add support for an associative marker


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23502 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/DAGISelEmitter.h b/utils/TableGen/DAGISelEmitter.h
index d169acf..f452901 100644
--- a/utils/TableGen/DAGISelEmitter.h
+++ b/utils/TableGen/DAGISelEmitter.h
@@ -87,7 +87,7 @@
     }
     
     // SelectionDAG node properties.
-    enum SDNP { SDNPCommutative };
+    enum SDNP { SDNPCommutative, SDNPAssociative };
 
     /// hasProperty - Return true if this node has the specified property.
     ///
@@ -205,8 +205,8 @@
       return false;
     }
     
-    /// canPatternMatch - Return false if it is impossible for this pattern to
-    /// match on this target.
+    /// canPatternMatch - If it is impossible for this pattern to match on this
+    /// target, fill in Reason and return false.  Otherwise, return true.
     bool canPatternMatch(std::string &Reason, DAGISelEmitter &ISE);
   };