Benchmark: Math.imul vs regular multiplication

Script Preparation code:

var x = 0x12345678;
var y;

Tests:

Math.imul
for (var i = 0; i < 10000; ++i) { y = Math.imul(x, i); }
Regular multiplication
for (var i = 0; i < 10000; ++i) { y = x * i; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Math.imul
Regular multiplication

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 days ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.7.2 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 18 on iOS 18.7

View result in a separate tab

Test name	Executions per second
Math.imul	154825.3 Ops/sec
Regular multiplication	282815.9 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is being tested?**

The provided benchmark compares two approaches to perform multiplication:

1. `Math.imul(x, y)` (also known as "bitwise multiplication" or "integer multiplication")
2. Regular multiplication using the `*` operator (`x * y`)

These tests aim to determine which approach is faster and more efficient for large integer multiplication.

**Options compared:**

Two options are being compared:

1. **Bitwise multiplication**: This method uses bitwise operations to multiply two integers, which can be more efficient than regular arithmetic operations.
2. **Regular multiplication**: This method uses the `*` operator, which performs traditional arithmetic multiplication.

**Pros and Cons:**

**Bitwise multiplication (Math.imul)**

Pros:

* Can be faster for large integer values due to bitwise operations
* May use fewer CPU cycles

Cons:

* More complex and harder to understand
* Not directly equivalent to regular multiplication in all cases

Regular multiplication (`x * y`)

Pros:

* Easier to understand and implement
* More straightforward to use

Cons:

* May be slower for large integer values due to arithmetic operations
* Can lead to overflow issues with very large integers

**Other considerations:**

When using bitwise multiplication, it's essential to ensure that the inputs are properly aligned in memory, as misalignment can lead to incorrect results.

In contrast, regular multiplication is generally more straightforward and easier to debug, but may be less efficient for very large integers.

**Library usage:**

There is no explicit library used in this benchmark. However, if we were to extend this test to include libraries like `BigInt` (introduced in ECMAScript 2020), bitwise multiplication would likely still outperform regular multiplication due to its inherent efficiency advantages.

**Special JavaScript features or syntax:**

None of the provided test cases rely on special JavaScript features or syntax that require explanation.

**Alternative approaches:**

Other alternatives for large integer multiplication could include:

* **Recursive multiplication**: This approach uses recursive function calls to multiply two integers. While it can be more intuitive, it's often slower than bitwise multiplication due to the overhead of recursive calls.
* **Sieve of Eratosthenes**: For very large integers, this algorithm uses a sieve-based approach to find prime factors and calculate the product. It's typically used for cryptographic purposes rather than general-purpose arithmetic.

Keep in mind that these alternatives might not be as efficient or practical for everyday JavaScript use cases, but they can be interesting exercises for those interested in exploring advanced algorithms.

Related benchmarks:

Math.imul vs regular multiplication (version: 0)

Comparing performance of: Math.imul vs Regular multiplication

Created: 3 years ago by: Guest

Jump to the latest result

Math.imul

Regular multiplication

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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