diff --git a/mlir/include/mlir/IR/Value.h b/mlir/include/mlir/IR/Value.h
--- a/mlir/include/mlir/IR/Value.h
+++ b/mlir/include/mlir/IR/Value.h
@@ -220,6 +220,9 @@
   }
 
   friend ::llvm::hash_code hash_value(Value arg);
+  bool operator<(const Value &rhs) const {
+    return ownerAndKind.getOpaqueValue() < rhs.ownerAndKind.getOpaqueValue();
+  }
 
 protected:
   /// Returns true if the given operation result can be packed inline.