Re: [RFC] lib/vsprintf.c: Even faster decimal conversion

From: Joe Perches
Date: Thu Mar 05 2015 - 11:03:43 EST


On Thu, 2015-03-05 at 16:22 +0100, Rasmus Villemoes wrote:
> On Sat, Feb 21 2015, Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> wrote:
>
> > [...] decimal conversion [...] it does indeed seem like there is
> > something to be gained, especially on 64 bits.
> >
> > $ ./test64
> > Distribution Function Cycles/conv Conv/1 sec
> > uniform([10, 2^64-1]) linux_put_dec 127.72 23047567
> > uniform([10, 2^64-1]) rv_put_dec 60.73 45932786
> > +/- -52.45% +99.30%
> [...]
> > 3 + neg_binom(0.50) linux_put_dec 16.85 159560933
> > 3 + neg_binom(0.50) rv_put_dec 12.59 204607570
> > +/- -25.31% +28.23%
>
> I'm assuming the underwhelming response means NAK.

Dunno why you assume that, sometimes it just takes
awhile for people to look at non-critical, infrequent
optimization changes like this.

Seems sensible enough to me though.

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