CMake/Modules/FindOpenMP.cmake

115 lines
3.6 KiB
CMake

# - Finds OpenMP support
# This module can be used to detect OpenMP support in a compiler.
# If the compiler supports OpenMP, the flags required to compile with
# openmp support are set.
#
# The following variables are set:
# OpenMP_C_FLAGS - flags to add to the C compiler for OpenMP support
# OpenMP_CXX_FLAGS - flags to add to the CXX compiler for OpenMP support
# OPENMP_FOUND - true if openmp is detected
#
# Supported compilers can be found at http://openmp.org/wp/openmp-compilers/
#=============================================================================
# Copyright 2009 Kitware, Inc.
# Copyright 2008-2009 André Rigland Brodtkorb <Andre.Brodtkorb@ifi.uio.no>
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
include(CheckCSourceCompiles)
include(CheckCXXSourceCompiles)
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
set(OpenMP_C_FLAG_CANDIDATES
#Gnu
"-fopenmp"
#Microsoft Visual Studio
"/openmp"
#Intel windows
"-Qopenmp"
#Intel
"-openmp"
#Empty, if compiler automatically accepts openmp
" "
#Sun
"-xopenmp"
#HP
"+Oopenmp"
#IBM XL C/c++
"-qsmp"
#Portland Group
"-mp"
)
set(OpenMP_CXX_FLAG_CANDIDATES ${OpenMP_C_FLAG_CANDIDATES})
# sample openmp source code to test
set(OpenMP_C_TEST_SOURCE
"
#include <omp.h>
int main() {
#ifdef _OPENMP
return 0;
#else
breaks_on_purpose
#endif
}
")
# use the same source for CXX as C for now
set(OpenMP_CXX_TEST_SOURCE ${OpenMP_C_TEST_SOURCE})
# if these are set then do not try to find them again,
# by avoiding any try_compiles for the flags
if(DEFINED OpenMP_C_FLAGS AND DEFINED OpenMP_CXX_FLAGS)
set(OpenMP_C_FLAG_CANDIDATES)
set(OpenMP_CXX_FLAG_CANDIDATES)
endif(DEFINED OpenMP_C_FLAGS AND DEFINED OpenMP_CXX_FLAGS)
# check c compiler
foreach(FLAG ${OpenMP_C_FLAG_CANDIDATES})
set(SAFE_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
set(CMAKE_REQUIRED_FLAGS "${FLAG}")
unset(OpenMP_FLAG_DETECTED CACHE)
message(STATUS "Try OpenMP C flag = [${FLAG}]")
check_c_source_compiles("${OpenMP_CXX_TEST_SOURCE}" OpenMP_FLAG_DETECTED)
set(CMAKE_REQUIRED_FLAGS "${SAFE_CMAKE_REQUIRED_FLAGS}")
if(OpenMP_FLAG_DETECTED)
set(OpenMP_C_FLAGS_INTERNAL "${FLAG}")
break()
endif(OpenMP_FLAG_DETECTED)
endforeach(FLAG ${OpenMP_C_FLAG_CANDIDATES})
# check cxx compiler
foreach(FLAG ${OpenMP_CXX_FLAG_CANDIDATES})
set(SAFE_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
set(CMAKE_REQUIRED_FLAGS "${FLAG}")
unset(OpenMP_FLAG_DETECTED CACHE)
message(STATUS "Try OpenMP CXX flag = [${FLAG}]")
check_cxx_source_compiles("${OpenMP_C_TEST_SOURCE}" OpenMP_FLAG_DETECTED)
set(CMAKE_REQUIRED_FLAGS "${SAFE_CMAKE_REQUIRED_FLAGS}")
if(OpenMP_FLAG_DETECTED)
set(OpenMP_CXX_FLAGS_INTERNAL "${FLAG}")
break()
endif(OpenMP_FLAG_DETECTED)
endforeach(FLAG ${OpenMP_CXX_FLAG_CANDIDATES})
set(OpenMP_C_FLAGS "${OpenMP_C_FLAGS_INTERNAL}"
CACHE STRING "C compiler flags for OpenMP parallization")
set(OpenMP_CXX_FLAGS "${OpenMP_CXX_FLAGS_INTERNAL}"
CACHE STRING "C++ compiler flags for OpenMP parallization")
# handle the standard arguments for find_package
find_package_handle_standard_args(OpenMP DEFAULT_MSG
OpenMP_C_FLAGS OpenMP_CXX_FLAGS )
mark_as_advanced(
OpenMP_C_FLAGS
OpenMP_CXX_FLAGS
)