feat: support Python APIs for Automatic Fallback

Signed-off-by: Bo Wang <wangbo1995ee@163.com>

py/trtorch/_compile_spec.py

@@ -122,6 +122,23 @@ def _parse_device(device_info: Dict[str, Any]) -> trtorch._C.Device:
 
     return info
 
+def _parse_torch_fallback(fallback_info: Dict[str, Any]) -> trtorch._C.TorchFallback:
+    info = trtorch._C.TorchFallback()
+    if "enabled" not in fallback_info:
+        raise KeyError("Enabled is required parameter")
+    else:
+        assert isinstance(fallback_info["enabled"], bool)
+        info.enabled = fallback_info["enabled"]
+    if "min_block_size" in fallback_info:
+        assert isinstance(fallback_info["min_block_size"], int)
+        info.min_block_size = fallback_info["min_block_size"]
+
+    if "forced_fallback_operators" in fallback_info:
+        assert isinstance(fallback_info["forced_fallback_operators"], list)
+        info.forced_fallback_operators = fallback_info["forced_fallback_operators"]
+
+    return info
+
 
 def _parse_compile_spec(compile_spec: Dict[str, Any]) -> trtorch._C.CompileSpec:
     info = trtorch._C.CompileSpec()
@@ -174,6 +191,10 @@ def _parse_compile_spec(compile_spec: Dict[str, Any]) -> trtorch._C.CompileSpec:
         assert type(compile_spec["max_batch_size"]) is int
         info.max_batch_size = compile_spec["max_batch_size"]
 
+    if "torch_fallback" in compile_spec:
+        info.torch_fallback = _parse_torch_fallback(compile_spec["torch_fallback"])
+
+
     return info
 
 
@@ -242,7 +263,13 @@ def TensorRTCompileSpec(compile_spec: Dict[str, Any]) -> torch.classes.tensorrt.
     d.set_dla_core(parsed_spec.device.dla_core)
     d.set_allow_gpu_fallback(parsed_spec.device.allow_gpu_fallback)
 
+    torch_fallback = torch.classes.tensorrt.TorchFallback()
+    torch_fallback.set_enabled(parsed_spec.torch_fallback.enabled)
+    torch_fallback.set_min_block_size(parsed_spec.torch_fallback.min_block_size)
+    torch_fallback.set_forced_fallback_operators(parsed_spec.torch_fallback.forced_fallback_operators)
+
     backend_spec.set_device(d)
+    backend_spec.set_torch_fallback(fallback)
     backend_spec.set_op_precision(int(parsed_spec.op_precision))
     backend_spec.set_disable_tf32(parsed_spec.disable_tf32)
     backend_spec.set_refit(parsed_spec.refit)

py/trtorch/csrc/register_tensorrt_classes.cpp

@@ -24,11 +24,19 @@ void RegisterTRTCompileSpec() {
   ADD_FIELD_GET_SET_REGISTRATION(TRTDeviceTSRegistration, trtorch::pyapi::Device, dla_core);
   ADD_FIELD_GET_SET_REGISTRATION(TRTDeviceTSRegistration, trtorch::pyapi::Device, allow_gpu_fallback);
 
+  static auto TRTORCH_UNUSED TRTFallbackTSRegistration =
+      torch::class_<trtorch::pyapi::TorchFallback>("tensorrt", "Fallback").def(torch::init<>());
+  ADD_FIELD_GET_SET_REGISTRATION(TRTFallbackTSRegistration, trtorch::pyapi::TorchFallback, enabled);
+  ADD_FIELD_GET_SET_REGISTRATION(TRTFallbackTSRegistration, trtorch::pyapi::TorchFallback, min_block_size);
+  ADD_FIELD_GET_SET_REGISTRATION(TRTFallbackTSRegistration, trtorch::pyapi::TorchFallback, forced_fallback_operators);
+
+
   static auto TRTORCH_UNUSED TRTCompileSpecTSRegistration =
       torch::class_<trtorch::pyapi::CompileSpec>("tensorrt", "CompileSpec")
           .def(torch::init<>())
           .def("append_input_range", &trtorch::pyapi::CompileSpec::appendInputRange)
           .def("set_device", &trtorch::pyapi::CompileSpec::setDeviceIntrusive)
+          .def("set_torch_fallback", &trtorch::pyapi::CompileSpec::setTorchFallbackIntrusive)
           .def("__str__", &trtorch::pyapi::CompileSpec::stringify);
 
