[clang] [llvm] [clang-tools-extra] [InstCombine] Convert or concat to fshl if opposite or concat exists (PR #68502)

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HaohaiWen wrote:

> For my money this was merged prematurely. There are still outstanding concerns about whether this transform is desirable, as well there is an outstanding comment about the implementation itself. I'm fairly agnostic about this code getting in, but I think it should be reverted until some degree of consensus is reached. It's painful to have comments/a PR languish without replies, but don't think the answer is to just push.

Thanks for kindly reminding. I think I've replied the concerns and wait a long time... I thought there should be no problem so I merged it...
Hi @nikic, any comments about the reply to your concerns? https://github.com/llvm/llvm-project/pull/68502#issuecomment-1813507499
If you have concerns that this patch is bad for some cases, or you have more suggestions, please let us know and we can improve it.


https://github.com/llvm/llvm-project/pull/68502