Performance difference between post- and pre- increment operators? [closed]

Answer 1

The required runtime for the increment itself ought to be the same, but if you are using a pre- or post-increment obviously may have impact on the performance of the surrounding code and a post-increment can in more situations be optimized away.

There are also some non-obvious cases, where the performance of the surrounding code is changed. At least when run with Oracle's server VM on x86 or x64 hardware, the following loops have a significant difference in their runtime:

long a=0, b=0;
for(int i=0;i<1000000;i++) {
    b = 3;
    a += i * (b++);
}

...

long a=0, b=0;
for(int i=0;i<1000000;i++) {
    b = 3;
    a += i * (++b);
}