[Cython] Bindings performance issue

[Vitja Makarov]

Hi!

Is bindings performance issue valuable?

$ cat bindbench.pyx
def wo_bindings():
    pass

def outer():
    def inner():
        pass
    return inner
with_bindings = outer()

$ python
>>> import timeit
>>> timeit.repeat('with_bindings()', setup='from bindbench import wo_bindings, with_bindings', repeat=1, number=100000000)
[6.169871807098389]
>>> timeit.repeat('wo_bindings()', setup='from bindbench import wo_bindings, with_bindings', repeat=1, number=100000000)
[4.609416961669922]

PyCBindings makes it 1.3 (difference is about 15ns on my laptop) times
slower for CPython interpreter execution.
As CPython has some optimizations for CFunctions and PyCFunctions.

Does it make sense for us? Or we can easily switch to bindings?

-- 
vitja.