[PATCH] D142901: [InstSimplify] Simplify UREM and SREM left shifted operands

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n added inline comments.


================
Comment at: llvm/lib/Analysis/InstructionSimplify.cpp:997
+                         const SimplifyQuery &Q) {
+  // rem X << S1, X << S2
+  // if (S1 >= S2) -> 0; else -> X << S1
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Maybe add a `TODO` for the more generalized case of `(rem (mul nsw/nuw X, C1), (mul nsw/nuw X, C2) if C1 % C2 == 0 -> 0` We seem to be missing it: https://godbolt.org/z/fzxb4sxb5


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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D142901/new/

https://reviews.llvm.org/D142901