Benchmark: Math.floor vs alternatives

Script Preparation code:

this.numA = Math.random() * 100;

Tests:

Math.floor
return Math.floor(this.numA);
Bitwise
return ~~this.numA;

Historical Performance Data aggregated from 25 community runs

Desktop Results:

Chrome 19 runs

Bitwise

67.2M/s

Math.floor

31.8M/s

Fastest: Bitwise (2.1x faster)

View exact numbers

✓ Bitwise: 67,208,808 ops/sec
• Math.floor: 31,767,204 ops/sec

Firefox 6 runs

Bitwise

630.8M/s

Math.floor

58.9M/s

Fastest: Bitwise (10.7x faster)

View exact numbers

✓ Bitwise: 630,804,608 ops/sec
• Math.floor: 58,889,524 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Math.floor
Bitwise

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36 Edg/151.0.0.0

Browser/OS: Chrome 151 on Windows

View result in a separate tab

Math.floor

196.3M/s

Bitwise

190.6M/s

View exact numbers

Test name	Executions per second
✓ Math.floor	196,273,344 Ops/sec
Bitwise	190,635,584 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases.

**Benchmark Overview**

The benchmark compares three approaches for rounding a floating-point number to the nearest integer: `Math.floor`, bitwise shift (`~~`), and other alternatives (not explicitly listed in the provided JSON).

**Script Preparation Code**

The script preparation code sets a random value between 0 and 100 for the variable `numA`.

**Html Preparation Code**

There is no HTML preparation code provided, which means that the test is focused solely on the JavaScript code.

**Individual Test Cases**

There are two individual test cases:

1. **`Math.floor`**: This test case measures the execution time of using the `Math.floor()` function to round down a floating-point number.
2. **`Bitwise`**: This test case measures the execution time of using the bitwise shift operator (`~~`) to round down a floating-point number.

**Pros and Cons**

* **`Math.floor`**:
	+ Pros: Widely supported, simple to understand, and efficient in most cases.
	+ Cons: Can be slower than bitwise shift for very large numbers due to the overhead of the `Math.floor()` function.
* **`Bitwise`**:
	+ Pros: Can be faster than `Math.floor` for very large numbers since it uses a simple bitwise operation.
	+ Cons: Less intuitive and may require more code to implement correctly.

Other alternatives are not explicitly mentioned in the provided JSON, but some common alternatives to `Math.floor()` include:

* **`-Math.ceil(num) + 1`**: This approach converts the number to its ceiling value using `Math.ceil()`, subtracts 1 to round down, and then casts it back to an integer.
* **`Number(num)`**: This approach simply converts the floating-point number to a decimal number using the `Number()` function.

**Library**

None of the test cases explicitly use any libraries. However, some JavaScript engines (like V8 in Chrome) may have built-in optimizations or implementations for these functions that could potentially affect the benchmark results.

**Special JS Feature/Syntax**

The benchmark does not specifically target any special JavaScript features or syntax beyond the basic rounding operators used.

**Other Considerations**

* The use of `~~` instead of `-Math.ceil(num) + 1` is an interesting choice, as it leverages a low-level bitwise operation that may be faster but less intuitive.
* The benchmark does not account for precision issues when working with very large or small numbers. In such cases, the choice of rounding method may have significant implications for accuracy and stability.

**Alternatives**

If you wanted to add additional alternatives to this benchmark, some options could include:

* Using a specialized library like `decimal.js` that provides decimal arithmetic operations.
* Implementing custom rounding algorithms using assembly language or other low-level languages (if you're targeting a specific platform).
* Comparing the performance of different CPU instructions for rounding numbers (e.g., using SIMD instructions).

Keep in mind that this is just one possible set of alternatives, and there are many other approaches depending on your specific requirements and use case.

Math.floor vs alternatives (version: 0) Benchmark.js

Comparing performance of: `Math.floor vs Bitwise`

Created: 5 years ago by: Registered User

Go to the latest result

Math.floor

Bitwise

Historical Performance Data aggregated from 25 community runs

Desktop Results:

Chrome 19 runs

Firefox 6 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Math.floor vs alternatives (version: 0) Benchmark.js

Comparing performance of: Math.floor vs Bitwise

Created: 5 years ago by: Registered User

Go to the latest result

Math.floor

Bitwise

Historical Performance Data aggregated from 25 community runs

Desktop Results:

Chrome 19 runs

Firefox 6 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `Math.floor vs Bitwise`