add pffft

pffft/cmake/FindPAPI.cmake

@@ -0,0 +1,25 @@
+# Find PAPI libraries
+# Once done this will define
+#  PAPI_FOUND - System has PAPI
+#  PAPI_INCLUDE_DIRS - The PAPI include directories
+#  PAPI_LIBRARIES - The libraries needed to use PAPI
+
+if(PAPI_INCLUDE_DIRS AND PAPI_LIBRARIES)
+  set(PAPI_FIND_QUIETLY TRUE)
+endif()
+
+find_path(PAPI_INCLUDE_DIRS NAMES papi.h HINTS ${PAPI_ROOT} PATH_SUFFIXES include)
+find_library(PAPI_LIBRARIES NAMES papi HINTS ${PAPI_ROOT} PATH_SUFFIXES lib lib64)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(PAPI DEFAULT_MSG PAPI_LIBRARIES PAPI_INCLUDE_DIRS)
+if(PAPI_FOUND AND NOT TARGET PAPI::PAPI)
+    set(PAPI_LIBRARIES ${PAPI_LIBRARIES} rt)
+
+    add_library(PAPI::PAPI SHARED IMPORTED)
+    set_target_properties(PAPI::PAPI PROPERTIES
+        INTERFACE_INCLUDE_DIRECTORIES "${PAPI_INCLUDE_DIRS}"
+        IMPORTED_LOCATION "${PAPI_LIBRARIES}")
+endif()
+
+mark_as_advanced(PAPI_INCLUDE_DIRS PAPI_LIBRARIES)