用来将一个整数除以2的更好的选项是什么？

Question

Which of the following techniques is the best option for dividing an integer by 2 and why?

Technique 1:

x = x >> 1;

Technique 2:

x = x / 2;

Here x is an integer.

转载于:https://stackoverflow.com/questions/10681375/which-is-better-option-to-use-for-dividing-an-integer-number-by-2

Answer 1

Use the operation that best describes what you are trying to do.

• If you are treating the number as a sequence of bits, use bitshift.
• If you are treating it as a numerical value, use division.

Note that they are not exactly equivalent. They can give different results for negative integers. For example:

-5 / 2  = -2
-5 >> 1 = -3

(ideone)