Index: mlir/lib/TableGen/Pattern.cpp
===================================================================
--- mlir/lib/TableGen/Pattern.cpp
+++ mlir/lib/TableGen/Pattern.cpp
@@ -257,7 +257,7 @@
     auto *operand = op->getArg(*argIndex).get<NamedTypeConstraint *>();
     // If this operand is variadic, then return a range. Otherwise, return the
     // value itself.
-    if (operand->isVariableLength()) {
+    if (operand->isVariadic()) {
       auto repl = formatv(fmt, name);
       LLVM_DEBUG(llvm::dbgs() << repl << " (VariadicOperand)\n");
       return std::string(repl);
Index: mlir/tools/mlir-tblgen/RewriterGen.cpp
===================================================================
--- mlir/tools/mlir-tblgen/RewriterGen.cpp
+++ mlir/tools/mlir-tblgen/RewriterGen.cpp
@@ -1221,6 +1221,8 @@
       "if (auto tmpAttr = {1}) {\n"
       "  tblgen_attrs.emplace_back(rewriter.getIdentifier(\"{0}\"), "
       "tmpAttr);\n}\n";
+  const char *addOperandCmd = "if (auto tmpOperand = {0}) {{\n"
+                              "  tblgen_values.push_back(tmpOperand);\n}\n";
   for (int argIndex = 0, e = resultOp.getNumArgs(); argIndex < e; ++argIndex) {
     if (resultOp.getArg(argIndex).is<NamedAttribute *>()) {
       // The argument in the op definition.
@@ -1257,22 +1259,22 @@
       os << formatv("for (auto v: {0}) {{\n  tblgen_values.push_back(v);\n}\n",
                     range);
     } else {
-      os << formatv("tblgen_values.push_back(");
+      std::string tmpSymbol;
       if (node.isNestedDagArg(argIndex)) {
-        os << symbolInfoMap.getValueAndRangeUse(
-            childNodeNames.lookup(argIndex));
+        tmpSymbol =
+            symbolInfoMap.getValueAndRangeUse(childNodeNames.lookup(argIndex));
       } else {
         DagLeaf leaf = node.getArgAsLeaf(argIndex);
         auto symbol =
             symbolInfoMap.getValueAndRangeUse(node.getArgName(argIndex));
         if (leaf.isNativeCodeCall()) {
-          os << std::string(
+          tmpSymbol = std::string(
               tgfmt(leaf.getNativeCodeTemplate(), &fmtCtx.withSelf(symbol)));
         } else {
-          os << symbol;
+          tmpSymbol = symbol;
         }
       }
-      os << ");\n";
+      os << formatv(addOperandCmd, tmpSymbol);
     }
   }
 }