PB_CpdotNN.c

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/* ---------------------------------------------------------------------
*
*  -- PBLAS auxiliary routine (version 2.0) --
*     University of Tennessee, Knoxville, Oak Ridge National Laboratory,
*     and University of California, Berkeley.
*     April 1, 1998
*
*  ---------------------------------------------------------------------
*/
/*
*  Include files
*/
#include "../pblas.h"
#include "../PBpblas.h"
#include "../PBtools.h"
#include "../PBblacs.h"
#include "../PBblas.h"

#ifdef __STDC__
void PB_CpdotNN( PBTYP_T * TYPE, int N, char * DOT,
                 char * X, int IX, int JX, int * DESCX, int INCX,
                 char * Y, int IY, int JY, int * DESCY, int INCY,
                 VVDOT_T FDOT )
#else
void PB_CpdotNN( TYPE, N, DOT, X, IX, JX, DESCX, INCX, Y, IY, JY, DESCY,
                 INCY, FDOT )
/*
*  .. Scalar Arguments ..
*/
   int            INCX, INCY, IX, IY, JX, JY, N;
   char           * DOT;
   PBTYP_T        * TYPE;
   VVDOT_T        FDOT;
/*
*  .. Array Arguments ..
*/
   int            * DESCX, * DESCY;
   char           * X, * Y;
#endif
{
/*
*  Purpose
*  =======
*
*  PB_CpdotNN forms the dot product of two subvectors,
*
*     DOT := sub( X )**T * sub( Y )  or   DOT := sub( X )**H * sub( Y ),
*
*  where
*
*     sub( X ) denotes X(IX,JX:JX+N-1) if INCX = M_X,
*                      X(IX:IX+N-1,JX) if INCX = 1 and INCX <> M_X, and,
*
*     sub( Y ) denotes Y(IY,JY:JY+N-1) if INCY = M_Y,
*                      Y(IY:IY+N-1,JY) if INCY = 1 and INCY <> M_Y.
*
*  Both subvectors are assumed to be not distributed.
*
*  Notes
*  =====
*
*  A description  vector  is associated with each 2D block-cyclicly dis-
*  tributed matrix.  This  vector  stores  the  information  required to
*  establish the  mapping  between a  matrix entry and its corresponding
*  process and memory location.
*
*  In  the  following  comments,   the character _  should  be  read  as
*  "of  the  distributed  matrix".  Let  A  be a generic term for any 2D
*  block cyclicly distributed matrix.  Its description vector is DESC_A:
*
*  NOTATION         STORED IN       EXPLANATION
*  ---------------- --------------- ------------------------------------
*  DTYPE_A (global) DESCA[ DTYPE_ ] The descriptor type.
*  CTXT_A  (global) DESCA[ CTXT_  ] The BLACS context handle, indicating
*                                   the NPROW x NPCOL BLACS process grid
*                                   A  is  distributed over. The context
*                                   itself  is  global,  but  the handle
*                                   (the integer value) may vary.
*  M_A     (global) DESCA[ M_     ] The  number of rows in the distribu-
*                                   ted matrix A, M_A >= 0.
*  N_A     (global) DESCA[ N_     ] The number of columns in the distri-
*                                   buted matrix A, N_A >= 0.
*  IMB_A   (global) DESCA[ IMB_   ] The number of rows of the upper left
*                                   block of the matrix A, IMB_A > 0.
*  INB_A   (global) DESCA[ INB_   ] The  number  of columns of the upper
*                                   left   block   of   the  matrix   A,
*                                   INB_A > 0.
*  MB_A    (global) DESCA[ MB_    ] The blocking factor used to  distri-
*                                   bute the last  M_A-IMB_A  rows of A,
*                                   MB_A > 0.
*  NB_A    (global) DESCA[ NB_    ] The blocking factor used to  distri-
*                                   bute the last  N_A-INB_A  columns of
*                                   A, NB_A > 0.
*  RSRC_A  (global) DESCA[ RSRC_  ] The process row over which the first
*                                   row of the matrix  A is distributed,
*                                   NPROW > RSRC_A >= 0.
*  CSRC_A  (global) DESCA[ CSRC_  ] The  process column  over  which the
*                                   first column of  A  is  distributed.
