1 files changed, 20 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 014889720a0..31c795c47d0 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -33675,6 +33675,26 @@ static SDValue combineShuffle(SDNode *N, SelectionDAG &DAG,
                        Movl, N->getOperand(0).getOperand(2));
   }
 
+  // If this a vzmovl of a full vector load, replace it with a vzload, unless
+  // the load is volatile.
+  if (N->getOpcode() == X86ISD::VZEXT_MOVL && N->getOperand(0).hasOneUse() &&
+      ISD::isNormalLoad(N->getOperand(0).getNode())) {
+    LoadSDNode *LN = cast<LoadSDNode>(N->getOperand(0));
+    if (!LN->isVolatile()) {
+      SDVTList Tys = DAG.getVTList(VT, MVT::Other);
+      SDValue Ops[] = { LN->getChain(), LN->getBasePtr() };
+      SDValue VZLoad =
+          DAG.getMemIntrinsicNode(X86ISD::VZEXT_LOAD, dl, Tys, Ops,
+                                  VT.getVectorElementType(),
+                                  LN->getPointerInfo(),
+                                  LN->getAlignment(),
+                                  MachineMemOperand::MOLoad);
+      DAG.ReplaceAllUsesOfValueWith(SDValue(LN, 0), VZLoad.getValue(1));
+      return VZLoad;
+    }
+  }
+
+
   // Look for a truncating shuffle to v2i32 of a PMULUDQ where one of the
   // operands is an extend from v2i32 to v2i64. Turn it into a pmulld.
   // FIXME: This can probably go away once we default to widening legalization.