Use not instead

CMakeLists.txt

@@ -27,16 +27,15 @@ if("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
     message(FATAL_ERROR "The binary and source directroy cannot be the same")
 endif()
 
-get_property(MIGRAPHX_GENERATOR_IS_MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
-
 # Setup valid strings for build type
 if (NOT CMAKE_CONFIGURATION_TYPES)
     set(CMAKE_CONFIGURATION_TYPES "Debug;Release;RelWithDebInfo;MinSizeRel" CACHE STRING "Configs")
 endif()
+
+get_property(MIGRAPHX_GENERATOR_IS_MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
 # This has to be initialized before the project() command appears
 # Set the default of CMAKE_BUILD_TYPE to be release, unless user specifies with -D.  MSVC_IDE does not use CMAKE_BUILD_TYPE
-if(MIGRAPHX_GENERATOR_IS_MULTI_CONFIG)
-else()
+if(NOT MIGRAPHX_GENERATOR_IS_MULTI_CONFIG)
     set(CMAKE_BUILD_TYPE Release CACHE STRING
         "Choose the type of build, options are: None Debug Release RelWithDebInfo MinSizeRel.")
     set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS ${CMAKE_CONFIGURATION_TYPES})