Re: [Gnuplot-info] integer vs. floating point division

[David K. <da...@gn...>]

Tait <gnu...@t4...> writes:

>> > I'd say integer division is gradually becoming an anachronism,
>> > and the new trend seems to be not just fixed floating-point but
>> > full rational-number support or arbitrary- (even infinite-)
>> > precision calculations, to avoid frustrating behaviors like
>> > ceil(900e-7/12e-7) => 76.
>> 
>> There you intrigue me.  I have a patch series queued that adds 64-bit
>> integer arithmetic with full overflow handling everywhere.  Would it indeed
>> be feasible to similarly upgrade the floating point evaluation code to
>> provide more  graceful handling of very large numbers?
>> The int64 conversion was surprisingly easy so I can believe that
>> modernizing the floating point would also be  straightforward.
>> But I wouldn't know where to start.  Do you have suggestions?
>
> That particular example will "misbehave" even with 64b doubles
> (or at least it did in my test, which is why I used that
> particular example). But in general, the only reason I see not
> to convert from float to double is that some platforms wouldn't
> have built-in double support.

Since historically double had been the _only_ floating point
_expression_ format in K&R C (as opposed to floating point storage
format that could be just float), platforms without built-in double
support would be really peculiar once using them for C became a
mainstream choice.

-- 
David Kastrup