1We have so far failed to find a good way to determine the stack base.
2It is highly recommended that GC_stackbottom be set explicitly on program
3startup.  The supplied value sometimes causes failure under AIX 4.1, though
4it appears to work under 3.X.  HEURISTIC2 seems to work under 4.1, but
5involves a substantial performance penalty, and will fail if there is
6no limit on stack size.
7
8There is no thread support.  (I assume recent versions of AIX provide
9pthreads?  I no longer have access to a machine ...)
10