-Remove PLATFORM_WORD_SIZE configuration

-Add detection for CMAKE_GENERATOR and CMAKE_CL_64 (working for x86 and x86_64 windows builds using Visual Studio)

CMakeLists.txt

@@ -3,7 +3,6 @@ project(libecc)
 include_directories(include)
 
 # Define options
-option(PLATFORM_WORD_SIZE                       "Platform word size (16, 32 or 64)"     "32")
 option(PLATFORM_INCLUDE_STDLIB                  "Platform provides STDLIB"                          ON)
 option(OPTION_SPECIFY_CONFIG                    "Customise libecc configuration"                    ON)
 option(OPTION_BUILD_SELF_TEST                   "Build libecc ec-self-tests"                        ON)
@@ -292,11 +291,16 @@ if (OPTION_SPECIFY_CONFIG)
         add_definitions(-DWITH_X448)
     endif(OPTION_SUPPORT_ECDH_X448)
 endif(OPTION_SPECIFY_CONFIG)
+include(CheckCXXSourceCompiles)
 
-if (NOT (PLATFORM_WORD_SIZE STREQUAL "16" OR PLATFORM_WORD_SIZE STREQUAL "32" OR PLATFORM_WORD_SIZE STREQUAL "64"))
-    set(PLATFORM_WORD_SIZE "32")
+if (CMAKE_GENERATOR MATCHES "Visual Studio")
+    if(CMAKE_CL_64)
+    	add_definitions(-D__x86_64__)
+    else()
+    	add_definitions(-D__i386__)
+    endif()
 endif()
-add_definitions(-DWORDSIZE=${PLATFORM_WORD_SIZE})
+
 if (PLATFORM_INCLUDE_STDLIB)
     add_definitions(-DWITH_STDLIB)
 endif()