GNU Info

(nasm.info)Section B.4.58

---

Next: Section B.4.59 Prev: Section B.4.57 Up: Section B.4

---

Enter node , (file) or (file)node

B.4.58. `DEC': Decrement Integer
--------------------------------

     DEC reg16                     ; o16 48+r             [8086]
     DEC reg32                     ; o32 48+r             [386]
     DEC r/m8                      ; FE /1                [8086]
     DEC r/m16                     ; o16 FF /1            [8086]
     DEC r/m32                     ; o32 FF /1            [386]

   `DEC' subtracts 1 from its operand. It does _not_ affect the carry
flag: to affect the carry flag, use `SUB something,1' (see *Note
Section B.4.305::). `DEC' affects all the other flags according to the
result.

   This instruction can be used with a `LOCK' prefix to allow atomic
execution.

   See also `INC' (*Note Section B.4.120::).