Benchmark: ParseInt vs conditional ~~ vs toFixed

Script Preparation code:

var num = Math.random() * 2^32;

Tests:

ParseInt
parseInt(num);
Bitwise invert2
~~(num);
Bitwise conditional invert2
num > 2147483648 ? parseInt(num) : ~~(num);
Number.toFixed
num.toFixed(0);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
ParseInt
Bitwise invert2
Bitwise conditional invert2
Number.toFixed

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 provided benchmark.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark compares different approaches for parsing an integer value, specifically `parseInt`, bitwise invert (`~~`), conditional bitwise invert with `parseInt` or `~~`, and `toFixed`.

**Script Preparation Code**

The script preparation code generates a random integer `num` within the range of 32-bit signed integers (i.e., `-2147483648` to `2147483647`). This value is used for all test cases.

**Individual Test Cases**

There are four test cases:

1. **ParseInt**: Measures the execution time of `parseInt(num)`.
2. **Bitwise invert2**: Measures the execution time of `~~(num)`, which performs a bitwise invert operation on the unsigned integer representation of `num`.
3. **Bitwise conditional invert2**: Measures the execution time of `(num > 2147483648 ? parseInt(num) : ~~(num))`. This test case conditionally applies `parseInt` or `~~` based on whether `num` is greater than the maximum value of a 32-bit signed integer.
4. **Number.toFixed**: Measures the execution time of `num.toFixed(0)`.

**Library and Special Features**

*   The only library used in this benchmark is `Math`, which provides mathematical functions such as `parseInt`, `~~`, and `toFixed`.
*   There are no special JavaScript features or syntaxes used in this benchmark, apart from bitwise operations (`~`).

**Approach Comparison**

The four test cases compare different approaches to parsing an integer value:

*   **ParseInt**: Uses the built-in `parseInt` function to parse the integer value. This approach is straightforward but may involve additional overhead due to function calls.
*   **Bitwise invert2**: Utilizes bitwise operations (`~~`) to convert the signed integer representation of `num` to its unsigned equivalent, and then inverts it. This approach can be faster than using `parseInt`, as it avoids function call overhead.
*   **Bitwise conditional invert2**: Conditionally applies either `parseInt` or `~~` based on whether the value exceeds the maximum 32-bit signed integer. This approach allows for a trade-off between performance and readability, depending on the specific use case.
*   **Number.toFixed**: Uses the built-in `toFixed` method to convert `num` to a string with a specified number of decimal places. While this approach is not primarily focused on parsing an integer value, it still involves conversion and formatting operations.

**Pros and Cons**

Here are some pros and cons associated with each approach:

*   **ParseInt**: Pros - straightforward and easy to understand; Cons - may incur additional overhead due to function calls.
*   **Bitwise invert2**: Pros - potentially faster than `parseInt` due to reduced function call overhead; Cons - requires understanding of bitwise operations and signed/unsigned integer representations.
*   **Bitwise conditional invert2**: Pros - allows for trade-off between performance and readability; Cons - may require additional mental processing for the conditional statement.
*   **Number.toFixed**: Pros - straightforward and easy to understand; Cons - not optimized for parsing integer values.

**Other Alternatives**

Other alternatives could include:

*   Using `Number()` instead of `parseInt` or `~~`, as it converts strings to numbers without specifying a radix.
*   Utilizing bitwise operations with other data types, such as characters or booleans, which might be faster than using functions like `parseInt` or `~~`.
*   Considering the use of assembly language or native code for benchmarking performance-critical code paths.

However, keep in mind that these alternatives may not be supported across all browsers or platforms and could add complexity to the benchmark.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:126.0) Gecko/20100101 Firefox/126.0

Browser/OS: Firefox 126 on Ubuntu

View result in a separate tab

Test name	Executions per second
ParseInt	617981504.0 Ops/sec
Bitwise invert2	572627648.0 Ops/sec
Bitwise conditional invert2	500059936.0 Ops/sec
Number.toFixed	15107920.0 Ops/sec

Related benchmarks:

ParseInt vs conditional ~~ vs toFixed (version: 0)

ParseInt vs conditional ~~

Comparing performance of: ParseInt vs Bitwise invert2 vs Bitwise conditional invert2 vs Number.toFixed

Created: one month ago by: Guest

Jump to the latest result

ParseInt

Bitwise invert2

Bitwise conditional invert2

Number.toFixed

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):