[PATCH] D53036: [InstCombine] Demand bits of UMin

[Sanjay Patel via Phabricator via llvm-commits]

spatel accepted this revision.
spatel added a comment.

LGTM - see inline for a couple of nits.



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Comment at: lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp:330-332
+      // The lowest non-zero bit of DemandMask is higher than the highest
+      // non-one bit of C
+      // This comes about from some maths on the above umax example
----------------
Period at end of each sentence. Rather than random math, note this as the DeMorgan'd version of the umax logic.


================
Comment at: lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp:335
+      if (match(RHS, m_APInt(C)) &&
+          DemandedMask.countTrailingZeros() >=
+              C->getBitWidth() - C->countLeadingOnes())
----------------
Might read easier and fit better in 80-cols if we give the CTZ a name and use it here and for umax:
unsigned LowestDemandedBit = DemandedMask.countTrailingZeros();


https://reviews.llvm.org/D53036