diffing file revisions across renames??

[Leo Razoumov]

I am using Mercurial 0.9.3 and find its file rename features very
useful, indeed.
I can list a file's history information across renames with "hg log
-f" but I have not found a way to diff two file revisions that across
renames. This would be very useful, for I tend to rename files quite
often as my project progresses.

Any help or/and advice is highly appreciated.

Thanks,
--Leo--