DragonFly On-Line Manual Pages

Search: Section:  

HPL_spreadN(3)               HPL Library Functions              HPL_spreadN(3)


NAME

       HPL_spreadN - Spread row panel U and forward current column panel.


SYNOPSIS

       #include "hpl.h"

       void HPL_spreadN( HPL_T_panel * PBCST, int * IFLAG, HPL_T_panel *
       PANEL, const enum HPL_SIDE SIDE, const int N, double * U, const int
       LDU, const int SRCDIST, const int * IPLEN, const int * IPMAP, const int
       * IPMAPM1 );


DESCRIPTION

       HPL_spreadN spreads the local array containing local pieces of U, so
       that on exit to this function,  a piece of  U  is contained in every
       process row. The array IPLEN contains the number of rows of U,  that
       should be spread on any given process row. This function also probes
       for the presence of the column panel PBCST. In case of success, this
       panel will be forwarded.  If  PBCST  is NULL on input,  this probing
       mechanism will be disabled.


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 spread) information.

       SIDE    (global input)          const enum HPL_SIDE
               On entry, SIDE specifies whether the local piece of U located
               in process IPMAP[SRCDIST] should be spread to the right or to
               the left. This feature is used by the equilibration process.

       N       (global input)          const int
               On entry,  N  specifies  the  local number of columns of U. N
               must be at least zero.

       U       (local input/output)    double *
               On entry,  U  is an array of dimension (LDU,*) containing the
               local pieces of U.

       LDU     (local input)           const int
               On entry, LDU specifies the local leading dimension of U. LDU
               should be at least MAX(1,IPLEN[nprow]).

       SRCDIST (local input)           const int
               On entry,  SRCDIST  specifies the source process that spreads
               its piece of U.

       IPLEN   (global input)          const int *
               On entry, IPLEN is an array of dimension NPROW+1.  This array
               is such that IPLEN[i+1] - IPLEN[i] is the number of rows of U
               in each process before process IPMAP[i], with the  convention
               that IPLEN[nprow] is the total number of rows. In other words
               IPLEN[i+1] - IPLEN[i]  is  the local number of rows of U that
               should be moved to process IPMAP[i].

       IPMAP   (global input)          const int *
               On entry, IPMAP is an array of dimension  NPROW.  This  array
               contains  the  logarithmic mapping of the processes. In other
               words, IPMAP[myrow]  is the absolute coordinate of the sorted
               process.

       IPMAPM1 (global input)          const int *
               On entry,  IPMAPM1 is an array of dimension NPROW. This array
               contains  the inverse of the logarithmic mapping contained in
               IPMAP: For i in [0.. NPROW) IPMAPM1[IPMAP[i]] = i.


SEE ALSO

       HPL_pdlaswp01N (3).

HPL 2.1                        October 26, 2012                 HPL_spreadN(3)

Search: Section: