From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Buck To: jfc@mit.edu (John Carr) Cc: rth@cygnus.com, egcs@cygnus.com Subject: Re: exception handling poll Date: Fri, 17 Oct 1997 15:05:00 -0000 Message-id: <199710171722.KAA07846@atrus.synopsys.com> References: <199710171340.JAA23714@contents-vnder-pressvre.MIT.EDU> X-SW-Source: 1997-10/msg00756.html > 2. Get the overhead for code not using exceptions, but compiled with > exceptions enabled, under 8% (for "typical" code, whatever that is). > If that means setjmp exceptions on x86, then we do that. Um, are you sure? setjmp exceptions put extra code in the text section, which must be paged in. .eh_frame, on the other hand, is not paged in normally (or at least, not once it is completely read-only), the extra space is on disk. Switching to setjmp exceptions means that you pay more RAM and CPU (since there is overhead even when exceptions are not thrown). You only save disk space. Is that really a good tradeoff? > 3. Document and warn that the next egcs release will be binary > incompatible if exceptions are used. Well, I think we're going to break compatibility for C++ soon. We pretty much have to to support namespaces and templated iostreams. And we'll pretty much want to to get more efficient mangling of template functions. Just for fun, try looking at the mangled symbols generated for the methods of map .