Re: [pcre-dev] Powerpc optimisation

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Author: Frederic Bonnard
Date:  
To: pcre-dev
Subject: Re: [pcre-dev] Powerpc optimisation
Thanks Zoltan for the quick reply.
- Ok I think I got it for SSE2.
- For SIMD instructions, I fear I don't have currently the knowledge for that but
would be willing to learn/help.
- A good start would be that 3rd point, about current code and performance
status on PPC vs x86.
I reused http://sljit.sourceforge.net/regex_perf.html, I hope it is relevant.
pcre directory has been updated to use latest 8.37 instead of 8.32.
My VMs were :
* x86-64 4x2.3GHz 4G memory on a x86-64 host
* ppc64el 4x3GHz 4G memory on a P8 host
* ppc64 4x3GHz 4G memory on a P8 host
All were installed with Ubuntu 14.04 LTS.
Note on Ubuntu for ppc64, default is to have binary in 32b running on a 64b
kernel, thus the binary 'runtest' is 32b. Maybe I'd need to try with 64b
binary.
Here is attached the results for those 3 environments. The goal is not to
find who's the best but rather find any odd behaviour. Also let's focus on
pcre/pcre-jit .
Any comment from experts eyes welcomed.
On my side, I see very comparable results between ppc64/pcc64el so no major
issue on ppc64el. Now, between x86 and ppc64el, the results for the latter
seem overall weaker, all the more that the x86 VM has lower freq.
Results would need maybe more repetition ? and percentage to compare but I
already see some x2 or x3 time slower results for pcre-jit :
.{0,3}(Tom|Sawyer|Huckleberry|Finn)
[a-zA-Z]+ing
^[a-zA-Z]{0,4}ing[^a-zA-Z]
[a-zA-Z]+ing$
^[a-zA-Z ]{5,}$
^.{16,20}$
"[^"]{0,30}[?!\.]"
Tom.{10,25}river|river.{10,25}Tom

Any special treatment for these that could make code generated on power weaker ?

Fred