[TF FE] Support Case operation

src/frontends/tensorflow/src/op/case.cpp

@@ -0,0 +1,72 @@
+#include "openvino/frontend/tensorflow/node_context.hpp"
+#include "openvino/frontend/tensorflow/translate_session.hpp"
+#include "openvino/opsets/opset11.hpp"
+#include "openvino/util/log.hpp"
+
+namespace ov {
+namespace frontend {
+namespace tensorflow {
+namespace op {
+
+using namespace ov::opsets;
+
+OutputVector translate_case_op(const NodeContext& node) {
+    // Validate the operation type
+    auto op_type = node.get_op_type();
+    TENSORFLOW_OP_VALIDATION(node, op_type == "Case",
+                             "Internal error: incorrect usage of translate_case_op.");
+
+    // Retrieve the number of branches and inputs
+    auto num_branches = node.get_attribute<int>("branches");
+    TENSORFLOW_OP_VALIDATION(node, num_branches > 0,
+                             "[TensorFlow Frontend] Case operation must have at least one branch.");
+
+    // The first input is the condition for selecting the branch
+    auto cond = node.get_input(0);
+
+    // Create a list to store sub-graphs for the branches
+    std::vector<std::shared_ptr<Model>> branch_graphs;
+    for (int i = 0; i < num_branches; ++i) {
+        std::string branch_name = "branch_" + std::to_string(i);
+        auto branch_body = node.get_attribute<std::string>(branch_name);
+
+        // Ensure that the branch model is correctly loaded
+        auto branch_model = node.get_translate_session()->get_body_ov_model(branch_body, node.get_inputs());
+        TENSORFLOW_OP_VALIDATION(node, branch_model, 
+                                 "[TensorFlow Frontend] Failed to retrieve body graph for branch: " + branch_name);
+        branch_graphs.push_back(branch_model);
+    }
+
+    // Create the nested If operation to represent the Case operation
+    std::shared_ptr<Model> current_model = nullptr;
+    for (int i = num_branches - 1; i >= 0; --i) {
+        auto if_op = std::make_shared<If>(cond);
+        if_op->set_then_body(branch_graphs[i]);
+
+        if (current_model) {
+            if_op->set_else_body(current_model);
+        } else {
+            // Default empty else body
+            auto placeholder_model = std::make_shared<Model>(OutputVector{}, ParameterVector{});
+            if_op->set_else_body(placeholder_model);
+        }
+
+        current_model = if_op->get_body_model();
+    }
+
+    // Set the outputs and names
+    auto outputs = current_model->get_results();
+    OutputVector ov_outputs;
+    for (size_t i = 0; i < outputs.size(); ++i) {
+        auto tensor = outputs[i]->output(0).get_tensor();
+        tensor.set_names({node.get_name() + ":" + std::to_string(i)});
+        ov_outputs.push_back(outputs[i]->output(0));
+    }
+
+    return ov_outputs;
+}
+
+}  // namespace op
+}  // namespace tensorflow
+}  // namespace frontend
+}  // namespace ov

src/frontends/tensorflow/src/op/case.hpp

@@ -0,0 +1,18 @@
+#ifndef CASE_HPP
+#define CASE_HPP
+
+#include "openvino/frontend/tensorflow/node_context.hpp"
+
+namespace ov {
+namespace frontend {
+namespace tensorflow {
+namespace op {
+
+OutputVector translate_case_op(const ov::frontend::tensorflow::NodeContext& node);
+
+}  // namespace op
+}  // namespace tensorflow
+}  // namespace frontend
+}  // namespace ov
+
+#endif  // CASE_HPP

src/frontends/tensorflow/src/op_table.cpp

@@ -19,6 +19,7 @@
 #include "openvino/op/bitwise_or.hpp"
 #include "openvino/op/bitwise_right_shift.hpp"
 #include "openvino/op/bitwise_xor.hpp"
+#include "case.hpp"
 #include "openvino/op/ceiling.hpp"
 #include "openvino/op/cos.hpp"
 #include "openvino/op/cosh.hpp"
@@ -87,6 +88,7 @@ TF_OP_CONVERTER(translate_assignvariable_op);
 TF_OP_CONVERTER(translate_add_variable_op);
 TF_OP_CONVERTER(translate_sub_variable_op);
 TF_OP_CONVERTER(translate_block_lstm_op);
+TF_OP_CONVERTER(translate_case_op);
 TF_OP_CONVERTER(translate_enter_op);
 TF_OP_CONVERTER(translate_exit_op);
 TF_OP_CONVERTER(translate_fifo_queue_op);
@@ -140,6 +142,7 @@ const std::map<std::string, CreatorFunction> get_supported_ops() {
         {"Asinh", CreatorFunction(translate_unary_op<v3::Asinh>)},
         {"Atan", CreatorFunction(translate_unary_op<v0::Atan>)},
         {"Atanh", CreatorFunction(translate_unary_op<v3::Atanh>)},
+        {"Case", CreatorFunction(translate_case_op)},
         {"Ceil", CreatorFunction(translate_unary_op<v0::Ceiling>)},
         {"Cos", CreatorFunction(translate_unary_op<v0::Cos>)},
         {"Cosh", CreatorFunction(translate_unary_op<v0::Cosh>)},