On Fri, Jun 04, 2021 at 12:24:07PM -0500, Segher Boessenkool wrote: > On Fri, Jun 04, 2021 at 10:10:29AM -0700, Linus Torvalds wrote: > > The compiler *cannot* just say "oh, I'll do that 'volatile asm > > barrier' whether the condition is true or not". That would be a > > fundamental compiler bug. > > Yes. So we can all agree on something like this? #define volatile_if(x) \ if (({ _Bool __x = (x); BUILD_BUG_ON(__builtin_constant_p(__x)); __x; }) && \ ({ barrier(); 1; })) Do we keep volatile_if() or do we like ctrl_dep_if() better?