//------------------------------------------------------------------------------
// GB_parition.h: definitions for partitioning an index range
//------------------------------------------------------------------------------

// SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2022, All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0

//------------------------------------------------------------------------------

#ifndef GB_PARTITION_H
#define GB_PARTITION_H

// GB_PART and GB_PARTITION:  divide the index range 0:n-1 equally
// for nthreads.  GB_PART(tid,n,nthreads) is the first index for thread tid.
#define GB_PART(tid,n,nthreads)  \
    (((tid) * ((double) (n))) / ((double) (nthreads)))

// thread tid will operate on the range k1:(k2-1)
#define GB_PARTITION(k1,k2,n,tid,nthreads)                                  \
    k1 = ((tid) ==  0          ) ?  0  : GB_PART ((tid),  n, nthreads) ;    \
    k2 = ((tid) == (nthreads)-1) ? (n) : GB_PART ((tid)+1,n, nthreads)

#endif

