Jump to content
  • Advertisement
Sign in to follow this  
cronocr

Unity Optimizing code statements into expressions?

This topic is 1851 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hi! I'm looking for ideas on how to convert code into expressions in C# for Unity. We have this basic list of statements:
 
Simple statements:
  • assignment: A:= A + 5
  • call: CLEARSCREEN()
  • return: return 5;
 
 
Compound statements:
  • if-statement: if A > 3 then WRITELN(A) else WRITELN("NOT YET"); end
  • switch-statement: switch (c) { case 'a': alert(); break; case 'q': quit(); break; }
  • while-loop: while NOT EOF DO begin READLN end
  • do-loop: do { computation(&i); } while (i < 10);
  • for-loop: for A:=1 to 10 do WRITELN(A) end
 
 
The expressions that replace these statements should be chained, for example using And operators (expression1 && expression2 && .. expresionN), so the order of execution is respected. Also the ?: operator is allowed.
 
Assignment
 
If we have this statement:
 
int a = 100;
 
Can be converted into:
 
((a = 100) == a)
 
Yet not perfect, since the comparison is not optimized in IL code. I also tried:
 
((a = 100) is int)
 
This throws a warning, the comparison is optimized but the assignment is removed too. Any other idea that only produces the assignment in IL code?
 
Call
 
A call is automatically converted into a expression, right? Well, not exactly. How do you chain a void function?
 
Also if you pass parameters by reference, you will need a variable external to the expression.
 
Return
 
This one is directly converted:
 
return 5;
(5)
 
If and Switch statements
 
The ?: operator replaces them:
 
if (a == 5) { b = "yes"; } else { b = "no"; }
((a == 5) ? "yes" : "no")
 
While, Do and For loops
 
Loop unwinding could be used here, if the number of iterations is fixed. Any ideas for variable length loops?

Share this post


Link to post
Share on other sites
Advertisement

Because C# doesn't support code inlining, and converting statements into expressions will remove boxing/unboxing which is pretty expensive and fragments the heap (in Unity this causes brain cancer), will remove calls to functions, and will allow the compiler to optimize some of the code of the inlined routine. I built a code processor that inlines C# code, so the optimization will be deeper if I can convert more statements smile.png

Edited by cronocr

Share this post


Link to post
Share on other sites

How is this actually slowing your program?

 

How is this something that actually needs a programmer to optimize it?

 

 

 

You are right that boxing is somewhat slow, so DON'T DO IT.  If you end up needing to routinely convert integers and bools into objects, you are likely doing something wrong at the algorithm level.  

 

Similarly, the 'is' operator is not exactly fast, and its presence is a generally symptom of a more significant fundamental design problem.  Casting an object to some type and then discarding the results is horrible anyway; if you cannot fix your algorithm's underlying problem that requires the cast, at least have the decency to perform the cast with 'as' and keep the successful results around.

 

Next up, chaining doesn't necessarily mean better performance -- each item is dependent on the previous results which is bad for the pipeline.  You can get pipeline bubbles or poor use of speculative execution and branch prediction if you make it too tight.  On modern hardware keeping it loose is usually better.  

 

 

 

You might manage to save a cycle or two if you hunt for things like this, but hunting for spare nanoseconds is not generally a good use of time.

 

Code optimization is generally about saving microseconds or bigger time units.

Share this post


Link to post
Share on other sites

How is this actually slowing your program?
 
How is this something that actually needs a programmer to optimize it?

 

You might manage to save a cycle or two if you hunt for things like this, but hunting for spare nanoseconds is not generally a good use of time.

 

Code optimization is generally about saving microseconds or bigger time units.

 

At the level I'm currently optimizing the system, everything is slowing it down. I already designed an optimized solution, and profiled the system to the "smallest" millisecond. Now I'm ready for the nanoseconds. Why doing this? Because it's cheap doing it with the automated inlining tool I have built.

 

 

You are right that boxing is somewhat slow, so DON'T DO IT.  If you end up needing to routinely convert integers and bools into objects, you are likely doing something wrong at the algorithm level.  

 

It's almost impossible not to generate boxing, not in a system with 9000+ lines of code. The way to actually get rid of it is inlining, so I'm going to do it.

 

 

Similarly, the 'is' operator is not exactly fast, and its presence is a generally symptom of a more significant fundamental design problem.  Casting an object to some type and then discarding the results is horrible anyway; if you cannot fix your algorithm's underlying problem that requires the cast, at least have the decency to perform the cast with 'as' and keep the successful results around.

 

Using the "is" operator is just a trick to convert the statement into a expression, the idea is finding a way for the compiler to remove it later, so it doesn't represent any cost.

 

 

Next up, chaining doesn't necessarily mean better performance -- each item is dependent on the previous results which is bad for the pipeline.  You can get pipeline bubbles or poor use of speculative execution and branch prediction if you make it too tight.  On modern hardware keeping it loose is usually better.  

 

We are not talking of the same thing here. I might have used a wrong term when referring to the AND operator, that "chains/adds/joins" expressions, so the execution sequence is respected.

