Index: lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -6397,10 +6397,7 @@
 
   MachineFunction &MF = getMachineFunction();
 
-  // FIXME: Volatile isn't really correct; we should keep track of atomic
-  // orderings in the memoperand.
-  auto Flags = MachineMemOperand::MOVolatile | MachineMemOperand::MOLoad |
-               MachineMemOperand::MOStore;
+  auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
   MachineMemOperand *MMO =
     MF.getMachineMemOperand(PtrInfo, Flags, MemVT.getStoreSize(), Alignment,
                             AAMDNodes(), nullptr, SSID, SuccessOrdering,
@@ -6432,11 +6429,7 @@
   MachineFunction &MF = getMachineFunction();
   // An atomic store does not load. An atomic load does not store.
   // (An atomicrmw obviously both loads and stores.)
-  // For now, atomics are considered to be volatile always, and they are
-  // chained as such.
-  // FIXME: Volatile isn't really correct; we should keep track of atomic
-  // orderings in the memoperand.
-  auto Flags = MachineMemOperand::MOVolatile;
+  auto Flags = MachineMemOperand::MONone;
   if (Opcode != ISD::ATOMIC_STORE)
     Flags |= MachineMemOperand::MOLoad;
   if (Opcode != ISD::ATOMIC_LOAD)
Index: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4278,6 +4278,7 @@
   AtomicOrdering Order = I.getOrdering();
   SyncScope::ID SSID = I.getSyncScopeID();
 
+  // FIXME: The chaining of atomic loads is unneccessarily conservative
   SDValue InChain = getRoot();
 
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();