Benchmark: Bitwise vs pow - MeasureThat.net

Tests:

Math.pow
const val = Math.pow(2, 12)
Operand pow
const val = 2 ** 12
Bitwise pow
const val = (1 << 12)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Math.pow
Operand pow
Bitwise pow

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark test cases and explain what's being tested, compared, and considered.

**Benchmark Test Cases**

The test cases compare three different ways to calculate the power of 2 in JavaScript:

1. **`Math.pow(2, 12)`**: This is a built-in JavaScript function that raises 2 to the power of 12.
2. **`2 ** 12`**: This uses the exponentiation operator (`**`) to raise 2 to the power of 12.
3. **`(1 << 12)`**: This uses bitwise shift left (`<<`) to raise 1 (which is equivalent to 2) to the power of 12.

The goal of this benchmark is to determine which method is the fastest, most efficient, and/or most optimal for calculating powers of 2 in JavaScript.

**Comparison Options**

Here's a brief overview of each option:

* **`Math.pow()`**: This is the built-in JavaScript function that raises one number to another power. It uses floating-point arithmetic and is generally slower than other methods.
* **`Operand pow` (`2 ** 12`)**: This uses the exponentiation operator (`**`) to raise a number to a power. The exponentiation operator is typically faster and more efficient than `Math.pow()`, especially for large powers like this one.
* **Bitwise pow (`(1 << 12)`)**: This uses bitwise shift left (`<<`) to raise a number to a power. Bitwise operations are generally very fast, but they can also be less readable and maintainable than other methods.

**Pros and Cons**

Here's a brief summary of the pros and cons for each option:

* **`Math.pow()`**:
	+ Pros: easy to read and understand, widely supported.
	+ Cons: may be slower due to floating-point arithmetic, less efficient for large powers.
* **`Operand pow` (`2 ** 12`)**:
	+ Pros: typically faster and more efficient than `Math.pow()`, more readable than bitwise methods.
	+ Cons: requires exponentiation operator support in JavaScript (not available in older browsers).
* **Bitwise pow (`(1 << 12)`)**:
	+ Pros: extremely fast, good for very large powers or performance-critical code.
	+ Cons: less readable and maintainable due to the use of bitwise operations.

**Library Considerations**

There is no library mentioned in the benchmark definition. However, if a library were used, it might provide additional functionality or optimization for calculating powers of 2.

**Special JS Features or Syntax**

None of the test cases use any special JavaScript features or syntax beyond what's already described above (i.e., exponentiation operator and bitwise shift left).

**Other Alternatives**

Here are some alternative methods that could be used to calculate powers of 2:

* **`Math.log2()`**: This function returns the base-2 logarithm of a number, which can be used to calculate powers of 2 using integer arithmetic.
* **`((1 << x) | (1 << x) - 1)`**: This uses bitwise operations to create a power of 2 by shifting left and subtracting 1.

Keep in mind that these alternatives might not provide the same performance benefits as the methods tested above, but they could be used in specific scenarios or for educational purposes.

Latest run results:

Run details: (Test run date: 11 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
Math.pow	2591437.0 Ops/sec
Operand pow	32986822.0 Ops/sec
Bitwise pow	33926440.0 Ops/sec

Related benchmarks:

Bitwise vs pow (version: 0)

Comparing performance of: Math.pow vs Operand pow vs Bitwise pow

Created: one year ago by: Guest

Jump to the latest result

Math.pow

Operand pow

Bitwise pow

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):