2011/4/10 Дмитрий Оксенчук: > I have tested performance of std::string compare methods and get > strange results. With -O2 optimization std::string::compare 30 times > faster then operator==. With -Os optimization operator== 5 times > faster then std::string::compare. Is this bug or feature? > > Full table (time for 10000000 comparisons in seconds): > -O0 -O1 -O2 -O3 -Os > compare 1.069 1.057 0.029 0.025 1.072 > operator== 0.461 0.990 0.980 1.022 0.201 Did you run the tests more than once and average the results? Your test code has no timing measurements in it, what are you measuring? The entire time for the executable to run? That includes time for the OS to create and run a new process, and will depend how busy the system is, so could have very little to do with the code in the executable.
