Benchmark: Bitwise vs String feature flags

Script Preparation code:

var BITWISE_FEATURE_A = 1;
var BITWISE_FEATURE_B = BITWISE_FEATURE_A<<1;
var BITWISE_FEATURE_C = BITWISE_FEATURE_B<<1;
var BITWISE_ENABLED = BITWISE_FEATURE_A ^ BITWISE_FEATURE_C;

var STRING_FEATURE_A = "yellow_scrollbar";
var STRING_FEATURE_B = "green_box";
var STRING_FEATURE_C = "blue_banner";
var STRING_ENABLED = STRING_FEATURE_A + STRING_FEATURE_C;

Tests:

Bitwise - Existing
BITWISE_ENABLED & BITWISE_FEATURE_A == BITWISE_FEATURE_A
Bitwise - Non-Existing
BITWISE_ENABLED & BITWISE_FEATURE_B == BITWISE_FEATURE_B
String - Existing
STRING_ENABLED.indexOf(STRING_FEATURE_C) != -1
String - Non-Existing
STRING_ENABLED.indexOf(STRING_FEATURE_B) != -1

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Bitwise - Existing
Bitwise - Non-Existing
String - Existing
String - Non-Existing

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark measures the performance of bitwise operations (using `<<` and `^`) versus string features in JavaScript.

**Script Preparation Code Analysis**

The script preparation code defines several variables:

* `BITWISE_FEATURE_A`, `BITWISE_FEATURE_B`, and `BITWISE_FEATURE_C`: These are bitwise constants defined using the left shift operator (`<<`). The values of these constants are calculated by shifting `BITWISE_FEATURE_A` to the left by 1, 2, and 3 bits, respectively.
* `BITWISE_ENABLED`: This variable is set to the result of the bitwise XOR operation between `BITWISE_FEATURE_A` and `BITWISE_FEATURE_C`. This operation checks whether a specific bit is set in one of the operands.
* `STRING_FEATURE_A`, `STRING_FEATURE_B`, and `STRING_FEATURE_C`: These are string literals defined using double quotes (`"..."`).
* `STRING_ENABLED`: This variable is set to the concatenation of `STRING_FEATURE_A` and `STRING_FEATURE_C`.

The script preparation code sets up two branches:

1. `BITWISE_ENABLED & BITWISE_FEATURE_A == BITWISE_FEATURE_A`
2. `BITWISE_ENABLED & BITWISE_FEATURE_B == BITWISE_FEATURE_B`

These two branches represent different scenarios: one where the bitwise operation is valid (using `BITWISE_FEATURE_A`), and another where it's not valid (using `BITWISE_FEATURE_B`).

**Test Cases Analysis**

There are four test cases in total:

1. "Bitwise - Existing"
2. "Bitwise - Non-Existing"
3. "String - Existing"
4. "String - Non-Existing"

Each test case defines a specific benchmark definition using the JavaScript `&&` operator, which evaluates to `true` if both operands are truthy.

**Library: String.indexOf()**

The `STRING_ENABLED.indexOf(STRING_FEATURE_C)` function is used in Test Case 3 ("String - Existing"). The `indexOf()` method returns the index of the first occurrence of a specified string within a given array. In this case, it's searching for `STRING_FEATURE_C` (`"blue_banner"`) within the concatenated string `STRING_ENABLED`.

**Special JS Feature/Syntax: None**

There are no special JavaScript features or syntax used in this benchmark.

**Pros and Cons of Different Approaches**

The main difference between the two approaches is whether the bitwise operation is valid or not. Here's a brief analysis:

* **Bitwise Approach**:
	+ Pros:
		- More efficient, as it only checks for specific bit patterns.
	+ Cons:
		- Less readable, as it requires an understanding of bitwise operations and bit manipulation.
* **String Feature Approach**:
	+ Pros:
		- Easier to understand, as it's more focused on string manipulation.
	+ Cons:
		- May be less efficient, as the `indexOf()` method has to search for a specific string within the concatenated string.

**Other Alternatives**

If you were to modify this benchmark to explore different approaches, here are some alternatives:

1. **Using regular expressions**: Instead of using `String.indexOf()`, you could use regular expressions (`RegExp`) to match a specific pattern.
2. **Using bitwise operations with integers**: You could modify the script preparation code to work with integer values instead of bitwise constants.
3. **Using different string concatenation methods**: Instead of using the `+` operator for string concatenation, you could explore other methods like `String.prototype.concat()` or template literals.

These alternatives would allow you to test the performance of different approaches and evaluate their trade-offs in terms of readability, efficiency, and maintainability.

Latest run results:

Run details: (Test run date: 2025 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.119 Safari/537.36

Browser/OS: Chrome 64 on Linux

View result in a separate tab

Test name	Executions per second
Bitwise - Existing	4837638.0 Ops/sec
Bitwise - Non-Existing	4810643.5 Ops/sec
String - Existing	5787751.0 Ops/sec
String - Non-Existing	6091951.0 Ops/sec

Related benchmarks:

Bitwise vs String feature flags (version: 0)

Comparing performance of: Bitwise - Existing vs Bitwise - Non-Existing vs String - Existing vs String - Non-Existing

Created: 6 years ago by: Guest

Jump to the latest result

Bitwise - Existing

Bitwise - Non-Existing

String - Existing

String - Non-Existing

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):