Use find_package for MPI (ROCm#92)

* Use find_package for MPI
* Minor fixes

Author: dsidler

CMakeLists.txt

@@ -3,27 +3,6 @@
 # ########################################################################
 #Adding pthread flag for linking
 set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pthread")
-macro(check_mpi mpi_compiler mpi_lib_a mpi_lib_so mpi_bin_dir mpi_base_lib_dir mpi_inc_dir)
-    find_program(MPI_MPICXX ${mpi_compiler} PATHS ${mpi_bin_dir} NO_DEFAULT_PATH)
-    if (MPI_MPICXX)
-        message ("-- ${mpi_compiler} found @ ${MPI_MPICXX}")
-        find_file(MPI_H mpi.h PATHS ${mpi_inc_dir} NO_DEFAULT_PATH)
-        message ("-- mpi.h is in ${MPI_H}")
-        find_file(MPI_LIB NAMES ${mpi_lib_so} ${mpi_lib_a} PATHS ${mpi_base_lib_dir} PATH_SUFFIXES lib lib64 lib/x86_64-linux-gnu NO_DEFAULT_PATH)
-        message ("-- libmpi is ${MPI_LIB}")
-	if (NOT MPI_H OR NOT MPI_LIB)
-	    set (MPI_MPICXX "MPI_MPICXX-NOTFOUND")
-	    set (MPI_H "MPI_H-NOTFOUND")
-	    set (MPI_LIB "MPI_LIB-NOTFOUND")
-	else()
-            add_definitions(-DMPI_SUPPORT)
-            include_directories(${mpi_inc_dir})
-            link_libraries(${MPI_LIB})
-	endif()
-    else()
-        message ("-- ${mpi_compiler} not found")
-    endif()
-endmacro()
 
 cmake_minimum_required(VERSION 3.16.3 FATAL_ERROR)
 
@@ -51,8 +30,7 @@ include(ROCMCheckTargetIds)
 include(ROCMClients)
 
 # Build variables
-option(NO_MPI "Build RCCL-tests without MPI support.")
-option(MPI_PATH "Use MPI in the specified directory.")
+option(USE_MPI "Build RCCL-tests with MPI support.")
 
 # Default GPU architectures to build
 #==================================================================================================
@@ -84,64 +62,23 @@ set(GPU_TARGETS "${SUPPORTED_GPUS}" CACHE STRING "List of specific GPU architect
 message(STATUS "Compiling for ${GPU_TARGETS}")
 
 find_package(RCCL HINTS CONFIG REQUIRED PATHS "${ROCM_PATH}")
+if (RCCL_FOUND)
+    message(STATUS "RCCL version : ${RCCL_VERSION}")
+    message(STATUS "RCCL include path : ${RCCL_INCLUDE_DIRS}")
+    message(STATUS "RCCL libraries : ${RCCL_LIBRARIES}")
+endif()
 
-if (NOT NO_MPI)
-    # CHECK for MPI Path first. User requested this directory explicitely
-    if (MPI_PATH)
-        set(mpi_spec_bin_dir "${MPI_PATH}/bin")
-	set(mpi_spec_inc_dir "${MPI_PATH}/include")
-        check_mpi(mpicxx libmpi.a libmpi.so ${mpi_spec_bin_dir} ${MPI_PATH} ${mpi_spec_inc_dir})
-	if (NOT MPI_MPICXX)
-            # Since the user explicitely requested this directory, abort if something went wrong.
-	    MESSAGE(FATAL_ERROR "Could not find MPI in ${MPI_PATH}")
-        endif()
-    endif()
-
-    # Check for MPICH Ubuntu installation
-    if (NOT MPI_MPICXX)
-        check_mpi(mpicxx.mpich libmpich.a libmpich.so /usr/bin /usr /usr/include/x86_64-linux-gnu/mpich)
-    endif()
-
-    # Check for Open MPI Ubuntu installation
-    if (NOT MPI_MPICXX)
-        check_mpi(mpicxx.openmpi libmpi.a libmpi.so /usr/bin  /usr/lib/x86_64-linux-gnu/openmpi /usr/lib/x86_64-linux-gnu/openmpi/include)
-    endif()
-
-    # Check for MPICH RHEL installation
-    if (NOT MPI_MPICXX)
-        check_mpi(mpicxx libmpich.a libmpich.so /usr/lib64/mpich/bin /usr/lib64/mpich /usr/include/mpich-x86_64)
-    endif()
-
-    # Check for Open MPI RHEL installation
-    if (NOT MPI_MPICXX)
-        check_mpi(mpicxx libmpi.a libmpi.so /usr/lib64/openmpi/bin /usr/lib64/openmpi /usr/include/openmpi-x64_64)
-    endif()
-
-    # Check for MPICH SLES installation
-    if (NOT MPI_MPICXX)
-        check_mpi(mpicxx libmpich.a libmpich.so /usr/lib64/mpi/gcc/mpich/bin /usr/lib64/mpi/gcc/mpich /usr/lib64/mpi/gcc/mpich/include)
-    endif()
-
-    # Check for Open MPI v4 SLES installation
-    if (NOT MPI_MPICXX)
-        check_mpi(mpicxx libmpi.a libmpi.so /usr/lib64/mpi/gcc/openmpi4/bin /usr/lib64/mpi/gcc/openmpi4 /usr/lib64/mpi/gcc/openmpi4/include)
-    endif()
-
-    # Check for Open MPI v3 SLES installation
-    if (NOT MPI_MPICXX)
-        check_mpi(mpicxx libmpi.a libmpi.so /usr/lib64/mpi/gcc/openmpi3/bin /usr/lib64/mpi/gcc/openmpi3 /usr/lib64/mpi/gcc/openmpi3/include)
-    endif()
-
-    # Check for Open MPI v2 SLES installation
-    if (NOT MPI_MPICXX)
-        check_mpi(mpicxx libmpi.a libmpi.so /usr/lib64/mpi/gcc/openmpi2/bin /usr/lib64/mpi/gcc/openmpi2 /usr/lib64/mpi/gcc/openmpi2/include)
-    endif()
-
-    if (NOT MPI_MPICXX)
+if (USE_MPI)
+    find_package(MPI REQUIRED)
+    if (MPI_FOUND)
+        message(STATUS "MPI include path : ${MPI_CXX_INCLUDE_PATH}")
+        message(STATUS "MPI libraries : ${MPI_CXX_LIBRARIES}")
+        add_definitions(-DMPI_SUPPORT)
+    else()
         message ("-- no MPI library found")
     endif()
 else()
-    message ("-- MPI support explicitely disabled")
+    message ("-- MPI support disabled")
 endif()
 
 set(ROCM_USE_DEV_COMPONENT OFF)  # This repo doesn't have a dev component

README.md

@@ -30,9 +30,7 @@ $ make
 When using the cmake build procedure, please make sure that RCCL has also been built using cmake (i.e. not using the install.sh script), since cmake will check
 for cmake target and config files that are created during the RCCL build.
 
-Using the cmake method also has the advantage that the build is automatically checking for MPI installations, i.e. it is not necessary to explicitly request
-MPI builds. A user can request to use a particular MPI library by using the MPI_PATH variable. MPI support can be explicitely disabled by adding the -DNO_MPI=1
-flag to the cmake command line.
+Using the cmake method also has the advantage that the build is automatically checking for MPI installations. The tests can be compiled with MPI support by adding the `-DUSE_MPI=ON` flag to the cmake command line. A user can request to use a particular MPI library by setting the environment variable `MPI_HOME` or add the path of the MPI library to the cmake prefix path with `-DCMAKE_PREFIX_PATH`.
 
 
 ## Usage