[PATCH] D121147: [x86] try harder to use shift instead of test if it can save some immediate bytes

[Matthias Braun via Phabricator via llvm-commits]

MatzeB added inline comments.


================
Comment at: llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:5632
           ShiftAmt = countLeadingZeros(Mask);
         }
         if (ShiftOpcode != ISD::DELETED_NODE) {
----------------
RKSimon wrote:
> If we added shifted mask detection would we hit any of the folds that D121320 is targetting?
Most likely yes. Let me try to put my transformation into this part of the code...


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  https://reviews.llvm.org/D121147/new/

https://reviews.llvm.org/D121147