avoid unnecessary register saves for setjmp

[Andrew Pinski]

On Nov 27, 2003, at 00:01, Zack Weinberg wrote:
> I'm going to take this opportunity to throw in a suggestion I've made
> before, which is that setjmp/longjmp should - always, not just when
> special variants are used - be converted by the front end into
> invocations of the exception-unwinding facility, which gives us tons
> more control.  (Obviously this only works with DWARF2 exception
> handling.)


But what about backwards compatibility aka use of setjmp/longjmp 
through libraries,
I know that Foundation and AppKit (Objective-C libraries) uses 
setjmp/longjmp and
the Objective-C front-end emits it now with @try/@catch/@finally/@throw.
(Apple does want to change it to dwarf-2 exceptions but cannot because 
backwards
compatibility).

Thanks,
Andrew Pinski
apinski@apple.com
pinskia@gcc.gnu.org
pinskia@physics.uc.edu