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Re: PATCH: Optimize memcmp for ia32

Ulrich Drepper <> writes:

> H. J. Lu wrote:
>> I tested it on all available Pentium 4/M processors.
> And because of your tests with P4s you replace the code for generic
> i386?  Not very logical, is it?
> Furthermore, the test case code is not a realistic benchmark.  For this
> you need to know the usual string sizes which happen on a normal system.
>  Do you have this data?  Well, I have some code which does measurements
> of the use of all string functions.  And guess what the outcome is?
> memcmp in the libc is not used at all during a normal system start and
> shutdown.  I've even started OO.o.
> There are probably places where the calls are handled by gcc and perhaps
> there are a few uses inside libc, but that's neglectable and where it is
> used the strings are very short.  This means you are optimizing
> something which needs no optimizing.  You are increasing the size of
> basically dead code.
> I've uploaded the data of the string function usage measurements.

What test program did you use?

 Andreas Jaeger,,
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