# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.

# AMBER: MKL support has been removed from this file so that it doesn't conflict with FindMKL
#  We also provide this to allow OpenBLAS to be used with older CMake versions

#.rst:
# FindBLAS
# --------
#
# Find BLAS library
#
# This module finds an installed fortran library that implements the
# BLAS linear-algebra interface (see http://www.netlib.org/blas/).  The
# list of libraries searched for is taken from the autoconf macro file,
# acx_blas.m4 (distributed at
# http://ac-archive.sourceforge.net/ac-archive/acx_blas.html).
#
# This module sets the following variables:
#
# ::
#
#   BLAS_FOUND - set to true if a library implementing the BLAS interface
#     is found
#   BLAS_LINKER_FLAGS - uncached list of required linker flags (excluding -l
#     and -L).
#   BLAS_LIBRARIES - uncached list of libraries (using full path name) to
#     link against to use BLAS
#   BLAS95_LIBRARIES - uncached list of libraries (using full path name)
#     to link against to use BLAS95 interface
#   BLAS95_FOUND - set to true if a library implementing the BLAS f95 interface
#     is found
#   BLA_STATIC  if set on this determines what kind of linkage we do (static)
#   BLA_VENDOR  if set checks only the specified vendor, if not set checks
#      all the possibilities
#   BLA_F95     if set on tries to find the f95 interfaces for BLAS/LAPACK
#
# ######### ## List of vendors (BLA_VENDOR) valid in this module #
# Goto,OpenBLAS,ATLAS PhiPACK,CXML,DXML,SunPerf,SCSL,SGIMATH,IBMESSL,
# ACML,ACML_MP,ACML_GPU,Apple, NAS, Generic

include(CMakePushCheckState)

cmake_push_check_state()

if(DEFINED ENV{BLA_VENDOR})
	set(BLA_VENDOR_DEFAULT $ENV{BLA_VENDOR})
else()
	set(BLA_VENDOR_DEFAULT "All")
endif ()

set(BLA_VENDOR ${BLA_VENDOR_DEFAULT} CACHE STRING "BLAS vendor to use for BLAS and Lapack.  Valid values: All, Goto, OpenBLAS, ATLAS, PhiPACK, CXML, DXML, SunPerf, SCSL, SGIMATH, IBMESSL, ACML, ACML_MP, ACML_GPU, Apple, NAS, Generic")
validate_configuration_enum(BLA_VENDOR  All Goto OpenBLAS ATLAS PhiPACK CXML DXML SunPerf SCSL SGIMATH IBMESSL ACML ACML_MP ACML_GPU Apple NAS Generic)

if(DEFINED BLAS_FIND_QUIETLY)
	set(CMAKE_REQUIRED_QUIET ${BLAS_FIND_QUIETLY})
endif()

set(_blas_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES})

# Check the language being used
if( NOT (CMAKE_C_COMPILER_LOADED OR CMAKE_CXX_COMPILER_LOADED OR CMAKE_Fortran_COMPILER_LOADED) )
	if(BLAS_FIND_REQUIRED)
		message(FATAL_ERROR "FindBLAS requires Fortran, C, or C++ to be enabled.")
	else()
		message(STATUS "Looking for BLAS... - NOT found (Unsupported languages)")
		return()
	endif()
endif()

macro(Check_Fortran_Libraries LIBRARIES _prefix _name _flags _list _thread)
	# This macro checks for the existence of the combination of fortran libraries
	# given by _list.  If the combination is found, this macro checks (using the
	# Check_Fortran_Function_Exists macro) whether can link against that library
	# combination using the name of a routine given by _name using the linker
	# flags given by _flags.  If the combination of libraries is found and passes
	# the link test, LIBRARIES is set to the list of complete library paths that
	# have been found.  Otherwise, LIBRARIES is set to FALSE.

