ScaLAPACK 2.1
2.1
ScaLAPACK: Scalable Linear Algebra PACKage
PB_Cfirstnb.c
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/* ---------------------------------------------------------------------
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*
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* -- PBLAS auxiliary routine (version 2.0) --
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* University of Tennessee, Knoxville, Oak Ridge National Laboratory,
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* and University of California, Berkeley.
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* April 1, 1998
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*
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* ---------------------------------------------------------------------
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*/
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/*
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* Include files
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*/
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#include "../pblas.h"
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#include "../PBpblas.h"
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#include "../PBtools.h"
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#include "../PBblacs.h"
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#include "../PBblas.h"
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#ifdef __STDC__
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int
PB_Cfirstnb
(
int
N,
int
I,
int
INB,
int
NB )
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#else
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int
PB_Cfirstnb
( N, I, INB, NB )
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/*
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* .. Scalar Arguments ..
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*/
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int
I, INB, N, NB;
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#endif
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{
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/*
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* Purpose
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* =======
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*
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* PB_Cfirstnb returns the global number of matrix rows or columns of the
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* first block, if N rows or columns are given out starting from the
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* global index I. Note that if N is equal 0, this routine returns 0.
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*
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* Arguments
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* =========
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*
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* N (global input) INTEGER
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* On entry, N specifies the number of rows/columns being dealt
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* out. N must be at least zero.
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*
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* I (global input) INTEGER
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* On entry, I specifies the global index of the matrix entry.
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* I must be at least zero.
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*
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* INB (global input) INTEGER
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* On entry, INB specifies the size of the first block of the
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* global matrix distribution. INB must be at least one.
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*
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* NB (global input) INTEGER
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* On entry, NB specifies the size of the blocks used to parti-
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* tion the matrix. NB must be at least one.
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*
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* -- Written on April 1, 1998 by
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* Antoine Petitet, University of Tennessee, Knoxville 37996, USA.
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*
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* ---------------------------------------------------------------------
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*/
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/*
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* .. Local Scalars ..
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*/
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int
inbt;
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/* ..
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* .. Executable Statements ..
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*
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*/
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inbt = ( ( INB -= I ) <= 0 ? ( (-INB) / NB + 1 ) * NB + INB : INB );
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return
(
MIN
( inbt, N ) );
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/*
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* End of PB_Cfirstnb
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*/
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}
PB_Cfirstnb
int PB_Cfirstnb(int N, int I, int INB, int NB)
Definition:
PB_Cfirstnb.c:22
MIN
#define MIN(a_, b_)
Definition:
PBtools.h:76
PBLAS
SRC
PTOOLS
PB_Cfirstnb.c
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