Re: gfortran fp16

["Thomas König" <tk@tkoenig.net>]

Hi,

be might complement to the QP support for POWER in gcc 12, and I have actually thought about doing. The library has its gotchas, though - I do not suppose we can count on fp16 support for trigonometrics and similar, for example, so we would probably have to use fp32 and convert (or imlement a lookup table, which would be cache-unfriendly) Plus, there appears to be more than one format on ARM, but we should probably restrict ourselves to IEEE.

So, not a really small project, but an interesting one.

Best regards

Thomas
> Am 16.05.2022 um 12: 50 schrieb Tobias Burnus <Tobias_Burnus@mentor.com>:
> On 16.05.22 09:51, nkToon Moene wrote:
>> Interesting question. We don't do that yet, as far as I know.
>> -------- Forwarded Message --------
>> From: 陈刚 <cglwdm@scu.edu.cn>
>> 
>> I want to use fp16 in fortran, does gfortran support the fp16?
> 
> I think adding fp16 to the compiler itself is not that difficult – it is
> "just" handling 'HF' mode via 'REAL(kind=2)'; this can be done rather
> quickly.
> 
> @陈刚: If you want to volunteer to add it (know someone who does), I can
> give some pointers.*
> 
> Additionally support in the libgfortran run-time library should be added
> and some testcases written to ensure it works. – I think that is also a
> smaller task, but has to be done in addition.
> 
> Tobias
> 
> *See https://gcc.gnu.org/contribute.html for a starter – but if
> interested, I will give explicit hints what needs to be changed how.
> 
> 
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