1 files changed, 138 insertions, 0 deletions
diff --git a/libs/mpi/example/reduce_performance_test.cpp b/libs/mpi/example/reduce_performance_test.cpp
new file mode 100644
index 000000000..40411b14a
--- /dev/null
+++ b/libs/mpi/example/reduce_performance_test.cpp
@@ -0,0 +1,138 @@
+// Copyright (C) 2006 Trustees of Indiana University
+//
+// Authors: Douglas Gregor
+//          Andrew Lumsdaine
+
+// Use, modification and distribution is subject to the Boost Software
+// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+// Performance test of the reduce() collective
+#include <boost/mpi.hpp>
+#include <boost/lexical_cast.hpp>
+
+namespace mpi = boost::mpi;
+
+struct add_int {
+  int operator()(int x, int y) const { return x + y; }
+};
+
+struct wrapped_int
+{
+  wrapped_int() : value(0) { }
+  wrapped_int(int value) : value(value) { }
+
+  template<typename Archiver>
+  void serialize(Archiver& ar, const unsigned int /*version*/) {
+    ar & value;
+  }
+
+  int value;
+};
+
+inline wrapped_int operator+(wrapped_int x, wrapped_int y)
+{
+  return wrapped_int(x.value + y.value);
+}
+
+namespace boost { namespace mpi {
+  template<> struct is_mpi_datatype<wrapped_int> : mpl::true_ { };
+} }
+
+struct serialized_int
+{
+  serialized_int() : value(0) { }
+  serialized_int(int value) : value(value) { }
+
+  template<typename Archiver>
+  void serialize(Archiver& ar, const unsigned int /*version*/) {
+    ar & value;
+  }
+
+  int value;
+};
+
+inline serialized_int operator+(serialized_int x, serialized_int y)
+{
+  return serialized_int(x.value + y.value);
+}
+
+int main(int argc, char* argv[])
+{
+  mpi::environment env(argc, argv);
+  mpi::communicator world;
+
+  int repeat_count = 100;
+  int outer_repeat_count = 2;
+
+  if (argc > 1) repeat_count = boost::lexical_cast<int>(argv[1]);
+  if (argc > 2) outer_repeat_count = boost::lexical_cast<int>(argv[2]);
+
+  if (world.rank() == 0)
+    std::cout << "# of processors: " << world.size() << std::endl
+              << "# of iterations: " << repeat_count << std::endl;
+
+  int value = world.rank();
+  int result;
+  wrapped_int wi_value = world.rank();
+  wrapped_int wi_result;
+  serialized_int si_value = world.rank();
+  serialized_int si_result;
+
+  // Spin for a while...
+  for (int i = 0; i < repeat_count/10; ++i) {
+    reduce(world, value, result, std::plus<int>(), 0);
+    reduce(world, value, result, add_int(), 0);
+    reduce(world, wi_value, wi_result, std::plus<wrapped_int>(), 0);
+    reduce(world, si_value, si_result, std::plus<serialized_int>(), 0);
+  }
+
+  for (int outer = 0; outer < outer_repeat_count; ++outer) {
+    // Raw MPI
+    mpi::timer time;
+    for (int i = 0; i < repeat_count; ++i) {
+      MPI_Reduce(&value, &result, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);
+    }
+    double reduce_raw_mpi_total_time = time.elapsed();
+
+    // MPI_INT/MPI_SUM case
+    time.restart();
+    for (int i = 0; i < repeat_count; ++i) {
+      reduce(world, value, result, std::plus<int>(), 0);
+    }
+    double reduce_int_sum_total_time = time.elapsed();
+
+    // MPI_INT/MPI_Op case
+    time.restart();
+    for (int i = 0; i < repeat_count; ++i) {
+      reduce(world, value, result, add_int(), 0);
+    }
+    double reduce_int_op_total_time = time.elapsed();
+
+    // MPI_Datatype/MPI_Op case
+    time.restart();
+    for (int i = 0; i < repeat_count; ++i) {
+      reduce(world, wi_value, wi_result, std::plus<wrapped_int>(), 0);
+    }
+    double reduce_type_op_total_time = time.elapsed();
+  
+    // Serialized/MPI_Op case
+    time.restart();
+    for (int i = 0; i < repeat_count; ++i) {
+      reduce(world, si_value, si_result, std::plus<serialized_int>(), 0);
+    }
+    double reduce_ser_op_total_time = time.elapsed();
+
+
+    if (world.rank() == 0)
+      std::cout << "\nInvocation\tElapsed Time (seconds)"
+                << "\nRaw MPI\t\t\t" << reduce_raw_mpi_total_time
+                << "\nMPI_INT/MPI_SUM\t\t" << reduce_int_sum_total_time
+                << "\nMPI_INT/MPI_Op\t\t" << reduce_int_op_total_time
+                << "\nMPI_Datatype/MPI_Op\t" << reduce_type_op_total_time
+                << "\nSerialized/MPI_Op\t" << reduce_ser_op_total_time 
+                << std::endl;
+  }
+
+  return 0;
+}