ietf-822
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Re: LZJU90 compression example(s)

1998-09-21 08:36:58
On Sat, 19 Sep 1998 17:53:20 EDT, you said:
Therefore, any comparision is not truely fair since I assume the Base64 code
I am using has be optimized to its fullest potential by Microsoft whereas
the LZJU90 code is not.

It is always bad to assume that production code has been optimized.

Do you have *any* reason to assume that Microsoft optimized this code?

Do you have any reason to even assume that the Microsoft code is in
fact a totally correct and bug-free Base64 encoder?  Have you stress-tested
it with various inputs? Does it Do The Right Thing in case of memory/disk
space exhaustion? (Try attaching an uncompressed GCC source tree tarball
and see what happens?)  Have you hand-checked the code for bogosity
such as un-needed debugging code inside the central loop?  Was the Microsoft
code either compiled with an optimizer that did CSE and code hoisting, or
was the code previously hand-tuned for this?

About all you've actually proven so far is that there's reason to suspect
that Microsoft has, in fact, NOT optimized this code - presumably because
they felt it was "fast enough" already, and they had other problems to deal
with, like making sure the program didn't induce a Blue Screen of Death....

-- 
                                Valdis Kletnieks
                                Computer Systems Senior Engineer
                                Virginia Tech

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