# c power of 2 bit shift

This does not of course apply to a right shift (power of two divide) because only a left (little endian) shift fills the gap with zeros. The << (left shift) in C or C++ takes two numbers, left shifts the bits of the first operand, the second operand decides the number of places to shift. The ^ (bitwise XOR) in C or C++ takes two numbers as operands and does XOR on every bit of two numbers. So when we say x 1, we are saying "shift the bits in the variable x left by 1 place". If x is a power of two, its lone 1 bit is in position n. This means ~x has a 0 in position n and 1s everywhere else. Note that in the edge case where v is 0, it returns 0, which isn't a power of 2; you might append the expression v += (v == 0) to remedy this if it matters. Note that in the third case, we shifted a bit off the end of the number! Bits that are shifted off the end of the binary number â¦ The left operands value is moved left by the number of bits specified by the right operand. There are two bit shift operators in C++: the left shift operator << and the right shift operator >>. Live Demo 1 << 4 = 16 = 2 4 â¦ 1 << n = 2 n. Right Shift ( >> ): Right shift operator is a binary operator which shift the some number of bits, in the given bit pattern, to the right and append 1 at the end. A >> 2 = 15 i.e., 0000 1111 The high-order empty bit positions are set based on the type of the left-hand operand as follows: If the left-hand operand is of type int or long, the right-shift operator performs an arithmetic shift: the value of the most significant bit (the sign bit) of the left-hand operand is propagated to the high-order empty bit positions. â¦ More on bitwise math may be found here. Checking if given 32 bit integer is power of 2: These operators cause the bits in the left operand to be shifted left or right by the number of positions specified by the right operand. In other words, the carry propagates all the way to position n. So what happens is â¦ AND - Value of c is 20 OR - Value of c is 21 Exclusive-OR - Value of c is 1 Bitwise shift operators. The result of XOR is 1 if the two bits are different. Syntax. New bits shifted in from the right side receive the value 0. A << 2 = 240 i.e., 1111 0000 >> Binary Right Shift Operator. In the bit shift version the key instruction is shll \$2, %eax which is a shift left logical - there's the divide, and everything else is just moving values around. This is the number 32 -- in fact, left shifting is the equivalent of multiplying by a power of two. variable << number_of_bits variable >> number_of_bits â¦ 0011 << 1 is 0110 0011 << 2 is 1100 0011 << 3 is 1000. Let n be the position of the leftmost 1 bit if x. Right shift is equivalent to dividing the bit pattern with 2k ( if we are shifting k bits ). This results in double the previous number. If we wanted to shift it to the left 2 places, we'd end up with 00100000; everything is moved to the left two places, and zeros are added as padding. 2. Example. Left and right are two shift operators provided by 'C' which are represented as follows: Operand << n (Left Shift) Operand >> n (Right Shift) int mult_by_pow_2(int number, int power) { return number<> 1 = 2 6 >> 1 = 3 5 >> 1 = 2 16 >> 4 = 1