[bugfix] fix 4d attention mask device (#85)

Author: hjh0119

src/twinkle/processor/base.py

@@ -246,8 +246,9 @@ def _create_4d_attention_mask(attention_mask):
         import torch
         seq_lens = [s.shape[0] for s in attention_mask]
         max_len = max(seq_lens)
-        attention_mask = torch.tril(torch.ones((len(seq_lens), max_len, max_len),
-                                               dtype=torch.bool)).view(len(seq_lens), 1, max_len, max_len)
+        device = attention_mask[0].device
+        attention_mask = torch.tril(torch.ones((len(seq_lens), max_len, max_len), dtype=torch.bool,
+                                               device=device)).view(len(seq_lens), 1, max_len, max_len)
         assert attention_mask.dtype is torch.bool, f'attention_mask.dtype: {attention_mask.dtype}'
         for i, seq_len in enumerate(seq_lens):
             attention_mask[i, :, :, seq_len:] = 0