var N = 1000000;var x = [], y = [], z = [];var xt = new Float32Array(1000000);var yt = new Float32Array(1000000);var zt = new Float32Array(1000000);var vectors = [];for(var i = 0; i < N; i++){ x[i] = Math.random(); y[i] = Math.random(); z[i] = Math.random(); xt[i] = x[i]; yt[i] = y[i]; zt[i] = z[i]; vectors[i] = { x: x[i], y: y[i], z: z[i] };}var vector;for (var i = 0, li=x.length; i < li; ++i) { x[i] *= 2; y[i] *= 2; z[i] *= 2;}for (var i = 0, li=vectors.length; i < li; ++i) { vector = vectors[i]; vector.x = 2 * vector.x; vector.y = 2 * vector.y; vector.z = 2 * vector.z;}for (var i = 0, li=x.length; i < li; ++i) { x[i] *= 2;}for (var i = 0, li=y.length; i < li; ++i) { y[i] *= 2;}for (var i = 0, li=z.length; i < li; ++i) { z[i] *= 2;}--enable-precise-memory-info flag.
| Test case name | Result |
|---|---|
| soa | |
| aos | |
| soa mark II |
| Test name | Executions per second |
|---|---|
| soa | 3.9 Ops/sec |
| aos | 1.4 Ops/sec |
| soa mark II | 3.9 Ops/sec |
Let's break down the provided benchmark and its individual test cases.
Benchmark Overview
The benchmark is designed to compare two different approaches to scaling an array of floating-point numbers in JavaScript. The goal is to measure which approach is faster, i.e., executes more instructions per second.
Script Preparation Code
The script preparation code creates four arrays:
x, y, and z are regular arrays with 1 million elements each.xt, yt, and zt are Float32Array objects, which are typed arrays optimized for floating-point numbers.Additionally, an array of objects vectors is created to hold the same data as the individual arrays.
Benchmark Definition
The benchmark consists of three test cases:
This test case uses a simple loop to iterate over each element in the x, y, and z arrays, multiplying each element by 2. The loop increments an index variable i from 0 to the length of the array.
Pros:
Cons:
This test case uses a loop to iterate over each element in the vectors array, which holds the same data as the individual arrays. For each iteration, it scales the corresponding x, y, and z components of the vector by 2.
Pros:
Cons:
vectors to hold the dataThis test case is similar to "soa" but instead of scaling all three arrays simultaneously, it scales each array individually using separate loops.
Pros:
Cons:
y and z) than in "soa"Library/Function Used
The Float32Array type is a built-in JavaScript array type optimized for floating-point numbers. It's used here to improve performance when working with large amounts of numerical data.
Special JS Features/Syntax
None of the benchmark code uses any special JavaScript features or syntax, making it accessible to a wide range of software engineers.
Other Alternatives
If you wanted to test different scaling approaches without using arrays, you could consider using other data structures like linked lists, trees, or even strings. Additionally, you might want to explore alternative algorithms for scaling numerical data, such as using SIMD instructions (Single Instruction, Multiple Data) or parallel processing techniques.
In summary, the "soa", "aos", and "soa mark II" test cases provide a simple and well-controlled comparison of scaling array operations in JavaScript. By understanding the pros and cons of each approach, developers can better choose the most efficient method for their specific use case.
