[Cython] Cygwin: Handling missing C99 long double functions

[Erik Bray]

On Thu, May 12, 2016 at 12:55 AM, Greg Ewing
<greg.ewing at canterbury.ac.nz> wrote:
> Erik Bray wrote:
>>
>> A developer who writes some code that
>> happens to use long double isn't going to think themselves "Gosh, I
>> guess I can't accept `long double` here because it may cause Cython to
>> generate code that contains "truncl"
>
>
> Sounds to me like Cython shouldn't be taking it upon
> itself to generate calls to truncl just because long
> double is being used. The programmer should have to
> call it explicitly if that's what they want.

Since it's just a small optimization it could be disabled without
trouble too.  Preferably with a #define that can be set or unset at
compile time.

Best,
Erik