devxlogo

A Fast Multiplication Method for Integer Numbers

A Fast Multiplication Method for Integer Numbers

The multiplication operation for integer numbers is implemented in the processor as repeated additions. The number of additions can be reduced by considering the representation in base 2 of the multiplier, as in this example:

 int i = 111;//We need to compute int j = i * 15; but 15 = 1 + 2 + 4 + 8 = 2^0 + 2^1 +2^2 + 2^3,//so we can reduce the multiplication to some shift operations and just 3 additionsint j = i + (I<<1) + (I<<2) + (I<<3);

If you have multiplications in some lengthy iterative loops, using this trick can substantially increase CPU saving.

See also  Monetize TikTok For Your Business
devxblackblue

About Our Editorial Process

At DevX, we’re dedicated to tech entrepreneurship. Our team closely follows industry shifts, new products, AI breakthroughs, technology trends, and funding announcements. Articles undergo thorough editing to ensure accuracy and clarity, reflecting DevX’s style and supporting entrepreneurs in the tech sphere.

See our full editorial policy.

About Our Journalist