Benchmark: Jump table vs switch case

Tests:

switch case
function thing(j) { switch(j) { case 0: return "rah"; case 1: return "lah"; case 2: return "sah"; case 3: return "blah"; } } for(let i = 0; i < 100000; i++) { for(let j = 0; thing(j) != "blah"; j++) { } }
jump table
let jumpTable = ["rah", "lah", "sah", "blah"]; for(let i = 0; i < 100000; i++) { for(let j = 0; jumpTable[j] != "blah"; j++) { } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
switch case
jump table

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark and the options being compared.

**Benchmark Overview**

The benchmark is comparing two approaches to handle different cases: Jump Table vs Switch Case.

**Options Being Compared**

1. **Switch Case**: This approach uses the `switch` statement with multiple `case` statements to determine which branch to execute.
2. **Jump Table**: This approach uses an array (jump table) to map values to their corresponding branches.

**Pros and Cons of Each Approach**

### Switch Case

Pros:

* Easy to understand and implement, especially for simple cases.
* Can be optimized using techniques like "switch-case with jump tables" or "goto-free switch".

Cons:

* Slow performance due to the overhead of parsing and executing multiple `case` statements.
* May lead to slower performance if the number of cases is large.

### Jump Table

Pros:

* Fast performance since it relies on array lookups, which are typically faster than function calls or jumps.

Cons:

* Can be harder to understand and implement, especially for complex cases.
* May require additional memory for the jump table.

**Library Usage**

In this benchmark, the `switch` statement is a built-in JavaScript feature. No libraries are used.

**Special JS Feature/Syntax**

There's no special JavaScript feature or syntax being tested in this benchmark.

**Other Considerations**

When choosing between these two approaches, consider the following factors:

* Code readability and maintainability: Switch case might be easier to understand for simple cases.
* Performance: Jump table is likely to outperform switch case due to its faster lookup times.
* Complexity: If you have a large number of cases, jump table might be more suitable.

**Alternatives**

If you're interested in exploring alternative approaches, consider the following:

* **Arrays and Array Methods**: You can use arrays to map values to their corresponding branches, which could potentially outperform both switch case and jump table.
* **Computed Properties**: In modern JavaScript, you can define computed properties on objects using the `get` method, which might provide a performance boost over traditional switch cases.
* **Native WebAssembly (WASM)**: If you're targeting specific hardware or have control over the execution environment, you might consider using WASM to execute optimized bytecode for your use case.

Keep in mind that the best approach depends on the specific requirements of your project and the characteristics of your data.

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/116.0.0.0 Safari/537.36

Browser/OS: Chrome 116 on Windows

View result in a separate tab

Test name	Executions per second
switch case	1241.9 Ops/sec
jump table	2393.9 Ops/sec

Related benchmarks:

Jump table vs switch case (version: 0)

Comparing performance of: switch case vs jump table

Created: one year ago by: Guest

Jump to the latest result

switch case

jump table

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):