diff --git a/src/Builder/FrontendDialectTransformer.cpp b/src/Builder/FrontendDialectTransformer.cpp
index c806eef..21c66a0 100644
--- a/src/Builder/FrontendDialectTransformer.cpp
+++ b/src/Builder/FrontendDialectTransformer.cpp
@@ -128,6 +128,13 @@ private:
     case onnx::AttributeProto::TENSOR:
       mlirAttr = onnxTensorProtoToDenseElmAttr(builder_, attr.t());
       break;
+    case onnx::AttributeProto::STRINGS: {
+      llvm::SmallVector<mlir::StringRef, 4> vectorStringRef;
+      for (const auto &item : attr.strings()) {
+        vectorStringRef.push_back(llvm::StringRef(item));
+      }
+      mlirAttr = builder_.getStrArrayAttr(llvm::makeArrayRef(vectorStringRef));
+    } break;
     default:
       llvm_unreachable("datatype for attribute is not implemented");
       break;
diff --git a/src/Builder/MLOpBuildTable.inc b/src/Builder/MLOpBuildTable.inc
deleted file mode 100644
index 58d3d3b..0000000
--- a/src/Builder/MLOpBuildTable.inc
+++ /dev/null
@@ -1,42 +0,0 @@
-//********************************************************
-//   Do not modify this file directly.
-//   This file is automatically generated via script.
-//   Details can be found in docs/readonnxdefs.md .
-//********************************************************
-
-if (opName == "ArrayFeatureExtractor")
-   buildOperation<mlir::MLONNXArrayFeatureExtractorOp>(node);
-if (opName == "Binarizer")
-   buildOperation<mlir::MLONNXBinarizerOp>(node);
-if (opName == "CastMap")
-   buildOperation<mlir::MLONNXCastMapOp>(node);
-if (opName == "CategoryMapper")
-   buildOperation<mlir::MLONNXCategoryMapperOp>(node);
-if (opName == "DictVectorizer")
-   buildOperation<mlir::MLONNXDictVectorizerOp>(node);
-if (opName == "FeatureVectorizer")
-   buildOperation<mlir::MLONNXFeatureVectorizerOp>(node);
-if (opName == "Imputer")
-   buildOperation<mlir::MLONNXImputerOp>(node);
-if (opName == "LabelEncoder")
-   buildOperation<mlir::MLONNXLabelEncoderOp>(node);
-if (opName == "LinearClassifier")
-   buildOperation<mlir::MLONNXLinearClassifierOp>(node);
-if (opName == "LinearRegressor")
-   buildOperation<mlir::MLONNXLinearRegressorOp>(node);
-if (opName == "Normalizer")
-   buildOperation<mlir::MLONNXNormalizerOp>(node);
-if (opName == "OneHotEncoder")
-   buildOperation<mlir::MLONNXOneHotEncoderOp>(node);
-if (opName == "SVMClassifier")
-   buildOperation<mlir::MLONNXSVMClassifierOp>(node);
-if (opName == "SVMRegressor")
-   buildOperation<mlir::MLONNXSVMRegressorOp>(node);
-if (opName == "Scaler")
-   buildOperation<mlir::MLONNXScalerOp>(node);
-if (opName == "TreeEnsembleClassifier")
-   buildOperation<mlir::MLONNXTreeEnsembleClassifierOp>(node);
-if (opName == "TreeEnsembleRegressor")
-   buildOperation<mlir::MLONNXTreeEnsembleRegressorOp>(node);
-if (opName == "ZipMap")
-   buildOperation<mlir::MLONNXZipMapOp>(node);
diff --git a/src/Dialect/ONNX/ONNXOps.td.inc b/src/Dialect/ONNX/ONNXOps.td.inc
index 89d969a..7089c14 100644
--- a/src/Dialect/ONNX/ONNXOps.td.inc
+++ b/src/Dialect/ONNX/ONNXOps.td.inc
@@ -204,7 +204,7 @@ def ONNXArgMaxOp:ONNX_Op<"ArgMax",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {-1};
+      return {4};
     }
   }];
 }
@@ -230,7 +230,7 @@ def ONNXArgMinOp:ONNX_Op<"ArgMin",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {-1};
+      return {4};
     }
   }];
 }
@@ -944,7 +944,7 @@ def ONNXDequantizeLinearOp:ONNX_Op<"DequantizeLinear",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {21};
+      return {7};
     }
   }];
 }
