Added MemOperands to Atomic operations since Atomics touches memory.
Added abstract class MemSDNode for any Node that have an associated MemOperand
Changed atomic.lcs => atomic.cmp.swap, atomic.las => atomic.load.add, and
atomic.lss => atomic.load.sub


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52706 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/CodeGenTarget.h b/utils/TableGen/CodeGenTarget.h
index 1191488..f53b6a9 100644
--- a/utils/TableGen/CodeGenTarget.h
+++ b/utils/TableGen/CodeGenTarget.h
@@ -30,6 +30,8 @@
 class CodeGenTarget;
 
 // SelectionDAG node properties.
+//  SDNPMemOperand: indicates that a node touches memory and therefore must
+//                  have an associated memory operand that describes the access.
 enum SDNP {
   SDNPCommutative, 
   SDNPAssociative, 
@@ -39,7 +41,8 @@
   SDNPOptInFlag,
   SDNPMayLoad,
   SDNPMayStore,
-  SDNPSideEffect
+  SDNPSideEffect,
+  SDNPMemOperand
 };
 
 // ComplexPattern attributes.