jwkrahn,

I benchmarked your code against mine, and for performance, my original 'UnPack' is faster on my hardware with debian linux and perl5.12.2.

case1 is mine, case2 is yours. I took out your test on the input since the input is CRC verified before calling 'UnPack'. I then modified my code to use 'for' instead of 'while' and using 'push' and now the results were only 2% faster.

This routine is called about 14 million times on a run of 100,000 inputs. The first time I profiled the program that this is part of, more than 50% of the time was spent in pack/unpack. I have done a lot of tweaking to get the performance. A year ago the 1st 100K run, I could only get 50 operations per second. Now on a 1,000K run, I get 1700 operations per second and pack/unpack is less than 10% of run time. 


Benchmark: timing 500000 iterations of case1, case2...
     case1:  3 wallclock secs ( 3.76 usr +  0.00 sys =  3.76 CPU) @ 13
+2978.72/s (n=500000)
     case2:  4 wallclock secs ( 4.11 usr +  0.00 sys =  4.11 CPU) @ 12
+1654.50/s (n=500000)
          Rate case2 case1
case2 119332/s    --   -9%
case1 131234/s   10%    --

[download]

This code was necessary to allow disk positioning on a 32 bit OS of 2**53 and 2**63 on 64 bit OS and still be network neutral. That also means I don't have to consider big/little endian problems. None of this would be necessary if pack/unpack had network neutral 64 bit integer that worked on both 32bit and 64bit hardware/OS.

Thank you

"Well done is better than well said." - Benjamin Franklin

In reply to Re^2: Force 'sub' return to be treated in list context? by flexvault
in thread Force 'sub' return to be treated in list context? by flexvault

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