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bit-manipulationbitwise-andparity

Is there any reason to use (nr & 1 == 0) over (nr % 2 == 0) to check for parity?

Is there any actual difference in performance? Is it faster? (lets say I use it in at least 100 cases in the same program, would it improve my program in terms of speed?)

Solution

  • This question might be more appropriate on Software Engineering Stack Exchange.

    If you're using an optimizing compiler chances are any form of n % <power of two> will get optimized to n & <power of two minus one> anyway, since they are equivalent but on pretty much every architecture I can think of the latter is much more efficient.

    The former form expresses your intent more clearly, though a lot of developers will recognize n & 1 as a "faster version" of n % 2.