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In the C programming language, operations can be performed on a bit level using bitwise operators. Bitwise operations are contrasted by byte-level operations which characterize the bitwise operators' logical counterparts, the AND, OR, NOT operators. Instead of performing on individual bits, byte-level operators perform on strings of eight bits ...
In computer programming, a bitwise operation operates on a bit string, a bit array or a binary numeral (considered as a bit string) at the level of its individual bits.It is a fast and simple action, basic to the higher-level arithmetic operations and directly supported by the processor.
A mask is data that is used for bitwise operations, particularly in a bit field. Using a mask, multiple bits in a Byte, nibble, word (etc.) can be set either on, off or inverted from on to off (or vice versa) in a single bitwise operation. More comprehensive applications of masking, when applied conditionally to operations, are termed predication.
^, the caret, has been used in several programming languages to denote the bitwise exclusive or operator, beginning with C [20] and also including C++, C#, D, Java, Perl, Ruby, PHP and Python.
Dennis Ritchie, creator of the C language, said of the precedence in C (shared by programming languages that borrow those rules from C, for example, C++, Perl and PHP) that it would have been preferable to move the bitwise operators above the comparison operators. [42]
All the operators (except typeof) listed exist in C++; the column "Included in C", states whether an operator is also present in C. Note that C does not support operator overloading. When not overloaded, for the operators && , || , and , (the comma operator ), there is a sequence point after the evaluation of the first operand.
[1] c := b and a # This separates out all bits set in both a, b. # All these bits would carry if bits were added individually, # that is, if the bits in a, b were to be added bit-wise. b := b xor a # This clears in b the bits set in both a, b (previously saved to c), # and sets in b all the other bits set in a.
Using a mask, multiple bits in a byte, nibble, word, etc. can be set either on or off, or inverted from on to off (or vice versa) in a single bitwise operation. An additional use of masking involves predication in vector processing , where the bitmask is used to select which element operations in the vector are to be executed (mask bit is ...