number of shifts, used in the nonsymmetric *> eigenvalue routines *> = 5: the minimum column dimension for blocking to be used; *> rectangular blocks must have dimension at least k by m, *> where k is given by ILAENV(2,...) and m by ILAENV(5,...) *> = 6: the crossover point for the SVD (when reducing an m by n *> matrix to bidiagonal form, if max(m,n)/min(m,n) exceeds *> this value, a QR factorization is used first to reduce *> the matrix to a triangular form) *> = 7: the number of processors *> = 8: another crossover point, for the multishift QR and QZ *> methods for nonsymmetric eigenvalue problems. *> = 9: maximum size of the subproblems at the bottom of the *> computation tree in the divide-and-conquer algorithm *> (used by xGELSD and xGESDD) *> =10: ieee NaN arithmetic can be trusted not to trap *> =11: infinity arithmetic can be trusted not to trap *> \endverbatim *> *> \param[in] NVALUE *> \verbatim *> NVALUE is INTEGER *> The value of the parameter specified by ISPEC. *> \endverbatim * * Authors: * ======== * *> \author Univ. of Tennessee *> \author Univ. of California Berkeley *> \author Univ. of Colorado Denver *> \author NAG Ltd. * *> \date December 2016 * *> \ingroup aux_lin * * ===================================================================== SUBROUTINE XLAENV( ISPEC, NVALUE ) * * -- LAPACK test routine (version 3.7.0) -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- * December 2016 * * .. Scalar Arguments .. INTEGER ISPEC, NVALUE * .. * * ===================================================================== * * .. Arrays in Common .. INTEGER IPARMS( 100 ) * .. * .. Common blocks .. COMMON / CLAENV / IPARMS * .. * .. Save statement .. SAVE / CLAENV / * .. * .. Executable Statements .. * IF( ISPEC.GE.1 .AND. ISPEC.LE.9 ) THEN IPARMS( ISPEC ) = NVALUE END IF * RETURN * * End of XLAENV * END