	# N.B. _prefix is the prefix applied to the names of all cached variables that
	# are generated internally and marked advanced by this macro.

	set(_libdir ${ARGN})

	set(_libraries_work TRUE)
	set(${LIBRARIES})
	set(_combined_name)

	foreach(_library ${_list})
		set(_combined_name ${_combined_name}_${_library})

		if(_libraries_work)
			if (BLA_STATIC)
				if (WIN32)
					set(CMAKE_FIND_LIBRARY_SUFFIXES .lib ${CMAKE_FIND_LIBRARY_SUFFIXES})
				endif ()
				if (APPLE)
					set(CMAKE_FIND_LIBRARY_SUFFIXES .lib ${CMAKE_FIND_LIBRARY_SUFFIXES})
				else ()
					set(CMAKE_FIND_LIBRARY_SUFFIXES .a ${CMAKE_FIND_LIBRARY_SUFFIXES})
				endif ()
			else ()
				if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
					# for ubuntu's libblas3gf and liblapack3gf packages
					set(CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES} .so.3gf)
				endif ()
			endif ()
			find_library(${_prefix}_${_library}_LIBRARY
				NAMES ${_library})
				
			#message("DEBUG: ${_prefix}_${_library}_LIBRARY: ${${_prefix}_${_library}_LIBRARY}, PATHS: ${_libdir}, NAMES: ${_library}")
			mark_as_advanced(${_prefix}_${_library}_LIBRARY)
			set(${LIBRARIES} ${${LIBRARIES}} ${${_prefix}_${_library}_LIBRARY})
			set(_libraries_work ${${_prefix}_${_library}_LIBRARY})
		endif()
	endforeach()
	if(_libraries_work)
		# Test this combination of libraries.
		set(CMAKE_REQUIRED_LIBRARIES ${_flags} ${${LIBRARIES}} ${_thread})
		#message("DEBUG: CMAKE_REQUIRED_LIBRARIES = ${CMAKE_REQUIRED_LIBRARIES}")
		if (CMAKE_Fortran_COMPILER_LOADED)
			check_fortran_function_exists("${_name}" ${_prefix}${_combined_name}_WORKS)
		else()
			check_function_exists("${_name}_" ${_prefix}${_combined_name}_WORKS)
			
			# try without the underscore
			if(NOT ${_prefix}${_combined_name}_WORKS)
				check_function_exists("${_name}" ${_prefix}${_combined_name}_WORKS_NOUNDERSCORE)
				if(${_prefix}${_combined_name}_WORKS_NOUNDERSCORE)
					set(${_prefix}${_combined_name}_WORKS TRUE CACHE BOOL "" FORCE)
				endif()
			endif()
		endif()
		set(CMAKE_REQUIRED_LIBRARIES)
		mark_as_advanced(${_prefix}${_combined_name}_WORKS)
		set(_libraries_work ${${_prefix}${_combined_name}_WORKS})
	endif()
	if(NOT _libraries_work)
		set(${LIBRARIES} FALSE)
	endif()
	#message("DEBUG: ${LIBRARIES} = ${${LIBRARIES}}")
endmacro()

set(BLAS_LINKER_FLAGS)
set(BLAS_LIBRARIES)
set(BLAS95_LIBRARIES)

if (BLA_VENDOR STREQUAL "Goto" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	# gotoblas (http://www.tacc.utexas.edu/tacc-projects/gotoblas2)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"goto2"
	""
	)
 endif()
endif ()

if (BLA_VENDOR STREQUAL "OpenBLAS" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	# OpenBLAS (http://www.openblas.net)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"openblas"
	""
	)
 endif()
endif ()

if (BLA_VENDOR STREQUAL "ATLAS" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	# BLAS in ATLAS library? (http://math-atlas.sourceforge.net/)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	dgemm
	""
	"f77blas;atlas"
	""
	)
 endif()
endif ()

# BLAS in PhiPACK libraries? (requires generic BLAS lib, too)
if (BLA_VENDOR STREQUAL "PhiPACK" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"sgemm;dgemm;blas"
	""
	)
 endif()
endif ()

# BLAS in Alpha CXML library?
if (BLA_VENDOR STREQUAL "CXML" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"cxml"
	""
	)
 endif()
endif ()

# BLAS in Alpha DXML library? (now called CXML, see above)
if (BLA_VENDOR STREQUAL "DXML" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"dxml"
	""
	)
 endif()
endif ()

# BLAS in Sun Performance library?
if (BLA_VENDOR STREQUAL "SunPerf" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	"-xlic_lib=sunperf"
	"sunperf;sunmath"
	""
	)
	if(BLAS_LIBRARIES)
		set(BLAS_LINKER_FLAGS "-xlic_lib=sunperf")
	endif()
 endif()
endif ()

# BLAS in SCSL library?  (SGI/Cray Scientific Library)
if (BLA_VENDOR STREQUAL "SCSL" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"scsl"
	""
	)
 endif()
endif ()

