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

[FX Coudert]

>>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 :-)

FX