Fix passing str dtype to static cache (#33741)

Co-authored-by: Guang Yang <guangyang@fb.com>

src/transformers/integrations/executorch.py

@@ -68,7 +68,7 @@ class TorchExportableModuleWithStaticCache(torch.nn.Module):
             config=self.model.config,
             batch_size=self.model.generation_config.cache_config.batch_size,
             max_cache_len=self.model.generation_config.cache_config.max_cache_len,
-            dtype=self.model.config.torch_dtype,
+            dtype=self.model.dtype,
         )
         self.is_causal = any("CausalLM" in arch for arch in self.model.config.architectures)
         if self.is_causal:

tests/utils/test_cache_utils.py

@@ -181,7 +181,7 @@ class CacheTest(unittest.TestCase):
 
         set_seed(0)
         device = "cpu"
-        dtype = torch.float32
+        dtype = "bfloat16"
         cache_implementation = "static"
         attn_implementation = "sdpa"  # Export and ExecuTorch only works for SdpaAttention
         batch_size = 1