[AArch64] Transfer memory operands when lowering vector load/store intrinsics

Summary:
Some vector loads and stores generated from AArch64 intrinsics alias each other
unnecessarily, preventing better scheduling.  We just need to transfer memory
operands during lowering.

Reviewers: mcrosier, t.p.northover, jmolloy

Subscribers: aemerson, rengolin, llvm-commits

Differential Revision: https://reviews.llvm.org/D26313

llvm-svn: 286168

1 files changed, 11 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp b/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
index 413c22eeb69..b075b76c8e9 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
@@ -1154,6 +1154,12 @@ void AArch64DAGToDAGISel::SelectLoad(SDNode *N, unsigned NumVecs, unsigned Opc,
         CurDAG->getTargetExtractSubreg(SubRegIdx + i, dl, VT, SuperReg));
 
   ReplaceUses(SDValue(N, NumVecs), SDValue(Ld, 1));
+
+  // Transfer memoperands.
+  MachineSDNode::mmo_iterator MemOp = MF->allocateMemRefsArray(1);
+  MemOp[0] = cast<MemIntrinsicSDNode>(N)->getMemOperand();
+  cast<MachineSDNode>(Ld)->setMemRefs(MemOp, MemOp + 1);
+
   CurDAG->RemoveDeadNode(N);
 }
 
@@ -1202,6 +1208,11 @@ void AArch64DAGToDAGISel::SelectStore(SDNode *N, unsigned NumVecs,
   SDValue Ops[] = {RegSeq, N->getOperand(NumVecs + 2), N->getOperand(0)};
   SDNode *St = CurDAG->getMachineNode(Opc, dl, N->getValueType(0), Ops);
 
+  // Transfer memoperands.
+  MachineSDNode::mmo_iterator MemOp = MF->allocateMemRefsArray(1);
+  MemOp[0] = cast<MemIntrinsicSDNode>(N)->getMemOperand();
+  cast<MachineSDNode>(St)->setMemRefs(MemOp, MemOp + 1);
+
   ReplaceNode(N, St);
 }