Update CXX and C compilers (#140)

Author: dnhsieh-intel

CMakeLists.txt

@@ -36,32 +36,9 @@ else()
     message(STATUS "CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
 endif()
 
-# Define required compilers for Windows before project
-if(WIN32)
-  set(CMAKE_CXX_COMPILER "clang-cl")
-  set(CMAKE_C_COMPILER "clang-cl")
-endif()
-
-project(oneMKL VERSION 0.1.0 LANGUAGES CXX)
-
+# Build options
 option(BUILD_SHARED_LIBS "Build dynamic libraries" ON)
 
-# Override default CXX compile/link lines for Windows after project
-if(WIN32)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unused-function -w")
-  foreach (flag_var
-           CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE
-           CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO)
-    string(REPLACE "/MD" "" ${flag_var} "${${flag_var}}")
-  endforeach()
-  set(CMAKE_CXX_COMPILE_OBJECT "<CMAKE_CXX_COMPILER> -fsycl /nologo <DEFINES> <INCLUDES> /EHsc <FLAGS> /Fo<OBJECT> -c <SOURCE>")
-  set(CMAKE_CXX_CREATE_STATIC_LIBRARY "lib /nologo <OBJECTS> /out:<TARGET>")
-  set(CMAKE_CXX_LINK_EXECUTABLE "<CMAKE_CXX_COMPILER> -fsycl /nologo <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
-endif()
-
-# Temporary disable sycl 2020 deprecations warnings
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DSYCL2020_DISABLE_DEPRECATION_WARNINGS")
-
 ## Backends
 option(ENABLE_MKLCPU_BACKEND "" ON)
 option(ENABLE_MKLGPU_BACKEND "" ON)
@@ -73,7 +50,13 @@ option(ENABLE_CURAND_BACKEND "" OFF)
 option(ENABLE_NETLIB_BACKEND "" OFF)
 set(ONEMKL_SYCL_IMPLEMENTATION "dpc++" CACHE STRING "Name of the SYCL compiler")
 
-## Domains
+## Testing
+option(BUILD_FUNCTIONAL_TESTS "" ON)
+
+## Documentation
+option(BUILD_DOC "" OFF)
+
+## Supported domains
 set(DOMAINS_LIST "")
 if(ENABLE_MKLCPU_BACKEND
         OR ENABLE_MKLGPU_BACKEND
@@ -91,6 +74,75 @@ if(ENABLE_MKLCPU_BACKEND
   list(APPEND DOMAINS_LIST "rng")
 endif()
 
