Benchmark: Math.ceil() vs. 0 bitshift

Script Preparation code:

var someFloat = 127.323542;

Tests:

Math.ceil()
Math.ceil(someFloat)
0 bitshift
someFloat >> 0

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Math.ceil()
0 bitshift

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36

Browser/OS: Chrome 132 on Windows

View result in a separate tab

Test name	Executions per second
Math.ceil()	194013408.0 Ops/sec
0 bitshift	216025056.0 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 Definition**

The provided JSON represents a benchmark definition, which consists of two main components:

1. **Script Preparation Code**: This code is executed before running each test case. In this case, it sets a variable `someFloat` to a specific value, 127.323542.
2. **Html Preparation Code**: There is no HTML preparation code provided.

**Individual Test Cases**

There are two individual test cases:

1. **Math.ceil() vs. 0 bitshift**
	* This benchmark compares the performance of two different approaches to round up a floating-point number:
		+ `Math.ceil(someFloat)`: Using the built-in `Math.ceil()` method.
		+ `someFloat >> 0` (0 bit shift): Performing a bitwise right shift operation on `someFloat`, which effectively rounds down and then rounds up due to the nature of two's complement representation in binary. To achieve the same effect as `Math.ceil()`, a left shift operation followed by another bitwise right shift would be needed, but 0 bit shift is used instead.
2. **Test Name**: Each test case has a unique name: "Math.ceil()" and "0 bitshift".

**Options Compared**

The two options being compared are:

* `Math.ceil(someFloat)`: The built-in method to round up a floating-point number.
* `someFloat >> 0` (0 bit shift): A bitwise operation that effectively rounds down and then rounds up.

**Pros and Cons of Each Approach**

1. **Math.ceil(someFloat)**:
	* Pros: Fast, easy to read, and widely supported.
	* Cons: May not be optimized for performance in every JavaScript engine or platform.
2. **someFloat >> 0 (0 bit shift)**:
	* Pros: Can potentially be faster than the built-in `Math.ceil()` method, as it bypasses the overhead of a function call.
	* Cons: Requires careful consideration of the bitwise operation's effects on the binary representation of floating-point numbers and can be less intuitive to understand.

**Library Usage**

None of the provided test cases use any external libraries. However, it is worth noting that some JavaScript engines or platforms might have built-in optimizations for certain operations, which could affect the performance differences between these two approaches.

**Special JS Feature or Syntax**

The `>>` operator (bit shift) and its effects on binary representation are specific to bitwise operations in JavaScript. This feature allows performing arithmetic operations using shifts instead of multiplication/division. While not unique to this benchmark, understanding bitwise operations is essential for optimizing performance-critical code.

**Other Alternatives**

If you want to explore alternative approaches or optimizations for rounding up floating-point numbers, consider the following:

* Using a binary search approach with logarithmic scaling.
* Employing SIMD (Single Instruction, Multiple Data) instructions, if available on your target platform.
* Investigating custom implementations using assembly language or low-level memory manipulation.

Keep in mind that these alternatives might not be as straightforward to implement or understand as the built-in `Math.ceil()` method.

Related benchmarks:

Math.ceil() vs. 0 bitshift (version: 0)

Comparing performance of: Math.ceil() vs 0 bitshift

Created: 2 years ago by: Guest

Jump to the latest result

Math.ceil()

0 bitshift

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):