Identify IEE

[N.M. Maclaren]

On Jul 3 2014, Uros Bizjak wrote:
>
>Maybe a new hook should be introduced instead: TARGET_IEEE_FORMAT_P
>(mode). For some targets, even soft-fp supports required rounding
>modes and can generate exceptions.

Before doing anything, it would be a good idea to decide on what IEEE
conformance means.  The 1984 standard was very much an assembler-level
one, and the 2008 one isn't much better.  Until recently, even at the
hardware level, the support for it was very patchy.  Among gcc targets,
there have been at least the following possibilities:

    Absolutely none
    The representation, excluding many of the exceptional values
    The representation in full, but not the semantics
    The semantics, but not the mode settings
    The semantics and mode settings, but not the trapping

And those are only the ones that I have seen!  Real gcc experts could
probably add to them.


Regards,
Nick Maclaren.