Benchmark: branchlessoffsetbyarrayfunctionbutnot

Script Preparation code:

var array = [function(e) {return e ** 2}, function(e) {return e ^ e}];
function option1(e) {return e ** 2}
function option2(e) {return e ^ e}
function a(a, b, c) {
  if(a < b) {
    return option1(c);
  } else return option2(c);
}
function b(a, b, c) {
  return array[(b < a) * 1](c);
}

Tests:

branch
a(10, 5, 100);
branchless
b(10, 5, 100)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
branch
branchless

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 benchmark and explain what's being tested, compared, and discussed.

**Benchmark Definition**

The JSON object represents a JavaScript microbenchmark named `branchlessoffsetbyarrayfunctionbutnot`. The description is "smth" (which seems to be placeholder text), but it doesn't provide any meaningful information about the benchmark. However, the script preparation code provides insight into what's being tested.

**Script Preparation Code**

The script preparation code defines:

1. An array `array` containing two functions: `e ** 2` and `e ^ e`.
2. Two functions `option1` and `option2`, which are used as alternatives for a condition in the main function.
3. A main function `a(a, b, c)` that takes three arguments: `a`, `b`, and `c`. This function uses the condition `(a < b)` to choose between `option1` and `option2`, applying the result to `c`.
4. Another function `b(a, b, c)` that uses a conditional expression to select one of the array elements based on the condition `(b < a) * 1`. The selected element is then applied to `c`.

**Comparison**

The benchmark compares two approaches:

1. **Branching**: This approach uses an `if` statement with a condition `a < b`, which involves branching (jumping to different code paths). The branch is used to choose between `option1` and `option2`.
2. **Branchless**: This approach avoids branching by using a conditional expression `(b < a) * 1` in the function `b(a, b, c)`. This allows the compiler or interpreter to eliminate the branch, potentially resulting in faster execution.

**Pros and Cons**

**Branching (a)**

Pros:

* Easy to understand and implement
* Suitable for simple cases

Cons:

* May lead to slower execution due to branching
* Compiler/Interpreter optimizations may not be effective

**Branchless (b)**

Pros:

* Potentially faster execution by avoiding branching
* Can benefit from compiler/interpreter optimizations

Cons:

* More complex and harder to understand, especially for beginners
* May require more careful consideration of conditional expressions

**Other Considerations**

1. **Variable Ordering**: The order of variables in the `if` statement can affect performance, as some compilers/interpreters may optimize for certain orders.
2. **Dead Code Elimination**: Modern compilers and interpreters often perform dead code elimination, which removes unreachable code to improve execution speed. This might impact the branching vs. branchless comparison.

**Library and Special JS Features**

The benchmark uses a feature in JavaScript called "conditional expressions" (also known as ternary operators). The `b` function uses this feature to select one of the array elements based on a condition. No libraries are explicitly mentioned, but modern JavaScript engines often include optimizations and features like dead code elimination.

**Alternatives**

If you're interested in comparing branching vs. branchless approaches, you can explore other microbenchmarks that test similar scenarios. Some examples might include:

1. MicroBench: A benchmarking framework for JavaScript that allows you to create custom benchmarks.
2. JSPerf: A popular online tool for testing and comparing the performance of different JavaScript code snippets.
3. Benchmark.js: A lightweight library for measuring the execution time of JavaScript code.

These alternatives can provide more flexibility and options for exploring branchless vs. branching approaches, as well as other aspects of JavaScript performance optimization.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.5060.114 Safari/537.36 Edg/103.0.1264.49

Browser/OS: Chrome 103 on Windows

View result in a separate tab

Test name	Executions per second
branch	5566383.5 Ops/sec
branchless	5548674.0 Ops/sec

Related benchmarks:

branchlessoffsetbyarrayfunctionbutnot (version: 0)

smth

Comparing performance of: branch vs branchless

Created: 2 years ago by: Guest

Jump to the latest result

branch

branchless

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):