Re: Proper fix for SIGFPE on FreeBSD

[David Chisnall]

On 17 Aug 2009, at 08:31, Richard Frith-Macdonald wrote:

> On 15 Aug 2009, at 18:10, David Chisnall wrote:
>
> > GNUstep currently does some asm magic to disable floating point  
> > exceptions on FreeBSD.  This sometimes, coincidentally, works, but  
> > often the flag is reset by various things.  This patch sets it via  
> > the standard libm interface, which ensures that it remains cleared.
>
> Thanks ... I didn't realise that the old fix was unreliable (don't  
> recall seeing bug reports about it ... probably not too many people  
> using FreeBSD).

It seems mostly reliable, but very occasionally you get a combination  
of settings that break it.

> It's good to have a better version.

Less assembly is always good. :-)

> Do you know if the issue applies to any other BSD variants?  If it  
> does, perhaps we should use autoconf to test for the header and  
> include/use the new fix on all BSDs rather than just on FreeBSD?

I had a look at the Mozilla codebase and they seem to only need this  
on FreeBSD (they don't do it with inline asm either, but they use the  
old-and-deprecated way of setting the flag).

David