Edited by cronocr

Share this post


Link to post
Share on other sites

Now I'm ready for the nanoseconds. Why doing this? Because it's cheap doing it with the automated inlining tool I have built.

 

You know that the time you spent actually developing this tool and feeding your code into it probably outweighs any such performance benefit by a factor of hundreds, right?

 

is_it_worth_the_time.png

 

Unless you spent less than a couple seconds or so developing this tool, you've already wasted your time working on something that is costing more time and effort than it is saving you. And that's without paraphrasing the above members with your fundamentally broken optimization approach.

Share this post


Link to post
Share on other sites

Unfortunately no one who has read this thread seems to know the answer to my question, and people started asking "why doing it". Well I'm giving you people a little light on the purpose of transforming statements into expressions, and one of the reasons is that there is no way to avoid boxing in a large project. I'm seeing it with a decompiler, I'm seeing it in the final build. I already tried to find different ways to remove boxing, but that makes the code un-elegant and difficult to maintain. There is no design flaw. So the way to further optimize is creating a workflow that allows me to work on the code elegantly, and an automated tool to do the dirty job by helping the compiler to do a deeper optimization. I'm already doing the inlining and I'm seeing the benefits, at the moment I just want to find if C# allows converting every statement into an expression. Too bad I probably touched a "language as religion" nerve here, because I'm getting lots of negativity from a simple question. You people can have lots of fun pushing the -1 vote, solving this problem is way more important to me. If you want to learn with me, welcome :)

 

Using another language is not an option (come on dry.png ). Using Expression Trees is not an option because it makes code unelegant, adds another library, and is not fully support on various platforms (Mono/Unity here). CodeDom in not an option because not being fully supported neither. Standard expressions with the language operators is available everywhere, are rather easy to generate, and not doubt are optimal. Any reason not to use them?

Share this post


Link to post
Share on other sites

This topic is 1851 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Guest
This topic is now closed to further replies.
Sign in to follow this  

  • Advertisement
  • Advertisement
  • Popular Tags

  • Similar Content

    • By ethancodes
      I'm working on a system for my game that will allow the player to stack pick ups in a queue. As one pick up expires, the next automatically activates. I'm having an issue though where if I pick up the first one, it activates fine, but if i pick up a second directly after it, it overrides the first one, activates the second one, and then once it has run it's course, everything goes back to normal gameplay, no first pick up. I'm not sure why this is happening. Hopefully someone can spot what I'm doing wrong in my code.
      Here is the code for the pick up manager:
      // Update is called once per frame void Update () { if (pickUpQueue.Count != 0 && !pickUpActive) { pickUpActive = true; pickUpQueue[0].ActivatePickUp(); } DeactivatePickUp(); } void DeactivatePickUp () { if (pickUpQueue.Count != 0 && pickUpActive) { Destroy (pickUpQueue [0]); pickUpQueue.RemoveAt (0); pickUpActive = false; } } And here is the PickUp:
      public override void ActivatePickUp () { ball.GetComponent<Ball>().Speed = 2.0f; //increase ball speed... ball.GetComponent<Ball>().StartCoroutine(timer); //...set time that power up is active }  
      There is also a Base Pick Up:
      public void OnCollisionEnter2D (Collision2D collision) { Vector2 tweak = new Vector2 (Random.Range(0f, 0.2f),Random.Range(0f, 0.2f)); this.gameObject.GetComponent<Rigidbody2D>().velocity += tweak; //if the pickup makes contact with the paddle or ball.... if (collision.gameObject.tag == "Paddle" || collision.gameObject.tag == "Ball") { GameObject.FindObjectOfType<GameManager>().GetComponent<PickUpManager>().pickUpQueue.Add(this); Destroy(gameObject); //...and finally destroy power up object } } As a side note, I am trying to find a solution to this that will work for all of my pickups. Some pickups are ammo based, some are timed. 
    • By D34DPOOL
      Edit Your Profile D34DPOOL 0 Threads 0 Updates 0 Messages Network Mod DB GameFront Sign Out Add jobEdit jobDeleteC# Programmer for a Unity FPS at Anywhere   Programmers located Anywhere.
      Posted by D34DPOOL on May 20th, 2018
      Hello, my name is Mason, and I've been working on a Quake style arena shooter about destroying boxes on and off for about a year now. I have a proof of concept with all of the basic features, but as an artist with little programming skill I've reached the end of my abilities as a programmer haha. I need someone to help fix bugs, optomize code, and to implent new features into the game. As a programmer you will have creative freedom to suggest new features and modes to add into the game if you choose to, I'm usually very open to suggestions :).
      What is required:
      Skill using C#
      Experience with Unity
      Experience using UNET (since it is a multiplayer game), or the effort and ability to learn it
      Compensation:
      Since the game currently has no funding, we can split whatever revenue the game makes in the future. However if you would perfer I can create 2D and/or 3D assets for whatever you need in return for your time and work.
      It's a very open and chill enviornment, where you'll have relative creative freedom. I hope you are interested in joining the team, and have a good day!
       
