Integrating Multithreading into the Spineless Tagless G-machine

To reduce the adverse effects of long latency communication operations in distributed implementations of the Spineless Tagless G-machine (STGM), a variant of the original abstract machine that contains explicit support for multithreading is introduced. In particular, source-to-source transformations can be used on the level of the abstract machine code to foster the tolerance to long latency communication. The changes to the original STG-language include a separation of demand from case selection together with the introduction of a new construct that provides an abstract notion of thread boundaries and thread synchronization.