1 files changed, 23 insertions, 11 deletions
diff --git a/lib/CodeGen/SelectionDAG/StatepointLowering.cpp b/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
index 395e9a8a4fc5..fad98b6f50dc 100644
--- a/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
@@ -378,7 +378,6 @@ spillIncomingStatepointValue(SDValue Incoming, SDValue Chain,
     // We use TargetFrameIndex so that isel will not select it into LEA
     Loc = Builder.DAG.getTargetFrameIndex(Index, Builder.getFrameIndexTy());
 
-#ifndef NDEBUG
     // Right now we always allocate spill slots that are of the same
     // size as the value we're about to spill (the size of spillee can
     // vary since we spill vectors of pointers too).  At some point we
@@ -387,12 +386,18 @@ spillIncomingStatepointValue(SDValue Incoming, SDValue Chain,
     MachineFrameInfo &MFI = Builder.DAG.getMachineFunction().getFrameInfo();
     assert((MFI.getObjectSize(Index) * 8) == Incoming.getValueSizeInBits() &&
            "Bad spill:  stack slot does not match!");
-#endif
 
+    // Note: Using the alignment of the spill slot (rather than the abi or
+    // preferred alignment) is required for correctness when dealing with spill
+    // slots with preferred alignments larger than frame alignment..
     auto &MF = Builder.DAG.getMachineFunction();
     auto PtrInfo = MachinePointerInfo::getFixedStack(MF, Index);
+    auto *StoreMMO =
+      MF.getMachineMemOperand(PtrInfo, MachineMemOperand::MOStore, 
+                              MFI.getObjectSize(Index),
+                              MFI.getObjectAlignment(Index));
     Chain = Builder.DAG.getStore(Chain, Builder.getCurSDLoc(), Incoming, Loc,
-                                 PtrInfo);
+                                 StoreMMO);
 
     MMO = getMachineMemOperand(MF, *cast<FrameIndexSDNode>(Loc));
     
@@ -1011,20 +1016,27 @@ void SelectionDAGBuilder::visitGCRelocate(const GCRelocateInst &Relocate) {
     return;
   }
 
-  SDValue SpillSlot =
-    DAG.getTargetFrameIndex(*DerivedPtrLocation, getFrameIndexTy());
+  unsigned Index = *DerivedPtrLocation;
+  SDValue SpillSlot = DAG.getTargetFrameIndex(Index, getFrameIndexTy());
 
   // Note: We know all of these reloads are independent, but don't bother to
   // exploit that chain wise.  DAGCombine will happily do so as needed, so
   // doing it here would be a small compile time win at most.
   SDValue Chain = getRoot();
 
-  SDValue SpillLoad =
-      DAG.getLoad(DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
-                                                           Relocate.getType()),
-                  getCurSDLoc(), Chain, SpillSlot,
-                  MachinePointerInfo::getFixedStack(DAG.getMachineFunction(),
-                                                    *DerivedPtrLocation));
+  auto &MF = DAG.getMachineFunction();
+  auto &MFI = MF.getFrameInfo();
+  auto PtrInfo = MachinePointerInfo::getFixedStack(MF, Index);
+  auto *LoadMMO =
+    MF.getMachineMemOperand(PtrInfo, MachineMemOperand::MOLoad, 
+                            MFI.getObjectSize(Index),
+                            MFI.getObjectAlignment(Index));
+
+  auto LoadVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
+                                                         Relocate.getType());
+
+  SDValue SpillLoad = DAG.getLoad(LoadVT, getCurSDLoc(), Chain,
+                                  SpillSlot, LoadMMO);
 
   DAG.setRoot(SpillLoad.getValue(1));