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fcamel/Test result

Created October 16, 2016 14:22
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Test result
$ g++ -std=c++11 count_bits.cpp -o count_bits -O3 && ./count_bits
count_directly : sum=7998166000, duration=3315520721 ns
count_by_table : sum=7998166000, duration=607687929 ns
count_by_table8 : sum=7998166000, duration=694708929 ns
count_by_bit_operation: sum=7998166000, duration=241576894 ns
count_by_popcnt : sum=7998166000, duration=69186289 ns
@arcbbb
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arcbbb commented Oct 17, 2016

Thanks for your article that shares this experiment. The algorithm of bit operation is amazing and impressive.
It is interesting that count_by_table8 is no faster than count_by_table in your result, since the table size are greatly reduced and should fit data cache well.
Then I did the same experiment on my laptop.
Here is my result https://gist.github.com/arcbbb/634323d2295a4beab1c080e0dc7bc2af
just to share the information with you that my laptop shows different result. quite interesting.

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