MIPS: test-float fma math tests trigger underflow exception

[Andrew Pinski]

On Wed, Jun 29, 2016 at 2:36 PM, Joseph Myers <joseph@codesourcery.com> wrote:
> On Wed, 29 Jun 2016, Aurelien Jarno wrote:
>
>> When building the GNU libc on MIPS (at least o32 and n64), one get the
>> following testsuite errors for the fma float tests:
>
> These are all processor bugs.  MIPS processors are specified to detect
> whether floating-point results are tiny, and so determine whether to raise
> the underflow exception, on an after-rounding basis.  Some MIPS processors
> appear to have bugs involving using before-rounding tininess detection in
> some cases.  These are tests where the expectations depend on whether the
> architecture is before-rounding or after-rounding (which is required by
> IEEE 754 to be consistent for all operations with binary floating-point
> results).
>
>> Does someone has an idea how this can be fixed?
>
> Report the bug to the processor providers.


Well Octeon is not going to be fixed.  There is no roadmap for an MIPS
based Octeon any more.
So the only thing we can do is issue an errata :).

Thanks,
Andrew Pinski

>
> --
> Joseph S. Myers
> joseph@codesourcery.com