[PATCH] D109155: [InstCombine] Fold BW/2+1 tops bits are same pattern

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

I agree that the double-the-bitwidth precondition is needed *for this pattern*, but there are other possible cases:
https://alive2.llvm.org/ce/z/RjUMzM (double)
https://alive2.llvm.org/ce/z/Jd3aHC (more than double => sext)
https://alive2.llvm.org/ce/z/CS2xkv (less than double => trunc)


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  https://reviews.llvm.org/D109155/new/

https://reviews.llvm.org/D109155