logical shift

A common logical operation is logical shift left or right.

There are two forms of logical shift, which differ in what happens at each end of the binary pattern.

In computer science, a logical shift is a bitwise operation that shifts all the bits of its operand.

In a logical shift, zeros are shifted in to replace the discarded bits.

The shifter supports arithmetic shifts, logical shifts, and rotate-through-carry operations.

A logical shift is often used when its operand is being treated as a sequence of bits rather than as a number.

If the first operand is of type uint or ulong, the right-shift is a logical shift.

The result in an ideal logical shift operation would be zero as the fill up bits are defined to be zero.

SHR (instruction), the x86 command for logical shift right (unsigned divide)

In C and C++, computations with the left operand as an unsigned integer use logical shifts.

When performed on an unsigned type, the operation performed is a logical shift, causing the blanks to be filled by 0s (zeros).

Logical shifts can be useful as efficient ways of performing multiplication or division of unsigned integers by powers of two.

The exception is the minor trap that arithmetic shifts may trigger arithmetic overflow whereas logical shifts do not.

The reserved opcode has been converted into a shift instruction, SHF, that supports arithmetic and logical shifts of arbitrary size in both directions.

For this reason, some microcontrollers such as PICs just have rotate and rotate through carry, and don't bother with arithmetic or logical shift instructions.

Then, treating the bits representing the floating point number as a 32-bit integer, a logical shift right of one bit is performed and the result subtracted from the "magic" value 0x5f3759df.

Unlike a logical shift, the vacant bit positions are not filled in with zeros but are filled in with the bits that are shifted out of the sequence.

(If you discourage when partner leads a high honor at Trick 1, you are normally saying that you are happy for him to make the logical shift, the one that he is most likely to produce based on the dummy.)

The naturalistic conception of humans, which has so far been unable to make the strictly logical shift from animals to humans themselves, and which sometimes argues that the problem lies in the absence of a "missing link" that is yet to be found, is mistaken.

Most C and C++ implementations, and Go, choose which right shift to perform depending on the type of integer being shifted: signed integers are shifted using the arithmetic shift, and unsigned integers are shifted using the logical shift.

Instead of being filled with all 0s, as in logical shift, when shifting to the right, the leftmost bit (usually the sign bit in signed integer representations) is replicated to fill in all the vacant positions (this is a kind of sign extension).

An arithmetic shift is usually equivalent to multiplying the number by a positive or a negative integral power of the radix, except for the effect of any rounding; compare the logical shift with the arithmetic shift, especially in the case of floating-point representation.

Unlike an arithmetic shift, a logical shift does not preserve a number's sign bit or distinguish a number's exponent from its mantissa; every bit in the operand is simply moved a given number of bit positions, and the vacant bit-positions are filled in, usually with zeros (compare with a circular shift).