[comp.arch] Request for object code compression idea

lam@uicbert.eecs.uic.edu (Michael Lam) (11/10/90)

In a previous posting, I asked for pointers to work on compressing
object code.

In case it wasn't clear what I meant, I'm looking for algorithms
_specifically_designed_ to compress compiled code, maybe even
tuned to a particular instruction set, _not_ for general-purpose 
compression algorithms.

I'm looking for large compression factors, not generality, and 
I'd prefer algorithms that are _very_ fast at doing that specific 
kind of thing.  (Slow algorithms would be interesting, too, if
only to give some kind of how effective things _can_ be.)

I heard somewhere that the Acorn RISC machine OS uses some kind
of compression for system code.  Does anybody know if this is
true, or any details of their scheme?  (Or how well it works?)

I've also heard a rumor that SPARC code can be compressed 2x,
but that may have just been somebody's guess.  Has anybody actually 
done this?

Michael Lam        lam@bert.eecs.uic.edu
EECS Dept.
University of Illinois at Chicago
Box 4348 (m/c 154)
Chicago, Illinois 60680