Thank you for linking. In this case, as I understand, you switched from a local array which is re-initialized with values upon each function invocation to a gl

Thank you for linking. In this case, as I understand, you switched from a local array which is re-initialized with values upon each function invocation to a global array that is pre-initialized before even the program starts. So my understanding is you're measuring the speed between repeated re-initialization of your local array and no initialization at all — not between "relative" stack access and "absolute" heap or global memory access. As I understand, to do it the way you wanted initially, your local array must be `static const` instead of just const (so that there's a single copy of it, essentially making it a global variable as well). To be honest, I am not sure why C compiler doesn't optimize it this way automatically, likely I don't know C spec well enough to know the reasons.