X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/933849e1079bf5389d6a38447d49cbe5cc65101d..414839787a24ee470f3124f95659a5f6569a2cd5:/src/smpi/colls/smpi_coll.cpp

diff --git a/src/smpi/colls/smpi_coll.cpp b/src/smpi/colls/smpi_coll.cpp
index c8c322e5d9..cf22e98031 100644
--- a/src/smpi/colls/smpi_coll.cpp
+++ b/src/smpi/colls/smpi_coll.cpp
@@ -1,6 +1,6 @@
 /* smpi_coll.c -- various optimized routing for collectives                 */
 
-/* Copyright (c) 2009-2022. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2009-2023. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
@@ -13,15 +13,17 @@
 #include "smpi_request.hpp"
 #include "xbt/config.hpp"
 
+#include <iomanip>
 #include <map>
+#include <numeric>
+#include <sstream>
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_coll, smpi, "Logging specific to SMPI collectives.");
 
-namespace simgrid {
-namespace smpi {
+namespace simgrid::smpi {
 
 std::map<std::string, std::vector<s_mpi_coll_description_t>, std::less<>> smpi_coll_descriptions(
-    {{std::string("gather"),
+    {{"gather",
       {{"default", "gather default collective", (void*)gather__default},
        {"ompi", "gather ompi collective", (void*)gather__ompi},
        {"ompi_basic_linear", "gather ompi_basic_linear collective", (void*)gather__ompi_basic_linear},
@@ -243,6 +245,29 @@ std::vector<s_mpi_coll_description_t>* colls::get_smpi_coll_descriptions(const s
   return &iter->second;
 }
 
+std::string colls::get_smpi_coll_help()
+{
+  size_t max_name_len =
+      std::accumulate(begin(smpi_coll_descriptions), end(smpi_coll_descriptions), 0, [](auto len, auto const& coll) {
+        return std::max(len, std::accumulate(begin(coll.second), end(coll.second), 0, [](auto len, auto const& descr) {
+                          return std::max<size_t>(len, descr.name.length());
+                        }));
+      });
+  std::ostringstream oss;
+  std::string title = "Available collective algorithms (select them with \"smpi/collective_name:algo_name\"):";
+  oss << title << '\n' << std::setfill('=') << std::setw(title.length() + 1) << '\n';
+  for (auto const& [coll, algos] : smpi_coll_descriptions) {
+    std::string line = "Collective: \"" + coll + "\"";
+    oss << line << '\n' << std::setfill('-') << std::setw(line.length() + 1) << '\n';
+    oss << std::setfill(' ') << std::left;
+    for (auto const& [name, descr, _] : algos)
+      oss << "  " << std::setw(max_name_len) << name << " " << descr << "\n";
+    oss << std::right << '\n';
+  }
+  oss << "Please see https://simgrid.org/doc/latest/app_smpi.html#available-algorithms for more information.\n";
+  return oss.str();
+}
+
 static s_mpi_coll_description_t* find_coll_description(const std::string& collective, const std::string& algo)
 {
   std::vector<s_mpi_coll_description_t>* table = colls::get_smpi_coll_descriptions(collective);
@@ -259,7 +284,8 @@ static s_mpi_coll_description_t* find_coll_description(const std::string& collec
   std::string name_list = table->at(0).name;
   for (unsigned long i = 1; i < table->size(); i++)
     name_list = name_list + ", " + table->at(i).name;
-  xbt_die("Collective '%s' has no algorithm '%s'! Valid algorithms: %s.", collective.c_str(), algo.c_str(), name_list.c_str());
+  xbt_die("Collective '%s' has no algorithm '%s'! Valid algorithms: %s. Please use --help-coll for details.",
+          collective.c_str(), algo.c_str(), name_list.c_str());
 }
 
 int (*colls::gather)(const void* send_buff, int send_count, MPI_Datatype send_type, void* recv_buff, int recv_count,
@@ -482,5 +508,4 @@ int colls::alltoallw(const void* sendbuf, const int* sendcounts, const int* send
   return Request::wait(&request, MPI_STATUS_IGNORE);
 }
 
-}
-}
+} // namespace simgrid::smpi