Applied review comments and added additional tests (WIP)

src/frontends/onnx/frontend/src/core/tensor.hpp

@@ -13,6 +13,7 @@
 #include "exceptions.hpp"
 #include "onnx_common/utils.hpp"
 #include "openvino/core/shape.hpp"
+#include "openvino/core/type/element_iterator.hpp"
 #include "openvino/core/type/element_type.hpp"
 #include "openvino/frontend/exception.hpp"
 #include "openvino/runtime/aligned_buffer.hpp"
@@ -281,24 +282,13 @@ class Tensor {
     std::shared_ptr<ov::op::v0::Constant> make_ov_constant(const ov::element::Type& type) const {
         std::shared_ptr<ov::op::v0::Constant> constant{nullptr};
         auto data = get_data<T>();
-        auto data_size = data.size();
-        switch (type) {
-        case ov::element::i4:
-        case ov::element::u4:
-            data_size *= 2;  // Each byte contains 2 data items
-            break;
+        auto element_count = data.size();
+        if(ov::element::is_nibble_type(type)) {
+            element_count *= 2;  // Each byte contains 2 data items
         }
-        if (data_size == shape_size(m_shape)) {
-            switch (type) {
-            case ov::element::i4:
-            case ov::element::u4:
-                constant = std::make_shared<ov::op::v0::Constant>(type, m_shape, data.data());
-                break;
-            default:
-                constant = std::make_shared<ov::op::v0::Constant>(type, m_shape, data);
-                break;
-            }
-        } else if (data_size == 0 && m_shape.size() == 0) {
+        if (element_count == shape_size(m_shape)) {
+            constant = std::make_shared<ov::op::v0::Constant>(type, m_shape, data.data());
+        } else if (element_count == 0 && m_shape.size() == 0) {
             constant = common::make_failsafe_constant(type);
         } else {
             FRONT_END_THROW("Tensor shape doesn't match data size");

src/frontends/onnx/tests/models/int4_input.prototxt

@@ -0,0 +1,57 @@
+ir_version: 9
+producer_name: "OpenVINO ONNX Frontend"
+graph {
+  name: "test"
+  node {
+    input: "I"
+    output: "O"
+    op_type: "Shape"
+  }
+  node {
+    input: "I"
+    output: "V"
+    op_type: "Identity"
+  }
+  input {
+    name: "I"
+    type {
+      tensor_type {
+        elem_type: 22
+        shape {
+          dim {
+            dim_value: 5
+          }
+        }
+      }
+    }
+  }
+  output {
+    name: "O"
+    type {
+      tensor_type {
+        elem_type: 7
+        shape {
+          dim {
+            dim_value: 1
+          }
+        }
+      }
+    }
+  }
+  output {
+    name: "V"
+    type {
+      tensor_type {
+        elem_type: 22
+        shape {
+          dim {
+            dim_value: 5
+          }
+        }
+      }
+    }
+  }
+}
+opset_import {
+  version: 21
+}

src/frontends/onnx/tests/models/uint4_input.prototxt

@@ -0,0 +1,57 @@
+ir_version: 9
+producer_name: "OpenVINO ONNX Frontend"
+graph {
+  name: "test"
+  node {
+    input: "I"
+    output: "O"
+    op_type: "Shape"
+  }
+  node {
+    input: "I"
+    output: "V"
+    op_type: "Identity"
+  }
+  input {
+    name: "I"
+    type {
+      tensor_type {
+        elem_type: 21
+        shape {
+          dim {
+            dim_value: 3
+          }
+        }
+      }
+    }
+  }
+  output {
+    name: "O"
+    type {
+      tensor_type {
+        elem_type: 7
+        shape {
+          dim {
+            dim_value: 1
+          }
+        }
+      }
+    }
+  }
+  output {
+    name: "V"
+    type {
+      tensor_type {
+        elem_type: 21
+        shape {
+          dim {
+            dim_value: 3
+          }
+        }
+      }
+    }
+  }
+}
+opset_import {
+  version: 21
+}

src/frontends/onnx/tests/onnx_import.in.cpp

@@ -167,6 +167,16 @@ OPENVINO_TEST(${BACKEND_NAME}, onnx_int4_const) {
     test_case.run();
 }
 
+OPENVINO_TEST(${BACKEND_NAME}, onnx_int4_input) {
+    const auto model = convert_model("int4_input.onnx");
+    auto test_case = test::TestCase(model);
+    test_case.add_input<uint8_t>({0xEF, 0x01, 0x70});
+    test_case.add_expected_output<int64_t>({5});
+    test_case.add_expected_output<uint8_t>({0xEF, 0x01, 0x70});
+
+    test_case.run();
+}
+
 OPENVINO_TEST(${BACKEND_NAME}, onnx_uint4_const) {
     auto model = convert_model("uint4_const.onnx");
 
@@ -175,6 +185,16 @@ OPENVINO_TEST(${BACKEND_NAME}, onnx_uint4_const) {
     test_case.run();
 }
 
+OPENVINO_TEST(${BACKEND_NAME}, onnx_uint4_input) {
+    const auto model = convert_model("uint4_input.onnx");
+    auto test_case = test::TestCase(model);
+    test_case.add_input<uint8_t>({0x01, 0xF0});
+    test_case.add_expected_output<int64_t>({3});
+    test_case.add_expected_output<uint8_t>({0x01, 0xF0});
+
+    test_case.run();
+}
+
 OPENVINO_TEST(${BACKEND_NAME}, onnx_model_add_abc_initializers) {
     auto model = convert_model("add_abc_initializers.onnx");