On Thu, May 12, 2016 at 02:14:52PM +0200, Peter Zijlstra wrote: > But this is a C function, with C calling convention. You're now assuming > GCC doesn't clobber anything with its prologue/epilogue. > > I think hpa meant to put it in an .S file and avoid all that.
I wanted to have gcc use %[w] and this way not hardcode the reg but the ABI kinda hardcodes it to rAX. And you're right about tracing funkyness adding glue so we're probably better off doing the .S thing directly and making it more robust this way. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --