Proposal: shoot vint64 through the head

[Joel Sherrill]

Sorry sent to early and from the wrong email address so it bounced.

A first step would just to have an NTP specific type derived from a
standard type.
Then at least the underlying 64-bit type would be hidden.

Worst case, we can do what RTEMS has had to do for our internal timestamp.
We
support multiple underlying data representations and although we default to
a
preferred 64-bit type, can use alternate representations. There are inline
methods
and macros to provide explicit operations on the timestamp. Native math is
not
assumed in this case. It completely encapsulates the type and operations.

This may be heavy handed for this case since there is not a defined
requirement
to do something like this but it can hide ugliness when you have to.

--joel


On Tue, Dec 1, 2015 at 12:57 PM, Mark Atwood <fallenpegasus at gmail.com>
wrote:

> In general yes, ESR and I share the policy of "if we need a hack for an
> odd case, deal with it when we have to".
>
> So, now this is a question for Eric:  You had said "There is some fairly
> nasty code in NTP's calendaring library to work around the absence of a
> true 64-bit integral type."  If we ever do have to hack back *in* support
> for the absence of a true 64bit, can it be done in a way that is less
> "nasty"?
>
> ..m
>
> On Tue, Dec 1, 2015 at 10:51 AM Joel Sherrill <joel.sherrill at gmail.com>
> wrote:
>
>> There are many other compilers including Green Hills, IAR, ARM,
>> Watcom, and a non-GCC from Wind River I can't remember the name of.
>>
>> I know the Green Hills and odd Wind River one are C99 with full stdint.h
>> types.
>> The others I don't know. IAR is primarily 8/16 bit CPUs.
>>
>> I would say we should follow ESR's policy of "it works for everything we
>> know about and if we need a hack for an odd case, deal with it when we
>> have to". :)
>>
>> --joel
>> On Tue, Dec 1, 2015 at 10:38 AM, Daniel Poirot <dtpoirot at gmail.com>
>> wrote:
>>
>>> There are lots of 'third tier' compilers and tools.
>>>
>>>
>>>
>>> GCC has the lion's share with the ARM Ltd. compiler the next nearest.
>>>
>>>
>>>
>>> For chips-which-aren't-ARM, just about all are GCC.
>>>
>>>
>>>
>>> -    Dan
>>>
>>>
>>>
>>>
>>>
>>> *From:* devel [mailto:devel-bounces at ntpsec.org] *On Behalf Of *Mark
>>> Atwood
>>> *Sent:* Tuesday, December 01, 2015 10:16 AM
>>> *To:* Eric S. Raymond; devel at ntpsec.org; Joel Sherrill
>>> *Subject:* Re: Proposal: shoot vint64 through the head
>>>
>>>
>>>
>>> I think this is actually a question for Joel.
>>>
>>>
>>>
>>> As in: out in the field, especially in small embedded systems, are there
>>> any important 32bit targets that are not compiled to with GCC, clang, or
>>> are ARM?
>>>
>>>
>>>
>>> ..m
>>>
>>> _______________________________________________
>>> devel mailing list
>>> devel at ntpsec.org
>>> http://lists.ntpsec.org/mailman/listinfo/devel
>>>
>>
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