Benchmark: ParseInt vs conditional ~~

Script Preparation code:

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

Tests:

ParseInt
parseInt(num);
Bitwise invert2
~~(num);
Bitwise conditional invert2
num > 2147483648 ? parseInt(num) : ~~(num);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
ParseInt
Bitwise invert2
Bitwise conditional invert2

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year 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	438869824.0 Ops/sec
Bitwise invert2	466688192.0 Ops/sec
Bitwise conditional invert2	411939136.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The test measures the performance of three different approaches to convert an unsigned 32-bit integer (`num`) into a signed integer:

1. `parseInt(num)`
2. Bitwise invert using the tilde operator (`~~` or `Bitwise invert2`)
3. Conditional bitwise invert using the greater-than operator and `parseInt` (`Bitwise conditional invert2`)

**Library and Special JS Features**

* There is no explicit library used in this benchmark.
* The tilde operator (`~`) is a built-in JavaScript operator that performs a bitwise NOT operation on its operand.

**Test Cases**

The test consists of three individual test cases:

1. `ParseInt`: Tests the performance of `parseInt(num)`.
2. `Bitwise invert2`: Tests the performance of `~~(num)`, which uses the tilde operator to perform a bitwise NOT operation.
3. `Bitwise conditional invert2`: Tests the performance of `num > 2147483648 ? parseInt(num) : ~~(num)`, which combines the bitwise NOT operation with a conditional statement.

**Comparison and Performance**

The test compares the performance of these three approaches on different browsers (Firefox 126) running on desktop platforms. The results are:

| Test Name | ExecutionsPerSecond |
| --- | --- |
| Bitwise invert2 | 466,688,192.0 |
| ParseInt | 438,986,824.0 |
| Bitwise conditional invert2 | 411,939,136.0 |

**Analysis**

* The results show that the bitwise NOT operation (`Bitwise invert2`) is the fastest approach, followed closely by `parseInt(num)`. This suggests that the overhead of the conditional statement in `Bitwise conditional invert2` might be significant.
* The use of `parseInt(num)` as a baseline is likely due to its simplicity and widespread usage.

**Pros and Cons**

* **Bitwise invert2 (~~)**:
	+ Pros: Fastest execution time, minimal overhead.
	+ Cons: Might not work correctly for negative numbers or integers outside the range of 32-bit unsigned integers.
* **ParseInt**:
	+ Pros: Simple and widely supported, handles negative numbers and larger integers.
	+ Cons: Might have higher overhead due to its parsing logic.
* **Bitwise conditional invert2**:
	+ Pros: Handles negative numbers and larger integers like `parseInt(num)`, but might have higher overhead due to the conditional statement.

**Alternatives**

If you need to convert an unsigned 32-bit integer into a signed integer, other approaches include:

1. Using the two's complement representation for negative numbers (not implemented in this benchmark).
2. Implementing your own parsing logic using bitwise operations and arithmetic.
3. Utilizing specialized libraries or functions designed for integer conversion.

Keep in mind that the choice of approach depends on the specific requirements and constraints of your project.

Related benchmarks:

ParseInt vs conditional ~~ (version: 0)

ParseInt vs conditional ~~

Comparing performance of: ParseInt vs Bitwise invert2 vs Bitwise conditional invert2

Created: one year ago by: Guest

Jump to the latest result

ParseInt

Bitwise invert2

Bitwise conditional invert2

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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