sp_ienv - eters for the local environment. See ISPEC for a description of the parameters.
#include <sunperf.h> int sp_ienv(int ispec); long sp_ienv_64(long ispec);
Oracle Solaris Studio Performance Library sp_ienv(3P) NAME sp_ienv - called by SuperLU routines to choose machine dependent param- eters for the local environment. See ISPEC for a description of the parameters. SYNOPSIS #include <sunperf.h> int sp_ienv(int ispec); long sp_ienv_64(long ispec); PURPOSE sp_ienv provides a set of parameters which should give good, but not optimal, performance on many of the currently available computers. Users are encouraged to modify this subroutine to set the tuning parameters for their particular machine using the option and problem size information in the arguments. ARGUMENTS ISPEC (input) Specifies the parameter to be returned by sp_ienv. = 1: the panel size w; a panel consists of w consecutive col- umns of matrix A in the process of Gaussian elimination. The best value depends on machine's cache characters. = 2: the relaxation parameter relax; if the number of nodes (columns) in a subtree of the elimination tree is less than relax, this subtree is considered as one supernode, regard- less of their row structures. = 3: the maximum size for a supernode; = 4: the minimum row dimension for 2-D blocking to be used; = 5: the minimum column dimension for 2-D blocking to be used; = 6: the estimated fills factor for L and U, compared with A; int sp_ienv (output) >= 0: the value of the parameter specified by ISPEC < 0: if SP_IENV = -k, the k-th argument had an illegal value. SEE ALSO http://crd.lbl.gov/~xiaoye/SuperLU/ James W. Demmel, Stanley C. Eisenstat, John R. Gilbert, Xiaoye S. Li and Joseph W. H. Liu, "A supernodal approach to sparse partial pivot- ing", SIAM J. Matrix Analysis and Applications, Vol. 20, Num. 3, 1999, pp. 720-755. 7 Nov 2015 sp_ienv(3P)