1HPL_pdlaswp00N(3)            HPL Library Functions           HPL_pdlaswp00N(3)
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NAME

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

9       #include "hpl.h"
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11       void  HPL_pdlaswp00N(  HPL_T_panel  * PBCST, int * IFLAG, HPL_T_panel *
12       PANEL, const int NN );
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DESCRIPTION

15       HPL_pdlaswp00N applies the  NB  row interchanges to  NN columns of  the
16       trailing submatrix and broadcast a column panel.
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18       Bi-directional   exchange  is used to perform the  swap :: broadcast of
19       the row  panel U at once, resulting in a lower number of messages  than
20       usual  as well as a lower communication volume. With P process rows and
21       assuming  bi-directional links,  the running time of this function  can
22       be approximated by:
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24          log_2(P) * (lat + NB*LocQ(N) / bdwth)
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26       where   NB   is the number of rows of the row panel U,  N is the global
27       number of columns being updated,  lat and bdwth  are the  latency   and
28       bandwidth   of   the  network  for  double  precision real words.  Mono
29       directional links will double this communication cost.
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ARGUMENTS

32       PBCST   (local input/output)    HPL_T_panel *
33               On entry,  PBCST  points to the data structure  containing  the
34               panel (to be broadcast) information.
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36       IFLAG   (local input/output)    int *
37               On  entry,  IFLAG  indicates  whether or not  the broadcast has
38               already been completed.  If not,  probing will occur,  and  the
39               outcome will be contained in IFLAG on exit.
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41       PANEL   (local input/output)    HPL_T_panel *
42               On  entry,   PANEL  points to the data structure containing the
43               panel (to be broadcast and swapped) information.
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45       NN      (local input)           const int
46               On entry, NN specifies  the  local  number  of columns  of  the
47               trailing   submatrix   to  be swapped and broadcast starting at
48               the current position. NN must be at least zero.
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SEE ALSO

51       HPL_pdgesv (3),   HPL_pdgesvK2 (3),    HPL_pdupdateNN (3),    HPL_pdup‐
52       dateTN (3),    HPL_pipid (3),    HPL_plindx0 (3),    HPL_dlaswp01N (3),
53       HPL_dlaswp02N (3),        HPL_dlaswp03N (3),         HPL_dlaswp04N (3),
54       HPL_dlaswp05N (3).
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58HPL 2.2                        February 24, 2016             HPL_pdlaswp00N(3)
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