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HPL_pdlaswp00N(3)            HPL Library Functions           HPL_pdlaswp00N(3)


NAME

       HPL_pdlaswp00N - Broadcast a column panel L and swap the row panel U.


SYNOPSIS

       #include "hpl.h"

       void HPL_pdlaswp00N( HPL_T_panel * PBCST, int * IFLAG, HPL_T_panel *
       PANEL, const int NN );


DESCRIPTION

       HPL_pdlaswp00N applies the  NB  row interchanges to  NN columns of the
       trailing submatrix and broadcast a column panel.

       Bi-directional  exchange  is used to perform the  swap :: broadcast of
       the row  panel U at once, resulting in a lower number of messages than
       usual as well as a lower communication volume. With P process rows and
       assuming  bi-directional links,  the running time of this function can
       be approximated by:

          log_2(P) * (lat + NB*LocQ(N) / bdwth)

       where  NB  is the number of rows of the row panel U,  N is the global
       number of columns being updated,  lat and bdwth  are the latency  and
       bandwidth  of  the  network  for  double  precision real words.  Mono
       directional links will double this communication cost.


ARGUMENTS

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

       IFLAG   (local input/output)    int *
               On entry, IFLAG  indicates  whether or not  the broadcast has
               already been completed.  If not,  probing will occur, and the
               outcome will be contained in IFLAG on exit.

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

       NN      (local input)           const int
               On entry, NN specifies  the  local  number  of columns of the
               trailing  submatrix  to  be swapped and broadcast starting at
               the current position. NN must be at least zero.


SEE ALSO

       HPL_pdgesv (3), HPL_pdgesvK2 (3), HPL_pdupdateNN (3),
       HPL_pdupdateTN (3), HPL_pipid (3), HPL_plindx0 (3), HPL_dlaswp01N (3),
       HPL_dlaswp02N (3), HPL_dlaswp03N (3), HPL_dlaswp04N (3),
       HPL_dlaswp05N (3).

HPL 2.1                        October 26, 2012              HPL_pdlaswp00N(3)

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