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SUBROUTINE XLAENV( ISPEC, NVALUE )
*
* -- LAPACK auxiliary routine (version 3.0) --
* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
* Courant Institute, Argonne National Lab, and Rice University
* June 30, 1999
*
* .. Scalar Arguments ..
INTEGER ISPEC, NVALUE
* ..
*
* Purpose
* =======
*
* XLAENV sets certain machine- and problem-dependent quantities
* which will later be retrieved by ILAENV.
*
* Arguments
* =========
*
* ISPEC (input) 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
*
* NVALUE (input) INTEGER
* The value of the parameter specified by ISPEC.
*
* =====================================================================
*
* .. 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
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