fast_imem.cpp

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/*
# =============================================================================
# Copyright (c) 2016 - 2021 Blue Brain Project/EPFL
#
# See top-level LICENSE file for details.
# =============================================================================
*/
 
#include "coreneuron/nrnconf.h"
#include "coreneuron/sim/fast_imem.hpp"
#include "coreneuron/utils/memory.h"
#include "coreneuron/mpi/nrnmpi.h"
#include "coreneuron/utils/nrnoc_aux.hpp"
 
namespace coreneuron {
 
extern int nrn_nthread;
extern NrnThread* nrn_threads;
bool nrn_use_fast_imem;
 
void fast_imem_free() {
    for (auto nt = nrn_threads; nt < nrn_threads + nrn_nthread; ++nt) {
        if (nt->nrn_fast_imem) {
            free_memory(nt->nrn_fast_imem->nrn_sav_rhs);
            free_memory(nt->nrn_fast_imem->nrn_sav_d);
            free_memory(nt->nrn_fast_imem);
            nt->nrn_fast_imem = nullptr;
        }
    }
}
 
void nrn_fast_imem_alloc() {
    if (nrn_use_fast_imem) {
        fast_imem_free();
        for (auto nt = nrn_threads; nt < nrn_threads + nrn_nthread; ++nt) {
            int n = nt->end;
            nt->nrn_fast_imem = (NrnFastImem*) ecalloc_align(1, sizeof(NrnFastImem));
            nt->nrn_fast_imem->nrn_sav_rhs = (double*) ecalloc_align(n, sizeof(double));
            nt->nrn_fast_imem->nrn_sav_d = (double*) ecalloc_align(n, sizeof(double));
        }
    }
}
 
void nrn_calc_fast_imem(NrnThread* nt) {
    int i1 = 0;
    int i3 = nt->end;
 
    double* vec_rhs = nt->_actual_rhs;
    double* vec_area = nt->_actual_area;
 
    double* fast_imem_d = nt->nrn_fast_imem->nrn_sav_d;
    double* fast_imem_rhs = nt->nrn_fast_imem->nrn_sav_rhs;
    nrn_pragma_acc(
        parallel loop present(vec_rhs, vec_area, fast_imem_d, fast_imem_rhs) if (nt->compute_gpu)
            async(nt->stream_id))
    nrn_pragma_omp(target teams distribute parallel for simd if(nt->compute_gpu))
    for (int i = i1; i < i3; ++i) {
        fast_imem_rhs[i] = (fast_imem_d[i] * vec_rhs[i] + fast_imem_rhs[i]) * vec_area[i] * 0.01;
    }
}
 
void nrn_calc_fast_imem_init(NrnThread* nt) {
    // See the corresponding NEURON nrn_calc_fast_imem_fixedstep_init
    int i1 = 0;
    int i3 = nt->end;
 
    double* vec_rhs = nt->_actual_rhs;
    double* vec_area = nt->_actual_area;
 
    double* fast_imem_rhs = nt->nrn_fast_imem->nrn_sav_rhs;
    nrn_pragma_acc(parallel loop present(vec_rhs, vec_area, fast_imem_rhs) if (nt->compute_gpu)
                       async(nt->stream_id))
    nrn_pragma_omp(target teams distribute parallel for simd if(nt->compute_gpu))
    for (int i = i1; i < i3; ++i) {
        fast_imem_rhs[i] = (vec_rhs[i] + fast_imem_rhs[i]) * vec_area[i] * 0.01;
    }
}
 
}  // namespace coreneuron