Re: timing in GP

[Karim Belabas <Karim.Belabas@math.u-bordeaux1.fr>]

* Loïc Grenié [2012-09-30 22:18]:
> 2012/9/30 Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>:
> > 2) the gettime interface:
> > The problem is that it is not reentrant.
> > Let say you write functions:
> > zet(N,s)=gettime();my(s=sum(n=1,N,n^-s));print("sum:",gettime());s
> > vecz(N,n)=gettime();my(v=vector(n,t,zet(N,.5+I*t)));print("vec:",gettime());v
[...]
> > The final time is wrong.
> >
> > We should provide a version of gettime that return the time in microseconds
> > since the start of the GP session so we could do
> > t=gettime2();....;print(gettime2()-t;
> 
>     I think getabstime() or something similar would be better but in general
>   it's a good idea.

It would return a t_INT, I suppose; not a C long as gettime does.
Otherwise it would wrap within less than an hour on 32-bit archs :-)

> > We could also provide a function printtime(t,s,...) which would do
> > print("Time ",s," :",gettime2()-t);
> 
>     Is it really necessary ?

I don't think so either.

Cheers,

    K.B.
-- 
Karim Belabas, IMB (UMR 5251)  Tel: (+33) (0)5 40 00 26 17
Universite Bordeaux 1          Fax: (+33) (0)5 40 00 69 50
351, cours de la Liberation    http://www.math.u-bordeaux1.fr/~belabas/
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