diff --git a/mlir/include/mlir/IR/OpBase.td b/mlir/include/mlir/IR/OpBase.td
--- a/mlir/include/mlir/IR/OpBase.td
+++ b/mlir/include/mlir/IR/OpBase.td
@@ -1653,6 +1653,10 @@
 def FirstAttrDerivedResultType :
   GenInternalOpTrait<"FirstAttrDerivedResultType">;
 
+// Op has a resizable operand list. Auto-generated build and parse functions
+// should construct it as such.
+def ResizableOperandList : GenInternalOpTrait<"ResizableOperandList">;
+
 // TODO(antiagainst): Turn the following into normal traits and generate
 // verification for them.
 
diff --git a/mlir/include/mlir/TableGen/Operator.h b/mlir/include/mlir/TableGen/Operator.h
--- a/mlir/include/mlir/TableGen/Operator.h
+++ b/mlir/include/mlir/TableGen/Operator.h
@@ -165,6 +165,9 @@
   // requiring the raw MLIR trait here.
   const OpTrait *getTrait(llvm::StringRef trait) const;
 
+  // Returns "true" if Op has a ResizableOperandList trait.
+  bool hasResizableOperandList() const;
+
   // Regions.
   using const_region_iterator = const NamedRegion *;
   const_region_iterator region_begin() const;
diff --git a/mlir/lib/TableGen/Operator.cpp b/mlir/lib/TableGen/Operator.cpp
--- a/mlir/lib/TableGen/Operator.cpp
+++ b/mlir/lib/TableGen/Operator.cpp
@@ -169,6 +169,10 @@
   return nullptr;
 }
 
+bool tblgen::Operator::hasResizableOperandList() const {
+  return getTrait("OpTrait::ResizableOperandList") != nullptr;
+}
+
 auto tblgen::Operator::region_begin() const -> const_region_iterator {
   return regions.begin();
 }
diff --git a/mlir/test/mlir-tblgen/op-operand.td b/mlir/test/mlir-tblgen/op-operand.td
--- a/mlir/test/mlir-tblgen/op-operand.td
+++ b/mlir/test/mlir-tblgen/op-operand.td
@@ -58,3 +58,23 @@
 // CHECK-NEXT: odsState.addOperands(input1);
 // CHECK-NEXT: odsState.addOperands(input2);
 // CHECK-NEXT: odsState.addOperands(input3);
+// CHECK-NOT: odsState.setOperandListToResizable
+
+// Check that resizable operand list flag is set up correctly in all generated
+// builders and in the parser.
+def OpE : NS_Op<"resizable_operand_list", [ResizableOperandList]> {
+  let arguments = (ins Variadic<AnyType>:$input);
+  let assemblyFormat = "$input attr-dict `:` type($input)";
+}
+
+// CHECK-LABEL: OpE::build(Builder *odsBuilder, OperationState &odsState, ValueRange
+// CHECK: odsState.setOperandListToResizable()
+
+// CHECK-LABEL: OpE::build(Builder *odsBuilder, OperationState &odsState, ArrayRef<Type>
+// CHECK: odsState.setOperandListToResizable()
+
+// CHECK-LABEL: OpE::build(Builder *, OperationState
+// CHECK: odsState.setOperandListToResizable()
+
+// CHECK-LABEL: OpE::parse
+// CHECK: result.setOperandListToResizable()
diff --git a/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp b/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
--- a/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
+++ b/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
@@ -685,6 +685,7 @@
     auto &m =
         opClass.newMethod("void", "build", paramList, OpMethod::MP_Static);
     auto &body = m.body();
+
     genCodeForAddingArgAndRegionForBuilder(
         body, /*isRawValueAttr=*/attrType == AttrParamKind::UnwrappedValue);
 
@@ -762,7 +763,9 @@
   auto &body = m.body();
 
   // Operands
-  body << "  " << builderOpState << ".addOperands(operands);\n\n";
+  body << "  " << builderOpState << ".addOperands(operands);\n";
+  if (op.hasResizableOperandList())
+    body << formatv("  {0}.setOperandListToResizable();\n\n", builderOpState);
 
   // Attributes
   body << "  " << builderOpState << ".addAttributes(attributes);\n";
@@ -843,7 +846,10 @@
   }
 
   // Operands
-  body << "  " << builderOpState << ".addOperands(operands);\n\n";
+  body << "  " << builderOpState << ".addOperands(operands);\n";
+  if (op.hasResizableOperandList())
+    body << formatv("  {0}.setOperandListToResizable();\n\n", builderOpState);
+
   // Attributes
   body << "  " << builderOpState << ".addAttributes(attributes);\n";
 
@@ -929,7 +935,9 @@
          << (numVariadicOperands != 0 ? " >= " : " == ")
          << numNonVariadicOperands
          << "u && \"mismatched number of parameters\");\n";
-  body << "  " << builderOpState << ".addOperands(operands);\n\n";
+  body << "  " << builderOpState << ".addOperands(operands);\n";
+  if (op.hasResizableOperandList())
+    body << formatv("  {0}.setOperandListToResizable();\n\n", builderOpState);
 
   // Attributes
   body << "  " << builderOpState << ".addAttributes(attributes);\n";
@@ -1099,6 +1107,8 @@
       body << "  if (" << argName << ")\n  ";
     body << "  " << builderOpState << ".addOperands(" << argName << ");\n";
   }
+  if (op.hasResizableOperandList())
+    body << formatv("  {0}.setOperandListToResizable();\n", builderOpState);
 
   // If the operation has the operand segment size attribute, add it here.
   if (op.getTrait("OpTrait::AttrSizedOperandSegments")) {
diff --git a/mlir/tools/mlir-tblgen/OpFormatGen.cpp b/mlir/tools/mlir-tblgen/OpFormatGen.cpp
--- a/mlir/tools/mlir-tblgen/OpFormatGen.cpp
+++ b/mlir/tools/mlir-tblgen/OpFormatGen.cpp
@@ -706,6 +706,10 @@
   genParserSuccessorResolution(op, body);
   genParserVariadicSegmentResolution(op, body);
 
+  // Mark the operation as having resizable operand list if required.
+  if (op.hasResizableOperandList())
+    body << "  result.setOperandListToResizable();\n";
+
   body << "  return success();\n";
 }