Date: Wed, 11 Jul 2007 16:51:22 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: "Sean C. Farley" <scf@FreeBSD.org> Cc: freebsd-arch@FreeBSD.org Subject: Re: Assembly string functions in i386 libc Message-ID: <200707112351.l6BNpMUN063847@apollo.backplane.com> References: <20070711134721.D2385@thor.farley.org> <20070711221338.GC20178@turion.vk2pj.dyndns.org> <200707112221.l6BML722062857@apollo.backplane.com> <20070711183217.C2385@thor.farley.org>
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:Since strlen() is used in every program directly or indirectly through
:libc, I thought it was beneficial to make it faster. In the case of
:i386, the C version used by all the other architectures, except for ARM,
:is much faster that the assembly version. This is without any
:optimization on its part.
:
:I need to test out grep (FreeGrep) to see how it behaves when calling
:regexec() (may use strlen() in certain cases) many times (i.e., grep -R
:on the source tree) using both versions.
:
:Sean
:--
:scf@FreeBSD.org
Yes, but there's a difference between using strlen() a couple of
times in the program and using it in a core processing loop or
other high-performance element of the program. And even if it is
used in such places it isn't going to be used so often that the
program would actually benefit from the few nanoseconds of improvement
you might get from it. The chances of that are nearly zero.
-Matt
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