On Fri, Nov 20, 2015 at 02:05:01PM +0100, Richard Henderson wrote: > I'd be perfectly happy to deprecate and later completely remove basic asm > within functions. > > Because IMO it's essentially useless. It has no inputs, no outputs, and no > way to tell the compiler what machine state has been changed. We can say > that "it clobbers everything", but that's not actually useful, and quite > difficult as you're finding out. > > It seems to me that it would be better to remove the feature, forcing what > must be an extremely small number of users to audit and update to extended > asm.
Should asm("bla"); then be an extended asm with no input, no outputs, no (non-automatic) clobbers? That would be the most straightforward and logical semantics, but will it break user code? Segher