Benchmark: Multiply vs subtract

Script Preparation code:

const length = 100000;
const tmp_nums=[];
for (let i = 0; i < length; i++) {
  tmp_nums.push(Date.now() + Math.random());
}
nums = [...tmp_nums];
nums_len = length;

Tests:

Multiply
const length = nums_len; for (let i = 0; i < length; i++) { nums[i] = nums[i] * -1; }
Subtract
const length = nums_len; for (let i = 0; i < length; i++) { nums[i] = 0 - nums[i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Multiply
Subtract

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Definition**

The provided JSON defines a benchmark named "Multiply vs subtract". This benchmark compares two approaches to make a number negative: multiplying by -1 and subtracting from 0.

**Script Preparation Code**

The script preparation code initializes an array `tmp_nums` with a fixed length of 100,000, and populates it with random numbers. Then, it creates another array `nums` that is a copy of `tmp_nums`.

**Html Preparation Code**

There is no HTML preparation code provided.

**Individual Test Cases**

The benchmark consists of two individual test cases:

1. **Multiply**: This test case multiplies each element in the `nums` array by -1.
2. **Subtract**: This test case subtracts each element in the `nums` array from 0.

**Options Compared**

The benchmark compares the execution times of two approaches to make a number negative:

*   Multiplying by -1 (`const nums[i] = nums[i] * -1;`)
*   Subtracting from 0 (`const nums[i] = 0 - nums[i];`)

**Pros and Cons of Each Approach**

*   **Multiplying by -1**: This approach is generally faster because it's a simple arithmetic operation that can be optimized by the JavaScript engine. However, it might require more memory allocations if the input array is very large.
*   **Subtracting from 0**: This approach is also fast but requires creating a temporary variable to hold the result of the subtraction, which might lead to slower performance due to additional memory allocations.

**Library Usage**

The benchmark uses no external libraries. The `Date` object is used for generating random numbers, and the `Math.random()` function returns a pseudo-random number between 0 (inclusive) and 1 (exclusive).

**Special JS Features/Syntax**

There are no special JavaScript features or syntax used in this benchmark.

**Other Considerations**

*   The input array size is fixed at 100,000 elements. Larger arrays might affect the performance of the benchmarks.
*   The `nums` array is created as a copy of the `tmp_nums` array using the spread operator (`const nums = [...tmp_nums];`). This ensures that both arrays have their own memory space and don't interfere with each other.

**Alternatives**

To create similar microbenchmarks, you can use other JavaScript engines or platforms like:

*   **Google Chrome's Benchmarking Tools**: A set of tools for creating and running benchmarks in Chrome.
*   **Node.js**: A JavaScript runtime that allows you to run benchmarks in a Node.js environment.
*   **V8 Benchmark Suite**: An open-source benchmark suite for the V8 JavaScript engine used by Google Chrome.

Keep in mind that each platform has its unique features, tools, and limitations. Measuring performance across different platforms can help identify optimal solutions for specific use cases.

Related benchmarks:

Multiply vs subtract (version: 0)

Is it faster to make a number negative by multiplying by negative one, og subtract the number from zero.

Comparing performance of: Multiply vs Subtract

Created: 2 years ago by: Guest

Jump to the latest result

Multiply

Subtract

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):