I understand what bitwise operations are, and I know how to use them in my code. However, are there situations where the processor will automatically use bitwise operations to perform a computation? For example, are there arithmetic operations which, when invoked, will cause the processor to internally use bitwise operations without my explicitly using them in code?
-
1Please rephraise the question because what you want to know is not clear.– RamhoundApr 21, 2014 at 18:51
-
I rephraised the question.– Acaz SouzaApr 21, 2014 at 19:46
-
This is still really hard to understand– RamhoundApr 21, 2014 at 22:04
Add a comment
|
2 Answers
Examples would be multiplication and division. Moving the bits to the left for one position is a multiplication with 2, moving them right for one position is a division by 2. It is faster for a processor to do the bit moving than calculating.
-
Don't forget modulo (%) a power of two, which can use
and.– user180742Apr 22, 2014 at 13:48
It's going to be processor dependent but I'd guess usually none unless specifically called by your code. If your code is anything but assembly, then this will usually depend on the compiler. You can see a long discussion on this here: https://stackoverflow.com/questions/235072/do-modern-compilers-optimize-the-x-2-operation-to-x-1
