Re: [PATCH] towupper/towlower: fast path for ascii chars

["A. Wilcox" <awilfox@adelielinux.org>]

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On 30/05/17 07:23, Natanael Copa wrote:
> Make a fast path for ascii chars which is assumed to be the most
> common case. This has significant performance benefit on xml json
> and similar


I'm not sure if that would be the common case when you are already
dealing with wide chars.  I would assume you're using wide chars for a
reason...


> { -	return __towcase(wc, 0); +	return (unsigned)wc < 128 ?
> toupper(wc) : __towcase(wc, 0); }
> 
> wint_t towlower(wint_t wc) { -	return __towcase(wc, 1); +	return
> (unsigned)wc < 128 ? tolower(wc) : __towcase(wc, 1); }


...so I would likely do something like:

return (unsigned)wc > 127 ? __towcase(wc, 1) : tolower(wc);

I think it comes down to silly style though.  Functionally it is
likely similar / the same.

Would be curious to see if there is any difference on other loads (and
on other architectures).


- --arw

- -- 
A. Wilcox (awilfox)
Project Lead, Adélie Linux
http://adelielinux.org
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