Fix gather op convert for Paddle-TensorRT (#46779) (#46825)

* fix gather op convert to only support int32 index as input.
* add ut

paddle/fluid/inference/tensorrt/op_teller.cc

@@ -534,6 +534,16 @@ struct SimpleOpTypeSetTeller : public Teller {
                      "the pass.";
           return false;
         }
+
+        auto index_var_name = desc.Input("Index")[0];
+        auto* index_var_desc = block->FindVar(index_var_name);
+
+        // The index input must be int32 datatype.
+        if (index_var_desc->GetDataType() !=
+            paddle::framework::proto::VarType_Type::VarType_Type_INT32) {
+          VLOG(3) << "gather op Index input data type must be int32";
+          return false;
+        }
 #if !IS_TRT_VERSION_GE(7000)
         auto* x_var_desc = block->FindVar(desc.Input("X")[0]);
         const auto x_shape = x_var_desc->GetShape();

python/paddle/fluid/tests/unittests/ir/inference/test_trt_convert_gather.py

@@ -42,6 +42,9 @@ class TrtConvertGatherTest(TrtLayerAutoScanTest):
         def generate_input2(index):
             return np.array(index).astype(np.int32)
 
+        def generate_input4(index):
+            return np.array(index).astype(np.int64)
+
         def generate_input3(axis):
             return np.array([axis]).astype(np.int32)
 
@@ -57,44 +60,48 @@ class TrtConvertGatherTest(TrtLayerAutoScanTest):
                                 "Index": ["index_data"],
                                 "Axis": ["axis_data"]
                         }]:
-                            self.shape = shape
-                            self.axis = axis
-                            self.input_num = len(input)
-                            dics = [{"overwrite": overwrite, "axis": axis}]
-                            ops_config = [{
-                                "op_type": "gather",
-                                "op_inputs": input,
-                                "op_outputs": {
-                                    "Out": ["output_data"]
-                                },
-                                "op_attrs": dics[0]
-                            }]
-                            ops = self.generate_op_config(ops_config)
-
-                            program_config = ProgramConfig(
-                                ops=ops,
-                                weights={},
-                                inputs={
-                                    "input_data":
-                                    TensorConfig(data_gen=partial(
-                                        generate_input1, shape)),
-                                    "index_data":
-                                    TensorConfig(data_gen=partial(
-                                        generate_input2, index)),
-                                } if len(input) == 2 else {
-                                    "input_data":
-                                    TensorConfig(data_gen=partial(
-                                        generate_input1, shape)),
-                                    "index_data":
-                                    TensorConfig(data_gen=partial(
-                                        generate_input2, index)),
-                                    "axis_data":
-                                    TensorConfig(data_gen=partial(
-                                        generate_input3, axis)),
-                                },
-                                outputs=["output_data"])
-
-                            yield program_config
+                            for index_type_int32 in [True, False]:
+                                self.shape = shape
+                                self.axis = axis
+                                self.input_num = len(input)
+                                self.index_type_int32 = index_type_int32
+                                dics = [{"overwrite": overwrite, "axis": axis}]
+                                ops_config = [{
+                                    "op_type": "gather",
+                                    "op_inputs": input,
+                                    "op_outputs": {
+                                        "Out": ["output_data"]
+                                    },
+                                    "op_attrs": dics[0]
+                                }]
+                                ops = self.generate_op_config(ops_config)
+
+                                program_config = ProgramConfig(
+                                    ops=ops,
+                                    weights={},
+                                    inputs={
+                                        "input_data":
+                                        TensorConfig(data_gen=partial(
+                                            generate_input1, shape)),
+                                        "index_data":
+                                        TensorConfig(data_gen=partial(
+                                            generate_input2
+                                            if index_type_int32 ==
+                                            True else generate_input4, index)),
+                                    } if len(input) == 2 else {
+                                        "input_data":
+                                        TensorConfig(data_gen=partial(
+                                            generate_input1, shape)),
+                                        "index_data":
+                                        TensorConfig(data_gen=partial(
+                                            generate_input2, index)),
+                                        "axis_data":
+                                        TensorConfig(data_gen=partial(
+                                            generate_input3, axis)),
+                                    },
+                                    outputs=["output_data"])
+
+                                yield program_config
 
     def sample_predictor_configs(
             self, program_config) -> (paddle_infer.Config, List[int], float):
@@ -162,7 +169,7 @@ class TrtConvertGatherTest(TrtLayerAutoScanTest):
             if self.input_num == 3:
                 return 0, 5
             else:
-                if dynamic_shape:
+                if dynamic_shape and self.index_type_int32 == True:
                     return 1, 3
                 else:
                     return 0, 4