Index: llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1600,9 +1600,13 @@
   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
   Chain = SP.getValue(1);
   unsigned Align = cast<ConstantSDNode>(Tmp3)->getZExtValue();
-  unsigned StackAlign =
-      DAG.getSubtarget().getFrameLowering()->getStackAlignment();
-  Tmp1 = DAG.getNode(ISD::SUB, dl, VT, SP, Size);       // Value
+  const TargetFrameLowering *TFL = DAG.getSubtarget().getFrameLowering();
+  unsigned Opc =
+    TFL->getStackGrowthDirection() == TargetFrameLowering::StackGrowsUp ?
+    ISD::ADD : ISD::SUB;
+
+  unsigned StackAlign = TFL->getStackAlignment();
+  Tmp1 = DAG.getNode(Opc, dl, VT, SP, Size);       // Value
   if (Align > StackAlign)
     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
                        DAG.getConstant(-(uint64_t)Align, dl, VT));