This Instruction is used to increment the destination operand(register or a memory location) by 1,while maintaining the state of the carry flag CF.
<u>DEC instruction</u>
This instruction is used to decrement the destination operand(register or a memory location) by 1,while maintaining the state of the carry flag CF.
Initially we use Inc and Dec instructions for the loop,many loops include multi precision arithmetic doing.For controlling the loops we use inc and dec instructions by setting the zero flag,but not effecting the carry flag.For multi precision arithmetic operations we use the carry state because it helps in a way that it reduces the complexity of code( without writing tons of code),so it is necessary to preserve carry flag.
