Re: [Starpu-devel] [patch request] Double comparison

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Nathalie Furmento, le Mon 30 Jan 2012 13:25:52 +0100, a écrit :
> +int _starpu_approximately_equal(double a, double b)
> +{
> +     int ai = (int) nearbyint(a * 1000.0);
> +     int bi = (int) nearbyint(b * 1000.0);
> +     return ai == bi;
> +}

Maybe make 1000 a parameter.

> -     if (exp == -1.0 && !model->benchmarking)
> +     if (_starpu_approximately_equal(exp, -1.0) && !model->benchmarking)

Mmm, no, such kind of comparisons are supposed to be exact: we really
put exactly there -1.0 as a markup. Using such a long function name
makes the code way less readable. At best we could introduce
_starpu_is_nan, and use nan instead of -1 as marker.

Same for all other occurrences.

>                               enum starpu_perf_archtype arch = 
> starpu_worker_get_perf_archtype(w);
> -                             if (t1->duration[arch] == 0.)
> +                             if (fpclassify(t1->duration[arch]) == FP_ZERO)

I'd say introduce _starpu_is_zero.

samuel