aaron.ballman added a comment. In D134456#3814820 <https://reviews.llvm.org/D134456#3814820>, @AntonBikineev wrote:
>> No, it sounds like we need a proposal for >> `[[likely_unless_the_optimizer_decides_otherwise]]` -- the `[[likely]]` >> attribute was intended for always-likely optimization decisions. > > Well, whatever the default behavior is chosen. Agreed -- and we can easily add such an attribute under the `clang` vendor namespace once we nail down the default behavior we want for `[[likely]]`. >> I agree that we should be consistent, but there's different ways we can be >> consistent. Consistent with what the feature paper intended? Consistent with >> our past decisions? Consistent with how other implementations behave? > > What I meant is that if the status quo is preserved, the never taken > [[likely]] branch would be considered as "unlikely'' after PGO (the purpose > of this patch). > >> What do other implementations that support PGO do? If PGO implementations >> consistently behave a certain way, that would be interesting to know. > > I just checked GCC and it seems like it considers likely as a forcing > optimization: https://godbolt.org/z/69E3383cq Thanks for checking! It doesn't seem to have any impact on ICC one way or the other (at least from my simple testing). Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D134456/new/ https://reviews.llvm.org/D134456 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
