logical shift
<programming> (Either shift left logical or shift right logical)
Machine-level operations available on nearly all processors which move each bit
in a word one or more bit positions in the given direction. A left shift moves
the bits to more significant positions (like multiplying by two), a right shift
moves them to less significant positions (like dividing by two). The comparison
with multiplication and division breaks down in certain circumstances - a
logical shift may discard bits that are shifted off either end of the word and
does not preserve the sign of the word (positive or negative).
Logical shift is approriate when treating the word as a bit string or a sequence
of bit fields, whereas arithmetic shift is appropriate when treating it as a
binary number. The word to be shifted is usually stored in a register, or
possibly in memory.
(1996-07-02)
Nearby terms:
Logical Link Control « Logical Link Control and
Adaptation Protocol « logical relation « logical
shift » logical shift left » logical shift right
» Logical Unit
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