[Info-vax] And another one bites the dust....

[David Wade]

On 18/02/2022 16:07, Arne Vajhøj wrote:
> On 2/18/2022 10:59 AM, Dan Cross wrote:
>> In article <620fb853$0$693$14726298 at news.sunsite.dk>,
>> Arne Vajhøj  <arne at vajhoej.dk> wrote:
>>> On 2/18/2022 10:12 AM, Dan Cross wrote:
>>>> In article <620e5870$0$701$14726298 at news.sunsite.dk>,
>>>> Arne Vajhøj  <arne at vajhoej.dk> wrote:
>>>>> On 2/17/2022 5:28 AM, Phillip Helbig (undress to reply) wrote:
>>>>>> In article <919fe330-a0dc-4784-bd2e-edea99790dc0n at googlegroups.com>,
>>>>>> "dthi... at gmail.com" <dthittner at gmail.com> writes:
>>>>>>> VSI Fortran is pretty much just rebranded HPE Fortran (FORTRAN-95
>>>>>>> standard, and not a complete implementation of it either). Later 
>>>>>>> FORTRAN
>>>>>>> standards (2003, 2008, 2108) have fully embraced object oriented 
>>>>>>> code
>>>>>>> practices and C interoperability.
>>>>>>
>>>>>> Isn't there supposed to be a much more modern, FLANG-based Fortran
>>>>>> compiler from VSI (presumably only) on x86?
>>>>>>
>>>>>> If so, when?
>>>>>
>>>>> VSI has stated their intention to go with flang. Which is really 
>>>>> saying
>>>>> that they have no intention of shoehorning the newer Fortran standards
>>>>> into the old compiler. Which makes sense.
>>>>
>>>> Not really. The old DEC GEM compilers were super cool.
>>>
>>> The cost.
>>
>> Which cost?  Bolting on a backend for x86_64 wouldn't be that
>> hard: they already have backends for VAX, MIPS, Alpha, and
>> Itanium.
> 
> ????
> 
> VSI is already doing that by utilizing LLVM.
> 
> But the topic was "shoehorning the newer Fortran standards
> into the old compiler".
> 
>> Keeping up with evolving language standards?  Yeah, that's an
>> issue.
> 
> Yes.
> 
>>>>> And since it will be LLVM based then it must be x86-64 only.
>>>>
>>>> Why do you say that? Just in the sense that they won't
>>>> backport to OpenVMS/Itanium or Alpha?  LLVM has backends
>>>> for non-x86 architectures.  (If I were VSI, I'd be
>>>> getting a jump on ports to ARM and RISC-V now.)
>>>
>>> I don't see flang/LLVM support Itanium or Alpha.
>>
>> Alpha support was dropped back in 2011:
>> https://github.com/llvm/llvm-project/commit/4c9fca99c9a6734bb33c34aeaf40b71c4002757e 
>>
>>
>> IA-64 was removed back in 2009.
>>
>> Bringing either back would probably be a pretty big lift,
>> but with commercial support, I imagine the LLVM folks would
>> be fine with it.  There's an MC68k backend, afterall.
> 
> I don't expect that to happen.
> 
>> But if VSI is cool with GEM on Alpha/Itanium, and LLVM on
>> x86_64, I guess that's their business.
> 
> That is what they say.
> 


It doesn't really matter what they "say", what is important is source 
code compatibility. From what I can see the LLVM compiler does not fully 
support the DEC extensions there may be issues.

If you need to make changes to stay on VMS then it becomes much harder 
to justify it.


>>> Maybe ARM or RISC-V some day in the future.
>>
>> It seems clear that there's an architectural shift away
>> from x86 happening.  Best to lay the groundwork now to
>> avoid being caught out.
> 
> Maybe, but even if it does happen then it will take many years.
> 

> Arne
> 
> 


Dave