Google Summer of Code 2013/cs648/Initial Meeting

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cps is analogous to coroutine_fn

cps is infact a GCC function attribute - __attribute__((cps))

A good first task is to check the annotations in the QEMU tree are correct as they are currently untested

Need to understand distinctions between packed/unpacked mode (also ecpc)

Suggest will take a week to read and understand the workings of cpc_runtime:

  • needs a blogpost to explain it as documentation once understood
  • any bugs/optimisations noticed should be submitted as (separate patches)

A good place to start is to examine the different stages of CPC translation (accessed with -stageX option)

Best test compilation is cpc/samples/loops.cpc

May turn out that coroutine_io.c is entirely built on coroutine.h primitives and therefore will not need editing for CPC variant.

Need to read and reimplement:

  • cpc_sleep
  • cpc_spawn (not annotated with cps)
  • cpc_yield
  • cpc_invoke/call

Don't need cpc_main loop

Extensions

Good extension is to skip translation if no cps functions, compile as C

Need to benchmark result extensively, is important for understanding different "calling conventions" -ecpc mode and packed vs unpacked


Milestone

Aim by Friday 21st is to produce a blog post documenting CPC memory format and how functions manipulate it

"anatomy of a continuation"

  • Define a CPC continuation as a datastructure
  • how it works in practise
  • detail cpc_push/cpc_invoke (also cpc-yield, cpc_spawn, cpc_patch)