4–40 Alpha Architecture Handbook
4.4.16 Scaled Quadword Subtract
Format:
Operation:
CASE
S4SUBQ: Rc ← LEFT_SHIFT(Rav,2) - Rbv
S8SUBQ: Rc ← LEFT_SHIFT(Rav,3) - Rbv
ENDCASE
Exceptions:
Instruction mnemonics:
Qualifiers:
Description:
Register Rb or a literal is subtracted from the scaled value of register Ra, which is scaled by 4
(for S4SUBQ) or 8 (for S8SUBQ), and the 64-bit difference is written to Rc.
SxSUBQ Ra.rq,Rb.rq,Rc.wq
!Operate format
SxSUBQ Ra.rq,#b.ib,Rc.wq
!Operate format
None
S4SUBQ Scaled Subtract Quadword by 4
S8SUBQ Scaled Subtract Quadword by 8
None