Hello guys and welcome to new post about Bit Shifting in low level programming .
Bit Shifting
Bit shifting is a the fastest way to multiply or divide a number by a power of 2 and used heavily in low level programming and cryptography.
For example we want to multiply the number 16 by 2, fisrt we need to convert the number 16 to binary which is 00010000 and then we need to shift the bits to the left by 1 which is 00100000 and then we need to convert the binary back to decimal which is 32.
Multiplication
To multiply a number by a power of 2, shift the bits to the left 2 times.
let x = 5;
let y = x << 2; // 5 * 2^2 = 20
Division
To divide a number by a power of 2, shift the bits to the right 2 times.
let x = 20;
let y = x >> 2; // 20 / 2^2 = 5
Square Root
The square root of a number is the number that when multiplied by itself gives the original number, for example, the square root of 9 is 3 because 3 * 3 = 9.
The process of calculating the square root of a number is to find the number that when multiplied by itself gives the original number. This is done by starting with 1 and then multiplying it by 2 until the result is greater than the original number. The last number that was multiplied by 2 is the square root of the original number.
This process can be done by bit shifting. The number 1 is shifted to the left by the power of 2 until the result is greater than the original number. The last number that was shifted is the square root of the original number.
fn sqrt(x: u32) -> u32 {
let mut y = 1;
while y << 1 < x {
y <<= 1;
}
y
}
fn main() {
let num = 64;
println!("The square root of {} is {}", num, sqrt(num));
} // The square root of 64 is 8
Conclusion
Bit shifting is a very useful tool in low level programming and cryptography and it’s very useful when doing performance critical math operations.
That’s all for this post, I hope you enjoyed it and learned something new.
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