Benchmark: Math floor vs | vs shift

HTML Preparation code:

var num = 32.4234234;

Tests:

Math.floor
var num = 32.4234234 / 2; Math.floor(num);
Bitwise OR
var num = 32.4234234 / 2; 0 | num;
Bitwise shift
var num = 32.4234234 / 2; num >> 1

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Math.floor
Bitwise OR
Bitwise shift

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36 OPR/96.0.0.0 (Edition Yx 05)

Browser/OS: Opera 96 on Windows

View result in a separate tab

Test name	Executions per second
Math.floor	16744365.0 Ops/sec
Bitwise OR	2195416832.0 Ops/sec
Bitwise shift	2215993856.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the JavaScript benchmarking tool, MeasureThat.net, and analyze the provided benchmark definition.

**Benchmark Overview**

The benchmark compares three different approaches to perform arithmetic operations on a floating-point number:

1. `Math.floor()`: Uses the built-in `floor()` method of the `Math` object.
2. Bitwise OR (`0 | num`): Performs a bitwise OR operation between 0 and the input number, effectively rounding down to the nearest integer.
3. Bitwise shift (`num >> 1`): Shifts the bits of the input number one position to the right, effectively rounding down to the nearest integer.

**Options Comparison**

Here's a comparison of the three approaches:

* **Math.floor()**: This is the most straightforward and efficient method, as it's a built-in function specifically designed for rounding numbers.
* Bitwise OR (`0 | num`): This approach relies on the properties of binary arithmetic to round down. The bitwise OR operation with 0 essentially performs a "masking" trick, where only the integer part of the number is kept.
* Bitwise shift (`num >> 1`): Similar to the bitwise OR approach, this method uses bit manipulation to extract the integer part of the number.

**Pros and Cons**

Here's a brief summary:

* **Math.floor()**: Pros:
	+ Fastest execution time due to being a built-in function.
	+ Most readable code (no special operators or syntax).
	Cons:
	+ Limited flexibility, as it only rounds down.
* Bitwise OR (`0 | num`): Pros:
	+ Can be faster than `Math.floor()` for certain inputs.
	+ No additional library dependencies required.
Cons:
	+ Requires understanding of bitwise arithmetic and its limitations.
	+ May not work correctly with negative numbers or floating-point precision issues.
* Bitwise shift (`num >> 1`): Pros:
	+ Similar to bitwise OR, but may be faster or more efficient in some cases.
Cons:
	+ Limited control over rounding behavior (only shifts the bits).
	+ Requires understanding of binary arithmetic.

**Library and Special JS Features**

The benchmark uses none of these special JS features:

* No external libraries are referenced.
* No advanced JavaScript syntax (e.g., async/await, arrow functions) is used.

**Other Alternatives**

If you need to perform similar rounding operations in your own code, consider using other methods:

1. `Number.EPSILON` for epsilon-based rounding: This involves comparing the difference between two numbers with a small positive value (`Number.EPSILON`) to determine if they are equal.
2. Custom implementation using floating-point arithmetic libraries (e.g., `jsFloat32`): These libraries provide optimized implementations of basic arithmetic operations, including rounding.

Keep in mind that these alternatives might have different performance characteristics and trade-offs compared to the benchmarked approaches.

The MeasureThat.net tool provides a convenient way to compare different approaches and identify potential optimizations for your code. By analyzing the provided benchmark definition and results, you can gain insights into the strengths and weaknesses of each method and make informed decisions about which approach to use in your own projects.

Related benchmarks:

Math floor vs | vs shift (version: 0)

Comparing performance of: Math.floor vs Bitwise OR vs Bitwise shift

Created: 5 years ago by: Guest

Jump to the latest result

Math.floor

Bitwise OR

Bitwise shift

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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