Re^3: Convert string to array - performance challenge

I think it depends a lot on the system, c-runtime

ActivePerl v5.8.9 built for MSWin32-x86-multi-thread, Binary build 825
+ [288577]
           Rate unpack_C unpack_a    split    regex
unpack_C 3.48/s       --      -5%      -7%      -9%
unpack_a 3.66/s       5%       --      -3%      -4%
split    3.76/s       8%       3%       --      -1%
regex    3.82/s      10%       4%       1%       --

           Rate unpack_C    regex unpack_a    split
unpack_C 3.56/s       --      -5%      -5%      -6%
regex    3.74/s       5%       --      -0%      -1%
unpack_a 3.74/s       5%       0%       --      -1%
split    3.79/s       7%       2%       1%       --


Rate    split unpack_C    regex unpack_a
split    3.45/s       --      -4%      -9%     -25%
unpack_C 3.58/s       4%       --      -6%     -22%
regex    3.79/s      10%       6%       --     -18%
unpack_a 4.60/s      34%      29%      21%       --
[download]

The newer versions (built using MinGW) are more consistent between runs

C:\perl\5.10.1\bin\MSWin32-x86-multi-thread\perl.exe

           Rate unpack_C    regex    split unpack_a
unpack_C 3.66/s       --      -2%     -15%     -22%
regex    3.74/s       2%       --     -14%     -21%
split    4.33/s      18%      16%       --      -8%
unpack_a 4.70/s      28%      26%       9%       --


C:\perl\5.11.1\bin\MSWin32-x86-multi-thread\perl.exe


           Rate    regex unpack_C    split unpack_a
regex    2.74/s       --     -28%     -38%     -39%
unpack_C 3.82/s      39%       --     -13%     -14%
split    4.40/s      60%      15%       --      -2%
unpack_a 4.47/s      63%      17%       2%       --
[download]

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Re^4: Convert string to array - performance challenge by BrowserUk (Patriarch) on Apr 08, 2010 at 07:23 UTC
I see some variablility, but nothing like those levels using AS perls. AS1007 64-bit: c:\test>junk Rate regex unpack_C unpack_a split regex 7.95/s -- -1% -10% -14% unpack_C 8.01/s 1% -- -10% -14% unpack_a 8.88/s 12% 11% -- -4% split 9.30/s 17% 16% 5% -- c:\test>junk Rate regex unpack_C unpack_a split regex 7.95/s -- -0% -8% -12% unpack_C 7.95/s 0% -- -8% -12% unpack_a 8.68/s 9% 9% -- -4% split 9.09/s 14% 14% 5% -- c:\test>junk Rate unpack_C regex unpack_a split unpack_C 8.02/s -- -0% -9% -11% regex 8.02/s 0% -- -9% -11% unpack_a 8.81/s 10% 10% -- -2% split 9.02/s 13% 13% 2% -- c:\test>junk Rate unpack_C regex unpack_a split unpack_C 7.95/s -- -0% -9% -13% regex 7.95/s 0% -- -9% -13% unpack_a 8.74/s 10% 10% -- -5% split 9.16/s 15% 15% 5% -- [download] AS826 32-bit: c:\test>\perl32\bin\perl junk.pl Rate unpack_C split regex unpack_a unpack_C 8.38/s -- -5% -9% -15% split 8.81/s 5% -- -5% -11% regex 9.23/s 10% 5% -- -6% unpack_a 9.86/s 18% 12% 7% -- c:\test>\perl32\bin\perl junk.pl Rate unpack_C split regex unpack_a unpack_C 8.45/s -- -5% -8% -15% split 8.87/s 5% -- -3% -11% regex 9.16/s 8% 3% -- -8% unpack_a 9.94/s 18% 12% 9% -- c:\test>\perl32\bin\perl junk.pl Rate unpack_C split regex unpack_a unpack_C 8.38/s -- -5% -8% -14% split 8.81/s 5% -- -4% -10% regex 9.16/s 9% 4% -- -6% unpack_a 9.78/s 17% 11% 7% -- c:\test>\perl32\bin\perl junk.pl Rate unpack_C split regex unpack_a unpack_C 8.38/s -- -5% -8% -14% split 8.81/s 5% -- -4% -10% regex 9.16/s 9% 4% -- -6% unpack_a 9.78/s 17% 11% 7% -- [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "I'd rather go naked than blow up my ass"	[reply] [d/l] [select]
Re^5: Convert string to array - performance challenge by ikegami (Patriarch) on Apr 08, 2010 at 16:54 UTC
`split //` was optimised to not use the regex engine on 9 Aug 2007. The 5.8 build you are using probably predates that. I got the same variability between regex and unpack_C with 5.10. They are basically equivalent in terms of performance.	[reply] [d/l]