Add printer for core op type

LiteRT-PiperOrigin-RevId: 774977275

Author: LukeBoyer

litert/core/model/model.h

@@ -1094,6 +1094,25 @@ void AbslStringify(Sink& sink, const std::vector<LiteRtTensor>& tensors) {
   sink.Append(")");
 }
 
+// OP PRINTING
+
+template <class Sink>
+void AbslStringify(Sink& sink, const LiteRtOpT& op) {
+  static constexpr auto kFmt = "%v%v%v->%v";
+  const auto& opts = ::litert::internal::GetTflOptions(op);
+  if (opts.type != ::tflite::BuiltinOptions_NONE) {
+    absl::Format(&sink, kFmt, op.OpCode(), opts, op.Inputs(), op.Outputs());
+    return;
+  }
+  absl::Format(&sink, kFmt, op.OpCode(), ::litert::internal::GetTflOptions2(op),
+               op.Inputs(), op.Outputs());
+}
+
+template <class Sink>
+void AbslStringify(Sink& sink, const LiteRtOpT* op) {
+  absl::Format(&sink, "null");
+}
+
 // OPTIONS PRINTING
 
 namespace litert::internal {

litert/core/model/model_test.cc

@@ -580,6 +580,36 @@ TEST(PrintingTest, TensoVector) {
   EXPECT_EQ(absl::StrFormat("%v", tensors), "(3d_i32<2x2x2>,3d_i32<2x2x2>)");
 }
 
+TEST(PrintingTest, Op) {
+  LiteRtOpT op;
+  op.SetOpCode(kLiteRtOpCodeTflAdd);
+
+  {
+    ::tflite::AddOptionsT add_opts;
+    add_opts.fused_activation_function = ::tflite::ActivationFunctionType_RELU;
+    add_opts.pot_scale_int16 = false;
+    TflOptions opts;
+    opts.type = ::tflite::BuiltinOptions_AddOptions;
+    opts.Set(std::move(add_opts));
+    litert::internal::SetTflOptions(op, std::move(opts));
+  }
+
+  LiteRtTensorT tensor;
+  tensor.SetType(MakeRankedTensorType(kLiteRtElementTypeInt32, {2, 2, 2}));
+  op.Inputs().push_back(&tensor);
+
+  LiteRtTensorT tensor2;
+  tensor2.SetType(MakeRankedTensorType(kLiteRtElementTypeInt32, {2}));
+  op.Inputs().push_back(&tensor2);
+
+  LiteRtTensorT tensor3;
+  tensor3.SetType(MakeRankedTensorType(kLiteRtElementTypeInt32, {2, 2, 2}));
+  op.Outputs().push_back(&tensor3);
+
+  EXPECT_EQ(absl::StrFormat("%v", op),
+            "tfl.add{fa=RELU}(3d_i32<2x2x2>,1d_i32<2>)->(3d_i32<2x2x2>)");
+}
+
 TEST(PrintingTest, TflOptions) {
   TflOptions opts;
   opts.type = ::tflite::BuiltinOptions_AddOptions;