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Re: [RFC] Statistics of non-ASCII characters in strings
- From: Florian Weimer <fweimer at redhat dot com>
- To: Wilco Dijkstra <wdijkstr at arm dot com>, libc-alpha at sourceware dot org
- Date: Tue, 23 Dec 2014 15:35:43 +0100
- Subject: Re: [RFC] Statistics of non-ASCII characters in strings
- Authentication-results: sourceware.org; auth=none
- References: <001401d01df6$0f7cc5a0$2e7650e0$ at com>
On 12/22/2014 03:46 PM, Wilco Dijkstra wrote:
Does anyone have statistics of how often strings contain non-ASCII characters? I'm asking because
it's feasible to make many string functions faster if they are predominantly ASCII by using a
different check for the null byte.
Why can't you do the equivalent of
X = ((X & 0x80) >> 1) | (X & 0x7F);
before the new check? Does this lengthen the dependency chain too much?
Florian Weimer / Red Hat Product Security