Why is controls over memmory layout important for Games?
If you work on Android games for example would you get any kind of control over mem layout, irrespective of the stack you will be using?
If you work on Android games for example would you get any kind of control over mem layout, irrespective of the stack you will be using?
class RGB { float r float g float b ... }
and then make an `ArrayList<RGB>` the list will end up using over 2x the memory (128 bytes for object headers, 64 bytes for pointers in the list) compared to a language with value types. What makes this even worse is that since you are using a list of pointers, you can't use SIMD for any of your computations, and accessing elements will be slow since the values won't be in cache.
Also, there is now a Vector API that let’s you use SIMD operations with configurable lane width (and a safe fallback to for loops for processors without the necessary instructions)
In particular for Java there's regularly dependent pointer loads, which are dreadfully slow on modern CPUs and also waste a significant amount of L1/L2 cache.