[CMake] How to activate SSE2 only for Win32 architecture build

[Jakub Zakrzewski]

> I would like to activate sse2 on my Windows build but only for 32 bit.

> I am using the foolowing code:
> SET(CMAKE_CXX_FLAGS "/arch:SSE2")

> Does anyone know how to activate this flag only for Win32 build? 

Maybe like that:

if(CMAKE_SIZEOF_VOID_P EQUAL 4) # 32-bit
	SET(CMAKE_CXX_FLAGS "/arch:SSE2")
endif()