Hello,

...

SPJ> tail calls is another,

nowadays gcc optimize tail calls

I found this thesis on the subject by Andreas Bauer:

"Compilation of Functional Programming Languages using GCC -- Tail Calls"

Do you know if it is his work that was incorporated into GCC?

no. Also, it is based on now obsolete version of the GCC (most of the tail call optimization is currently handled in a completely different way). If anyone has some concrete proposals on improvements of handling of tail calls in GCC that could help GHC, please use the gcc bugzilla (http://gcc.gnu.org/bugzilla/) to file an improvement request, and add me to CC, I will look what I can do. Zdenek