[PATCH] D76500: GlobalISel: Lower funnel shifts

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


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Comment at: llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:4167-4168
+LegalizerHelper::lowerFunnelShift(MachineInstr &MI) {
+  // G_FSHL: (X << (Z % BW)) | (Y >> (BW - (Z % BW)))
+  // G_FSHR: (X << (BW - (Z % BW))) | (Y >> (Z % BW))
+  Register Dst = MI.getOperand(0).getReg();
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This won't work when Z is 0 if shifting by BW is undefined.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D76500/new/

https://reviews.llvm.org/D76500