# BLAS in SGIMATH library?
if (BLA_VENDOR STREQUAL "SGIMATH" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"complib.sgimath"
	""
	)
 endif()
endif ()

# BLAS in IBM ESSL library? (requires generic BLAS lib, too)
if (BLA_VENDOR STREQUAL "IBMESSL" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"essl;blas"
	""
	)
 endif()
endif ()

#BLAS in acml library?
if (BLA_VENDOR MATCHES "ACML" OR BLA_VENDOR STREQUAL "All")
 if( ((BLA_VENDOR STREQUAL "ACML") AND (NOT BLAS_ACML_LIB_DIRS)) OR
		 ((BLA_VENDOR STREQUAL "ACML_MP") AND (NOT BLAS_ACML_MP_LIB_DIRS)) OR
		 ((BLA_VENDOR STREQUAL "ACML_GPU") AND (NOT BLAS_ACML_GPU_LIB_DIRS))
	 )
	 # try to find acml in "standard" paths
	 if( WIN32 )
		file( GLOB _ACML_ROOT "C:/AMD/acml*/ACML-EULA.txt" )
	 else()
		file( GLOB _ACML_ROOT "/opt/acml*/ACML-EULA.txt" )
	 endif()
	 if( WIN32 )
		file( GLOB _ACML_GPU_ROOT "C:/AMD/acml*/GPGPUexamples" )
	 else()
		file( GLOB _ACML_GPU_ROOT "/opt/acml*/GPGPUexamples" )
	 endif()
	 list(GET _ACML_ROOT 0 _ACML_ROOT)
	 if(NOT "${_ACML_GPU_ROOT}" STREQUAL "")
	list(GET _ACML_GPU_ROOT 0 _ACML_GPU_ROOT)
	 endif()
			
	 if( _ACML_ROOT )
		get_filename_component( _ACML_ROOT ${_ACML_ROOT} PATH )
		if( SIZEOF_INTEGER EQUAL 8 )
		 set( _ACML_PATH_SUFFIX "_int64" )
		else()
		set( _ACML_PATH_SUFFIX "" )
	 endif()
	 if( CMAKE_Fortran_COMPILER_ID STREQUAL "Intel" )
		set( _ACML_COMPILER32 "ifort32" )
		set( _ACML_COMPILER64 "ifort64" )
	 elseif( CMAKE_Fortran_COMPILER_ID STREQUAL "SunPro" )
		set( _ACML_COMPILER32 "sun32" )
		set( _ACML_COMPILER64 "sun64" )
	 elseif( CMAKE_Fortran_COMPILER_ID STREQUAL "PGI" )
		set( _ACML_COMPILER32 "pgi32" )
		if( WIN32 )
		 set( _ACML_COMPILER64 "win64" )
		else()
		 set( _ACML_COMPILER64 "pgi64" )
		endif()
	 elseif( CMAKE_Fortran_COMPILER_ID STREQUAL "Open64" )
		# 32 bit builds not supported on Open64 but for code simplicity
		# We'll just use the same directory twice
		set( _ACML_COMPILER32 "open64_64" )
		set( _ACML_COMPILER64 "open64_64" )
	 elseif( CMAKE_Fortran_COMPILER_ID STREQUAL "NAG" )
		set( _ACML_COMPILER32 "nag32" )
		set( _ACML_COMPILER64 "nag64" )
	 else()
		set( _ACML_COMPILER32 "gfortran32" )
		set( _ACML_COMPILER64 "gfortran64" )
	 endif()

	 if( BLA_VENDOR STREQUAL "ACML_MP" )
		set(_ACML_MP_LIB_DIRS
		 "${_ACML_ROOT}/${_ACML_COMPILER32}_mp${_ACML_PATH_SUFFIX}/lib"
		 "${_ACML_ROOT}/${_ACML_COMPILER64}_mp${_ACML_PATH_SUFFIX}/lib" )
	 else()
		set(_ACML_LIB_DIRS
		 "${_ACML_ROOT}/${_ACML_COMPILER32}${_ACML_PATH_SUFFIX}/lib"
		 "${_ACML_ROOT}/${_ACML_COMPILER64}${_ACML_PATH_SUFFIX}/lib" )
	 endif()
	endif()
 elseif(BLAS_${BLA_VENDOR}_LIB_DIRS)
	 set(_${BLA_VENDOR}_LIB_DIRS ${BLAS_${BLA_VENDOR}_LIB_DIRS})
 endif()

