In this blog post, we’ll delve into the unroll<N>() template function for template unrolling, understand its mechanics, and see how it can

Practical C++17: Loop Unrolling with Lambdas and Fold Expressions - C++ Stories

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2024-09-23 05:00:01

In this blog post, we’ll delve into the unroll<N>() template function for template unrolling, understand its mechanics, and see how it can improve your code. We’ll look at lambdas, fold expressions, and integer sequences.

In a recent article Vector math library codegen in Debug · Aras’ website - Aras Pranckevičius discusses some coding techniques that help with performance of debug code… and I came across an intriguing technique utilized in the Blender Math library that he used in his text.

Before we go into the intricacies of the unroll() function, it’s good to learn such a technique is valuable. In performance-critical applications—such as graphics rendering, real-time simulations, or high-frequency trading—every millisecond counts. Traditional loops, while easy to write, introduce runtime overhead that can be minimized or eliminated using compile-time optimizations like loop unrolling.

In short, template unrolling automates the expansion of loops during compilation, replacing iterative constructs with repetitive code blocks.