void invoke() {
if (!has_contiguous_data(lhs)) TRIQS_RUNTIME_ERROR << "mpi gather of array into a non contiguous view";
auto c = laz.c;
auto recvcounts = std::vector<int>(c.size());
auto displs = std::vector<int>(c.size() + 1, 0);
int sendcount = laz.ref.domain().number_of_elements();
auto D = mpi::mpi_datatype<typename A::value_type>();
auto d = laz.domain();
if (laz.all || (laz.c.rank() == laz.root)) resize_or_check_if_view(lhs, d.lengths());
void *lhs_p = lhs.data_start();
const void *rhs_p = laz.ref.data_start();
auto mpi_ty = mpi::mpi_datatype<int>();
if (!laz.all)
MPI_Gather(&sendcount, 1, mpi_ty, &recvcounts[0], 1, mpi_ty, laz.root, c.get());
else
MPI_Allgather(&sendcount, 1, mpi_ty, &recvcounts[0], 1, mpi_ty, c.get());
for (int r = 0; r < c.size(); ++r) displs[r + 1] = recvcounts[r] + displs[r];
if (!laz.all)
MPI_Gatherv((void *)rhs_p, sendcount, D, lhs_p, &recvcounts[0], &displs[0], D, laz.root, c.get());
else
MPI_Allgatherv((void *)rhs_p, sendcount, D, lhs_p, &recvcounts[0], &displs[0], D, c.get());
}
//---------------------------------
void _invoke(triqs::mpi::tag::allgather) {
lhs.resize(laz.domain());
// almost the same preparation as gather, except that the recvcounts are ALL gathered...
auto c = laz.c;
auto recvcounts = std::vector<int>(c.size());
auto displs = std::vector<int>(c.size() + 1, 0);
int sendcount = laz.ref.domain().number_of_elements();
auto mpi_ty = mpi::mpi_datatype<int>::invoke();
MPI_Allgather(&sendcount, 1, mpi_ty, &recvcounts[0], 1, mpi_ty, c.get());
for (int r = 0; r < c.size(); ++r) displs[r + 1] = recvcounts[r] + displs[r];
MPI_Allgatherv((void *)laz.ref.data_start(), sendcount, D(), (void *)lhs.data_start(), &recvcounts[0], &displs[0], D(),
c.get());
}
//---------------------------------
void _invoke(triqs::mpi::tag::gather) {
auto d = laz.domain();
if (laz.c.rank() == laz.root) lhs.resize(d);
auto c = laz.c;
auto recvcounts = std::vector<int>(c.size());
auto displs = std::vector<int>(c.size() + 1, 0);
int sendcount = laz.ref.domain().number_of_elements();
auto mpi_ty = mpi::mpi_datatype<int>::invoke();
MPI_Gather(&sendcount, 1, mpi_ty, &recvcounts[0], 1, mpi_ty, laz.root, c.get());
for (int r = 0; r < c.size(); ++r) displs[r + 1] = recvcounts[r] + displs[r];
MPI_Gatherv((void *)laz.ref.data_start(), sendcount, D(), (void *)lhs.data_start(), &recvcounts[0], &displs[0], D(), laz.root,
c.get());
}
//---------------------------------
void _invoke(triqs::mpi::tag::scatter) {
lhs.resize(laz.domain());
auto c = laz.c;
auto slow_size = first_dim(laz.ref);
auto slow_stride = laz.ref.indexmap().strides()[0];
auto sendcounts = std::vector<int>(c.size());
auto displs = std::vector<int>(c.size() + 1, 0);
int recvcount = mpi::slice_length(slow_size - 1, c.size(), c.rank()) * slow_stride;
for (int r = 0; r < c.size(); ++r) {
sendcounts[r] = mpi::slice_length(slow_size - 1, c.size(), r) * slow_stride;
displs[r + 1] = sendcounts[r] + displs[r];
}
MPI_Scatterv((void *)laz.ref.data_start(), &sendcounts[0], &displs[0], D(), (void *)lhs.data_start(), recvcount, D(),
laz.root, c.get());
}
void invoke() {
if (!has_contiguous_data(lhs)) TRIQS_RUNTIME_ERROR << "mpi scatter of array into a non contiguous view";
resize_or_check_if_view(lhs, laz.domain().lengths());
auto c = laz.c;
auto slow_size = first_dim(laz.ref);
auto slow_stride = laz.ref.indexmap().strides()[0];
auto sendcounts = std::vector<int>(c.size());
auto displs = std::vector<int>(c.size() + 1, 0);
int recvcount = mpi::slice_length(slow_size - 1, c.size(), c.rank()) * slow_stride;
auto D = mpi::mpi_datatype<typename A::value_type>();
for (int r = 0; r < c.size(); ++r) {
sendcounts[r] = mpi::slice_length(slow_size - 1, c.size(), r) * slow_stride;
displs[r + 1] = sendcounts[r] + displs[r];
}
MPI_Scatterv((void *)laz.ref.data_start(), &sendcounts[0], &displs[0], D, (void *)lhs.data_start(), recvcount, D, laz.root,
c.get());
}
void invoke() {
if (!has_contiguous_data(lhs)) TRIQS_RUNTIME_ERROR << "mpi reduction of array into a non contiguous view";
auto rhs_n_elem = laz.ref.domain().number_of_elements();
auto c = laz.c;
auto root = laz.root;
auto D = mpi::mpi_datatype<typename A::value_type>();
bool in_place = (lhs.data_start() == laz.ref.data_start());
// some checks.
if (in_place) {
if (rhs_n_elem != lhs.domain().number_of_elements())
TRIQS_RUNTIME_ERROR << "mpi reduce of array : same pointer to data start, but differnet number of elements !";
} else { // check no overlap
if ((c.rank() == root) || laz.all) resize_or_check_if_view(lhs, laz.domain().lengths());
if (std::abs(lhs.data_start() - laz.ref.data_start()) < rhs_n_elem)
TRIQS_RUNTIME_ERROR << "mpi reduce of array : overlapping arrays !";
}
void *lhs_p = lhs.data_start();
void *rhs_p = (void *)laz.ref.data_start();
if (!laz.all) {
if (in_place)
MPI_Reduce((c.rank() == root ? MPI_IN_PLACE : rhs_p), rhs_p, rhs_n_elem, D, MPI_SUM, root, c.get());
else
MPI_Reduce(rhs_p, lhs_p, rhs_n_elem, D, MPI_SUM, root, c.get());
} else {
if (in_place)
MPI_Allreduce(MPI_IN_PLACE, rhs_p, rhs_n_elem, D, MPI_SUM, c.get());
else
MPI_Allreduce(rhs_p, lhs_p, rhs_n_elem, D, MPI_SUM, c.get());
}
}
//---------------------------------
void _invoke(triqs::mpi::tag::all_reduce) {
// ADD debug check under macro that all nodes have same size
lhs.resize(laz.domain());
MPI_Allreduce((void *)laz.ref.data_start(), (void *)lhs.data_start(), laz.ref.domain().number_of_elements(), D(), MPI_SUM, laz.c.get());
}
//---------------------------------
void _invoke(triqs::mpi::tag::reduce) {
if (laz.c.rank() == laz.root) lhs.resize(laz.domain());
MPI_Reduce((void *)laz.ref.data_start(), (void *)lhs.data_start(), laz.ref.domain().number_of_elements(), D(), MPI_SUM, laz.root, laz.c.get());
}
