Bill Allombert on Wed, 29 Nov 2023 23:12:53 +0100


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Re: log_int_rat 

On Wed, Nov 29, 2023 at 10:41:17PM +0100, Ruud H.G. van Tol wrote:
> 
> On 2023-11-29 22:15, Ruud H.G. van Tol wrote:
> > [...]
> 
> I was surprised by this performance difference:
> 
> ? localbitprec(10000); my(L = 1-log(2)/log(3)); [ 1 + floor(n/L)
> |n<-[0..10^5] ];
> cpu time = 1,061 ms, real time = 1,064 ms.
> 
> ? localbitprec(10000); my(L = log(2)/log(3/2)); [ 1 + n + floor(n*L)
> |n<-[0..10^5] ];
> cpu time = 80 ms, real time = 82 ms.
> 
> What would explain that?

Division is slower than multiplication...

Cheers,
Bill