[gfortran,patch] -ffpe-trap library support for SysV

[Steve Kargl]

On Thu, Oct 13, 2005 at 11:37:57PM +0200, FX Coudert wrote:
> >>What I wanted to say is: there's no C99 way to ask for a FPE to be 
> >>raised on individually selected exceptions. That is, there is no C99 way 
> >>to do:
> >>
> >> float x;
> >> raise_fpe_on_ieee_exception(EXCEPTION_INVALID);
> >> x = -2;
> >> x = sqrt(x); // This raises a FPE
> >
> >FYI (you probably already know this), glibc does offer this
> >functionality: feenableexcept and fedisableexcept.  If there's really
> >no C99 way to accomplish the same thing, perhaps FreeBSD should adopt
> >that?
> 
> Yes, feenableexcept/fedisableexcept are already used in libgfortran when 
> available.
> 
> As for FreeBSD, I guess they should work on a way to do this, apart from 
> assembler :-)
> 

FreeBSD has feenableexcept/fedisableexcept.  From the fenv(3) manpage

STANDARDS
     Except as noted below, <fenv.h> conforms to ISO/IEC 9899:1999
     (``ISO C99'').  The feenableexcept(), fedisableexcept(), and
     fegetexcept() routines are extensions.

HISTORY
     The <fenv.h> header first appeared in FreeBSD 5.3.  It supersedes the
     non-standard routines defined in <ieeefp.h> and documented in
     fpgetround(3).


-- 
Steve