remove unused nccl.cmake

cmake/external/nccl.cmake

-# Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-# http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-if(NOT WITH_GPU)
-  return()
-endif()
-
-include(ExternalProject)
-
-set(NCCL_SOURCE_DIR ${THIRD_PARTY_PATH}/nccl)
-
-include_directories(${NCCL_SOURCE_DIR}/src/extern_nccl/src)
-
-if(WITH_DSO)
-  # If we use DSO, we do not build nccl, just download the dependencies
-  set(NCCL_BUILD_COMMAND "")
-  set(NCCL_INSTALL_COMMAND "")
-  set(NCCL_INSTALL_DIR "")
-else()
-  # otherwise, we build nccl and link it.
-  set(NCCL_INSTALL_DIR ${THIRD_PARTY_PATH}/install/nccl)
-  # Note: cuda 8.0 is needed to make nccl
-  # When cuda is not installed on the system directory, need to set CUDA_HOME to your cuda root
-  set(NCCL_BUILD_COMMAND "make -j 8")
-  set(NCCL_INSTALL_COMMAND  "make install PREFIX=${NCCL_INSTALL_DIR}")
-endif()
-
-ExternalProject_Add(
-    extern_nccl
-    ${EXTERNAL_PROJECT_LOG_ARGS}
-    GIT_REPOSITORY  "https://github.com/NVIDIA/nccl.git"
-    GIT_TAG         "v1.3.4-1"
-    PREFIX          "${NCCL_SOURCE_DIR}"
-    UPDATE_COMMAND  ""
-    CONFIGURE_COMMAND ""
-    BUILD_COMMAND     "${NCCL_BUILD_COMMAND}"
-    INSTALL_COMMAND   "${NCCL_INSTALL_COMMAND}"
-    INSTALL_DIR       "${NCCL_INSTALL_DIR}"
-    TEST_COMMAND      ""
-)
-
-if(WITH_DSO)
-  if(${CMAKE_VERSION} VERSION_LESS "3.3.0")
-    set(dummyfile ${CMAKE_CURRENT_BINARY_DIR}/lib_nccl_dummy.c)
-    file(WRITE ${dummyfile} "const char * dummy_nccl = \"${dummyfile}\";")
-    add_library(nccl STATIC ${dummyfile})
-  else()
-    add_library(nccl INTERFACE)
-  endif()
-else()
-  add_library(nccl STATIC IMPORTED GLOBAL)
-  set_property(TARGET nccl PROPERTY IMPORTED_LOCATION
-               ${NCCL_INSTALL_DIR}/lib/libnccl_static.a)
-endif()
-
-add_dependencies(nccl extern_nccl)