if test "x$asm_optimisation$sse_os" = "xyesyes" ; then XIPH_ADD_CFLAGS([-msse2]) fi -msse2 tells the compiler that it can generate SSE2 instructions. The resulting code will _not_ run on CPUs without SSE2. This is counter to the assembly optimizations themselves, which check at runtime if extensions like SSE etc. are available. This doesn't matter for x86-64, which includes SSE2 by definition, but it should affect ia32. -- Christian "naddy" Weisgerber naddy at mips.inka.de