   ADD_FIELD_GET_SET_REGISTRATION(TRTCompileSpecTSRegistration, trtorch::pyapi::CompileSpec, op_precision);

py/trtorch/csrc/tensorrt_classes.cpp

@@ -107,6 +107,9 @@ core::CompileSpec CompileSpec::toInternalCompileSpec() {
   info.convert_info.engine_settings.device.gpu_id = device.gpu_id;
   info.convert_info.engine_settings.device.dla_core = device.dla_core;
   info.convert_info.engine_settings.device.allow_gpu_fallback = device.allow_gpu_fallback;
+  info.convert_info.engine_settings.torch_fallback.enabled = torch_fallback.enabled;
+  info.convert_info.engine_settings.torch_fallback.min_block_size = torch_fallback.min_block_size;
+  info.convert_info.engine_settings.torch_fallback.forced_fallback_operators = torch_fallback.forced_fallback_operators;
 
   info.convert_info.engine_settings.capability = toTRTEngineCapability(capability);
   TRTORCH_CHECK(num_min_timing_iters >= 0, "num_min_timing_iters must be 0 or greater");

py/trtorch/csrc/tensorrt_classes.h

@@ -78,6 +78,17 @@ struct Device : torch::CustomClassHolder {
 std::string to_str(DeviceType value);
 nvinfer1::DeviceType toTRTDeviceType(DeviceType value);
 
+struct TorchFallback : torch::CustomClassHolder {
+  bool enabled;
+  int64_t min_block_size;
+  std::vector<std::string> forced_fallback_operators;
+  TorchFallback() : enabled(false), min_block_size(1) {}
+
+  ADD_FIELD_GET_SET(enabled, bool);
+  ADD_FIELD_GET_SET(min_block_size, int64_t);
+  ADD_FIELD_GET_SET(forced_fallback_operators, std::vector<std::string>);
+};
+
 enum class EngineCapability : int8_t {
   kDEFAULT,
   kSAFE_GPU,
@@ -98,6 +109,10 @@ struct CompileSpec : torch::CustomClassHolder {
     device = *d;
   }
 
+  void setTorchFallbackIntrusive(const c10::intrusive_ptr<TorchFallback> &fb) {
+    torch_fallback = *fb;
+  }
+
   ADD_ENUM_GET_SET(op_precision, DataType, static_cast<int64_t>(DataType::kChar));
   ADD_FIELD_GET_SET(disable_tf32, bool);
   ADD_FIELD_GET_SET(refit, bool);
@@ -109,6 +124,7 @@ struct CompileSpec : torch::CustomClassHolder {
   ADD_FIELD_GET_SET(workspace_size, int64_t);
   ADD_FIELD_GET_SET(max_batch_size, int64_t);
   ADD_FIELD_GET_SET(device, Device);
+  ADD_FIELD_GET_SET(torch_fallback, TorchFallback);
 
   std::vector<InputRange> input_ranges;
   DataType op_precision = DataType::kFloat;
@@ -117,6 +133,7 @@ struct CompileSpec : torch::CustomClassHolder {
   bool debug = false;
   bool strict_types = false;
   Device device;
+  TorchFallback torch_fallback;
   EngineCapability capability = EngineCapability::kDEFAULT;
   int64_t num_min_timing_iters = 2;
   int64_t num_avg_timing_iters = 1;

py/trtorch/csrc/trtorch_py.cpp

@@ -124,6 +124,12 @@ PYBIND11_MODULE(_C, m) {
       .def_readwrite("dla_core", &Device::dla_core)
       .def_readwrite("allow_gpu_fallback", &Device::allow_gpu_fallback);
 
+  py::class_<TorchFallback>(m, "TorchFallback")
+      .def(py::init<>())
+      .def_readwrite("enabled", &TorchFallback::enabled)
+      .def_readwrite("min_block_size", &TorchFallback::min_block_size)
+      .def_readwrite("forced_fallback_operators", &TorchFallback::forced_fallback_operators);
+
   m.doc() =
       "TRTorch Internal C Bindings: Ahead of Time compilation for PyTorch JIT. A tool to convert PyTorch JIT to TensorRT";
   m.def(