More backref performance - no strncmp

[James Antill]

"Bonzini" <bonzini@gnu.org> writes:

> I think that using strncmp to match backreferences is incorrect because it
> fails when matching nuls, not to mention inefficient.  Also, the return
> value of memcmp and strncmp is quite `complicated' to compute while we only
> need a yes/no answer.  For this reason the attached patch replaces strncmp
> with a customized memcmp.  Performance improvement is on the order of 5%
> (2.1 s before, 1.98s after on factor.sed).
> 
> 2002-10-23  Paolo Bonzini  (bonzini@gnu.org)
> 
>         * posix/regexec.c (my_memcmp): new function.
>         Used instead of strncmp throughout the file.

 Your my_memcmp() API is different from memcmp() only in the return
value, and given the amount of optimization for the system one I'd be
surprised if your version wasn't slower.

-- 
# James Antill -- james@and.org
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* ^From: .*james@and\.org
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