Aspects

vs

Division

In mathematics, division (÷) is an arithmetic elementary operation.

Multiplying

This is one of the four elementary, mathematical operations of arithmetic; with the others being addition, subtraction and division.

Step reciprocal quaternion

Example

"Division dividing a quaternion named p by a quaternion named q is nothing more than multiplying p by the reciprocal of q"

from question

Quaternion division and hyperbolic tangent tanh

"I suppose one minor thing you can do unless you re already doing it is that in the 3rd step multiplying by the reciprocal of the sum instead of dividing by the sum;division is a lot more expensive than multiplication"

from question

Implementing matrix vector multiplication in assembly

"Division of quaternion a by quaternion b is nothing more than multiplying a by the multiplicative inverse of b"

from question

Quaternions' adding, subtracting and division operations on 3d models

"Use the product computed in the previous step multiplying it by the number entering the window and divide by the number exiting the window;division is slower but it will pay off for larger values of c"

from question

I want to replace BigInteger for loop in Stream Api

Decimal multiplication floor

Example

"Using a division is a lot slower than multiplying by decimal number 5 s just an approximation"

from question

Create sine lookup table in C++

"Essentially you will and up with multiplying m with a number between 0 up to but not including 1 and finally we are taking the floor of the result of that to get an integer. this is slower than division method but it doesn t matter what you choose for m value of m is not critical"

from question

What is the motivation behind the procedure for multiplication method for hashing?

"This explains why you are not seeing multiplication as faster than division when timing with instead let s write setup code which performs multiplication and division on random numbers yields on my machine multiplying is faster 99.00 of the time"

from question

Is multiplying really faster than dividing?

"According to agner s instruction tables a single fp division is slower than a single reciprocal op and a single multiplying op"

from question

Why is fp division op slower than reciprocal op plus multiply op

"I presume that you know that using a division is a lot slower than multiplying by decimal number 5 is always slower than 0.2"

from question

Create sine lookup table in C++

"Sure that s probably compiled or jit d away but you should avoid division in performance critical code it s far slower than multiplying"

from question

Any ideas on how to optimize this code? I cant seem to come up with anything that works

"These can be compared to multiplying by 2 x left-shift or divinding by 2 x right-shift but it should be noted that a binary shift is much faster than a division operation"

from question

Bitwise operator x >> 1 and x >> 0

"If your magnitude of your numbers will be roughly within the range 1e+ -12 start by finding the smallest power of ten which is smaller than your number multiplying that by 100 000 multiplying your number by that round to the nearest unit and divide by that power of ten;because division is often much slower than multiplication if performance is critical you might keep a table with powers of ten and their reciprocals"

from question

Java: convert float to double preserving decimal point precision

"Also 64-bit multiplying was slightly slower on some cpus and 64-bit division is significantly slower than 32-bit even on current intel cpus"

from question

A 64-bit number does not fit in the register in x86_64 mode

"But determining the digit and the carry by division is much more concise and for the larger factors also much more efficient when multiplying a digit by 100 the result is on average 450 requiring 45 subtractions but two divisions are sufficient for all factors"

from question

Algorithm slowness for Project Euler #20

Minor enhancements basic

Example

"Note that i ve incorporated dshin s comment that multiplying is faster than division however the performance improvement is about 90 removing the binary search 10 multiplication vs"

from question

How to speed up a C++ sparse matrix manipulation?

"There could be a few minor enhancements to be made such as multiplying by 0.5 instead of dividing by 2.0 as division is slower but the basic premise should hopefully help"

from question

Calculate target angle based on two 3D Vectors?

Others

Example

The value of i is less than 2 64 so the error after multiplying is less than 1 5;after the division by 4 the error is less than 1 5 2 minus

from question

Why does GCC use multiplication by a strange number in implementing integer division?

Repeated add sub is normally a terrible way to multiplying divide but you want to loop that many times anyway so you use that as the loop counter;this is called a strength reduction optimization because division is stronger slower more expensive than subtraction

from question

Assembly language making a for loop that runs n/10 times

Perhaps it s the case that division is much more accurate than reciprocal plus multiplying

from question

Why is fp division op slower than reciprocal op plus multiply op

This would change a multiplying and three divisions into four multiplies and one division;division is much more expensive than multiplication

from question

Decrease in instructions retired after loop Unrolling

But in normal case it takes n 2 comparison so you half the height of tree but you multiplying each merge with two so total running time is not better than division to 2 part

from question

Time complexity using N way Merge

While working with integer division it s better to multiplying first and divide later to minimize the rounding error

from question

How to return result of a SELECT inside a function in PostgreSQL?

Think of the hardware involved and you ll understand a lot better why it takes so much longer to divide than multiplying;both operations are done down at the floating point unit fpu level and even in the world of integral alus the division circuit is a far busier place than a multiplication circuit

from question

Why is float division slow?

You can reason directly by multiplying one side of the inequality by the unity h x h x and then multiplying through by h x;but i thought canceling by division was clearer

from question

Result of multiplying both sides of not-big-O relationship by the same function?

I read about python following pemdas that is precedence of multiplying is more than division

from question

Operator precedence in Python -PEMDAS

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