Benny Amorsen wrote:
"MK" == Mark Kirkwood <[EMAIL PROTECTED]> writes:


MK> Here are the results after building gcc 4.1.2 (repeating results
MK> for gcc 3.4.6 for comparison). I suspect that performance is
MK> probably impacted because gcc 4.1.2 (and also the rest of the
MK> tool-chain) is built with gcc 3.4.6 - but it certainly suggests
MK> that the newer gcc versions don't like the slice-8 algorithm for
MK> some reason.

They don't seem to like the old CRC algorithms either. It is quite
strange, such dramatic performance regressions from 3.x to 4.x are
rare.


Right - I think the regression is caused by libc and kernel being built with gcc 3.4.6 and the test program being built with gcc 4.1.2. Rebuilding *everything* with 4.1.2 (which I'm not sure is possible for FreeBSD at the moment) would probably get us back to numbers that looked more like my Gentoo ones [1].

Cheers

Mark

[1] Note that the upgrade process for switching Gentoo from gcc 3.4 to 4.1 involves precisely this - build 4.1, then rebuild everything using 4.1 (including 4.1 itself!)

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