AND - Logical AND

Opcode

Instruction

Op/ En

64-bit Mode

Compat/ Leg Mode

Description

24 ib

AND AL, imm8

I

Valid

Valid

AL AND imm8.

25 iw

AND AX, imm16

I

Valid

Valid

AX AND imm16.

25 id

AND EAX, imm32

I

Valid

Valid

EAX AND imm32.

REX.W + 25 id

AND RAX, imm32

I

Valid

N.E.

RAX AND imm32 sign-extended to 64-bits.

80 /4 ib

AND r/m8, imm8

MI

Valid

Valid

r/m8 AND imm8.

REX + 80 /4 ib

AND r/m8*, imm8

MI

Valid

N.E.

r/m8 AND imm8.

81 /4 iw

AND r/m16, imm16

MI

Valid

Valid

r/m16 AND imm16.

81 /4 id

AND r/m32, imm32

MI

Valid

Valid

r/m32 AND imm32.

REX.W + 81 /4 id

AND r/m64, imm32

MI

Valid

N.E.

r/m64 AND imm32 sign extended to 64-bits.

83 /4 ib

AND r/m16, imm8

MI

Valid

Valid

r/m16 AND imm8 (sign-extended).

83 /4 ib

AND r/m32, imm8

MI

Valid

Valid

r/m32 AND imm8 (sign-extended).

REX.W + 83 /4 ib

AND r/m64, imm8

MI

Valid

N.E.

r/m64 AND imm8 (sign-extended).

20 /r

AND r/m8, r8

MR

Valid

Valid

r/m8 AND r8.

REX + 20 /r

AND r/m8*, r8*

MR

Valid

N.E.

r/m64 AND r8 (sign-extended).

21 /r

AND r/m16, r16

MR

Valid

Valid

r/m16 AND r16.

21 /r

AND r/m32, r32

MR

Valid

Valid

r/m32 AND r32.

REX.W + 21 /r

AND r/m64, r64

MR

Valid

N.E.

r/m64 AND r32.

22 /r

AND r8, r/m8

RM

Valid

Valid

r8 AND r/m8.

REX + 22 /r

AND r8*, r/m8*

RM

Valid

N.E.

r/m64 AND r8 (sign-extended).

23 /r

AND r16, r/m16

RM

Valid

Valid

r16 AND r/m16.

23 /r

AND r32, r/m32

RM

Valid

Valid

r32 AND r/m32.

REX.W + 23 /r

AND r64, r/m64

RM

Valid

N.E.

r64 AND r/m64.

NOTES:

*In 64-bit mode, r/m8 can not be encoded to access the following byte registers if a REX prefix is used: AH, BH, CH, DH.

Instruction Operand Encoding

Op/En

Operand 1

Operand 2

Operand 3

Operand 4

RM

ModRM:reg (r, w)

ModRM:r/m (r)

N/A

N/A

MR

ModRM:r/m (r, w)

ModRM:reg (r)

N/A

N/A

MI

ModRM:r/m (r, w)

imm8/16/32

N/A

N/A

I

AL/AX/EAX/RAX

imm8/16/32

N/A

N/A

Description

Performs a bitwise AND operation on the destination (first) and source (second) operands and stores the result in the destination operand location. The source operand can be an immediate, a register, or a memory location; the destination operand can be a register or a memory location. (However, two memory operands cannot be used in one instruction.) Each bit of the result is set to 1 if both corresponding bits of the first and second operands are 1; otherwise, it is set to 0.

This instruction can be used with a LOCK prefix to allow the it to be executed atomically.

In 64-bit mode, the instruction's default operation size is 32 bits. Using a REX prefix in the form of REX.R permits access to additional registers (R8-R15). Using a REX prefix in the form of REX.W promotes operation to 64 bits. See the summary chart at the beginning of this section for encoding data and limits.

Operation 

DEST := DEST AND SRC;

Flags Affected

The OF and CF flags are cleared; the SF, ZF, and PF flags are set according to the result. The state of the AF flag is undefined.

Protected Mode Exceptions

#GP(0)

If the destination operand points to a non-writable 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 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.

#UD

If the LOCK prefix is used but the destination is not a memory operand.

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.

#UD

If the LOCK prefix is used but the destination is not a memory operand.

Virtual-8086 Mode Exceptions

#GP(0)

If a memory operand effective address is outside the CS, DS, ES, FS, or GS segment limit.

#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.

#UD

If the LOCK prefix is used but the destination is not a memory operand.

Compatibility Mode Exceptions

Same exceptions as in protected mode.

64-Bit Mode Exceptions

#SS(0)

If a memory address referencing the SS segment is in a non-canonical form.

#GP(0)

If the memory address is in a non-canonical form.

#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.

#UD

If the LOCK prefix is used but the destination is not a memory operand.