On Fri, Sep 6, 2019 at 5:14 PM Segher Boessenkool <seg...@kernel.crashing.org> wrote: > > On Fri, Sep 06, 2019 at 04:42:58PM -0700, Nick Desaulniers via gcc-patches > wrote: > > Just to prove my point about version checks being brittle, it looks > > like Rasmus' version check isn't even right. GCC supported `asm > > inline` back in the 8.3 release, not 9.1 as in this patch: > > Yes, I backported it so that it is available in 7.5, 8.3, and 9.1, so > that more users will have this available sooner. (7.5 has not been > released yet, but asm inline has been supported in GCC 7 since Jan 2 > this year).
Ah, ok that makes sense. How would you even write a version check for that? Which looks better? #if __GNU_MAJOR__ > 9 || __GNU_MAJOR__ == 8 && __GNU_MINOR__ >= 3 || __GNU_MAJOR__ == 7 && __GNU_MINOR__ >= 5 || __CLANG_MAJOR__ == 42 // make use of `asm inline` #endif or #ifdef __CC_HAS_ASM_INLINE__ // make use of `asm inline` #endif > > > Or was it "broken" until 9.1? Lord knows, as `asm inline` wasn't in > > any release notes or bug reports I can find: > > https://gcc.gnu.org/ml/gcc-patches/2019-02/msg01143.html > > It never was accepted, and I dropped the ball. Ah, ok, that's fine, so documentation was at least written. Tracking when and where patches land (or don't) is difficult when patch files are emailed around. I try to keep track of when and where our kernel patches land, but I frequently drop the ball there. > > Segher, next time there's discussion about new C extensions for the > > kernel, can you please include me in the discussions? > > You can lurk on gcc-patches@ and/or gcc@? Please "interrupt" me when you're aware of such discussions, rather than me "polling" a mailing list. (I will buy you a tasty beverage of your preference). I'm already subscribed to more mailing lists than I have time to read. > But I'll try to remember, sure. > Not that I am involved in all such discussions myself, mind. But you _did_ implement `asm inline`. ;) -- Thanks, ~Nick Desaulniers
