Benchmark: Using at() vs [offset + n] for multiple assignment

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

var array = new Float32Array(1000);

Tests:

Assignment with offsets
const length = array.length / 5; for (let i = 0; i < length; i+=5) { array[i + 0] = 1; array[i + 1] = 3; array[i + 2] = 3; array[i + 3] = 7; array[i + 4] = 5; }
at()
const length = array.length / 5; for (let i = 0; i < length; i+=5) { array.at([1, 3, 3, 7, 5], i); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Assignment with offsets
at()

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:133.0) Gecko/20100101 Firefox/133.0

Browser/OS: Firefox 133 on Linux

View result in a separate tab

Test name	Executions per second
Assignment with offsets	14261388.0 Ops/sec
at()	83886.6 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):

LLMs can make mistakes. Check important info.

The benchmark defined in the provided JSON compares two different methods of assigning values to elements in a typed array (`Float32Array`) in JavaScript. The focus is on performance differences between using direct access with offsets and utilizing the `at()` method.

### Benchmark Overview

1. **Methods Compared:**
   - **Assignment with offsets:** This method uses direct indexing to assign values. Specifically, it accesses each index using a combination of a base index calculated from `i` and the offsets for each value.
   - **Using `at()`:** This method uses the `at()` method of the typed array to retrieve elements from the given array in a more abstract way. In this case, it is called with a list of hardcoded values and an index `i`.

### Detailed Examination

#### 1. Assignment with Offsets
- **Code Snippet:**
  ```javascript
  const length = array.length / 5;
  for (let i = 0; i < length; i+=5) {
    array[i + 0] = 1;
    array[i + 1] = 3;
    array[i + 2] = 3;
    array[i + 3] = 7;
    array[i + 4] = 5;
  }
  ```
- **Pros:**
  - **Performance:** Direct indexing tends to be faster since it avoids function call overhead.
  - **Simplicity:** More straightforward and traditional approach, easy to grasp for most developers.
  
- **Cons:**
  - **Hardcoding:** The values are hardcoded, which may reduce flexibility, although it is suitable for benchmarks and specific use cases.

#### 2. Using `at()`
- **Code Snippet:**
  ```javascript
  const length = array.length / 5;
  for (let i = 0; i < length; i+=5) {
    array.at([1, 3, 3, 7, 5], i);
  }
  ```
- **Library/Feature Description:** The `at()` method is a built-in JavaScript method available for arrays and typed arrays. It is generally used for retrieving values from the specified index. However, in this example, it appears to be misused because `at()` doesn't directly set values but retrieves elements based on indices passed. The correct usage would involve reading the values at specific indices rather than writing.
  
- **Pros:**
  - **Clarity and Readability:** When well-used, it may improve the clarity of what is being attempted.
  
- **Cons:**
  - **Performance Overhead:** Being a method call, it usually incurs more overhead than direct assignment.
  - **Incorrect Usage:** The way it's implemented here may lead to misunderstandings, as `at()` is not intended for assignments in the provided manner.

### Benchmark Results
- **Assignments with offsets:** This method performed significantly better, achieving approximately **14,261,388 executions per second**.
- **Using `at()`:** This method significantly lagged behind, with about **83,886 executions per second**.

### Other Considerations
- **Alternatives:** Besides the methods tested, the alternatives can include:
  - **Using `forEach()` or `map()`**: These array methods provide functional programming approaches but add more overhead and complexity, especially in benchmarking contexts.
  - **Typed array methods:** Depending on the requirements, other typed array methods such as `set()` could be considered when bulk operations are necessary.

### Conclusion
Selecting the appropriate method for array manipulation depends heavily on context. The benchmark highlights a stark difference in performance between direct assignment and using the `at()` method. While `at()` can add readability in certain contexts, it is essential to leverage it correctly and understand the implications on performance. For optimal speed, especially in performance-critical applications, direct indexing remains the more suitable approach.

Related benchmarks:

Using at() vs [offset + n] for multiple assignment (version: 1)

Comparing performance of: Assignment with offsets vs at()

Created: one year ago by: Guest

Jump to the latest result

Assignment with offsets

at()

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):