On Wed, Dec 14, 2016 at 09:49:32AM +0000, Andrew Haley wrote: > On 13/12/16 18:15, Segher Boessenkool wrote: > > Clobbering "memory" does not work here. Clobbering "rsp" however seems > > to work. But, "seems to", I don't think there is a guarantee anywhere. > > Clobbering the stack pointer forces the use of the frame pointer, but is > > that guaranteed even? > > No, I think we shouldn't do that. If it's necessary to save things on > the stack all we need to do is to avoid the red zone. That really isn't > hard. That was a workaround for doing this with released compiler versions, like e.g. anything you build current glibc with. Segher
