Posts Tagged array

Dangers of Arrays in Burst

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Normally Burst-compiled jobs can’t use managed arrays, but there’s an exception for static readonly fields. This comes with several dangers, which we’ll explore today.

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BitArray32 and BitArray64

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C# already has two bit array types, but both are lacking. BitArray is a class so it requires heap allocation and GC. BitVector32 is a struct, but it’s usage is bizzare, it’s implemented inefficiently, it’s not enumerable, and there’s no 64-bit version. Today we’ll create a new, simple type to remedy these issues and add a new tool to our toolbox!

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SmallBuffer: A Stack-Based Array

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Sometimes you just want a small array without the heap allocations and GC. Existing solutions like stackalloc require unsafe code, don’t allow for dynamic growth, and don’t support foreach loops. So today we’ll design and build a code generator that puts a new tool in your toolbox!

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Object Graph Visualizer

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C# makes it easy to create large graphs of objects connected by their fields. The larger this graph grows, the more complex it is to deal with objects in the graph. It’s hard to look at code or set a breakpoint in a debugger and get an intuitive sense of all these connections. So today we’ll write a small tool to visualize an object graph!

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Enumerables Without the Garbage: Part 8

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NativeArray<T> is great, but very limited in functionality. We can fix this surprisingly easily! Today we revive a two year old series that created the iterator project. Iterators are like a no-GC version of IEnumerable<T> and LINQ which have a lot of power but only support managed arrays (T[]) and List<T>. Today we’ll add support for NativeArray<T> and inherit support for the same functionality. We’ll also spruce up the project with proper unit tests, assembly definitions, and runtime tests to confirm that zero garbage is created. Read on to see how this was done and how to use iterators with NativeArray<T>.

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LINQ Performance Update

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It’s been over three years since the last article on LINQ performance. That was all the way back in the Unity 5.0 days using Mono as a scripting backend. Today we’ll update that article’s test with Unity 2018.1 and IL2CPP to see how LINQ fares these days. Is it any better? Read on to find out!

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Loops in IL2CPP

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There are many permutations of loops we can write, but what do they compile to? We should know the consequences of using an array versus a List<T>, for versus foreach, caching Length, and other factors. So today’s article dives into the C++ code that IL2CPP outputs when we write these various types of loops to examine the differences. We’ll even go further and look at the ARM assembly that the C++ compiles to and really find out how much overhead our choices are costing us.

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Three IL2CPP Optimizations

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This week we’ll take a break from the C++ Scripting series to explore three optimizations we can make to our C# code so that IL2CPP generates faster C++ code for us. We’ll cover three areas that yield big speedups: casting, array bounds checking, and null checking.

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C++ Scripting: Part 27 – Foreach Loops

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C++ doesn’t have a foreach keyword, but it does have an equivalent in “range for loops”. Today we’ll implement support for them so we can easily loop over arrays and types implementing IEnumerable and IEnumerable<T>.

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C++ Scripting: Part 20 – Performance Improvements

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The last time we looked at performance was way back in part four of the series. Ever since then we’ve been relentlessly adding more and more features to the C++ scripting system. So today we’ll take a break from feature additions to improve the system’s performance in a couple of key areas.

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