libjava status on Tru64 UNIX V5.1

Andrew Haley aph@cambridge.redhat.com
Thu Mar 21 07:12:00 GMT 2002


Jeff Sturm writes:
 > On Thu, 21 Mar 2002, Andrew Haley wrote:
 > >  > But what's the impact of sjlj exceptions on C++ (performance or otherwise)?
 > > 
 > > Neither are good: I don't know which is worse.
 > 
 > My naive guess that -fcheck-references is worse because it's going to
 > impact nearly every method, whereas try...catch blocks are relatively
 > infrequent (at least in my code).

Yes, but -fcheck-references doesn't require -fnon-call-exceptions,
which also has fairly serious consequences for every method.  If a
processor can schedule pointer checks in prallel with other code --
and many can -- it might well turn out to be faster to check than to
rely on SIGSEGV.

 > It'd be interesting to benchmark each on a real program, something like
 > the Xerces parser.

Perhaps, but it would require caution not to extrapolate the results
to other processors.

Andrew.



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