[PATCH] D34160: [Power9] Exploit vinserth instruction

[Nemanja Ivanovic via Phabricator via llvm-commits]

nemanjai added inline comments.


================
Comment at: lib/Target/PowerPC/PPCISelLowering.cpp:7903
+    // undef.
+    if (V2.isUndef()) {
+      ShiftElts = 0;
----------------
You should be able to get rid of this condition here.
- Move the assignment `if (V.isUndef()) V2 = V1;` above here
- Use the `OriginalOrderLow` if the two vectors are the same

The rest should fall out naturally and we'll do the shift for the single-input case as well. And the code will also be simpler.


Repository:
  rL LLVM

https://reviews.llvm.org/D34160