Re: [RFC] LZO de/compression support - take 6

From: Daniel Hazelton
Date: Mon May 28 2007 - 10:50:22 EST


On Monday 28 May 2007 10:40:31 Nitin Gupta wrote:
> Hi,
>
> Attached is tester code used for testing.
> (developed by Daniel Hazelton -- modified slightly to now use 'take 6'
> version for 'TinyLZO')
>
> Cheers,
> Nitin
>

<snip>
I haven't tested with version 6, but after removing the LZO_CHECK_MPOS_NON_DET
macro from the 'take 5' code and replacing the open-coded byte-for-byte
copies with calls to memcpy:

10000 run averages:
'Tiny LZO':
Combined: 57.4691 usec
Compression: 39.8837 usec
Decompression: 17.5854 usec
'miniLZO':
Combined: 64.0484 usec
Compression: 46.0604 usec
Decompression: 17.988 usec

which means:
Overall TinyLZO is 10.2% faster
TinyLZO compresses 13.4% faster
TinyLZO decompresses 2.23% faster

-Benchmark run a a Pentium-M 1.73GHz, 1GB Ram
With the speed-up seen with just the removal of the LZO_CHECK_MPOS_NON_DET I
wasn't sure that changing the open-coded copy to a call to memcpy() was going
to have a big impact on the code, but it does appear to have has several
percentage points of difference. (Though I am unsure about the speed increase
with the decompression - I didn't touch that file when making this set of
changes. I'm going to make the memcpy() changes to 'take 6' and see if the
speed-up holds true)

DRH
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