[MachineMemOperand][AtomicSDNode] Remove getSuccessOrdering()

[qcolombet]

Hi Konstantin,

LGTM.

Cheers,
-Quentin

include/llvm/CodeGen/MachineMemOperand.h

public:
   /// Return the range tag for the memory reference.
   const MDNode *getRanges() const { return Ranges; }
 
   /// Return the synchronization scope for this memory operation.
   SynchronizationScope getSynchScope() const {
     return static_cast<SynchronizationScope>(AtomicInfo.SynchScope);
   }
 
-  /// Return the atomic ordering requirements for this memory operation.
+  /// Return the atomic ordering requirements for this memory operation. For
+  /// cmpxchg atomic operations, return the atomic ordering requirements when
+  /// store occurs.
   AtomicOrdering getOrdering() const {
     return static_cast<AtomicOrdering>(AtomicInfo.Ordering);
   }
 
   /// For cmpxchg atomic operations, return the atomic ordering requirements
-  /// when store occurs.
-  AtomicOrdering getSuccessOrdering() const {
-    return getOrdering();
-  }
-
-  /// For cmpxchg atomic operations, return the atomic ordering requirements
   /// when store does not occur.
   AtomicOrdering getFailureOrdering() const {
     return static_cast<AtomicOrdering>(AtomicInfo.FailureOrdering);
   }
 
   bool isLoad() const { return FlagVals & MOLoad; }
   bool isStore() const { return FlagVals & MOStore; }
   bool isVolatile() const { return FlagVals & MOVolatile; }

include/llvm/CodeGen/SelectionDAGNodes.h

public:
   AAMDNodes getAAInfo() const { return MMO->getAAInfo(); }
 
   /// Returns the Ranges that describes the dereference.
   const MDNode *getRanges() const { return MMO->getRanges(); }
 
   /// Return the synchronization scope for this memory operation.
   SynchronizationScope getSynchScope() const { return MMO->getSynchScope(); }
 
-  /// Return the atomic ordering requirements for this memory operation.
+  /// Return the atomic ordering requirements for this memory operation. For
+  /// cmpxchg atomic operations, return the atomic ordering requirements when
+  /// store occurs.
   AtomicOrdering getOrdering() const { return MMO->getOrdering(); }
 
   /// Return the type of the in-memory value.
   EVT getMemoryVT() const { return MemoryVT; }
 
   /// Return a MachineMemOperand object describing the memory
   /// reference performed by operation.
   MachineMemOperand *getMemOperand() const { return MMO; }
public:
   /// otherwise.
   bool isCompareAndSwap() const {
     unsigned Op = getOpcode();
     return Op == ISD::ATOMIC_CMP_SWAP ||
            Op == ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS;
   }
 
   /// For cmpxchg atomic operations, return the atomic ordering requirements
-  /// when store occurs.
-  AtomicOrdering getSuccessOrdering() const {
-    assert(isCompareAndSwap() && "Must be cmpxchg operation");
-    return MMO->getSuccessOrdering();
-  }
-
-  /// For cmpxchg atomic operations, return the atomic ordering requirements
   /// when store does not occur.
   AtomicOrdering getFailureOrdering() const {
     assert(isCompareAndSwap() && "Must be cmpxchg operation");
     return MMO->getFailureOrdering();
   }
 
   // Methods to support isa and dyn_cast
   static bool classof(const SDNode *N) {