Re: 70x speed-up for seq's common cases

[Pádraig Brady]

On 09/14/2012 07:54 AM, Jim Meyering wrote:
> Inspired by Pádraig's April-fools post,
>    http://thread.gmane.org/gmane.comp.gnu.coreutils.general/972
> and spurred by the fact that Torbjorn and Niels had to roll
> their own seq-like program to test their new factoring code
> (http://gmplib.org:8000/factoring), I have made coreutils' seq
> usable for arbitrarily large, non-negative whole numbers.
> This has two advantages:
>
>      - correctness with large numbers
>      - improved performance in common cases
>
> For very large numbers, the new seq now appears to be correct:
>
>      $ b=10000000000000000000000000000000000000000000000000000000000000
>      $ src/seq ${b}09 ${b}11
>      1000000000000000000000000000000000000000000000000000000000000009
>      1000000000000000000000000000000000000000000000000000000000000010
>      1000000000000000000000000000000000000000000000000000000000000011
>
> while the old one would infloop, printing garbage:
>
>      $ seq ${b}09 ${b}11 |head -2
>      999999999999999999965225407341472151966654053379893968647487488
>      999999999999999999965225407341472151966654053379893968647487488
>
> This also means that nt-factor's tests can now use coreutils' seq
> to generate their inputs.

Excellent :)

How about the attached follow up to enable the
fast code in more cases?

cheers,
Pádraig.

seq-more-fast.diff
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