[llvm] 805148e - [X86][SSE] combineHorizOpWithShuffle - consistently use getTargetShuffleInputs to decode shuffles

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2021-03-29T11:31:19+01:00
New Revision: 805148eaf27f61f214bc6193bf8ec7f076cbb40e

URL: https://github.com/llvm/llvm-project/commit/805148eaf27f61f214bc6193bf8ec7f076cbb40e
DIFF: https://github.com/llvm/llvm-project/commit/805148eaf27f61f214bc6193bf8ec7f076cbb40e.diff

LOG: [X86][SSE] combineHorizOpWithShuffle - consistently use getTargetShuffleInputs to decode shuffles

Minor cleanup before I start trying to merge the unary/binary shuffle combining paths.

Added: 
    

Modified: 
    llvm/lib/Target/X86/X86ISelLowering.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index bf89782ea017..9cbfae445a54 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -43196,15 +43196,21 @@ static SDValue combineHorizOpWithShuffle(SDNode *N, SelectionDAG &DAG,
     // If the op is an unary shuffle that can scale to v2x64,
     // then we can perform this as a v4x32 post shuffle.
     auto AdjustOp = [&](SDValue V, int Offset) {
-      auto *SVN = dyn_cast<ShuffleVectorSDNode>(V);
-      SmallVector<int, 2> ScaledMask;
-      if (!SVN || !SVN->getOperand(1).isUndef() ||
-          !scaleShuffleElements(SVN->getMask(), 2, ScaledMask) ||
-          !N->isOnlyUserOf(V.getNode()))
+      SmallVector<SDValue> ShuffleOps;
+      SmallVector<int> ShuffleMask, ScaledMask;
+      if (!getTargetShuffleInputs(V, ShuffleOps, ShuffleMask, DAG))
         return SDValue();
+
+      resolveTargetShuffleInputsAndMask(ShuffleOps, ShuffleMask);
+      if (isAnyZero(ShuffleMask) || ShuffleOps.size() != 1 ||
+          !ShuffleOps[0].getValueType().is128BitVector() ||
+          !N->isOnlyUserOf(V.getNode()) ||
+          !scaleShuffleElements(ShuffleMask, 2, ScaledMask))
+        return SDValue();
+
       PostShuffle[Offset + 0] = ScaledMask[0] < 0 ? -1 : Offset + ScaledMask[0];
       PostShuffle[Offset + 1] = ScaledMask[1] < 0 ? -1 : Offset + ScaledMask[1];
-      return SVN->getOperand(0);
+      return DAG.getBitcast(V.getValueType(), ShuffleOps[0]);
     };
 
     SDValue Src0 = AdjustOp(N0, 0);