1 files changed, 35 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index d8b2c55eefe..71d53a389e9 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -1604,6 +1604,7 @@ const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
   case ARMISD::VTRN:          return "ARMISD::VTRN";
   case ARMISD::VTBL1:         return "ARMISD::VTBL1";
   case ARMISD::VTBL2:         return "ARMISD::VTBL2";
+  case ARMISD::VMOVN:         return "ARMISD::VMOVN";
   case ARMISD::VMULLs:        return "ARMISD::VMULLs";
   case ARMISD::VMULLu:        return "ARMISD::VMULLu";
   case ARMISD::UMAAL:         return "ARMISD::UMAAL";
@@ -6891,6 +6892,29 @@ static bool isReverseMask(ArrayRef<int> M, EVT VT) {
   return true;
 }
 
+static bool isVMOVNMask(ArrayRef<int> M, EVT VT, bool Top) {
+  unsigned NumElts = VT.getVectorNumElements();
+  // Make sure the mask has the right size.
+  if (NumElts != M.size() || (VT != MVT::v8i16 && VT != MVT::v16i8))
+      return false;
+
+  // If Top
+  //   Look for <0, N, 2, N+2, 4, N+4, ..>.
+  //   This inserts Input2 into Input1
+  // else if not Top
+  //   Look for <0, N+1, 2, N+3, 4, N+5, ..>
+  //   This inserts Input1 into Input2
+  unsigned Offset = Top ? 0 : 1;
+  for (unsigned i = 0; i < NumElts; i+=2) {
+    if (M[i] >= 0 && M[i] != (int)i)
+      return false;
+    if (M[i+1] >= 0 && M[i+1] != (int)(NumElts + i + Offset))
+      return false;
+  }
+
+  return true;
+}
+
 // If N is an integer constant that can be moved into a register in one
 // instruction, return an SDValue of such a constant (will become a MOV
 // instruction).  Otherwise return null.
@@ -7485,6 +7509,9 @@ bool ARMTargetLowering::isShuffleMaskLegal(ArrayRef<int> M, EVT VT) const {
   else if (Subtarget->hasNEON() && (VT == MVT::v8i16 || VT == MVT::v16i8) &&
            isReverseMask(M, VT))
     return true;
+  else if (Subtarget->hasMVEIntegerOps() &&
+           (isVMOVNMask(M, VT, 0) || isVMOVNMask(M, VT, 1)))
+    return true;
   else
     return false;
 }
@@ -7760,6 +7787,14 @@ static SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG,
             .getValue(WhichResult);
       }
     }
+    if (ST->hasMVEIntegerOps()) {
+      if (isVMOVNMask(ShuffleMask, VT, 0))
+        return DAG.getNode(ARMISD::VMOVN, dl, VT, V2, V1,
+                           DAG.getConstant(0, dl, MVT::i32));
+      if (isVMOVNMask(ShuffleMask, VT, 1))
+        return DAG.getNode(ARMISD::VMOVN, dl, VT, V1, V2,
+                           DAG.getConstant(1, dl, MVT::i32));
+    }
 
     // Also check for these shuffles through CONCAT_VECTORS: we canonicalize
     // shuffles that produce a result larger than their operands with: