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/*
* decomp.h
*
* Created on: Oct 2018
* Author: Norbert Podhorszki
*/
#include "decomp.h"
void decompColumnMajor(const size_t ndim, const size_t rank, const size_t *decomp, size_t *pos)
{
// pos[k] = rank / prod(decomp[i], i=0..k-1) % decomp[k]
size_t prod = 1;
for (size_t k = 0; k < ndim; ++k)
{
pos[k] = rank / prod % decomp[k];
prod *= decomp[k];
}
}
void decompRowMajor(const size_t ndim, const size_t rank, const size_t *decomp, size_t *pos)
{
// pos[k] = rank / prod(decomp[i], i=k+1..n-1) % decomp[k]
size_t prod = 1;
for (int k = static_cast<int>(ndim) - 1; k >= 0; --k)
{
pos[k] = rank / prod % decomp[k];
prod *= decomp[k];
}
}
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