fix: distingush engines based on compilation settings in addition to …

…graph structure

Signed-off-by: Naren Dasan <naren@narendasan.com>

py/torch_tensorrt/_Input.py

@@ -220,6 +220,34 @@ def __str__(self) -> str:
     def __repr__(self) -> str:
         return self.__str__()
 
+    @staticmethod
+    def equivalent_spec(a: Input, b: Input) -> bool:
+        if a.shape_mode != b.shape_mode:
+            return False
+
+        if a.shape_mode == Input._ShapeMode.DYNAMIC:
+            assert isinstance(a.shape, dict)
+            assert isinstance(b.shape, dict)
+            checks = [
+                a.shape["min_shape"] == b.shape["min_shape"],
+                a.shape["opt_shape"] == b.shape["opt_shape"],
+                a.shape["max_shape"] == b.shape["max_shape"],
+                a.dtype == b.dtype,
+                a.format == b.format,
+                a.low_tensor_domain_incl == b.low_tensor_domain_incl,
+                a.high_tensor_domain_excl == b.high_tensor_domain_excl,
+            ]
+            return all(checks)
+        else:
+            checks = [
+                a.shape == b.shape,
+                a.dtype == b.dtype,
+                a.format == b.format,
+                a.low_tensor_domain_incl == b.low_tensor_domain_incl,
+                a.high_tensor_domain_excl == b.high_tensor_domain_excl,
+            ]
+            return all(checks)
+
     @staticmethod
     def _supported_input_size_type(input_size: Any) -> bool:
         if isinstance(input_size, torch.Size):

py/torch_tensorrt/dynamo/conversion/_TRTInterpreter.py

@@ -545,7 +545,7 @@ def run(
                         serialized_engine,
                         self._input_names,
                         self._output_names,
-                        engine_input_specs,
+                        cached_engine_input_specs,
                         engine_compilation_settings,
                         self.weight_name_map,
                     ) = cached_data
@@ -559,6 +559,16 @@ def run(
                         setting_compatiblity
                     ), f"Attempted to refit a prebuilt engine with incompatible settings: {incompattible_settings}, (old_settings: {engine_compilation_settings}, new_settings: {self.compilation_settings})"
 
+                    for i, e in enumerate(
+                        [
+                            Input.equivalent_spec(c, i)
+                            for c, i in zip(cached_engine_input_specs, self.input_specs)
+                        ]
+                    ):
+                        assert (
+                            e
+                        ), f"Found that cached engine was built for a different input size (input: {i}, cached size: {cached_engine_input_specs[i]}, new size: {self.input_specs[i]}"
+
                     _LOGGER.info(
                         "Found the cached engine that corresponds to this graph. It is directly loaded."
                     )