junparser added a comment. In D71903#1804016 <https://reviews.llvm.org/D71903#1804016>, @modocache wrote:
> I'm currently working on ensuring that CGSCC optimizations are rerun to > optimize coroutine funclets -- the primary feedback I received on this and on > D71899 <https://reviews.llvm.org/D71899> -- but I just realized I didn't > respond to one comment on this set of reviews, from @junparser: > > > There is another issue we should consider: clang is crashed when compile > > coroutine with -disable-llvm-passes and output an object file. > > It's always been the case, since the coroutine intrinsics and passes were > first added to LLVM, that attempting to codegen without first running > coroutine passes would cause a crash during instruction selection. So `clang > -Xclang -disable-llvm-passes -c` has always crashed Clang during LLVM ISel, > as it does in this example that uses Clang 9.0.0 and the legacy pass manager: > https://godbolt.org/z/Mj2R5G > > Personally I'm of the opinion that this is less than ideal... I may be wrong, > but I don't think there are very many other C++ features that *require* Clang > to run LLVM passes (perhaps the `always_inline` attribute requires LLVM > passes to be run for correctness? I'm not sure). So I would like to see this > eventually addressed somehow. > > > Is it reasonable to run coroutine passes even -disable-llvm-passes is > > enabled? > > My personal opinion is that this would not be reasonable. The option > `-disable-llvm-passes` should, from my point of view, prevent any and all > LLVM passes from being run. I also frequently make use of this option when > debugging the LLVM IR being output for C++ coroutines code, so if > `-disable-llvm-passes` didn't disable coroutines passes, I'd need another > option that did > (`-disable-llvm-passes-no-really-even-coroutine-passes-them-too` 😅). > > All this being said, considering this behavior has existed in the legacy PM > since day one, I think we should start a separate discussion on if/how to > change that behavior. I'm working on an update for these patches to address > funclet optimization, but the update will not change the fact that coroutine > passes are not run when `-disable-llvm-passes` is specified. I think that's > an orthogonal issue. make sense to me, thanks! Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D71903/new/ https://reviews.llvm.org/D71903 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
