Name
HPL_pdmxswp swaps and broacast the pivot row.
Synopsis
#include "hpl.h"
void
HPL_pdmxswp(
HPL_T_panel *
PANEL,
const int
M,
const int
II,
const int
JJ,
double *
WORK
);
Description
HPL_pdmxswp
swaps  and  broadcasts  the  absolute value max row using
bi-directional exchange.  The buffer is partially set by HPL_dlocmax.
 
Bi-directional  exchange  is  used  to  perform  the  swap::broadcast
operations  at once  for one column in the panel.  This  results in a
lower number of slightly larger  messages than usual.  On P processes
and assuming bi-directional links,  the running time of this function
can be approximated by
 
   log_2( P ) * ( lat + ( 2 * N0 + 4 ) / bdwth )
 
where  lat and bdwth are the latency and bandwidth of the network for
double precision real elements.  Communication  only  occurs  in  one
process  column. Mono-directional links  will cause the communication
cost to double.
Arguments
PANEL   (local input/output)          HPL_T_panel *
        On entry,  PANEL  points to the data structure containing the
        panel information.
M       (local input)                 const int
        On entry,  M specifies the local number of rows of the matrix
        column on which this function operates.
II      (local input)                 const int
        On entry, II  specifies the row offset where the column to be
        operated on starts with respect to the panel.
JJ      (local input)                 const int
        On entry, JJ  specifies the column offset where the column to
        be operated on starts with respect to the panel.
WORK    (local workspace)             double *
        On entry, WORK  is a workarray of size at least 2 * (4+2*N0).
        It  is assumed that  HPL_dlocmax  was called  prior  to  this
        routine to  initialize  the first four entries of this array.
        On exit, the  N0  length max row is stored in WORK[4:4+N0-1];
        Note that this is also the  JJth  row  (or column) of L1. The
        remaining part is used as a temporary array.
See Also
HPL_dlocmax,
HPL_dlocswpN,
HPL_dlocswpT,
HPL_pdpancrN,
HPL_pdpancrT,
HPL_pdpanllN,
HPL_pdpanllT,
HPL_pdpanrlN,
HPL_pdpanrlT,
HPL_pdrpancrN,
HPL_pdrpancrT,
HPL_pdrpanllN,
HPL_pdrpanllT,
HPL_pdrpanrlN,
HPL_pdrpanrlT,
HPL_pdfact.