Do not add -mabi flags for Loongson when the compiler is flang

Author: martin-frbg

cmake/fc.cmake

@@ -61,21 +61,25 @@ if (${F_COMPILER} STREQUAL "GFORTRAN" OR ${F_COMPILER} STREQUAL "F95" OR CMAKE_F
     endif ()
     if (LOONGARCH64)
       if (BINARY64)
-	CHECK_C_COMPILER_FLAG("-mabi=lp64d" COMPILER_SUPPORT_LP64D_ABI)
-        if(COMPILER_SUPPORT_LP64D_ABI)
-	  set(FCOMMON_OPT "${FCOMMON_OPT} -mabi=lp64d")
-	else()
-	  set(FCOMMON_OPT "${FCOMMON_OPT} -mabi=lp64")
-	endif ()
+        if (NOT CMAKE_Fortran_COMPILER_ID MATCHES "LLVMFlang.*")
+	  CHECK_C_COMPILER_FLAG("-mabi=lp64d" COMPILER_SUPPORT_LP64D_ABI)
+          if(COMPILER_SUPPORT_LP64D_ABI)
+	    set(FCOMMON_OPT "${FCOMMON_OPT} -mabi=lp64d")
+	  else()
+	    set(FCOMMON_OPT "${FCOMMON_OPT} -mabi=lp64")
+	  endif ()
+        endif ()
         if (INTERFACE64) 
           set(FCOMMON_OPT "${FCOMMON_OPT} -fdefault-integer-8") 
         endif () 
       else ()
-	CHECK_C_COMPILER_FLAG("-mabi=ilp32d" COMPILER_SUPPORT_ILP32D_ABI)
-	if(COMPILER_SUPPORT_ILP32D_ABI)
-	  set(FCOMMON_OPT "${FCOMMON_OPT} -mabi=ilp32d")
-	else()
-	  set(FCOMMON_OPT "${FCOMMON_OPT} -mabi=lp32")
+        if (NOT CMAKE_Fortran_COMPILER_ID MATCHES "LLVMFlang.*")
+	  CHECK_C_COMPILER_FLAG("-mabi=ilp32d" COMPILER_SUPPORT_ILP32D_ABI)
+	  if(COMPILER_SUPPORT_ILP32D_ABI)
+	    set(FCOMMON_OPT "${FCOMMON_OPT} -mabi=ilp32d")
+	  else()
+	    set(FCOMMON_OPT "${FCOMMON_OPT} -mabi=lp32")
+          endif ()
 	endif ()
       endif ()
     endif ()