Benchmark: Plus equals is slow

Tests:

Plus equals
let x = 0; for (var i=0; i < 1000; i++) { x += 2 + i; }
Plus
let x = 0; for (var i=0; i < 1000; i++) { x = x + 2 + i; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Plus equals
Plus

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

I'll break down the provided JSON data and explain what's being tested, compared, and other considerations.

**Benchmark Definition**

The benchmark definition is a simple JavaScript snippet that demonstrates a specific use case: comparing the performance of two ways to add numbers in a loop. The code defines a variable `x` and increments it by `2 + i` or simply `x + 2 + i` in each iteration of a loop.

**Options Compared**

Two options are being compared:

1. **Plus equals**: This is when the expression `x += 2 + i` is used, which increments `x` directly.
2. **Plus**: This is when the expression `x = x + 2 + i` is used, which assigns a new value to `x`.

**Pros and Cons**

*   **Plus equals**:
    *   Pros: Can be slightly faster because it avoids an extra assignment operation. In some cases, this can lead to a small performance boost.
    *   Cons: May not be immediately clear to developers due to its unusual syntax. This can lead to confusion when debugging or reading the code.
*   **Plus**:
    *   Pros: Easier to read and understand because it uses a more conventional assignment operation (`=`).
    *   Cons: Can be slightly slower than `plus equals` due to the extra assignment.

**Library Usage**

In this benchmark, no libraries are explicitly mentioned or used. However, some JavaScript engines might use optimizations or built-in functions that could affect performance, but these would not be considered "libraries" in the classical sense.

**Special JS Features or Syntax**

There is no special JavaScript feature or syntax being tested in this benchmark. The code uses standard JavaScript syntax and doesn't involve any advanced features like async/await, destructuring, or object methods.

**Other Considerations**

When evaluating performance differences between `plus equals` and `plus`, it's essential to consider the following:

*   **Readability**: While `plus` might be easier to understand due to its more conventional syntax, this comes at a potential cost in terms of readability.
*   **Maintenance**: When using `plus equals`, developers may need to look beyond the initial code snippet to comprehend what's happening. This can make maintenance more difficult if they're not familiar with this particular pattern.

**Alternative Approaches**

If you were to create an alternative benchmark, you might consider testing other ways to add numbers in a loop, such as:

*   **Using `let` and `const`**: You could explore the performance of using different assignment operators or scoping rules for variables.
*   **Native WebAssembly support**: If supported by your JavaScript engine, you could test the performance benefits of compiling code to WebAssembly (WASM) for execution.
*   **Loop optimization techniques**: This might involve testing specific loop optimizations such as loop unrolling, dead code elimination, or register allocation.

Feel free to ask any further questions.

Latest run results:

Run details: (Test run date: 8 years ago)

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.106 Safari/537.36

Browser/OS: Chrome 51 on Windows 7

View result in a separate tab

Test name	Executions per second
Plus equals	433097.3 Ops/sec
Plus	1082441.6 Ops/sec

Related benchmarks:

Plus equals is slow (version: 0)

Why the hell

Comparing performance of: Plus equals vs Plus

Created: 8 years ago by: Guest

Jump to the latest result

Plus equals

Plus

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):