[X86][SSE] combineX86ShuffleChain - remove unused shuffle(vzext_load(),undef) combine.

This should always be caught by the various VZEXT_MOVL handling in combineTargetShuffle and SimplifyDemandedVectorEltsForTargetNode.

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 77406b1..5a4986a 100644 (file)
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -34260,22 +34260,6 @@ static SDValue combineX86ShuffleChain(ArrayRef<SDValue> Inputs, SDValue Root,
   APInt Zeroable = KnownUndef | KnownZero;
 
   if (UnaryShuffle) {
-    // If we are shuffling a X86ISD::VZEXT_LOAD then we can use the load
-    // directly if we don't shuffle the lower element and we shuffle the upper
-    // (zero) elements within themselves.
-    if (V1.getOpcode() == X86ISD::VZEXT_LOAD &&
-        (cast<MemIntrinsicSDNode>(V1)->getMemoryVT().getScalarSizeInBits() %
-         MaskEltSizeInBits) == 0) {
-      unsigned Scale =
-          cast<MemIntrinsicSDNode>(V1)->getMemoryVT().getScalarSizeInBits() /
-          MaskEltSizeInBits;
-      ArrayRef<int> HiMask(Mask.data() + Scale, NumMaskElts - Scale);
-      if (isSequentialOrUndefInRange(Mask, 0, Scale, 0) &&
-          isUndefOrZeroOrInRange(HiMask, Scale, NumMaskElts)) {
-        return DAG.getBitcast(RootVT, V1);
-      }
-    }
-
     // Attempt to match against broadcast-from-vector.
     // Limit AVX1 to cases where we're loading+broadcasting a scalar element.
     if ((Subtarget.hasAVX2() ||