################################################################################
#
# \file      cmake/FindMKL.cmake
# \author    J. Bakosi
# \copyright 2012-2015, Jozsef Bakosi, 2016, Los Alamos National Security, LLC.
# \brief     Find the Math Kernel Library from Intel
# \date      Thu 26 Jan 2017 02:05:50 PM MST
#
################################################################################

# Find the Math Kernel Library from Intel
#
#  MKL_FOUND - System has MKL
#  MKL_INCLUDE_DIRS - MKL include files directories
#  MKL_LIBRARIES - The MKL libraries
#  MKL_INTERFACE_LIBRARY - MKL interface library
#  MKL_SEQUENTIAL_LAYER_LIBRARY - MKL sequential layer library
#  MKL_CORE_LIBRARY - MKL core library
#
#  The environment variables MKLROOT and INTEL are used to find the library.
#  Everything else is ignored. If MKL is found "-DMKL_ILP64" is added to
#  CMAKE_C_FLAGS and CMAKE_CXX_FLAGS.
#
#  Example usage:
#
#  find_package(MKL)
#  if(MKL_FOUND)
#    target_link_libraries(TARGET ${MKL_LIBRARIES})
#  endif()

# If already in cache, be silent
if (MKL_INCLUDE_DIRS AND MKL_LIBRARIES AND MKL_INTERFACE_LIBRARY AND
    MKL_SEQUENTIAL_LAYER_LIBRARY AND MKL_CORE_LIBRARY)
  set (MKL_FIND_QUIETLY TRUE)
endif()

if(NOT BUILD_SHARED_LIBS)
  if (WIN32)
    set(INT_LIB "mkl_intel_ilp64.lib")
    set(SEQ_LIB "mkl_sequential.lib")
    set(THR_LIB "mkl_intel_thread.lib")
    set(COR_LIB "mkl_core.lib")
  else()
    set(INT_LIB "libmkl_intel_ilp64.a")
    set(SEQ_LIB "libmkl_sequential.a")
    set(THR_LIB "libmkl_intel_thread.a")
    set(COR_LIB "libmkl_core.a")
  endif()
else()
  set(INT_LIB "mkl_intel_ilp64")
  set(SEQ_LIB "mkl_sequential")
  set(THR_LIB "mkl_intel_thread")
  set(COR_LIB "mkl_core")
endif()

if(MSVC)
  set(ProgramFilesx86 "ProgramFiles(x86)")
  set(INTEL_ROOT_DEFAULT $ENV{${ProgramFilesx86}}/IntelSWTools/compilers_and_libraries/windows)
else()
  set(INTEL_ROOT_DEFAULT "/opt/intel")
endif()
set(INTEL_ROOT ${INTEL_ROOT_DEFAULT} CACHE PATH "Folder contains intel libs")
find_path(MKL_ROOT include/mkl.h PATHS $ENV{MKLROOT} ${INTEL_ROOT}/mkl
                                   DOC "Folder contains MKL")

find_path(MKL_INCLUDE_DIR NAMES mkl.h HINTS ${MKL_ROOT}/include /usr/include/mkl)


find_library(MKL_INTERFACE_LIBRARY
             NAMES ${INT_LIB}
             PATHS ${MKL_ROOT}/lib
                   ${MKL_ROOT}/lib/intel64
                   ${MKL_ROOT}/lib/intel64_win
                   ${INTEL_ROOT}/mkl/lib/intel64)

find_library(MKL_SEQUENTIAL_LAYER_LIBRARY
             NAMES ${SEQ_LIB}
             PATHS ${MKL_ROOT}/lib
                   ${MKL_ROOT}/lib/intel64
                   ${INTEL_ROOT}/mkl/lib/intel64)

find_library(MKL_CORE_LIBRARY
             NAMES ${COR_LIB}
             PATHS ${MKL_ROOT}/lib
                   ${MKL_ROOT}/lib/intel64
                   ${INTEL_ROOT}/mkl/lib/intel64)

set(MKL_INCLUDE_DIRS ${MKL_INCLUDE_DIR})
set(MKL_LIBRARIES ${MKL_INTERFACE_LIBRARY} ${MKL_SEQUENTIAL_LAYER_LIBRARY} ${MKL_CORE_LIBRARY})

if(NOT WIN32 AND NOT APPLE)
  # Added -Wl block to avoid circular dependencies.
  # https://stackoverflow.com/questions/5651869/what-are-the-start-group-and-end-group-command-line-options
  # https://software.intel.com/en-us/articles/intel-mkl-link-line-advisor
  set(MKL_LIBRARIES -Wl,--start-group ${MKL_LIBRARIES} -Wl,--end-group)
elseif(APPLE)
  # MacOS does not support --start-group and --end-group
  set(MKL_LIBRARIES -Wl,${MKL_LIBRARIES} -Wl,)
endif()

# message("1 ${MKL_INCLUDE_DIR}")
# message("2 ${MKL_INTERFACE_LIBRARY}")
# message("3 ${MKL_SEQUENTIAL_LAYER_LIBRARY}")
# message("4 ${MKL_CORE_LIBRARY}")

if (MKL_INCLUDE_DIR AND
    MKL_INTERFACE_LIBRARY AND
    MKL_SEQUENTIAL_LAYER_LIBRARY AND
    MKL_CORE_LIBRARY)


    if (NOT DEFINED ENV{CRAY_PRGENVPGI} AND
        NOT DEFINED ENV{CRAY_PRGENVGNU} AND
        NOT DEFINED ENV{CRAY_PRGENVCRAY} AND
        NOT DEFINED ENV{CRAY_PRGENVINTEL} AND
        NOT MSVC)
      set(ABI "-m64")
    endif()

    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DMKL_ILP64 ${ABI}")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DMKL_ILP64 ${ABI}")

else()
  set(MKL_INCLUDE_DIRS "")
  set(MKL_LIBRARIES "")
  set(MKL_INTERFACE_LIBRARY "")
  set(MKL_SEQUENTIAL_LAYER_LIBRARY "")
  set(MKL_CORE_LIBRARY "")

endif()

# Handle the QUIETLY and REQUIRED arguments and set MKL_FOUND to TRUE if
# all listed variables are TRUE.
INCLUDE(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(MKL DEFAULT_MSG MKL_LIBRARIES MKL_INCLUDE_DIRS MKL_INTERFACE_LIBRARY MKL_SEQUENTIAL_LAYER_LIBRARY MKL_CORE_LIBRARY)

MARK_AS_ADVANCED(MKL_INCLUDE_DIRS MKL_LIBRARIES MKL_INTERFACE_LIBRARY MKL_SEQUENTIAL_LAYER_LIBRARY MKL_CORE_LIBRARY)