 if( BLA_VENDOR STREQUAL "ACML_MP" )
	foreach( BLAS_ACML_MP_LIB_DIRS ${_ACML_MP_LIB_DIRS})
	 check_fortran_libraries (
		 BLAS_LIBRARIES
		 BLAS
		 sgemm
		 "" "acml_mp;acml_mv" "" ${BLAS_ACML_MP_LIB_DIRS}
	 )
	 if( BLAS_LIBRARIES )
		break()
	 endif()
	endforeach()
 elseif( BLA_VENDOR STREQUAL "ACML_GPU" )
	foreach( BLAS_ACML_GPU_LIB_DIRS ${_ACML_GPU_LIB_DIRS})
	 check_fortran_libraries (
		 BLAS_LIBRARIES
		 BLAS
		 sgemm
		 "" "acml;acml_mv;CALBLAS" "" ${BLAS_ACML_GPU_LIB_DIRS}
	 )
	 if( BLAS_LIBRARIES )
		break()
	 endif()
	endforeach()
 elseif(DEFINED _ACML_LIB_DIRS)
	foreach( BLAS_ACML_LIB_DIRS ${_ACML_LIB_DIRS} )
	 check_fortran_libraries (
		 BLAS_LIBRARIES
		 BLAS
		 sgemm
		 "" "acml;acml_mv" "" ${BLAS_ACML_LIB_DIRS}
	 )
	 if( BLAS_LIBRARIES )
		break()
	 endif()
	endforeach()
 endif()

 # Either acml or acml_mp should be in LD_LIBRARY_PATH but not both
 if(NOT BLAS_LIBRARIES)
	
	if(WIN32)
		set(ACML_NAME libacml_dll)
	else()
		set(ACML_NAME acml)
	endif()
 
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	${ACML_NAME}
	""
	"${_ACML_ROOT}/ifort64/lib"
	)
 endif()
 if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"acml_mp;acml_mv"
	""
	)
 endif()
 if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"acml;acml_mv;CALBLAS"
	""
	)
 endif()
endif () # ACML

# Apple BLAS library?
if (BLA_VENDOR STREQUAL "Apple" OR BLA_VENDOR STREQUAL "All")
if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	dgemm
	""
	"Accelerate"
	""
	)
 endif()
endif ()

if (BLA_VENDOR STREQUAL "NAS" OR BLA_VENDOR STREQUAL "All")
 if ( NOT BLAS_LIBRARIES )
		check_fortran_libraries(
		BLAS_LIBRARIES
		BLAS
		dgemm
		""
		"vecLib"
		""
		)
 endif ()
endif ()
# Generic BLAS library?
if (BLA_VENDOR STREQUAL "Generic" OR BLA_VENDOR STREQUAL "All")
 if(NOT BLAS_LIBRARIES)
	check_fortran_libraries(
	BLAS_LIBRARIES
	BLAS
	sgemm
	""
	"blas"
	""
	)
 endif()
endif ()


if(BLA_F95)
 if(BLAS95_LIBRARIES)
		set(BLAS95_FOUND TRUE)
	else()
		set(BLAS95_FOUND FALSE)
	endif()

	if(NOT BLAS_FIND_QUIETLY)
		if(BLAS95_FOUND)
			message(STATUS "A library with BLAS95 API found.")
		else()
			if(BLAS_FIND_REQUIRED)
				message(FATAL_ERROR
				"A required library with BLAS95 API not found. Please specify library location.")
			else()
				message(STATUS
				"A library with BLAS95 API not found. Please specify library location.")
			endif()
		endif()
	endif()
	set(BLAS_FOUND TRUE)
	set(BLAS_LIBRARIES "${BLAS95_LIBRARIES}")
else()
	if(BLAS_LIBRARIES)
		set(BLAS_FOUND TRUE)
	else()
		set(BLAS_FOUND FALSE)
	endif()

	if(NOT BLAS_FIND_QUIETLY)
		if(BLAS_FOUND)
			message(STATUS "A library with BLAS API found.")
		else()
			if(BLAS_FIND_REQUIRED)
				message(FATAL_ERROR
				"A required library with BLAS API not found. Please specify library location."
				)
			else()
				message(STATUS
				"A library with BLAS API not found. Please specify library location."
				)
			endif()
		endif()
	endif()
endif()

cmake_pop_check_state()
set(CMAKE_FIND_LIBRARY_SUFFIXES ${_blas_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES})