Benchmark: Negate Number - MeasureThat.net

Script Preparation code:

var x = -42.42;
var y;

Tests:

Multiply by -1
y = -x
Math.abs
y = Math.abs(x)
Bitwise NOT plus addition
y = ~x + 1

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Multiply by -1
Math.abs
Bitwise NOT plus addition

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

The provided JSON represents a benchmark named "Negate Number" and contains three test cases:

**Benchmark Definition:**

* The script preparation code is `var x = -42.42; var y;`, which initializes two variables, `x` with the value `-42.42` and `y` as an uninitialized variable.
* The HTML preparation code is empty (`null`).

This setup creates a simple scenario where we can test various operations on `x` and compare their performance.

**Test Cases:**

The three test cases are defined in the "Individual test cases" section:

1. **Multiply by -1**: This test case uses the bitwise NOT operator (~) to negate `x`, then multiplies the result by -1.
2. **Math.abs**: This test case uses the built-in Math.abs() function to calculate the absolute value of `x`.
3. **Bitwise NOT plus addition**: This test case uses the bitwise NOT operator (~) to negate `x`, then adds 1 to the result.

**Options Compared:**

The benchmark compares three different approaches:

* **Bitwise NOT plus addition** (Test Case 2): Uses the bitwise NOT operator to negate `x` and then adds 1 to the result.
* **Multiply by -1** (Test Case 1): Uses the multiplication operator (*) to multiply `x` by -1.
* **Math.abs** (Test Case 2): Uses the built-in Math.abs() function to calculate the absolute value of `x`.

**Pros and Cons:**

Here's a brief summary of each approach:

* **Bitwise NOT plus addition**:
	+ Pros: Can be faster than using multiplication or Math.abs(), as it avoids a function call.
	+ Cons: May not be as readable or maintainable, especially for developers without knowledge of bitwise operations.
* **Multiply by -1**:
	+ Pros: Easy to understand and implement, as it's a simple multiplication operation.
	+ Cons: Can be slower than using bitwise NOT plus addition or Math.abs(), due to the extra multiplication step.
* **Math.abs**:
	+ Pros: Fast, readable, and maintainable, as it's a built-in function that performs an efficient calculation.
	+ Cons: May have overhead due to the function call.

**Library:**

None of these test cases rely on any external libraries. However, some modern JavaScript engines may use internal optimizations or specializations for certain functions, like Math.abs(), which can affect performance.

**Special JS Features/Syntax:**

None of the test cases rely on specific JavaScript features or syntax beyond basic arithmetic operations and bitwise NOT. The only notable feature is the use of the bitwise NOT operator (~), but even that is a standard operation in many programming languages.

**Other Alternatives:**

If you were to create an alternative benchmark for these test cases, you could consider adding more complexity to `x` or introducing additional variables to make the calculations more challenging. Some ideas include:

* Using larger or smaller values for `x`.
* Introducing additional operations, such as divisions or comparisons.
* Using different types of data structures (e.g., arrays or objects) in the test cases.

Keep in mind that the goal of a benchmark is to compare performance across different approaches, so it's essential to carefully design and execute your tests to ensure accurate results.

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/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Windows

View result in a separate tab

Test name	Executions per second
Multiply by -1	8425013.0 Ops/sec
Math.abs	4650216.0 Ops/sec
Bitwise NOT plus addition	8709693.0 Ops/sec

Related benchmarks:

Negate Number (version: 0)

Comparing performance of: Multiply by -1 vs Math.abs vs Bitwise NOT plus addition

Created: one year ago by: Guest

Jump to the latest result

Multiply by -1

Math.abs

Bitwise NOT plus addition

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):