echristo added a subscriber: erichkeane. echristo added inline comments.
================ Comment at: clang/lib/Sema/SemaOverload.cpp:9749 + if (isBetterMultiversionCandidate(Cand1, Cand2)) + return true; + ---------------- rjmccall wrote: > yaxunl wrote: > > rjmccall wrote: > > > If we move anything below this check, it needs to figure out a tri-state > > > so that it can return false if `Cand2` is a better candidate than > > > `Cand1`. Now, that only matters if multiversion functions are supported > > > under CUDA, but if you're relying on them not being supported, that > > > should at least be commented on. > > multiversion host functions is orthogonal to CUDA therefore should be > > supported. multiversion in device, host device, and global functions are > > not supported. However this change does not make things worse, and should > > continue to work if they are supported. > > > > host/device based overloading resolution is mostly for determining > > viability of a function. If two functions are both viable, other factors > > should take precedence in preference. This general rule has been taken for > > cases other than multiversion, I think it should also apply to multiversion. > > > > I will make isBetterMultiversionCandidate three states. > > This general rule has been taken for cases other than multiversion, I think > > it should also apply to multiversion. > > Well, but the multiversion people could say the same: that multiversioning is > for picking an alternative among otherwise-identical functions, and HD and H > functions are not otherwise-identical. > > CC'ing @echristo for his thoughts on the right ordering here. Adding @erichkeane here as well. I think this makes sense, but I can see a reason to multiversion a function that will run on host and device. A version of some matrix mult that takes advantage of 3 host architectures and one cuda one? Am I missing something here? CHANGES SINCE LAST ACTION https://reviews.llvm.org/D77954/new/ https://reviews.llvm.org/D77954 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
