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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__
int PB_Cfirstnb( int N, int I, int INB, int NB )
#else
int PB_Cfirstnb( N, I, INB, NB )
/*
* .. Scalar Arguments ..
*/
int I, INB, N, NB;
#endif
{
/*
* Purpose
* =======
*
* PB_Cfirstnb returns the global number of matrix rows or columns of the
* first block, if N rows or columns are given out starting from the
* global index I. Note that if N is equal 0, this routine returns 0.
*
* Arguments
* =========
*
* N (global input) INTEGER
* On entry, N specifies the number of rows/columns being dealt
* out. N must be at least zero.
*
* I (global input) INTEGER
* On entry, I specifies the global index of the matrix entry.
* I must be at least zero.
*
* INB (global input) INTEGER
* On entry, INB specifies the size of the first block of the
* global matrix distribution. INB must be at least one.
*
* NB (global input) INTEGER
* On entry, NB specifies the size of the blocks used to parti-
* tion the matrix. NB must be at least one.
*
* -- Written on April 1, 1998 by
* Antoine Petitet, University of Tennessee, Knoxville 37996, USA.
*
* ---------------------------------------------------------------------
*/
/*
* .. Local Scalars ..
*/
int inbt;
/* ..
* .. Executable Statements ..
*
*/
inbt = ( ( INB -= I ) <= 0 ? ( (-INB) / NB + 1 ) * NB + INB : INB );
return( MIN( inbt, N ) );
/*
* End of PB_Cfirstnb
*/
}
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