+# Define required CXX compilers before project
+if(CMAKE_CXX_COMPILER OR NOT ONEMKL_SYCL_IMPLEMENTATION STREQUAL "dpc++")
+  if(WIN32)
+    string(REPLACE "\\" "/" CMAKE_CXX_COMPILER ${CMAKE_CXX_COMPILER})
+  endif()
+else()
+  if(ENABLE_CUBLAS_BACKEND OR ENABLE_CURAND_BACKEND)
+    set(CMAKE_CXX_COMPILER "clang++")
+  elseif(ENABLE_MKLGPU_BACKEND)
+    set(CMAKE_CXX_COMPILER "dpcpp")
+  else()
+    find_program(DPCPP_PATH dpcpp)
+    if(DPCPP_PATH)
+      message(STATUS "CXX compiler: dpcpp was found in PATH, using dpcpp")
+      set(CMAKE_CXX_COMPILER "dpcpp")
+    else()
+      if(WIN32)
+        message(STATUS "CXX compiler: dpcpp was not found in PATH, using clang-cl instead")
+        set(CMAKE_CXX_COMPILER "clang-cl")
+      else()
+        message(STATUS "CXX compiler: dpcpp was not found in PATH, using clang++ instead")
+        set(CMAKE_CXX_COMPILER "clang++")
+      endif()
+    endif()
+  endif()
+endif()
+
+# Define required C compilers before project
+if(CMAKE_C_COMPILER OR NOT ONEMKL_SYCL_IMPLEMENTATION STREQUAL "dpc++")
+  if(WIN32)
+    string(REPLACE "\\" "/" CMAKE_C_COMPILER ${CMAKE_C_COMPILER})
+  endif()
+else()
+  find_program(ICX_PATH icx)
+  if(ICX_PATH)
+    message(STATUS "C compiler: icx was found in PATH, using icx")
+    set(CMAKE_C_COMPILER "icx")
+  else()
+    if(WIN32)
+      message(STATUS "C compiler: icx was not found in PATH, using clang-cl instead")
+      set(CMAKE_C_COMPILER "clang-cl")
+    else()
+      message(STATUS "C compiler: icx was not found in PATH, using clang instead")
+      set(CMAKE_C_COMPILER "clang")
+    endif()
+  endif()
+endif()
+
+project(oneMKL VERSION 0.2.0 LANGUAGES CXX)
+
+# Override default CXX compile/link lines for Windows after project
+if(WIN32 AND ONEMKL_SYCL_IMPLEMENTATION STREQUAL "dpc++")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unused-function -w")
+  foreach (flag_var
+           CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE
+           CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO)
+    string(REPLACE "/MD" "" ${flag_var} "${${flag_var}}")
+  endforeach()
+  set(CMAKE_CXX_COMPILE_OBJECT "<CMAKE_CXX_COMPILER> -fsycl /nologo <DEFINES> <INCLUDES> /EHsc <FLAGS> /Fo<OBJECT> -c <SOURCE>")
+  set(CMAKE_CXX_CREATE_STATIC_LIBRARY "lib /nologo <OBJECTS> /out:<TARGET>")
+  set(CMAKE_CXX_LINK_EXECUTABLE "<CMAKE_CXX_COMPILER> -fsycl /nologo <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
+endif()
+
+# Temporary disable sycl 2020 deprecations warnings
+if(ONEMKL_SYCL_IMPLEMENTATION STREQUAL "dpc++")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DSYCL2020_DISABLE_DEPRECATION_WARNINGS")
+endif()
+
+# Target domains
 if(NOT TARGET_DOMAINS OR TARGET_DOMAINS STREQUAL "None")
   # Set to all by default
   set(TARGET_DOMAINS ${DOMAINS_LIST})
@@ -111,12 +163,6 @@ else()
 endif()
 message(STATUS "TARGET_DOMAINS: ${TARGET_DOMAINS}")
 
-## Testing
-option(BUILD_FUNCTIONAL_TESTS "" ON)
-
-## Documentation
-option(BUILD_DOC "" OFF)
-
 # Set output directories for the project
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)

README.md

@@ -45,6 +45,7 @@ oneMKL is part of [oneAPI](https://oneapi.io).
 ## Table of Contents
 
 - [Support and Requirements](#support-and-requirements)
+- [Selection of Compilers](#selection-of-compilers)
 - [Build Setup](#build-setup)
 - [Building with Conan](#building-with-conan)
 - [Building with CMake](#building-with-cmake)
@@ -80,8 +81,8 @@ oneapi::mkl::blas::column_major::gemm(gpu_queue, transA, transB, m, ...);
 How to build an application with run-time dispatching:
 
 ```cmd
-$> clang++ -fsycl –I$ONEMKL/include app.cpp
-$> clang++ -fsycl app.o –L$ONEMKL/lib –lonemkl
+$> dpcpp -fsycl –I$ONEMKL/include app.cpp
+$> dpcpp -fsycl app.o –L$ONEMKL/lib –lonemkl
 ```
 
