Benchmark: array.slice(0,4) vs. 4 index calls

Tests:

slice
const n = 15000000; const array = new Uint8ClampedArray(n); let sum = 0; for (let i = 0; i < n; i += 4) { let [a, b, c, d] = array.slice(i, 4); sum += (a + b + c + d); }
index
const n = 15000000; const array = new Uint8ClampedArray(n); let sum = 0; for (let i = 0; i < n; i += 4) { let a = array[i]; let b = array[i+1]; let c = array[i+2]; let d = array[i+3]; sum += (a + b + c + d); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
index

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

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**Benchmark Definition**

The provided JSON represents a benchmark definition, which outlines two test cases:

1. `array.slice(0,4) vs. 4 index calls`
2. `const n = 15000000; const array = new Uint8ClampedArray(n); ...`

These tests aim to compare the performance of two approaches for accessing an array of integers.

**Options Compared**

The benchmark compares two options:

A) Using `array.slice(0,4)` to extract a subset of 4 elements from the array.
B) Using four individual index accesses (`array[i]`, `array[i+1]`, `array[i+2]`, and `array[i+3]`) to access the same subset of 4 elements.

**Pros and Cons**

### Option A: `array.slice(0,4)`

Pros:

* Efficient in terms of memory usage, as it creates a new array with only the desired elements.
* Can be faster due to optimized slicing algorithms in modern JavaScript engines.

Cons:

* Creates an additional object in memory, which can lead to increased garbage collection overhead.
* May incur overhead due to the creation of a new array.

### Option B: 4 index accesses

Pros:

* No extra memory allocation is required, as only the existing array is accessed directly.
* Can be faster due to reduced memory allocation and copying overhead.

Cons:

* Requires four separate index accesses, which can lead to increased branching and computation overhead.
* May not be optimized for performance by JavaScript engines.

**Library and Purpose**

None of the tests use a specific library or framework. The benchmark focuses solely on comparing two basic approaches for accessing an array.

**Special JS Feature or Syntax**

There is no special feature or syntax used in this benchmark. Both tests rely on standard JavaScript features and syntax.

**Other Alternatives**

Other alternatives could include:

* Using `Array.prototype.subarray()` instead of `slice()`
* Using `buffer.slice()` or similar optimized slicing functions for Uint8ClampedArrays
* Using SIMD instructions (e.g., AVX) for parallelized access to array elements

However, these alternatives are not part of the provided benchmark and would require additional changes to the test code.

**Benchmark Preparation Code**

The benchmark preparation code is empty, indicating that the script starts from a clean slate with no pre-executed setup or teardown logic.

Keep in mind that this explanation provides a high-level overview of the benchmark. If you'd like to know more about specific aspects or details, feel free to ask!

Related benchmarks:

array.slice(0,4) vs. 4 index calls (version: 0)

Comparing performance of: slice vs index

Created: 2 years ago by: Guest

Jump to the latest result

slice

index

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):