DragonFly On-Line Manual Pages

HPL_plindx1(3)               HPL Library Functions              HPL_plindx1(3)

NAME
       HPL_plindx1 - Compute local swapping index arrays.

SYNOPSIS
       #include "hpl.h"

       void HPL_plindx1( HPL_T_panel * PANEL, const int K, const int * IPID,
       int * IPA, int * LINDXA, int * LINDXAU, int * IPLEN, int * IPMAP, int *
       IPMAPM1, int * PERMU, int * IWORK );

DESCRIPTION
       HPL_plindx1 computes two local arrays  LINDXA and  LINDXAU  containing
       the  local  source and final destination position  resulting from the
       application of row interchanges.  In addition, this function computes
       three arrays IPLEN, IPMAP and IPMAPM1  that contain  the  logarithmic
       mapping information for the spreading phase.

ARGUMENTS
       PANEL   (local input/output)    HPL_T_panel *
               On entry,  PANEL  points to the data structure containing the
               panel information.

       K       (global input)          const int
               On entry, K specifies the number of entries in IPID.  K is at
               least 2*N, and at most 4*N.

       IPID    (global input)          const int *
               On entry,  IPID  is an array of length K. The first K entries
               of that array contain the src and final destination resulting
               from the application of the interchanges.

       IPA     (global output)         int *
               On exit,  IPA  specifies  the number of rows that the current
               process row has that either belong to U  or should be swapped
               with remote rows of A.

       LINDXA  (global output)         int *
               On entry, LINDXA  is an array of dimension 2*N. On exit, this
               array contains the local indexes of the rows of A I have that
               should be copied into U.

       LINDXAU (global output)         int *
               On exit, LINDXAU  is an array of dimension 2*N. On exit, this
               array contains  the local destination  information encoded as
               follows.  If LINDXAU(k) >= 0, row  LINDXA(k)  of A  is  to be
               copied in U at position LINDXAU(k).  Otherwise, row LINDXA(k)
               of A should be locally copied into A(-LINDXAU(k),:).

       IPLEN   (global output)         int *
               On entry, IPLEN is an array of dimension NPROW + 1. On  exit,
               this array is such that  IPLEN[i]  is the number of rows of A
               in  the  processes  before  process  IPMAP[i]  after the sort
               with the convention that IPLEN[nprow]  is the total number of
               rows of the panel.  In other words IPLEN[i+1]-IPLEN[i] is the
               local number of rows of A that should be moved to the process
               IPMAP[i]. IPLEN is such that the number of rows of the source
               process  row can be computed as  IPLEN[1] - IPLEN[0], and the
               remaining  entries  of  this  array  are  sorted  so that the
               quantities IPLEN[i+1] - IPLEN[i] are logarithmically sorted.

       IPMAP   (global output)         int *
               On entry, IPMAP is an array of dimension NPROW. On exit, this
               array contains  the logarithmic mapping of the processes.  In
               other words, IPMAP[myrow] is the corresponding sorted process
               coordinate.

       IPMAPM1 (global output)         int *
               On entry, IPMAPM1  is an array of dimension NPROW.  On  exit,
               this  array  contains  the inverse of the logarithmic mapping
               contained  in  IPMAP:  IPMAPM1[ IPMAP[i] ] = i,  for all i in
               [0.. NPROCS)

       PERMU   (global output)         int *
               On entry,  PERMU  is an array of dimension JB. On exit, PERMU
               contains  a sequence of permutations,  that should be applied
               in increasing order to permute in place the row panel U.

       IWORK   (workspace)             int *
               On entry, IWORK is a workarray of dimension 2*JB.

SEE ALSO
       HPL_pdlaswp00N (3), HPL_pdlaswp00T (3), HPL_pdlaswp01N (3),
       HPL_pdlaswp01T (3).

HPL 2.1                        October 26, 2012                 HPL_plindx1(3)