@@ -1091,7 +1091,7 @@ def ONNXDynamicQuantizeLinearOp:ONNX_Op<"DynamicQuantizeLinear",
       return 3;
     }
     static std::vector<int> getTypeMap() {
-      return {1,-1,1};
+      return {1,7,1};
     }
   }];
 }
@@ -2914,7 +2914,7 @@ def ONNXNonMaxSuppressionOp:ONNX_Op<"NonMaxSuppression",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {22};
+      return {4};
     }
   }];
 }
@@ -2938,7 +2938,7 @@ def ONNXNonZeroOp:ONNX_Op<"NonZero",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {-1};
+      return {4};
     }
   }];
 }
@@ -5144,7 +5144,7 @@ def ONNXStringNormalizerOp:ONNX_Op<"StringNormalizer",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {20};
+      return {11};
     }
   }];
 }
@@ -5526,7 +5526,7 @@ def ONNXUniqueOp:ONNX_Op<"Unique",
       return 4;
     }
     static std::vector<int> getTypeMap() {
-      return {20,-1,-1,-1};
+      return {20,4,4,4};
     }
   }];
 }
@@ -5823,7 +5823,7 @@ def ONNXFeatureVectorizerOp:ONNX_Op<"FeatureVectorizer",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {-1};
+      return {7};
     }
   }];
 }
@@ -5929,7 +5929,7 @@ def ONNXLinearClassifierOp:ONNX_Op<"LinearClassifier",
       return 2;
     }
     static std::vector<int> getTypeMap() {
-      return {-1,-1};
+      return {-1,7};
     }
   }];
 }
@@ -5959,7 +5959,7 @@ def ONNXLinearRegressorOp:ONNX_Op<"LinearRegressor",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {-1};
+      return {7};
     }
   }];
 }
@@ -5990,7 +5990,7 @@ def ONNXNormalizerOp:ONNX_Op<"Normalizer",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {-1};
+      return {7};
     }
   }];
 }
@@ -6021,7 +6021,7 @@ def ONNXOneHotEncoderOp:ONNX_Op<"OneHotEncoder",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {-1};
+      return {7};
     }
   }];
 }
@@ -6054,7 +6054,7 @@ def ONNXSVMClassifierOp:ONNX_Op<"SVMClassifier",
       return 2;
     }
     static std::vector<int> getTypeMap() {
-      return {-1,-1};
+      return {-1,7};
     }
   }];
 }
@@ -6083,7 +6083,7 @@ def ONNXSVMRegressorOp:ONNX_Op<"SVMRegressor",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {-1};
+      return {7};
     }
   }];
 }
@@ -6106,7 +6106,7 @@ def ONNXScalerOp:ONNX_Op<"Scaler",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {-1};
+      return {7};
     }
   }];
 }
@@ -6153,7 +6153,7 @@ def ONNXTreeEnsembleClassifierOp:ONNX_Op<"TreeEnsembleClassifier",
       return 2;
     }
     static std::vector<int> getTypeMap() {
-      return {-1,-1};
+      return {-1,7};
     }
   }];
 }
@@ -6200,7 +6200,7 @@ def ONNXTreeEnsembleRegressorOp:ONNX_Op<"TreeEnsembleRegressor",
       return 1;
     }
     static std::vector<int> getTypeMap() {
-      return {-1};
+      return {7};
     }
   }];
 }
diff --git a/utils/gen_onnx_mlir.py b/utils/gen_onnx_mlir.py
index 393c266..06c1e47 100644
--- a/utils/gen_onnx_mlir.py
+++ b/utils/gen_onnx_mlir.py
@@ -427,7 +427,15 @@ def get_allowed_elem_types(schema, input):
     # return allowed_types_str
     # TODO: enable type constraints.
     if input.typeStr :
-         tstr = input.typeStr
+        tstr = input.typeStr
+        structure, element = get_data_structure_element(tstr);
+        # In case the type is directly specified
+        if structure and element :
+            t = np_type_to_tblgen_attr_type(element)
+            if t == None :
+                return allowed_structure, None
+            else :
+                return structure, [t]
     else :
         return None
     if schema.type_constraints: