Benchmark: divide by 2 vs multiply by 0.5 - 1

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:

div by 2
const length = nums_len; for (let i = 0; i < length; i++) { nums[i] /= 2; }
div by 2.0
const length = nums_len; for (let i = 0; i < length; i++) { nums[i] /= 2.0; }
multiply by 0.5
const length = nums_len; for (let i = 0; i < length; i++) { nums[i] *= 0.5; }
bitwise
const length = nums_len; for (let i = 0; i < length; i++) { nums[i] = nums[i] >> 1; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
div by 2
div by 2.0
multiply by 0.5
bitwise

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Windows

View result in a separate tab

Test name	Executions per second
div by 2	147.5 Ops/sec
div by 2.0	143.1 Ops/sec
multiply by 0.5	148.6 Ops/sec
bitwise	72.6 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark test and explain what's being tested, compared options, pros/cons, library usage, special JavaScript features, and other considerations.

**Benchmark Test: Division by 2 vs Multiplication by 0.5**

The provided JSON defines a benchmark test that compares three different approaches to divide a large array of numbers by 2 or multiply it by 0.5:

1. **Division by 2 (div by 2)**: The test uses the `/` operator to perform division.
2. **Division by 2 with floating-point precision (div by 2.0)**: The test uses the `2.0` literal value to specify a decimal number, ensuring precise control over the division result.
3. **Multiplication by 0.5**: The test uses the `*` operator to perform multiplication.

**Comparison Options**

The three options being compared are:

* Division by 2 (div by 2)
	+ Pro: Simple and easy to implement
	+ Con: May lose precision due to floating-point representation issues
* Division by 2 with floating-point precision (div by 2.0)
	+ Pro: Preserves precise control over the division result
	+ Con: More complex implementation
* Multiplication by 0.5
	+ Pro: Efficient and simple implementation
	+ Con: May not be as precise as division by 2 or div by 2.0

**Library Usage**

There is no explicit library usage in the provided benchmark test.

**Special JavaScript Features (None)**

There are no special JavaScript features, such as `let` or `const`, being used in this benchmark test.

**Other Considerations**

* The use of a large array (`nums_len`) to test performance
* The random values generated for each iteration using `Date.now() + Math.random()` to simulate real-world data
* The execution count per second (ExecutionsPerSecond) reported by the browser, which provides an estimate of the benchmark's overall performance

**Alternatives**

If you were to write a similar benchmark test from scratch, you might consider alternative approaches, such as:

* Using `BigInt` for precise arithmetic operations (e.g., division)
* Implementing a custom loop or iterator for optimal performance
* Utilizing browser-specific optimizations, like SIMD instructions (e.g., SSE or AVX)

Keep in mind that this benchmark test is designed to demonstrate the relative performance of different approaches, so the choice of alternatives would depend on your specific use case and requirements.

Related benchmarks:

divide by 2 vs multiply by 0.5 - 1 (version: 0)

Comparing performance of: div by 2 vs div by 2.0 vs multiply by 0.5 vs bitwise

Created: one year ago by: Guest

Jump to the latest result

div by 2

div by 2.0

multiply by 0.5

bitwise

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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