On Thu, Jan 11, 2018 at 10:32:31AM +0100, Peter Zijlstra wrote: > can't you do lovely things like: > > volatile asm ("call __fill_rsb_thunk_%1" : : "r" (dummy)) > > which would still let gcc select the register ?
Calling a function from asm is nasty because you need to pay attention to clobbered registers as gcc doesn't see the function. What one can do, I *think*, is do a non-inlined wrapping function and do all the alternative_call() fun inside. There you can do all the fun and have callee-clobbered regs which you can use. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.