Interesting paper on Supporting Binary Compatibility with Static Compilation

Sun Nov 10 10:39:00 GMT 2002

Bryce McKinlay writes:
 > Andrew Haley wrote:
 > 
 > >Mark Wielaard writes:
 > > > http://flint.cs.yale.edu/flint/publications/bincomp.html
 > > > Supporting Binary Compatibility with Static Compilation
 > > > Dachuan Yu, Zhong Shao, Valery Trifonov
 > > > Department of Computer Science, Yale University
 > >
 > 
 > Thanks for posting that, Mark. I hadn't seen the final version of the 
 > paper. It is definately essential reading for anyone trying to 
 > understand the issues with binary compatibility.
 > 
 > >2% of _total_ runtime? That seems like an awful lot. Still, if it's
 > >needed to achieve binary compatibility I suppose we'll have to live
 > >with it. However, given my current interest in improving run-time
 > >performance I don't like to see regressions.
 > 
 > A ~2% slow down was the worst case measured for the Java Grande 
 > benchmarks, for an application whose runtime is particularly dominated 
 > by virtual dispatch. Some of the benchmarks actually speed up with 
 > indirect dispatch. I would expect a modest performance hit once binary 
 > compatiblity for fields is implemented however, if the application 
 > frequently references fields across different compilation units.
Well, I don't suppose that's such an important requirement -- I guess
access to static fields is usually bad programming style anyway.
Am I right in thinking that the only compiler changes (that I can get
my hands on) are the -findirect-dispatch patch that's already checked
in, or are there some patches somewhere that implement more of the
techniques described in the paper?
Even if those patches are old or somewhat broken I'd still be
interested to see them.
Andrew.