Add support for Flang compiler in CMakeLists and FindSIMD, this cover…

… both Flang and aocc-flang (#282)

Co-authored-by: Kévin Camus <[email protected]>

CMakeLists.txt

@@ -276,6 +276,20 @@ elseif(CMAKE_Fortran_COMPILER_ID STREQUAL "IntelLLVM")
   set(CMAKE_Fortran_FORMAT_FIXED_FLAG "-free")
   # List of Fortran flags for Intel's LLVM based compiler ends here
 
+#List of Fortran flags for LLVM "classic" Flang based compiler begins here
+	#This include flang and aocc-flang and shouldn't be confused with flang-new (LLVMFlang in cmake)
+elseif(CMAKE_Fortran_COMPILER_ID STREQUAL "Flang")
+  list(APPEND Fortran_FLAGS "-O2" "-cpp" "-mcmodel=large")
+  list(APPEND Fortran_FLAGS "-D_MPI_")
+  list(APPEND Fortran_FLAGS "-DCLUSTER")
+  if (TREXIO_FOUND)
+    list(APPEND Fortran_FLAGS "-ltrexio")
+  endif()
+
+  set(CMAKE_Fortran_FORMAT_FIXED_FLAG "-ffixed-form -ffixed-line-length-132")
+
+#List of Fortran flags for LLVM Flang based compiler ends here
+
 elseif(Fortran_COMPILER_ID MATCHES "PGI")
   list(APPEND CMAKE_Fortran_FLAGS "-Mfreeform -Mdclchk -Mstandard -Mallocatable=03")
 endif()

CMakeModules/FindSIMD.cmake

@@ -16,6 +16,8 @@ if(VECTORIZED STREQUAL "yes")
                 	list(APPEND Fortran_FLAGS "-axCORE-AVX512")
                 elseif(CMAKE_Fortran_COMPILER_ID MATCHES "GNU")
                         list(APPEND Fortran_FLAGS "-march=native")
+		elseif(CMAKE_Fortran_COMPILER_ID STREQUAL "Flang")
+                        list(APPEND Fortran_FLAGS "-march=native")
                 else()
                         list(APPEND Fortran_FLAGS "-axCORE-AVX512")
                 endif()
@@ -26,7 +28,9 @@ if(VECTORIZED STREQUAL "yes")
                         list(APPEND Fortran_FLAGS "-march=core-avx2")
                 elseif(CMAKE_Fortran_COMPILER_ID MATCHES "GNU")
                     	list(APPEND Fortran_FLAGS "-march=native")
-                else()
+ 		elseif(CMAKE_Fortran_COMPILER_ID STREQUAL "Flang")      
+                         list(APPEND Fortran_FLAGS "-march=native")      
+		else()
                         list(APPEND Fortran_FLAGS "-axCORE-AVX2")
                 endif()
                 set(TARGET_ARCHITECTURE "avx2")
@@ -43,26 +47,30 @@ else()
 	message(STATUS "Vectorization is default  " )
 	if(_cpu_flags MATCHES "avx512")
 	        if(CMAKE_Fortran_COMPILER_ID MATCHES "Intel")
-				list(APPEND Fortran_FLAGS "-axCORE-AVX512")
+			list(APPEND Fortran_FLAGS "-axCORE-AVX512")
 	        elseif(CMAKE_Fortran_COMPILER_ID MATCHES "GNU")
-				list(APPEND Fortran_FLAGS "-march=native")
-	        elseif(CMAKE_Fortran_COMPILER_ID MATCHES "NVHPC")
-				list(APPEND Fortran_FLAGS "-Mvect")
+			list(APPEND Fortran_FLAGS "-march=native")
+		elseif(CMAKE_Fortran_COMPILER_ID MATCHES "NVHPC")
+			list(APPEND Fortran_FLAGS "-Mvect")
+		elseif(CMAKE_Fortran_COMPILER_ID STREQUAL "Flang")
+			list(APPEND Fortran_FLAGS "-march=native")
         	else()
-				list(APPEND Fortran_FLAGS "-axCORE-AVX512")
+			list(APPEND Fortran_FLAGS "-axCORE-AVX512")
             endif()
 		set(TARGET_ARCHITECTURE "avx512")
 		add_definitions(-DVECTORIZATION="avx512")
 	elseif(_cpu_flags MATCHES "avx2")
         	if(CMAKE_Fortran_COMPILER_ID MATCHES "Intel")
-  				list(APPEND Fortran_FLAGS "-march=core-avx2")
+  			list(APPEND Fortran_FLAGS "-march=core-avx2")
 	        elseif(CMAKE_Fortran_COMPILER_ID MATCHES "GNU")
-        	    list(APPEND Fortran_FLAGS "-march=native")
-			elseif(CMAKE_Fortran_COMPILER_ID MATCHES "NVHPC")
-				list(APPEND Fortran_FLAGS "-Mvect")
-	    	else()
-  				list(APPEND Fortran_FLAGS "-axCORE-AVX2")
-			endif()
+       	 		list(APPEND Fortran_FLAGS "-march=native")
+		elseif(CMAKE_Fortran_COMPILER_ID MATCHES "NVHPC")
+			list(APPEND Fortran_FLAGS "-Mvect")
+		elseif(CMAKE_Fortran_COMPILER_ID STREQUAL "Flang")
+                        list(APPEND Fortran_FLAGS "-march=native")
+		else()
+  			list(APPEND Fortran_FLAGS "-axCORE-AVX2")
+		endif()
 		set(TARGET_ARCHITECTURE "avx2")
 		add_definitions(-DVECTORIZATION="avx2")
 	endif()