Re: Assembly string functions in i386 libc

On Fri, 13 Jul 2007, Dag-Erling Smørgrav wrote:

"Sean C. Farley" <scf@xxxxxxxxxxx> writes:
On Thu, 12 Jul 2007, Dag-Erling Smørgrav wrote:
The first rule of optimization is: don't do it.
The second rule of optimization is: don't do it yet.
The third rule of optimization is: don't optimize what you haven't
measured.
I am a rule breaker at least for the first two. :) I tried to
follow the third rule.

Can you show us an actual application that spends a significant part
of its run time in strlen()?
My test program that loops over strlen().

So the answer is no, and you don't understand the third rule which you
claim to follow.

I never claimed to succeed; I only tried. The two types of tests I can
think would be useful were execution of strlen() by itself and within a
common program. I had thought I had tested the first type of test. The
second one I did later with different versions of strlen() using diff.
What types of tests would have been better? I know about gprof for
finding where a specific program is spending its time, but I was
focusing on the strlen() call.

Also, having two different versions in the source tree is still puzzling
me.

Sean
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