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dft_tools/triqs/mpi/vector.hpp
Olivier Parcollet 9c129cb224 [mpi] draft of gf support
- done Matsubara freq for testing and rereading.
- TODO: generalize to other meshes.
- draft for multi var gf
2014-10-18 21:20:01 +02:00

121 lines
4.4 KiB
C++

/*******************************************************************************
*
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
*
* Copyright (C) 2014 by O. Parcollet
*
* TRIQS is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* TRIQS. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
#pragma once
namespace triqs {
namespace mpi {
// When value_type is a basic type, we can directly call the C API
template <typename T> struct mpi_impl_std_vector_basic {
static MPI_Datatype D() { return mpi_datatype<T>::invoke(); }
// -----------
static void reduce_in_place(communicator c, std::vector<T> &a, int root) {
MPI_Reduce((c.rank() == root ? MPI_IN_PLACE : a.data()), a.data(), a.size(), D(), MPI_SUM, root, c.get());
}
static void allreduce_in_place(communicator c, std::vector<T> &a, int root) {
MPI_Allreduce(MPI_IN_PLACE, a.data(), a.size(), D(), MPI_SUM, root, c.get());
}
// -----------
static void broadcast(communicator c, std::vector<T> &a, int root) {
size_t s=a.size();
MPI_Bcast(&s, 1, mpi_datatype<size_t>::invoke(), root, c.get());
if(c.rank() != root) a.resize(s);
MPI_Bcast(a.data(), a.size(), D(), root, c.get()); }
// -----------
static std::vector<T> invoke(tag::reduce, communicator c, T const &a, int root) {
std::vector<T> b(a.size());
MPI_Reduce(a.data(), b.data(), a.size(), D(), MPI_SUM, root, c.get());
return b;
}
// -----------
static std::vector<T> invoke(tag::allreduce, communicator c, std::vector<T> const &a, int root) {
std::vector<T> b(a.size());
MPI_Allreduce(a.data(), b.data(), a.size(), D(), MPI_SUM, root, c.get());
return b;
}
// -----------
static std::vector<T> invoke(tag::scatter, communicator c, std::vector<T> const &a, int root) {
auto slow_size = a.size();
auto sendcounts = std::vector<int>(c.size());
auto displs = std::vector<int>(c.size() + 1, 0);
int recvcount = slice_length(slow_size - 1, c.size(), c.rank());
std::vector<T> b(recvcount);
for (int r = 0; r < c.size(); ++r) {
sendcounts[r] = slice_length(slow_size - 1, c.size(), r);
displs[r + 1] = sendcounts[r] + displs[r];
}
MPI_Scatterv((void *)a.data(), &sendcounts[0], &displs[0], D(), (void *)b.data(), recvcount, D(), root, c.get());
return b;
}
// -----------
static std::vector<T> invoke(tag::gather, communicator c, std::vector<T> const &a, int root) {
long size = reduce(a.size(), c, root);
std::vector<T> b(size);
auto recvcounts = std::vector<int>(c.size());
auto displs = std::vector<int>(c.size() + 1, 0);
int sendcount = a.size();
auto mpi_ty = mpi::mpi_datatype<int>::invoke();
MPI_Gather(&sendcount, 1, mpi_ty, &recvcounts[0], 1, mpi_ty, root, c.get());
for (int r = 0; r < c.size(); ++r) displs[r + 1] = recvcounts[r] + displs[r];
MPI_Gatherv((void *)a.data(), sendcount, D(), (void *)b.data(), &recvcounts[0], &displs[0], D(), root, c.get());
return b;
}
// -----------
static std::vector<T> invoke(tag::allgather, communicator c, std::vector<T> const &a, int root) {
long size = allreduce(a.size(), c, root);
std::vector<T> b(size);
auto recvcounts = std::vector<int>(c.size());
auto displs = std::vector<int>(c.size() + 1, 0);
int sendcount = a.size();
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 *)a.data(), sendcount, D(), (void *)b.data(), &recvcounts[0], &displs[0], D(), c.get());
return b;
}
};
template <typename T>
struct mpi_impl<std::vector<T>, std14::enable_if_t<std::is_arithmetic<T>::value ||
triqs::is_complex<T>::value>> : mpi_impl_std_vector_basic<T> {};
// vector <T> for T non basic
}
} // namespace