Add patterns to use post-increment addressing for Neon VST1-lane instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126477 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index a506cff..f0d5a7d 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -126,6 +126,7 @@
   bool SelectAddrMode5(SDValue N, SDValue &Base,
                        SDValue &Offset);
   bool SelectAddrMode6(SDNode *Parent, SDValue N, SDValue &Addr,SDValue &Align);
+  bool SelectAddrMode6Offset(SDNode *Op, SDValue N, SDValue &Offset);
 
   bool SelectAddrModePC(SDValue N, SDValue &Offset, SDValue &Label);
 
@@ -886,6 +887,20 @@
   return true;
 }
 
+bool ARMDAGToDAGISel::SelectAddrMode6Offset(SDNode *Op, SDValue N,
+                                            SDValue &Offset) {
+  LSBaseSDNode *LdSt = cast<LSBaseSDNode>(Op);
+  ISD::MemIndexedMode AM = LdSt->getAddressingMode();
+  if (AM != ISD::POST_INC)
+    return false;
+  Offset = N;
+  if (ConstantSDNode *NC = dyn_cast<ConstantSDNode>(N)) {
+    if (NC->getZExtValue() * 8 == LdSt->getMemoryVT().getSizeInBits())
+      Offset = CurDAG->getRegister(0, MVT::i32);
+  }
+  return true;
+}
+
 bool ARMDAGToDAGISel::SelectAddrModePC(SDValue N,
                                        SDValue &Offset, SDValue &Label) {
   if (N.getOpcode() == ARMISD::PIC_ADD && N.hasOneUse()) {