On 09/12/2013 02:11 PM, Dridi Boukelmoune wrote: > I don't understand the last 5 lines of __asm in both functions, I've > never seen this syntax before. It's gcc's extended asm syntax (Aka. "inline asm in C"): c.f. http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html ff. Ralf