Benchmark: Math.floor vs bitwise <<

Tests:

Math.floor
var x = Math.random() * 100; x = Math.floor(x);
Bitwise
var x = Math.random() * 100; x = x << 0;

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: 10 months ago)

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 138 on Android

View result in a separate tab

Test name	Executions per second
Math.floor	36154284.0 Ops/sec
Bitwise	36132896.0 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 JSON and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark definition is essentially a piece of code that tests two different approaches to rounding down a random number between 0 and 100. The two approaches are:

1. **Math.floor**: This function returns the largest integer less than or equal to the input value.
2. **Bitwise shift**: This approach uses the left shift operator (`<<`) to effectively multiply the number by 2, which then allows for a bitwise right shift operation (`>>`) to truncate the decimal part and obtain the rounded-down integer.

**Script Preparation Code**

There is no script preparation code provided in this benchmark definition. However, it's worth noting that typically, some setup or initialization code would be included here to ensure consistent results across different browsers and devices.

**Html Preparation Code**

Similarly, there is no HTML preparation code provided in this benchmark definition. This might suggest that the testing framework assumes a clean slate and doesn't require any specific HTML environment for the tests to run.

**Individual Test Cases**

The two test cases are:

1. **Math.floor**: Tests the use of `Math.floor` to round down a random number.
2. **Bitwise**: Tests the bitwise shift approach to achieve the same rounding effect.

**Library and Purpose**

There is no explicit library mentioned in this benchmark definition. However, it's likely that the testing framework uses some underlying JavaScript libraries or APIs to execute the tests and provide results.

**Special JS Feature or Syntax**

The only notable feature here is the use of bitwise shift operators (`<<` and `>>`) to achieve rounding down a number. While not unique to JavaScript, this approach can be less straightforward to read and maintain compared to using `Math.floor`.

**Pros and Cons**

Here's a brief summary:

* **Math.floor**:
	+ Pros: Widely supported across browsers and devices, easy to understand and implement.
	+ Cons: May have performance implications due to the need for an additional mathematical operation.
* **Bitwise shift**:
	+ Pros: Can be faster than `Math.floor` in some cases (e.g., when dealing with very large numbers).
	+ Cons: Less readable and maintainable, relies on specific bitwise operations that might not be immediately apparent.

**Other Alternatives**

Some other alternatives for achieving rounding down a number include:

* Using `Number.EPSILON` to check for very small values and add 0 if necessary.
* Employing approximations or heuristics based on the expected range of input values.
* Utilizing specialized libraries or functions optimized for performance.

Keep in mind that these alternatives might not be as straightforward or widely supported as using `Math.floor`.

**Test User Considerations**

When running this benchmark, test users should consider factors like:

* Browser and device support: How well does each approach perform across different browsers and devices?
* Performance implications: Are there any significant performance differences between the two approaches?
* Readability and maintainability: Which approach is more readable and easier to understand for future developers?

By considering these factors, test users can gain a deeper understanding of the strengths and weaknesses of each approach.

Related benchmarks:

Math.floor vs bitwise << (version: 0)

Comparing performance of: Math.floor vs Bitwise

Created: 8 years ago by: Registered User

Jump to the latest result

Math.floor

Bitwise

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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