Benchmark: bit shift vs divide by 2

Script Preparation code:

digit = 100

Tests:

bit shift
100 >> 1
divide
100 / 2

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
bit shift
divide

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 134 on Android

View result in a separate tab

Test name	Executions per second
bit shift	126588216.0 Ops/sec
divide	126591872.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Overview**

The provided JSON represents a simple benchmark that compares two approaches to perform a specific operation: shifting bits versus dividing by 2.

**Tested Operations**

In this benchmark, we have two test cases:

1. `100 >> 1` (Bit Shift): This operation shifts the binary representation of the number 100 one position to the right, effectively dividing it by 2.
2. `100 / 2` (Divide by 2): This operation divides the number 100 by 2.

**Comparison Options**

The benchmark compares two options:

1. **Bit Shift**: Shifting bits is a CPU-based approach that uses bitwise operations to achieve division by 2. It's often faster than using division, as it requires fewer arithmetic operations.
2. **Divide by 2**: Using the `/` operator is a more traditional JavaScript approach that performs division directly.

**Pros and Cons**

Here are the pros and cons of each approach:

* **Bit Shift**:
	+ Pros: Often faster due to lower overhead, can be optimized for specific CPU architectures.
	+ Cons: May not work correctly for negative numbers or non-integer values, requires explicit handling of integer overflow.
* **Divide by 2**:
	+ Pros: Works with all numeric types, including floats and decimals, no need to worry about integer overflow.
	+ Cons: Generally slower due to increased arithmetic complexity.

**Library Usage**

In this benchmark, there is no explicit library usage. However, the `>>` operator used in the `bit shift` test case uses a bitwise operation, which relies on the JavaScript engine's implementation of binary operations.

**Special JS Features/Syntax**

There are no special JavaScript features or syntax used in this benchmark that aren't part of standard JavaScript.

**Other Considerations**

When building benchmarks like this one, it's essential to consider factors such as:

* **Test case size**: Larger numbers may benefit from different approaches.
* **Floating-point vs integer arithmetic**: Benchmarking floating-point operations can be more complex due to the inherent imprecision in these calculations.
* **Multi-threading and parallelism**: Modern CPUs often have multiple cores, which can lead to performance differences between single-core and multi-core benchmarks.

**Alternative Approaches**

If you want to explore alternative approaches for this benchmark, consider:

* **Arithmetic libraries**: Use specialized arithmetic libraries like `fastmath` or `arbitrary-precision arithmetic` libraries for more accurate results.
* **GPU acceleration**: Utilize the GPU's computational capabilities using WebGPU or WebGL to accelerate certain operations.

For a more in-depth exploration of JavaScript performance optimization and benchmarking, I recommend checking out resources like the Mozilla Developer Network (MDN) Performance Guide or books on web performance optimization.

Related benchmarks:

bit shift vs divide by 2 (version: 0)

Comparing performance of: bit shift vs divide

Created: one year ago by: Guest

Jump to the latest result

bit shift

divide

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):