While profiling a piece of software I came across a quite surprising finding: a lot of cycles were lost in
stl::vector<bool>::operator[]
It took me quite some time to actually believe that it was really that method that was slow. Some test and a quick Internet search showed that the implementation of the
stl::vector is memory usage optimized when the template argument is
bool.
Two possible solution to this problem that I found are:
- use a
stl::deque<bool> instead of a stl::vector<bool>
- use an integer instead of a boolean
The speedup gained by opting for the second solution was in the order
4x.
