https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91886
--- Comment #27 from Rich Felker <bugdal at aerifal dot cx> --- > Have I already mentioned that if any program "in the wild" will use "ws" with > GCC 10, then of course we can add an alias (to "wa") for it? No program > should > use "ws" in inline assembler, ever, but if some programs cannot fix that, we > can fix it for them, sure. I would very much appreciate it if the "ws" (and "ww") aliases could be added. I hope you can appreciate how clang users would respond when linked to this BZ ticket after musl broke for them, if we just changed it to use "wa". Even if (rather, "even though" - I believe you that they're wrong) clang is wrong to reject "wa" here, it would come across to them as completely unreasonable that we broke the constraints that previously worked fine on all compilers. I'm not sure if you would rather us have to do some sort of configure-time check here. Maybe one can be devised that doesn't risk wrong semantics when we can only measure whether the compiler accepts it, not whether it generates the wrong code, but I don't know how (and what's to guarantee that someday someone won't, seeing the combinations "ws" and "ww" as unused, invent a new meaning for one of them?), and even if it is possible, I would find such a configure check to be really ugly long-term maintenance cost in relation to a simple alias to preserve the long-documented behavior.
