fix graph break for compile

src/axolotl/monkeypatch/utils.py

@@ -16,15 +16,24 @@ from transformers.utils import is_torch_bf16_gpu_available
 
 @torch.jit.script
 def get_max_seqlen_in_batch(attention_mask: torch.Tensor) -> torch.Tensor:
-    max_num = int(torch.max(attention_mask).item())
-    batch_size, _ = attention_mask.shape
-    counts = torch.zeros((batch_size, max_num), dtype=torch.int32)
-    for i in range(1, max_num + 1):
-        mask = attention_mask == i
-        counts[:, i - 1] = torch.sum(mask, dim=-1).to(dtype=torch.int32)
+    # Keep max_num as a tensor instead of extracting to Python int
+    max_num = torch.max(attention_mask)
+
+    # Create a range tensor for comparison
+    range_tensor = torch.arange(
+        1, max_num + 1, device=attention_mask.device, dtype=attention_mask.dtype
+    )
+
+    # Vectorized approach - compare attention_mask with each value in range
+    mask = attention_mask.unsqueeze(-1) == range_tensor.unsqueeze(0).unsqueeze(0)
+
+    # Sum along sequence dimension to get counts
+    counts = mask.sum(dim=1).to(dtype=torch.int32)
+
+    # Flatten and filter non-zero values
     result = counts.flatten()
-    nonzero_indices = torch.nonzero(result).squeeze(-1)
-    return result[nonzero_indices]
+    nonzero_mask = result != 0
+    return result[nonzero_mask]
 
 
 @torch.jit.script