*                                   NPCOL > CSRC_A >= 0.
*  LLD_A   (local)  DESCA[ LLD_   ] The  leading dimension  of the local
*                                   array  storing  the  local blocks of
*                                   the distributed matrix A,
*                                   IF( Lc( 1, N_A ) > 0 )
*                                      LLD_A >= MAX( 1, Lr( 1, M_A ) )
*                                   ELSE
*                                      LLD_A >= 1.
*
*  Let K be the number of  rows of a matrix A starting at the global in-
*  dex IA,i.e, A( IA:IA+K-1, : ). Lr( IA, K ) denotes the number of rows
*  that the process of row coordinate MYROW ( 0 <= MYROW < NPROW ) would
*  receive if these K rows were distributed over NPROW processes.  If  K
*  is the number of columns of a matrix  A  starting at the global index
*  JA, i.e, A( :, JA:JA+K-1, : ), Lc( JA, K ) denotes the number  of co-
*  lumns that the process MYCOL ( 0 <= MYCOL < NPCOL ) would  receive if
*  these K columns were distributed over NPCOL processes.
*
*  The values of Lr() and Lc() may be determined via a call to the func-
*  tion PB_Cnumroc:
*  Lr( IA, K ) = PB_Cnumroc( K, IA, IMB_A, MB_A, MYROW, RSRC_A, NPROW )
*  Lc( JA, K ) = PB_Cnumroc( K, JA, INB_A, NB_A, MYCOL, CSRC_A, NPCOL )
*
*  Arguments
*  =========
*
*  TYPE    (local input) pointer to a PBTYP_T structure
*          On entry,  TYPE  is a pointer to a structure of type PBTYP_T,
*          that contains type information (See pblas.h).
*
*  N       (global input) INTEGER
*          On entry,  N  specifies the  length of the  subvectors to  be
*          multiplied. N must be at least zero.
*
*  DOT     (local output) pointer to CHAR
*          On exit, DOT  specifies the dot product of the two subvectors
*          sub( X ) and sub( Y ) only in their scope (See below for fur-
*          ther details).
*
*  X       (local input) pointer to CHAR
*          On entry, X is an array of dimension (LLD_X, Kx), where LLD_X
*          is   at  least  MAX( 1, Lr( 1, IX ) )  when  INCX = M_X   and
*          MAX( 1, Lr( 1, IX+N-1 ) )  otherwise,  and,  Kx  is  at least
*          Lc( 1, JX+N-1 )  when  INCX = M_X  and Lc( 1, JX ) otherwise.
*          Before  entry,  this  array contains the local entries of the
*          matrix X.
*
*  IX      (global input) INTEGER
*          On entry, IX  specifies X's global row index, which points to
*          the beginning of the submatrix sub( X ).
*
*  JX      (global input) INTEGER
*          On entry, JX  specifies X's global column index, which points
*          to the beginning of the submatrix sub( X ).
*
*  DESCX   (global and local input) INTEGER array
*          On entry, DESCX  is an integer array of dimension DLEN_. This
*          is the array descriptor for the matrix X.
*
*  INCX    (global input) INTEGER
*          On entry,  INCX   specifies  the  global  increment  for  the
*          elements of  X.  Only two values of  INCX   are  supported in
*          this version, namely 1 and M_X. INCX  must not be zero.
*
*  Y       (local input) pointer to CHAR
*          On entry, Y is an array of dimension (LLD_Y, Ky), where LLD_Y
*          is   at  least  MAX( 1, Lr( 1, IY ) )  when  INCY = M_Y   and
*          MAX( 1, Lr( 1, IY+N-1 ) )  otherwise,  and,  Ky  is  at least
*          Lc( 1, JY+N-1 )  when  INCY = M_Y  and Lc( 1, JY ) otherwise.
*          Before  entry,  this array  contains the local entries of the
*          matrix Y.
*
*  IY      (global input) INTEGER
*          On entry, IY  specifies Y's global row index, which points to
*          the beginning of the submatrix sub( Y ).
*
*  JY      (global input) INTEGER
*          On entry, JY  specifies Y's global column index, which points
*          to the beginning of the submatrix sub( Y ).
*
*  DESCY   (global and local input) INTEGER array
*          On entry, DESCY  is an integer array of dimension DLEN_. This