 - **Compile-time dispatching**: The application uses a templated backend selector API where the template parameters specify the required backends and third-party libraries and the application is linked with the required oneMKL backend wrapper libraries (libraries can be static or dynamic).
@@ -110,6 +111,8 @@ $> clang++ -fsycl –I$ONEMKL/include app.cpp
 $> clang++ -fsycl app.o –L$ONEMKL/lib –lonemkl_blas_mklcpu –lonemkl_blas_cublas
 ```
 
+*Refer to [Selection of Compilers](#selection-of-compilers) for the choice between `dpcpp` and `clang++` compilers.*
+
 ### Supported Configurations:
 
 Supported domains: BLAS, LAPACK, RNG
@@ -366,6 +369,16 @@ Python | 3.6 or higher | No | *N/A* | *Pre-installed or Installed by user* | [PS
 
 ---
 
+## Selection of Compilers
+
+A compiler needs to be chosen according to the required backend of your application.
+
+- If your application requires Intel GPU, use [Intel(R) oneAPI DPC++ Compiler](https://software.intel.com/en-us/oneapi/dpc-compiler) `dpcpp`.
+- If your application requires NVIDIA GPU, use the latest release of `clang++` from [Intel project for LLVM* technology](https://github.com/intel/llvm/releases).
+- If neither Intel GPU nor NVIDIA GPU is required, you can use either [Intel(R) oneAPI DPC++ Compiler](https://software.intel.com/en-us/oneapi/dpc-compiler) `dpcpp` or `clang++` on Linux and `clang-cl` on Windows from [Intel project for LLVM* technology](https://github.com/intel/llvm/releases).
+
+---
+
 ## Build Setup
 
 1. Install Intel(R) oneAPI DPC++ Compiler (select variant as per requirement).
@@ -515,10 +528,11 @@ conan build ..
 ```bash
 # Inside <path to onemkl>
 mkdir build && cd build
-export CXX=<path_to_dpcpp_compiler>/bin/dpcpp;
-cmake .. [-DMKL_ROOT=<mkl_install_prefix>] \                    # required only if environment variable MKLROOT is not set
-         [-DREF_BLAS_ROOT=<reference_blas_install_prefix>] \    # required only for testing
-         [-DREF_LAPACK_ROOT=<reference_lapack_install_prefix>]  # required only for testing
+cmake .. [-DCMAKE_CXX_COMPILER=<path_to_dpcpp_compiler>/bin/dpcpp] \  # required only if dpcpp is not found in environment variable PATH
+         [-DCMAKE_C_COMPILER=<path_to_icx_compiler>/bin/icx]       \  # required only if icx is not found in environment variable PATH
+         [-DMKL_ROOT=<mkl_install_prefix>] \                          # required only if environment variable MKLROOT is not set
+         [-DREF_BLAS_ROOT=<reference_blas_install_prefix>] \          # required only for testing
+         [-DREF_LAPACK_ROOT=<reference_lapack_install_prefix>]        # required only for testing
 cmake --build .
 ctest
 cmake --install . --prefix <path_to_install_dir>
@@ -527,11 +541,11 @@ cmake --install . --prefix <path_to_install_dir>
 ```bash
 # Inside <path to onemkl>
 md build && cd build
-cmake .. -G Ninja
-                  [-DMKL_ROOT=<mkl_install_prefix>] \                    # required only if environment variable MKLROOT is not set
-                  [-DREF_BLAS_ROOT=<reference_blas_install_prefix>] \    # required only for testing
-                  [-DREF_LAPACK_ROOT=<reference_lapack_install_prefix>]  # required only for testing
-
+cmake .. -G Ninja [-DCMAKE_CXX_COMPILER=<path_to_dpcpp_compiler>\bin\dpcpp] \  # required only if dpcpp is not found in environment variable PATH
+                  [-DCMAKE_C_COMPILER=<path_to_icx_compiler>\bin\icx]       \  # required only if icx is not found in environment variable PATH
+                  [-DMKL_ROOT=<mkl_install_prefix>] \                          # required only if environment variable MKLROOT is not set
+                  [-DREF_BLAS_ROOT=<reference_blas_install_prefix>] \          # required only for testing
+                  [-DREF_LAPACK_ROOT=<reference_lapack_install_prefix>]        # required only for testing
 ninja 
 ctest
 cmake --install . --prefix <path_to_install_dir>
@@ -546,11 +560,12 @@ With the cuBLAS backend:
 ```bash
 # Inside <path to onemkl>
 mkdir build && cd build
-export CXX=<path_to_dpcpp_compiler>/bin/dpcpp;
-cmake .. -DENABLE_CUBLAS_BACKEND=True                      \
-         -DENABLE_MKLCPU_BACKEND=False                     \   # disable Intel MKL CPU backend
-         -DENABLE_MKLGPU_BACKEND=False                     \   # disable Intel MKL GPU backend
-         [-DREF_BLAS_ROOT=<reference_blas_install_prefix>] \   # required only for testing
+cmake .. [-DCMAKE_CXX_COMPILER=<path_to_clang++_compiler>/bin/clang++] \  # required only if clang++ is not found in environment variable PATH
+         [-DCMAKE_C_COMPILER=<path_to_clang_compiler>/bin/clang]       \  # required only if clang is not found in environment variable PATH
+         -DENABLE_CUBLAS_BACKEND=True  \
+         -DENABLE_MKLCPU_BACKEND=False \                                  # disable Intel MKL CPU backend
+         -DENABLE_MKLGPU_BACKEND=False \                                  # disable Intel MKL GPU backend
+         [-DREF_BLAS_ROOT=<reference_blas_install_prefix>] \              # required only for testing
 cmake --build .
 ctest
 cmake --install . --prefix <path_to_install_dir>