[Bug fixes] update input_spec for forward (#7648)

* update input_spec for forward

* update opt casting

Author: wj-Mcat

paddlenlp/generation/utils.py

@@ -15,6 +15,7 @@
 from __future__ import annotations
 
 import copy
+import inspect
 from typing import Union
 
 import paddle
@@ -1203,10 +1204,13 @@ def sample(
         return input_ids[:, origin_len:], scores
 
     def _get_model_inputs_spec(self, dtype: str):
-        return {
+        spec = {
             "input_ids": paddle.static.InputSpec(shape=[None, None], dtype="int64"),
             "attention_mask": paddle.static.InputSpec(shape=[None, None], dtype="int64"),
         }
+        if "position_ids" in inspect.getfullargspec(self.forward).args:
+            spec["position_ids"] = paddle.static.InputSpec(shape=[None, None], dtype="int64")
+        return spec
 
     def to_static(self, path: str, config: dict):
         """export generation model to static

paddlenlp/transformers/opt/modeling.py

@@ -81,7 +81,7 @@ def _expand_mask(mask, tgt_length):
     tgt_length = tgt_length if tgt_length is not None else src_length
 
     expanded_mask = ~(paddle.cast(mask[:, None, None, :], "bool"))
-    expanded_mask = paddle.cast(expanded_mask, dtype=paddle.float32)
+    expanded_mask = paddle.cast(expanded_mask, dtype=paddle.get_default_dtype())
 
     expanded_mask = expanded_mask.expand([batch_size, 1, tgt_length, src_length])
     expanded_mask = expanded_mask * float(finfo(paddle.get_default_dtype()).min)