لطفا منتظر باشید ...
SUB Arithmetic Subtraction
Flags affected:
O D I T S Z A P C OF: Overflow flag TF: Trap flag AF: Aux carry
F F F F F F F F F DF: Direction flag SF: Sign flag PF: Parity flag
* * * * * * IF: Interrupt flag ZF: Zero flag CF: Carry flag
Legal forms:
SUB r8,r8
SUB m8,r8
SUB r8,m8
SUB r16,r16
SUB m16,r16
SUB r16,m16
SUB r32,r32 386+
SUB m32,r32 386+
SUB r32,m32 386+
SUB r8,i8
SUB m8,i8
SUB r16,i16
SUB m16,i16
SUB r32,i32 386+
SUB m32,i32 386+
SUB r16,i8
SUB m16,i8
SUB r32,i8 386+
SUB m32,i8 386+
SUB AL,i8
SUB AX,i16
SUB EAX,i32 386+
Examples:
SUB BX,DI
SUB AX,0FFFFH ;Uses single-byte opcode
SUB AL,42H ;Uses single-byte opcode
SUB BP,17H
SUB ECX,DWORD [ESI+5]
SUB EAX,17
SUB WORD [BX+SI+Inset],5
SUB WORD [ES:BX],0B800H
Notes:
SUB performs a subtraction without borrow, where the source is subtracted from the destination, and the result replaces the destination. If the result is negative, the Carry flag is set. Multiple-precision subtraction can be performed by following SUB with SBB (Subtract with Borrow) which takes the Carry flag into account as a borrow.
r8 = AL AH BL BH CL CH DL DH r16 = AX BX CX DX BP SP SI DI
sr = CS DS SS ES FS GS r32 = EAX EBX ECX EDX EBP ESP ESI EDI
m8 = 8-bit memory data m16 = 16-bit memory data
m32 = 32-bit memory data i8 = 8-bit immediate data
i16 = 16-bit immediate data i32 = 32-bit immediate data
d8 = 8-bit signed displacement d16 = 16-bit signed displacement
d32 = 32-bit unsigned displacement
