Add support for POWER architecture

cmake/Modules/DetectArchitecture.cmake

@@ -103,6 +103,7 @@ else()
     detect_architecture("__i386__" x86)
     detect_architecture("__arm__" ARM)
     detect_architecture("__aarch64__" ARM64)
+    detect_architecture("__PPC64__" PPC64)
 endif()
 if (NOT DEFINED ARCHITECTURE)
   message(FATAL_ERROR "Not supported. Please add needed architecture detection.")
@@ -172,6 +173,9 @@ if (ARCH_OPT)
   if(MSVC AND NOT MARCH_NATIVE_SUPPORTED)
     set(CMAKE_REQUIRED_FLAGS "/arch:${ARCH_OPT}")
     add_compile_options(${CMAKE_REQUIRED_FLAGS})
+  elseif (ARCHITECTURE_PPC64)
+    set(CMAKE_REQUIRED_FLAGS "-mcpu=${ARCH_OPT}")
+    add_compile_options(-mcpu=${ARCH_OPT})
   else()
     set(CMAKE_REQUIRED_FLAGS "-march=${ARCH_OPT}")
     add_compile_options(-march=${ARCH_OPT})