Lua is faster than Fortran???

[sturlamolden]

On 4 Jul, 10:03, Stefan Behnel <stefan... at behnel.de> wrote:

> Sort of. One of the major differences is the "number" type, which is (by
> default) a floating point type - there is no other type for numbers. The
> main reason why Python is slow for arithmetic computations is its integer
> type (int in Py3, int/long in Py2), which has arbitrary size and is an
> immutable object. So it needs to be reallocated on each computation.

That is why Lua got it right. A floating point type has a mantissa and
can duck type an integer. MATLAB does the same.

Sturla







If it
> was easily mappable to a CPU integer, Python implementations could just do
> that and be fast. But its arbitrary size makes this impossible (or requires
> a noticeable overhead, at least). The floating point type is less of a
> problem, e.g. Cython safely maps that to a C double already. But the
> integer type is.
>
> So it's not actually surprising that Lua beats CPython (and the other
> dynamic languages) in computational benchmarks.
>
> It's also not surprising to me that a JIT compiler beats a static compiler.
> A static compiler can only see static behaviour of the code, potentially
> with an artificially constructed idea about the target data. A JIT compiler
> can see the real data that flows through the code and can optimise for that.
>
> Stefan