message: parallel_for: use int64 number of segments to guard against int32 overflow.
diff: @@ -1924,7 +1924,8 @@ def _convert_unsortedsegmentsum(pfor_input):
  segment_offset = array_ops.reshape(segment_offset,
  array_ops.concat([[n], ones], axis=0))
  segment_ids += segment_offset
  - num_segments *= n
  + num_segments = math_ops.cast(num_segments, dtypes.int64) * math_ops.cast(
  + n, dtypes.int64)
  output = math_ops.unsorted_segment_sum(data, segment_ids, num_segments)
  new_output_shape = array_ops.concat(
  [[n, -1], array_ops.shape(output)[1:]], axis=0)
  