*          is the array descriptor for the matrix Y.
*
*  INCY    (global input) INTEGER
*          On entry,  INCY   specifies  the  global  increment  for  the
*          elements of  Y.  Only two values of  INCY   are  supported in
*          this version, namely 1 and M_Y. INCY  must not be zero.
*
*  FDOT    (local input) pointer to a function of type VVDOT
*          On entry, FDOT points to a subroutine that computes the local
*          dot product of two vectors.
*
*  Further Details
*  ===============
*
*  When  the  result  of  a vector-oriented PBLAS call is a scalar, this
*  scalar  is set only within the process scope which owns the vector(s)
*  being operated on. Let sub( X ) be a generic term for the input  vec-
*  tor(s). Then, the processes owning the correct the answer is determi-
*  ned as follows:  if  an  operation involves more than one vector, the
*  processes receiving the result will be the union of the following set
*  of processes for each vector:
*
*  If N = 1, M_X = 1 and INCX = 1,  then  one cannot determine if a pro-
*  cess  row  or  process column owns the vector operand, therefore only
*  the process owning sub( X ) receives the correct result;
*
*  If  INCX = M_X, then sub( X )  is a vector distributed over a process
*  row. Each process in this row receives the result;
*
*  If  INCX = 1, then  sub( X )  is  a vector distributed over a process
*  column. Each process in this column receives the result;
*
*  -- Written on April 1, 1998 by
*     Antoine Petitet, University of Tennessee, Knoxville 37996, USA.
*
*  ---------------------------------------------------------------------
*/
/*
*  .. Local Scalars ..
*/
   char           Xscope, Yscope, * top;
   int            RRorCC, Xcol, Xii, XisR, XisRow, Xjj, Xld, Xlinc, XmyprocD,
                  XmyprocR, XnprocsR, XprocR, Xrow, Ycol, Yii, YisR, YisRow,
                  Yjj, Yld, Ylinc, YmyprocD, YmyprocR, YnprocsR, YprocR, Yrow,
                  csrc, ctxt, ione=1, mycol, myrow, npcol, nprow, rsrc, size;
/*
*  .. Local Arrays ..
*/
   char           * buf = NULL;
/* ..
*  .. Executable Statements ..
*
*/
/*
*  Retrieve process grid information
*/
   Cblacs_gridinfo( ( ctxt = DESCX[CTXT_] ), &nprow, &npcol, &myrow, &mycol );
/*
*  Retrieve sub( X )'s local information: Xii, Xjj, Xrow, Xcol ...
*/
   PB_Cinfog2l( IX, JX, DESCX, nprow, npcol, myrow, mycol, &Xii, &Xjj,
                &Xrow, &Xcol );
   if( ( XisRow = ( INCX == DESCX[M_] ) ) != 0 )
   {
      Xld      = DESCX[LLD_];          Xlinc    = Xld;
      XmyprocD = mycol; XprocR = Xrow; XmyprocR = myrow; XnprocsR = nprow;
      XisR     = ( ( Xrow == -1 ) || ( XnprocsR == 1 ) );
   }
   else
   {
      Xld      = DESCX[LLD_];          Xlinc    = 1;
      XmyprocD = myrow; XprocR = Xcol; XmyprocR = mycol; XnprocsR = npcol;
      XisR     = ( ( Xcol == -1 ) || ( XnprocsR == 1 ) );
   }
/*
*  Retrieve sub( Y )'s local information: Yii, Yjj, Yrow, Ycol ...
*/
   PB_Cinfog2l( IY, JY, DESCY, nprow, npcol, myrow, mycol, &Yii, &Yjj,
                &Yrow, &Ycol );
   if( ( YisRow = ( INCY == DESCY[M_] ) ) != 0 )
   {
      Yld      = DESCY[LLD_];          Ylinc    = Yld;
      YmyprocD = mycol; YprocR = Yrow; YmyprocR = myrow; YnprocsR = nprow;
      YisR     = ( ( Yrow == -1 ) || ( YnprocsR == 1 ) );
   }
   else
   {
      Yld      = DESCY[LLD_];          Ylinc    = 1;
      YmyprocD = myrow; YprocR = Ycol; YmyprocR = mycol; YnprocsR = npcol;
      YisR     = ( ( Ycol == -1 ) || ( YnprocsR == 1 ) );
   }
/*
*  Are sub( X ) and sub( Y ) both row or column vectors ?
*/
   RRorCC = ( ( XisRow && YisRow ) || ( !( XisRow ) && !( YisRow ) ) );
/*
*  Neither sub( X ) nor sub( Y ) are distributed
*/
   if( !XisR )
   {
/*
*     sub( X ) is not replicated
*/
      if( !( YisR ) )
      {
/*
*  sub( Y ) is not replicated
*/
         if( ( XmyprocR != XprocR ) && ( YmyprocR != YprocR ) )
/*
*  If I am not in XprocR or YprocR, then return immediately
*/
            return;

