[llvm] [InstCombine] Fold `select Cond, not X, X` into `Cond ^ X` (PR #93591)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

Compile-time impact: http://llvm-compile-time-tracker.com/compare.php?from=4b5e0a1d12f0d624852c6d7c82207647ed5282aa&to=c7fb076906dff0f140462c093571e7f555d1271e&stat=instructions%3Au

https://github.com/llvm/llvm-project/pull/93591