Move all smpi colls to cpp.

[simgrid.git] / src / smpi / colls / barrier-mvapich2-pair.cpp

diff --git a/src/smpi/colls/barrier-mvapich2-pair.cpp b/src/smpi/colls/barrier-mvapich2-pair.cpp
new file mode 100644 (file)
index 0000000..2ef6ad1
--- /dev/null
+++ b/src/smpi/colls/barrier-mvapich2-pair.cpp
@@ -0,0 +1,98 @@
+/* Copyright (c) 2013-2014. 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. */
+
+/*
+ * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
+ *                         University Research and Technology
+ *                         Corporation.  All rights reserved.
+ * Copyright (c) 2004-2006 The University of Tennessee and The University
+ *                         of Tennessee Research Foundation.  All rights
+ *                         reserved.
+ * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
+ *                         University of Stuttgart.  All rights reserved.
+ * Copyright (c) 2004-2005 The Regents of the University of California.
+ *                         All rights reserved.
+ * Copyright (c) 2008      Sun Microsystems, Inc.  All rights reserved.
+ *
+ * Additional copyrights may follow
+ */
+ 
+ /* -*- Mode: C; c-basic-offset:4 ; -*- */
+/*
+ *
+ *  (C) 2001 by Argonne National Laboratory.
+ *      See COPYRIGHT in top-level directory.
+ */
+
+/* Copyright (c) 2001-2014, The Ohio State University. All rights
+ * reserved.
+ *
+ * This file is part of the MVAPICH2 software package developed by the
+ * team members of The Ohio State University's Network-Based Computing
+ * Laboratory (NBCL), headed by Professor Dhabaleswar K. (DK) Panda.
+ *
+ * For detailed copyright and licensing information, please refer to the
+ * copyright file COPYRIGHT in the top level MVAPICH2 directory.
+ *
+ */
+
+#include "colls_private.h"
+#include "coll_tuned_topo.h"
+
+int smpi_coll_tuned_barrier_mvapich2_pair(MPI_Comm comm)
+{
+
+    int size, rank;
+    int d, dst, src;
+    int mpi_errno = MPI_SUCCESS;
+
+    size = smpi_comm_size(comm);
+    /* Trivial barriers return immediately */
+    if (size == 1)
+        return MPI_SUCCESS;
+
+    rank =  smpi_comm_rank(comm);
+    int N2_prev = 1;
+    /*  N2_prev = greatest power of two < size of Comm  */
+    for( N2_prev = 1; N2_prev <= size; N2_prev <<= 1 );
+    N2_prev >>= 1;
+    
+    int surfeit = size - N2_prev;
+
+    /* Perform a combine-like operation */
+    if (rank < N2_prev) {
+        if (rank < surfeit) {
+            /* get the fanin letter from the upper "half" process: */
+            dst = N2_prev + rank;
+            smpi_mpi_recv(NULL, 0, MPI_BYTE, dst, COLL_TAG_BARRIER,
+                                     comm, MPI_STATUS_IGNORE);
+        }
+
+        /* combine on embedded N2_prev power-of-two processes */
+        for (d = 1; d < N2_prev; d <<= 1) {
+            dst = (rank ^ d);
+            smpi_mpi_sendrecv(NULL, 0, MPI_BYTE, dst, COLL_TAG_BARRIER, NULL,
+                                 0, MPI_BYTE, dst, COLL_TAG_BARRIER, comm,
+                                 MPI_STATUS_IGNORE);
+        }
+
+        /* fanout data to nodes above N2_prev... */
+        if (rank < surfeit) {
+            dst = N2_prev + rank;
+            smpi_mpi_send(NULL, 0, MPI_BYTE, dst, COLL_TAG_BARRIER,
+                                     comm);
+        }
+    } else {
+        /* fanin data to power of 2 subset */
+        src = rank - N2_prev;
+        smpi_mpi_sendrecv(NULL, 0, MPI_BYTE, src, COLL_TAG_BARRIER,
+                                     NULL, 0, MPI_BYTE, src, COLL_TAG_BARRIER,
+                                     comm, MPI_STATUS_IGNORE);
+    }
+
+    return mpi_errno;
+
+}