[2020] Profiling: Optimisation | Riot Games Engineering

Originally posted by trc1234

It's C++, but I don't think any programmer should limit what jobs they can take by the languages they know. Languages are syntactically different, but the underlying concepts and design patterns are identical so new languages should be pretty easy to pick up (unless they are in a completely different paradigm of course). Especially since the field is changing so fast and many languages are no longer being used (for example VB6 is basically dead except a few crazy excel programmers use it) and many new languages are appearing.

This kind of assembly level optimisation the article was talking about is particularly niche topic which most programmers do not need to be too concerned about (this is probably true at Riot too). And I'm sure at Riot they use many different languages as well as hiring many different programming roles.

Originally posted by velrak

Am i understanding that image right and rendering the HUD takes about the same amount of time as the entire rest of the graphics? That seems crazy

Originally posted by [deleted]

If Im looking to work for Riot someday, how much of this sort of thing should I know, as far as this sort of code optimization and assembly? Im a CS major but honestly it feels like they never teach anything about practical real world software development :/

Originally posted by C0ldSn4p

/u/RiotTony : Actually you can inline virtual function if you statically force the call of a precise function implementation

Here is a code sample:

// Compile with: icpc -std=c++11 -O2 main.cpp 
#include <stdio.h>

class Base {
  public:
    virtual int foo() {return 42;}
};


class Child : public Base {
  public:
    int foo() {return 69;}
};

void bar(Child c) {
  printf("%d", c.Child::foo());
}

void bar2(Child c) {
  printf("%d", c.Base::foo());
}

int main(){
  Child c;
  bar(c);
  bar2(c);
}

If you run it you will get the output 6942 showing that first foo from the child was called and the foo from the base (despite using a child object). Also if you look at the assembly (-S option at compilation) you can see in the method bar and bar2 that the values 42 and 69 are hardcoded proving that the correct foo methods were inlined despite being virtual one.

Ofc this is a very specific use case but still, virtual doesn't always mean that you have to give up performances and inlining

Originally posted by LoLFirestorm

Will league ever get multithreaded without a complete game and graphics engine rework?
I'm no programmer but I believe the stuff like UI which is not super time sensitive down to tenths of a milisecond could be executed on a separate core just fine with some work and as far as I'm aware this doesn't take place right now.
My current system is very much an edge case but it's absolutely hilarious to me that I can run Doom 2016 at ultra settings and get 100-120FPS with dips to 80 and on the very same machine league will hover in 60-80 range after leaving the fountain and dip as low as 30 in super lategame teamfights. This is at a mix of medium and high settings btw but these seem to make basically no difference when the bottleneck is on the CPU side like in my case (I'm still running a Phenom II after all these years but I got myself an RX 480 before the mining boom).
I don't think it's alright that even proffesional streamers running pretty beastly builds and encoding on a separate computer with a capture card are often far from saturating a 144Hz monitor with frames during teamfights.