Hi Mika, I know nothing about MASM, I just wanted to note that there is a test/testendian.cpp program in MUSCLE that you can run to test whether your swap functions are working correctly.... you can also use it to see how much of a speedup you get with the inline assembly functions enabled versus disabled. Good luck, Jeremy On Thursday 17 February 2005 07:28, Mika Lindqvist wrote: > Just wanted to check if we have MASM experts who could double-check my > latest experiment ;) It's not optimized or cleaned up yet... My first > experimenting with inline assembler ;)