Benchmark: for-loop cached variables / access caching

Script Preparation code:

var arr = [31,12321,213,21321,321321,321321,1];
var processFunc = a => a + 1;

Tests:

caching variable (for global)
for (let i = arr.length, tmp; i--;) { processFunc(tmp = arr[i]); processFunc(tmp); processFunc(tmp); };
single access cache
for (let i = arr.length; i--;) { let tmp = arr[i]; processFunc(tmp); processFunc(tmp); processFunc(tmp); };
zero cache - 3x access
for (let i = arr.length; i--;) { processFunc(arr[i]); processFunc(arr[i]); processFunc(arr[i]); };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
caching variable (for global)
single access cache
zero cache - 3x access

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 15_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.5 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 15 on iOS 15.5

View result in a separate tab

Test name	Executions per second
caching variable (for global)	113254.6 Ops/sec
single access cache	110179.3 Ops/sec
zero cache - 3x access	71260.4 Ops/sec

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

LLMs can make mistakes. Check important info.

The provided JSON represents a JavaScript microbenchmark test case on MeasureThat.net. The benchmark measures the performance of different caching strategies for accessing and modifying variables in a loop.

**Benchmark Definition**

The benchmark definition consists of three test cases:

1. "caching variable (for global)": In this approach, the `tmp` variable is declared outside the loop and assigned a value from the array on each iteration.
2. "single access cache": In this approach, a new local variable `tmp` is declared inside the loop and assigned a value from the array on each iteration.
3. "zero cache - 3x access": This is the baseline case where the function `processFunc` is called three times with the same argument (`arr[i]`) without any caching.

**Options Compared**

The benchmark compares the performance of these three approaches:

* Caching variables outside the loop (global scope)
* Single access caching inside the loop
* Zero caching with multiple accesses

**Pros and Cons of Each Approach**

1. **Caching variables outside the loop (global scope)**:
	* Pros: Can potentially improve performance by reusing values stored in a variable.
	* Cons: May lead to memory leaks if not managed properly, and can be slower due to the overhead of accessing global variables.
2. **Single access caching inside the loop**:
	* Pros: Reduces the number of function calls and accesses to `arr[i]`, which can improve performance.
	* Cons: Requires more memory for local variables, and may not be suitable for large datasets or complex data structures.
3. **Zero cache - 3x access**:
	* Pros: Provides a baseline measure for comparison and helps identify any potential bottlenecks in the code.
	* Cons: Inefficient use of resources due to repeated accesses to `arr[i]`.

**Library Usage**

The benchmark does not explicitly mention using any libraries, but it's worth noting that MeasureThat.net likely uses some internal library or framework to manage the benchmarking process.

**Special JS Features/Syntax**

This benchmark does not explicitly use any special JavaScript features or syntax. However, it's worth mentioning that the `let` keyword is used for variable declarations in the "single access cache" approach, which is a feature introduced in ECMAScript 2015 (ES6).

Related benchmarks:

for-loop cached variables / access caching (version: 0)

Comparing performance of: caching variable (for global) vs single access cache vs zero cache - 3x access

Created: 2 years ago by: Guest

Jump to the latest result

caching variable (for global)

single access cache

zero cache - 3x access

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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