      To apply email me at mangemason@yahoo.com
    • By davejones
      Is there a way to automatically change the start position of an animation? I have a bunch of animations set up on 3D models in unity. The issue is that I need to move the 3D models, however when I do so the animation start positions are not updated and I have to do it manually.

      Changing the transform of key frames is time consuming with the amount of animations I have, so I was wondering if there was a way to do it automatically?
    • By MoreLion
      hey all! We are looking for members for our Unity horror game! 
      Here’s the story:
      After a deadly virus plunges the world into chaos killing 85% of the human population there are now what they call “zones” these zones are watched very closely by the surviving government, people are checked every day for the virus, even if you touch the spit or any human waste or fluids of the victim who is infected, you will die. But one day, people in the west zone start to go missing, 1 woman goes outside the walls to uncover the mystery, is there more to the virus than meets the eye?, That is where your story starts.
      This game is not a long development game, I have loads other game ideas,
      I will also allow you to have a bit of creative freedom if you wish to add or share a idea!
      And no, it’s not a zombie game lol I feel like zombie games are too generic, in this game you will encounter terrifying beasts!
      There is some concept art one of our concept artists have made
      If interested email liondude12@gmail.com
    • By Canadian Map Makers
      GOVERNOR is a modernized version of the highly popular series of “Caesar” games. Our small team has already developed maps, written specifications, acquired music and performed the historical research needed to create a good base for the programming part of the project.

      Our ultimate goal is to create a world class multi-level strategic city building game, but to start with we would like to create some of the simpler modules to demonstrate proof of concept and graphical elegance.

       

      We would like programmers and graphical artists to come onboard to (initially) create:

      A module where Province wide infrastructure can be built on an interactive 3D map of one of the ancient Roman Provinces.
      A module where city infrastructure can be built on a real 3D interactive landscape.
      For both parts, geographically and historically accurate base maps will be prepared by our team cartographer. Graphics development will be using Blender. The game engine will be Unity.

       

      More information, and examples of the work carried out so far can be found at http://playgovernor.com/ (most of the interesting content is under the Encyclopedia tab).

       

      This project represents a good opportunity for upcoming programmers and 3D modeling artists to develop something for their portfolios in a relatively short time span, working closely with one of Canada’s leading cartographers. There is also the possibility of being involved in this project to the point of a finished game and commercial success! Above all, this is a fun project to work on.

       

      Best regards,

      Steve Chapman (Canadian Map Makers)

       
    • By Scouting Ninja
      So I have hundreds of moving objects that need to check there speed. One of the reasons they need to check there speed is so they don't accelerate into oblivion, as more and more force is added to each object.
      At first I was just using the Unity vector3.magnitude. However this is actually very slow; when used hundreds of times.
      Next I tried the dot-product check:  vector3.dot(this.transform.foward, ShipBody.velocity) The performance boost was fantastic. However this only measures speed in the forward direction. Resulting in bouncing objects accelerating way past the allowed limit.
       
      I am hoping someone else knows a good way for me to check the speed with accuracy, that is fast on the CPU. Or just any magnitude calculations that I can test when I get home later.
       
      What if I used  vector3.dot(ShipBody.velocity.normalized, ShipBody.velocity)?
      How slow is it to normalize a vector, compared to asking it's magnitude?
    • By Ds ds
      Hi, my name is Andres, I'm a programmer with a technician degree and a Diploma in C#, looking for a project in Unity to start my career in game development. I don't do it for a paid but a recognition and start a portfolio, preferably a 2D game. Thanks for read, have a nice day. 
       
    • By Victor Rodriguez
      Hi there! Is the first time that I'm posting here so I'm sorry if I'm doing it wrong ha. 
      So here it comes, my doubt is, I'm doing a game with different levels, each of these levels in one different scene. Each scene contains to cameras that you can change pressing a button. Everything works fine. 
      The only problem is that I would like it to look a bit more professional, and I would like that if you finish the level with camera2, the next level start the same way. I've been thinking about using dontdestroyonloadon both cameras, but obviously this cameras need to be attached to the player to make the movement work, what do you recommend? Sorry If I've explained it in a messy way, and feel free to dm me for anything. Thanks in advance! 
    • By Ike aka Dk
      Hello everyone 
      I am a programmer from Baku.
      I need a 3D Modeller for my shooter project in unity.I have 2 years Unity exp.
      Project will paid when we finish the work 
      If you interested write me on email:
      mr.danilo911@gmail.com
    • By markoal
      Hi,
      I'm Unity developer from Croatia and I'm looking to work on the paid project in my spare time.
      I have 5+ years of experience in Unity and I'm familiar with almost anything, including all platforms (also Switch, PS4 and Xbox).
      Feel free to contact me.
  • Advertisement
  • Popular Now

  • Forum Statistics

    • Total Topics
      631367
    • Total Posts
      2999594
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

Participate in the game development conversation and more when you create an account on GameDev.net!

Sign me up!