         size = TYPE->size;

         if( RRorCC )
         {
/*
*  sub( X ) and sub( Y ) are both row or column vectors
*/
            if( XprocR == YprocR )
            {
/*
*  sub( X ) and sub( Y ) are in the same process row or column
*/
               FDOT( &N, DOT, Mptr( X, Xii, Xjj, Xld, size ), &Xlinc, Mptr( Y,
                     Yii, Yjj, Yld, size ), &Ylinc );
            }
            else
            {
/*
*  sub( X ) and sub( Y ) are in a different process row or column
*/
               if( XmyprocR == XprocR )
               {
                  buf = PB_Cmalloc( N * size );
/*
*  Send sub( X ) to where sub( Y ) resides, and receive sub( Y ) from the same
*  location.
*/
                  if( XisRow )
                  {
                     TYPE->Cgesd2d( ctxt, 1, N, Mptr( X, Xii, Xjj, Xld, size ),
                                    Xld, YprocR, XmyprocD );
                     TYPE->Cgerv2d( ctxt, 1, N, buf, 1, YprocR, XmyprocD );
                  }
                  else
                  {
                     TYPE->Cgesd2d( ctxt, N, 1, Mptr( X, Xii, Xjj, Xld, size ),
                                    Xld, XmyprocD, YprocR );
                     TYPE->Cgerv2d( ctxt, N, 1, buf, N, XmyprocD, YprocR );
                  }
                  FDOT( &N, DOT, Mptr( X, Xii, Xjj, Xld, size ), &Xlinc, buf,
                        &ione );
                  if( buf ) free( buf );
               }

               if( YmyprocR == YprocR )
               {
                  buf = PB_Cmalloc( N * size );
/*
*  Send sub( Y ) to where sub( X ) resides, and receive sub( X ) from the same
*  location.
*/
                  if( YisRow )
                  {
                     TYPE->Cgesd2d( ctxt, 1, N, Mptr( Y, Yii, Yjj, Yld, size ),
                                    Yld, XprocR, YmyprocD );
                     TYPE->Cgerv2d( ctxt, 1, N, buf, 1, XprocR, YmyprocD );
                  }
                  else
                  {
                     TYPE->Cgesd2d( ctxt, N, 1, Mptr( Y, Yii, Yjj, Yld, size ),
                                    Yld, YmyprocD, XprocR );
                     TYPE->Cgerv2d( ctxt, N, 1, buf, N, YmyprocD, XprocR );
                  }
                  FDOT( &N, DOT, buf, &ione, Mptr( Y, Yii, Yjj, Yld, size ),
                        &Ylinc );
                  if( buf ) free( buf );
               }
            }
         }
         else
         {
/*
*  sub( X ) and sub( Y ) are not both row or column vectors
*/
            if( ( XmyprocR == XprocR ) && ( YmyprocR == YprocR ) )
            {
/*
*  If I am at the intersection of the process row and column, then compute the
*  dot product and broadcast it in my process row and column.
*/
               FDOT( &N, DOT, Mptr( X, Xii, Xjj, Xld, size ), &Xlinc, Mptr( Y,
                     Yii, Yjj, Yld, size ), &Ylinc );
               top = PB_Ctop( &ctxt, BCAST, ROW,    TOP_GET );
               TYPE->Cgebs2d( ctxt, ROW,    top, 1, 1, DOT, 1 );
               top = PB_Ctop( &ctxt, BCAST, COLUMN, TOP_GET );
               TYPE->Cgebs2d( ctxt, COLUMN, top, 1, 1, DOT, 1 );
            }
            else if( XmyprocR == XprocR )
            {
               if( XisRow ) { Xscope = CROW; rsrc = XprocR; csrc = YprocR; }
               else      { Xscope = CCOLUMN; rsrc = YprocR; csrc = XprocR; }
               top = PB_Ctop( &ctxt, BCAST, &Xscope, TOP_GET );
               TYPE->Cgebr2d( ctxt, &Xscope, top, 1, 1, DOT, 1, rsrc, csrc );
            }
            else if( YmyprocR == YprocR )
            {
               if( YisRow ) { Yscope = CROW; rsrc = YprocR; csrc = XprocR; }
               else      { Yscope = CCOLUMN; rsrc = XprocR; csrc = YprocR; }
               top = PB_Ctop( &ctxt, BCAST, &Yscope, TOP_GET );
               TYPE->Cgebr2d( ctxt, &Yscope, top, 1, 1, DOT, 1, rsrc, csrc );
            }
         }
      }
      else
      {
/*
*  sub( Y ) is replicated
*/
         if( XmyprocR == XprocR )
         {
/*
*  If I am in the process row (resp. column) owning sub( X ), then compute the
*  dot product and broadcast in my column (resp. row).
*/
            size = TYPE->size;

