You can press the Return key? :)

    const uint64_t *p=bsearch(&ref->u,
                              df->file_offsets,
                              df->num_file_offsets,
                              sizeof df->file_offsets[0],
                              &CompareU64s);

That's from emacs. It's a bit hit or miss whether editors do something nice like the above, or just indent the arguments by one stop, but other options seem to be fairly rare.

I generally have one function call per line for ease of debugging. Nothing worse than having to do a fiddly step in/step out dance when you're trying to think about what's going on. But it's also good for keeping on top of line lengths too.