4.4.3 Quadword Add

Format:

ADDQ

Ra.rq,Rb.rq,Rc.wq

!Operate format

ADDQ

Ra.rq,#b.ib,Rc.wq

!Operate format

Operation:

Rc Rav + Rbv

Exceptions:

Integer Overflow

Instruction mnemonics:

ADDQ

Add Quadword

Qualifiers:

Integer Overflow Enable (/V)

Description:

Register Ra is added to register Rb or a literal and the 64-bit sum is written to Rc.

On overflow, the least significant 64 bits of the true result are written to the destination register.

The unsigned compare instructions can be used to generate carry. After adding two values, if the sum is less unsigned than either one of the inputs, there was a carry out of the most signifi- cant bit.

Instruction Descriptions 4–27

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Compaq ECQD2KCTE manual Quadword Add, Addq