Re: state of the ports

[Florian Weimer <fweimer@redhat.com>]

* Xi Ruoyao:

> On Fri, 2024-02-02 at 15:51 +0800, Xi Ruoyao wrote:
>> On Fri, 2024-02-02 at 03:35 +0100, Andreas K. Huettel wrote:
>> > mips (n64)
>> >  - mostly math failures
>> 
>> They are some sort of 2 ulp vs expected 1 ulp things.  I'm not yet sure
>> if they are hardware issues or Glibc bugs.
>
> Something like:
>
> testing double (without inline functions)
> Failure: Test: j0 (0x4.130e7p+4)
> Result:
>  is:         -1.0474906594151864e-04  -0x1.b759740016860p-14
>  should be:  -1.0474906594151868e-04  -0x1.b759740016863p-14
>  difference:  4.0657581468206416e-20   0x1.8000000000000p-65
>  ulp       :  3.0000
>  max.ulp   :  2.0000
> Maximal error of `j0'
>  is      : 3 ulp
>  accepted: 2 ulp
> Failure: Test: j0_downward (0xa.5b833p+4)
> Result:
>  is:          1.4785400727226293e-05   0x1.f01da00ab51d1p-17
>  should be:   1.4785400727226283e-05   0x1.f01da00ab51cbp-17
>  difference:  1.0164395367051604e-20   0x1.8000000000000p-67
>  ulp       :  6.0000
>  max.ulp   :  5.0000
> Maximal error of `j0_downward'
>  is      : 6 ulp
>  accepted: 5 ulp
> Failure: Test: j0_towardzero (0xa.5b833p+4)
> Result:
>  is:          1.4785400727226271e-05   0x1.f01da00ab51c4p-17
>  should be:   1.4785400727226283e-05   0x1.f01da00ab51cbp-17
>  difference:  1.1858461261560204e-20   0x1.c000000000000p-67
>  ulp       :  7.0000
>  max.ulp   :  6.0000
> Maximal error of `j0_towardzero'
>  is      : 7 ulp
>  accepted: 6 ulp
>
> Test suite completed:
>   212 test cases plus 208 tests for exception flags and
>     208 tests for errno executed.
>   6 errors occurred.
>
> I'm really not an expert in numerical analysis.  Any pointer to debug
> such a thing further?

I think these are well within the bounds that other ports accept.  If
there are genuine bugs, the results are off by thousands or millions of
ulps.

Thanks,
Florian