Remove strlen in C++ benchmark#63
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ulfjack merged 1 commit intoulfjack:masterfrom Aug 8, 2018
dtolnay:bench
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Avoiding strlen makes the benchmark more comparable across languages that would not want a null terminator, such as Rust. This strlen in bench32 was 20% of the iteration time on my machine.
StephanTLavavej
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Accepting ulfjack#63 will change bench32()'s timings (in a desirable way). That makes this a good time to simplify bench64() (changing its timings in a minor, neutral way). Instead of calling a 32-bit Mersenne Twister twice, which exactly replicated the previous third-party implementation, we can simply use the Standard's 64-bit Mersenne Twister. It generates every uint64_t with equal probability, so the test is essentially unaffected. (The exact values differ from the previous technique, so the timings might change very slightly, as if a different seed were chosen.) Calling std::mt19937 twice versus calling std::mt19937_64 once has somewhat different performance characteristics, but the benchmark doesn't time this, so it doesn't matter.
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Thanks! Yeah, I remember that that was a large change in the 64-bit case. Weird that I missed updating the 32-bit case. shrug |
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Avoiding strlen makes the benchmark more comparable across languages that would not want a null terminator, such as Rust.
This strlen in bench32 was 20% of the iteration time on my machine.