[PATCH] D27811: [CostModel][X86] Add support for broadcast shuffle costs

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: lib/Analysis/CostModel.cpp:520-522
+      if (Shuffle->isSplat(&BroadcastIndex) && BroadcastIndex == 0)
+        return TTI->getShuffleCost(TargetTransformInfo::SK_Broadcast,
+                                   VecTypOp0, 0, nullptr);
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andreadb wrote:
> Is this code still needed?
> r290810 introduced a check for `isZeroEltBroadcastVectorMask' at line 530.
Thanks - I missed that for some reason.

What should we do? Keep with the separate Broadcast matching helpers or merge and use ShuffleVectorInst::isSplat ?


Repository:
  rL LLVM

https://reviews.llvm.org/D27811