MaskRay added a comment. `ZB_Max` is the strange mode that should be dropped, perhaps also `ZB_Undefined`.
In D141798#4064114 <https://reviews.llvm.org/D141798#4064114>, @arsenm wrote: >> If you care about compilation speed, you should build LLVM with an >> appropriate -march= to take advantage of lzcnt and tzcnt. > > I think this is bad reasoning, nobody really uses -march I agree. The reason should be clarified that the lzcnt performance here really doesn't matter. Note: https://stackoverflow.com/questions/21390165/why-does-breaking-the-output-dependency-of-lzcnt-matter lzcnt/tzcnt have false dependencies on older (pre-Skylake) Intel processors. But this doesn't really matter for LLVM, at least the minor issue does not justify keeping the weird mode `ZB_Undefined`. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D141798/new/ https://reviews.llvm.org/D141798 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
