Hi Jean-Marc, Wouldn't you compile the SSE routine in one source file with the switch, and the non-SSE routine in a different source file (along with all the rest of the other source code) without the switch. Then algorithmically determine if the SSE support is available and programmatically set a function pointer to the correct routine, and utilize the SSE or non-SSE routine via that function pointer mechanism. ? --Eljay
