It may be old C++ and optimizations. On my computer I obtained almost the same speed:
One loop: 1.577 ms
Two loops: 1.507 ms
I run Visual Studio 2015 on an E5-1620 3.5 GHz processor with 16 GB RAM.
It may be old C++ and optimizations. On my computer I obtained almost the same speed:
One loop: 1.577 ms
Two loops: 1.507 ms
I run Visual Studio 2015 on an E5-1620 3.5 GHz processor with 16 GB RAM.