[pypy-dev] Dispatch on type

[Armin Rigo]

Hi,

On 15 July 2014 18:37, Eleytherios Stamatogiannakis <estama at gmail.com> wrote:
> t = type(var)
> if t is int:
>         i(v)
> elif t is long:
>         l(v)
> elif t is float:
>         f(v)
> elif t is str:
>         s(v)
> elif t is unicode:
>         u(v)
> ...

This should already give you the fastest possible execution on PyPy,
because the first type inspection should promote the type in the JIT.
All subsequent "if" checks are constant-folded.  However, to be sure,
you need to check with jitviewer.

Note however that if all paths are eventually compiled by the JIT, the
promotion will have a number of different cases, and searching through
them is again done by linear search for now.  This can be regarded as
a bug waiting for improvement.


A bientôt,

Armin.