Hello! 1. There is a decent difference between calculations on Visual studio compiler and gcc 7.1 in calculation result of my program. 2. When optimization in gcc are disabled, then there is no difference. 3. When I have replaced O2 with keys from O1 and O2 ( https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html), then there is no difference in results, but there is a calculation speed degradation compared to O2.
