[PATCH] D157755: [InstSimplify] Use knownbits for simplifying `(icmp ugt/ule (or X, Y), X)`; PR64610

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n added inline comments.


================
Comment at: llvm/lib/Analysis/InstructionSimplify.cpp:3135-3140
+        // Get NOT of knownbits by swapping ones/zeros
+        std::swap(RHSKnown.One, RHSKnown.Zero);
+        KnownBits UniqueBits = RHSKnown & YKnown;
+        // We know there is a unique bit so equality conditions cannot be
+        // false.
+        if (UniqueBits.isNonZero())
----------------
nikic wrote:
> 
Is that right. It's really 'have a common bit not set', it's okay if there are some though


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https://reviews.llvm.org/D157755