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Instruction Descriptions 4–41
4.5 Logical and Shift Instructions
The logical instructions perform quadword Boolean operations. The conditional move integer
instructions perform conditionals without a branch. The shift instructions perform left and right
logical shift and right arithmetic shift. These are summarized in Table 4–6.
Software Note:
There is no arithmetic left shift instruction. Where an arithmetic left shift would be used, a
logical shift will do. For multiplying by a small power of two in address computations,
logical left shift is acceptable.
Integer multiply should be used to perform an arithmetic left shift with overflow checking.
Bit field extracts can be done with two logical shifts. Sign extension can be done with a left
logical shift and a right arithmetic shift.
Table 4–6: Logical and Shift Instructions Summary
Mnemonic Operation
AND Logical Product
BIC Logical Product with Complement
BIS Logical Sum (OR)
EQV Logical Equivalence (XORNOT)
ORNOT Logical Sum with Complement
XOR Logical Difference
CMOVxx Conditional Move Integer
SLL Shift Left Logical
SRA Shift Right Arithmetic
SRL Shift Right Logical