[Toybox] Performance on compress.c

[Rob Landley]

On 07/09/2015 05:41 AM, Yeongdeok Suh wrote:
> I discovered slow decompression while testing gunzip.
> I want to discuss about this improvement.
> 
> I gunzipped an 15MB *.tar.gz file on the ARM board, and it takes around
> 17 sec.
> It's too slow, so I want to improve this for ARM based environment.
> (x86 was okay)

So I looked at it some more and the deflate performance is kinda
pathetic, I did "time zcat linux-4.0.tar.gz > /dev/null" and toybox's
zcat is about half the speed of the ubuntu zcat. (I was going for simple
code and didn't particularly optimize it at all.)

So I agree it could be faster and I'm all for speeding it up, but I need
to figure out where the slowness _is_ first.

> As I debugged the src,
> below while loop takes too much time when decoded huffman symbol is over
> 256.

Could you tell me how you "debugged the src"? (What profiling tool did
you use?)

Rob

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