[PATCH] D64517: [InstCombine] Dropping redundant masking before left-shift [2/5] (PR42563)

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri marked an inline comment as done.
lebedev.ri added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp:121
+    // FIXME: could also rely on ConstantRange.
+    if (!match(ShAmtsDiff, m_NonNegative()))
+      return nullptr;
----------------
It may be possible to use `SimplifyICmpInst()` here,
we also could ask it about `ShiftShAmt u>= MaskShAmt`
May look into that after patchset.


Repository:
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https://reviews.llvm.org/D64517