p2c shipped with RedHat systems is old and has a huge number of problems associated with it. Unfortunately its author said that he didn't have any spare time to continue maintaining it. We at BFM have been using p2c for quite a long time and have made (primarily Harvey J. Stein <hjstein.il>) a number of large patches for it. I've put the new version of p2c (dubbed 1.22) on gribble. Look at the ChangeLog to get an idea of what changes were made. Note also a 'p2c.patch' file, that contains *some* (NOT all) changes against the plain p2c - you DON'T have to apply it - it's already in. I must warn that we still don't rely on p2c on an Alpha platform - it still generates incorrect code from time to time.
Fixed this problem, see changelog for details. Makefiles needed many modifications.