Benchmark: X / (2^n) vs X>>n

Script Preparation code:

//2^3=8
//2^7=128
var a=8,b=1024,c=15;

Tests:

a/8
a/8;
a>>3
a>>3;
b/128
b/128;
b>>7
b>>7;
c>>3&1
c>>3&1;
c/8&1
c/8&1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
a/8
a>>3
b/128
b>>7
c>>3&1
c/8&1

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The benchmarking process involves measuring the execution time of different JavaScript expressions on various browsers.

The provided JSON data defines six individual test cases:

1. `a/8`
2. `a>>3`
3. `b/128`
4. `b>>7`
5. `c>>3&1`
6. `c/8&1`

These test cases compare the execution time of two different JavaScript expressions:

* **Arithmetic Right Shift** (`>>`): performs a bitwise right shift operation on a binary number.
* **Arithmetic Left Division** (`/`): performs a division operation on two numbers.

Each test case measures the execution time of one of these operations using two different expressions. For example, `a/8` and `a>>3` both measure the execution time of left division and right shift, respectively.

**Options Compared**

The benchmark compares the following options:

* **Arithmetic Right Shift (`>>`)** vs **Arithmetic Left Division (`/`)**
* Different exponent values (e.g., `2^3`, `2^7`)
* Different divisor values (e.g., `8`, `128`)

**Pros and Cons of Each Approach**

1. **Arithmetic Right Shift (`>>`)**:
	* Pros: Can be faster for certain binary operations, especially when dealing with large integers.
	* Cons: Can be slower for some decimal operations due to the need for implicit conversions.
2. **Arithmetic Left Division (`/`)**:
	* Pros: Often faster and more readable than right shift operations for decimal calculations.
	* Cons: May be slower for certain binary operations, especially when dealing with large integers.

**Library Used**

In the provided test cases, the `a` and `b` variables are initialized using string literals. These strings are likely representing powers of 2 (e.g., `"8"` is equivalent to `2^3`).

The purpose of initializing these variables is to simplify the benchmarking process by ensuring that the same values are used for both arithmetic left division and right shift operations.

**Special JS Feature**

The test case `c>>3&1` uses a bitwise AND operation (`&`) on the result of the right shift operation. This is an example of using bitwise operators in combination with arithmetic operations to optimize performance.

**Other Alternatives**

MeasureThat.net also allows users to create benchmarks that compare other JavaScript expressions, such as:

* **Arithmetic Multiplication (`*`)** vs **Arithmetic Division (`/`)**
* Different assignment operators (e.g., `=` vs `+=`)
* Different loop constructs (e.g., `for` loops vs `while` loops)

Users can explore these alternative benchmarks to compare the performance of different JavaScript operations and optimize their code accordingly.

Latest run results:

Run details: (Test run date: 8 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.59 Safari/537.36 OPR/41.0.2353.46

Browser/OS: Opera 41 on Windows

View result in a separate tab

Test name	Executions per second
a/8	11270191.0 Ops/sec
a>>3	11078762.0 Ops/sec
b/128	11210658.0 Ops/sec
b>>7	11282474.0 Ops/sec
c>>3&1	11295149.0 Ops/sec
c/8&1	11323736.0 Ops/sec

Related benchmarks:

X / (2^n) vs X>>n (version: 1)

Comparing performance of: a/8 vs a>>3 vs b/128 vs b>>7 vs c>>3&1 vs c/8&1

Created: 8 years ago by: Registered User

Jump to the latest result

a/8

a>>3

b/128

b>>7

c>>3&1

c/8&1

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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