# Other Sources of Wisdom

Believe it or not, but there are other people besides you who are masochistic enough to study the innards of the beast. Some of the have been kind (or cruel?) enough to share their insights with us. Here is a probably incomplete list:

- The STG Survival Sheet has -- according to its header -- been written by `a poor wee soul',1 which probably has been pushed into the torments of madness by the very act of contemplating the inner workings of the STG runtime system. This document discusses GHC's runtime system with a focus on support for parallel processing (aka GUM).
- Instructions on Adding an Optimisation Pass to the Glasgow Haskell Compiler have been compiled by Olaf Chitil. Unfortunately, this document is already a little aged.
- Andrew Tolmach has defined an external representation of GHC's Core language and also implemented a GHC pass that emits the intermediate form into `.hcr` files. The option `-fext-core` triggers GHC to emit Core code after optimisation; in addition, `-fno-code` is often used to stop compilation after Core has been emitted.

1Usually reliable sources have it that the poor soul in question is no one less than GUM hardcore hacker Hans-Wolfgang Loidl.

Last modified: Tue Nov 13 10:56:57 EST 2001