[llvm] [InstCombine] Canonicalise packed-integer-selecting shifts (PR #162147)

[Yingwei Zheng via llvm-commits]

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@@ -800,6 +800,48 @@ Value *InstCombinerImpl::SimplifyDemandedUseBits(Instruction *I,
         Known.Zero.setHighBits(ShiftAmt);  // high bits known zero.
     } else {
       llvm::computeKnownBits(I, Known, Q, Depth);
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dtcxzyw wrote:

The known bits are unused if it is simplified. We should move this behind the new folding logic.


https://github.com/llvm/llvm-project/pull/162147