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<TITLE>HPL_pdlaswp00N HPL 2.0 Library Functions September 10, 2008</TITLE> 
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<H1>Name</H1>
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<B>HPL_pdlaswp00N</B> Broadcast a column panel L and swap the row panel U.
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<H1>Synopsis</H1>
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<CODE>#include "hpl.h"</CODE><BR><BR>
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<CODE>void</CODE>
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<CODE>HPL_pdlaswp00N(</CODE>
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<CODE>HPL_T_panel *</CODE>
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<CODE>PBCST</CODE>,
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<CODE>int *</CODE>
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<CODE>IFLAG</CODE>,
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<CODE>HPL_T_panel *</CODE>
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<CODE>PANEL</CODE>,
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<CODE>const int</CODE>
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<CODE>NN</CODE>
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<CODE>);</CODE>
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<H1>Description</H1>
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<B>HPL_pdlaswp00N</B>
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applies the  NB  row interchanges to  NN columns of the
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trailing submatrix and broadcast a column panel.
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Bi-directional  exchange  is used to perform the  swap :: broadcast of
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the row  panel U at once, resulting in a lower number of messages than
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usual as well as a lower communication volume. With P process rows and
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assuming  bi-directional links,  the running time of this function can
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be approximated by:
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   log_2(P) * (lat + NB*LocQ(N) / bdwth)
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where  NB  is the number of rows of the row panel U,  N is the global
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number of columns being updated,  lat and bdwth  are the latency  and
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bandwidth  of  the  network  for  double  precision real words.  Mono
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directional links will double this communication cost.
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<H1>Arguments</H1>
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<PRE>
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PBCST   (local input/output)          HPL_T_panel *
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        On entry,  PBCST  points to the data structure containing the
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        panel (to be broadcast) information.
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</PRE>
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<PRE>
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IFLAG   (local input/output)          int *
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        On entry, IFLAG  indicates  whether or not  the broadcast has
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        already been completed.  If not,  probing will occur, and the
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        outcome will be contained in IFLAG on exit.
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</PRE>
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<PRE>
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PANEL   (local input/output)          HPL_T_panel *
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        On entry,  PANEL  points to the data structure containing the
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        panel (to be broadcast and swapped) information.
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</PRE>
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<PRE>
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NN      (local input)                 const int
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        On entry, NN specifies  the  local  number  of columns of the
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        trailing  submatrix  to  be swapped and broadcast starting at
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        the current position. NN must be at least zero.
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</PRE>
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<H1>See Also</H1>
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<A HREF="HPL_pdgesv.html">HPL_pdgesv</A>,
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<A HREF="HPL_pdgesvK2.html">HPL_pdgesvK2</A>,
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<A HREF="HPL_pdupdateNN.html">HPL_pdupdateNN</A>,
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<A HREF="HPL_pdupdateTN.html">HPL_pdupdateTN</A>,
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<A HREF="HPL_pipid.html">HPL_pipid</A>,
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<A HREF="HPL_plindx0.html">HPL_plindx0</A>,
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<A HREF="HPL_dlaswp01N.html">HPL_dlaswp01N</A>,
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<A HREF="HPL_dlaswp02N.html">HPL_dlaswp02N</A>,
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<A HREF="HPL_dlaswp03N.html">HPL_dlaswp03N</A>,
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<A HREF="HPL_dlaswp04N.html">HPL_dlaswp04N</A>,
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<A HREF="HPL_dlaswp05N.html">HPL_dlaswp05N</A>.
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