Why does IRA force all pseudos live across a setjmp call to be spilled?

[Eric Botcazou]

> I can't argue with anything in that comment, other than the conclusion. :-)
> It's not the compiler's job to implement the setjmp/longjmp save/restore.
> Maybe Kenny was working around a problem with some target's buggy setjmp
> and spilling everything "fixed" it?

What are the requirements imposed on setjmp exactly and by whom?  The psABI on 
SPARC (the SCD) has an explicit note saying that setjmp/sigsetjmp/vfork don't 
(have to) preserve the usual non-volatile registers.

-- 
Eric Botcazou