            FDOT( &N, DOT, Mptr( X, Xii, Xjj, Xld, size ), &Xlinc, Mptr( Y, Yii,
                  Yjj, Yld, size ), &Ylinc );

            if( XisRow )
            {
               top = PB_Ctop( &ctxt, BCAST, COLUMN, TOP_GET );
               TYPE->Cgebs2d( ctxt, COLUMN, top, 1, 1, DOT, 1 );
            }
            else
            {
               top = PB_Ctop( &ctxt, BCAST, ROW,    TOP_GET );
               TYPE->Cgebs2d( ctxt, ROW,    top, 1, 1, DOT, 1 );
            }
         }
         else
         {
/*
*  Otherwise, receive the dot product
*/
            if( XisRow )
            {
               top = PB_Ctop( &ctxt, BCAST, COLUMN, TOP_GET );
               TYPE->Cgebr2d( ctxt, COLUMN, top, 1, 1, DOT, 1, XprocR,
                              XmyprocD );
            }
            else
            {
               top = PB_Ctop( &ctxt, BCAST, ROW,    TOP_GET );
               TYPE->Cgebr2d( ctxt, ROW,    top, 1, 1, DOT, 1, XmyprocD,
                              XprocR );
            }
         }
      }
   }
   else
   {
/*
*  sub( X ) is replicated
*/
      if( YisR || ( YmyprocR ==  YprocR ) )
      {
/*
*  If I own a piece of sub( Y ), then compute the dot product
*/
         size = TYPE->size;

         FDOT( &N, DOT, Mptr( X, Xii, Xjj, Xld, size ), &Xlinc, Mptr( Y, Yii,
               Yjj, Yld, size ), &Ylinc );
      }

      if( !YisR )
      {
/*
*  If sub( Y ) is not replicated, then broadcast the result to the other
*  processes that own a piece of sub( X ), but were not involved in the above
*  dot-product computation.
*/
         if( YisRow )
         {
            top = PB_Ctop( &ctxt, BCAST, COLUMN, TOP_GET );
            if( YmyprocR == YprocR )
               TYPE->Cgebs2d( ctxt, COLUMN, top, 1, 1, DOT, 1 );
            else
               TYPE->Cgebr2d( ctxt, COLUMN, top, 1, 1, DOT, 1, YprocR,
                              YmyprocD );
         }
         else
         {
            top = PB_Ctop( &ctxt, BCAST, ROW,    TOP_GET );
            if( YmyprocR == YprocR )
               TYPE->Cgebs2d( ctxt, ROW, top, 1, 1, DOT, 1 );
            else
               TYPE->Cgebr2d( ctxt, ROW, top, 1, 1, DOT, 1, YmyprocD, YprocR );
         }
      }
   }
/*
*  End of PB_CpdotNN
*/
}