[Paddle-TRT] fix_fill_constant (#44481)

* fix_fill_constant

* fix_fill_constant

* fix_ernie

paddle/fluid/inference/tensorrt/convert/fill_constant_op.cc

@@ -32,6 +32,10 @@ class FillConstantOpConverter : public OpConverter {
         PADDLE_GET_CONST(std::string, op_desc.GetAttr("str_value"));
     std::vector<int64_t> shape =
         PADDLE_GET_CONST(std::vector<int64_t>, op_desc.GetAttr("shape"));
+    if (str_value == "") {
+      float value = PADDLE_GET_CONST(float, op_desc.GetAttr("value"));
+      str_value = std::to_string(value);
+    }
     std::unique_ptr<framework::Tensor> out_tensor(new framework::Tensor());
     out_tensor->Resize(phi::make_ddim(shape));
     nvinfer1::DataType trt_dtype = nvinfer1::DataType::kFLOAT;

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

@@ -42,8 +42,14 @@ class TrtConvertSplitTest(TrtLayerAutoScanTest):
                 for dtype in [5, 2, 3]:
                     for str_value in ["2", "23", "-1"]:
                         self.num_input = num_input
+                        value = float(str_value)
+                        if np.random.choice([False, True]):
+                            str_value = str_value
+                        else:
+                            str_value = ""
                         dics = [{
                             "str_value": str_value,
+                            "value": value,
                             "shape": shape,
                             "dtype": dtype
                         }, {