Benchmark: Round float fa - MeasureThat.net

Script Preparation code:

var time = 1223856000000, result;

Tests:

Without die 100
result = ((Date.now() - time) / 315576000)
Double bitwise not with division 100
result = ~~((Date.now() - time) / 315576000) / 100;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Without die 100
Double bitwise not with division 100

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 benchmark and its components to explain what's being tested.

**Benchmark Definition**

The JSON object contains two benchmark definitions:

1. `Round float fa`:
	* This is likely a test case for evaluating the performance of rounding floating-point numbers in JavaScript.
	* The script preparation code creates a timestamp (`time`) and declares a variable `result`.
2. `Double bitwise not with division 100`:
	* This test case seems to evaluate the performance of using bitwise NOT (`~`) on double-precision floating-point numbers, followed by division by 100.

**Comparison Options**

The two benchmark definitions use different approaches:

1. `Round float fa`: This approach involves subtracting the timestamp from the current time in seconds ( converted to milliseconds), dividing the result by a fixed value (315576000, which is approximately the number of seconds in a year), and then using a bitwise AND operation with 0 (to round down) or not performing any operation (i.e., just using the result as is). This test case likely aims to measure the overhead of rounding floating-point numbers.
2. `Double bitwise not with division 100`: In this approach, the timestamp is subtracted from the current time in seconds and then divided by a large value (100). The result is then passed through a bitwise NOT operation (`~`). Finally, the result is divided by another fixed value (100) to measure the overhead of the bitwise NOT operation followed by division.

**Pros and Cons**

1. `Round float fa`:
	* Pros: Simple and focused on a specific aspect of JavaScript performance.
	* Cons: May not accurately represent real-world use cases, which often involve more complex calculations.
2. `Double bitwise not with division 100`:
	* Pros: More representative of real-world scenarios that involve numerical computations and bit operations.
	* Cons: The use of the bitwise NOT operation might lead to compiler optimizations or caching effects that are not relevant to pure arithmetic performance.

**Other Considerations**

The benchmark definition does not mention any specific libraries, special JavaScript features, or syntax beyond what is inherently part of the language. However, it's worth noting that the use of bitwise operations and division can be optimized by the JavaScript engine in various ways (e.g., using SIMD instructions or compiler-specific optimizations).

**Alternative Approaches**

To improve accuracy or gain insights into different performance aspects:

1. **Modify the `Round float fa` test case**: Consider adding more complexity to the arithmetic operation, such as multiplying the result by a large value or involving multiple rounding operations.
2. **Add additional tests**: Include other benchmarks that evaluate the performance of specific JavaScript features or libraries (e.g., for matrix operations, cryptographic functions, or GUI rendering).
3. **Use a variety of inputs and edge cases**: Varying the input values, handling edge cases, or testing different data types can provide more comprehensive insights into the performance characteristics of JavaScript.

Please note that measuring performance in JavaScript is challenging due to various factors like compiler optimizations, caching effects, and platform-specific behaviors.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Firefox/91.0

Browser/OS: Firefox 91 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
Without die 100	6941062.5 Ops/sec
Double bitwise not with division 100	6954968.5 Ops/sec

Related benchmarks:

Round float fa (version: 0)

Comparing performance of: Without die 100 vs Double bitwise not with division 100

Created: 3 years ago by: Guest

Jump to the latest result

Without die 100

Double bitwise not with division 100

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):