Re: [PATCH v1 1/1] lib/string: Use strchr() in strpbrk()

[Andy Shevchenko]

On Sat, Jan 28, 2023 at 4:51 PM David Laight <David.Laight@xxxxxxxxxx> wrote:
>
> From: Andy Shevchenko
> > Sent: 27 January 2023 15:52
> >
> > Use strchr() instead of open coding it as it's done elsewhere in
> > the same file. Either we will have similar to what it was or possibly
> > better performance in case architecture implements its own strchr().
>
> Except that you get a whole load of calls to strchr() for (typically)
> very few characters.
> So the cost of the calls dominates, anything that tries to speed up
> strchr() for long strings will also slow things down.

Hmm... I haven't seen the calls, I assume gcc simply inlined a copy of that.

...

> Although I very much doubt strpbrk() is used anywhere where
> performance matters.

strsep()/strspn() are the users.

-- 
With Best Regards,
Andy Shevchenko