3-301
INSTRUCTION SET REFERENCE
INC—Increment by 1
Description
This instruction adds one to the destination operand, while preserving the state of the CF flag.
The destination operand can be a register or a memory location. This instruction allows a loop
counter to be updated without disturbing the CF flag. (Use a ADD instruction with an immediate
operand of 1 to perform an increment operation that does updates the CF flag.)
Operation
DEST
<
DEST +1;
Flags Affected
The CF flag is not affected. The OF, SF, ZF, AF, and PF flags are set according to the result.
Protected Mode Exceptions
#GP(0)
If the destination operand is located in a nonwritable segment.
If a memory operand effective address is outside the CS, DS, ES, FS, or
GS segment limit.
If the DS, ES, FS, or GS register is used to access memory and it contains
a null segment selector.
#SS(0)
If a memory operand effective address is outside the SS segment limit.
#PF(fault-code)If a page fault occurs.
#AC(0)
If alignment checking is enabled and an unaligned memory reference is
made while the current privilege level is 3.
Real-Address Mode Exceptions
#GP
If a memory operand effective address is outside the CS, DS, ES, FS, or
GS segment limit.
#SS
If a memory operand effective address is outside the SS segment limit.
Opcode
Instruction
Description
FE /0
INC r/m8
Increment r/m byte by 1
FF /0
INC r/m16
Increment r/m word by 1
FF /0
INC r/m32
Increment r/m doubleword by 1
40+ rw
INC r16
Increment word register by 1
40+ rd
INC r32
Increment doubleword register by 1
