Intel IA-32手册
Volume 2A Instruction Set Reference, A-M.
第635
页
88 /r MOV r/m8,r8 Valid Valid Move r8 to r/m8.
REX + 88 /r MOV r/m8***,r8*** Valid N.E. Move r8 to r/m8.
89 /r MOV r/m16,r16 Valid Valid Move r16 to r/m16.
89 /r MOV r/m32,r32 Valid Valid Move r32 to r/m32.
REX.W + 89 /r MOV r/m64,r64 Valid N.E. Move r64 to r/m64.
8A /r MOV r8,r/m8 Valid Valid Move r/m8 to r8.
REX + 8A /r MOV r8***,r/m8*** Valid N.E. Move r/m8 to r8.
8B /r MOV r16,r/m16 Valid Valid Move r/m16 to r16.
8B /r MOV r32,r/m32 Valid Valid Move r/m32 to r32.
REX.W + 8B /r MOV r64,r/m64 Valid N.E. Move r/m64 to r64.
8C /r MOV r/m16,Sreg** Valid Valid Move segment register to
r/m16.
REX.W + 8C /r MOV r/m64,Sreg** Valid Valid Move zero extended 16-bit
segment register to r/m64.
8E /r MOV Sreg,r/m16** Valid Valid Move r/m16 to segment
register.
REX.W + 8E /r MOV Sreg,r/m64** Valid Valid Move lower 16 bits of
r/m64 to segment register.
A0 MOV AL,moffs8* Valid Valid Move byte at (seg:offset) to
AL.
REX.W + A0 MOV AL,moffs8* Valid N.E. Move byte at (offset) to AL.
A1 MOV AX,moffs16* Valid Valid Move word at (seg:offset)
to AX.
A1 MOV EAX,moffs32* Valid Valid Move doubleword at
(seg:offset) to EAX.
REX.W + A1 MOV RAX,moffs64* Valid N.E. Move quadword at (offset)
to RAX.
A2 MOV moffs8,AL Valid Valid Move AL to (seg:offset).
REX.W + A2 MOV moffs8***,AL Valid N.E. Move AL to (offset).
A3 MOV moffs16*,AX Valid Valid Move AX to (seg:offset).
A3 MOV moffs32*,EAX Valid Valid Move EAX to (seg:offset).
REX.W + A3 MOV moffs64*,RAX Valid N.E. Move RAX to (offset).
B0+ rb MOV r8, imm8 Valid Valid Move imm8 to r8.
REX + B0+ rb MOV r8***, imm8 Valid N.E. Move imm8 to r8.
B8+ rw MOV r16, imm16 Valid Valid Move imm16 to r16.
B8+ rd MOV r32, imm32 Valid Valid Move imm32 to r32.
REX.W + B8+ rd MOV r64, imm64 Valid N.E. Move imm64 to r64.
C6 /0 MOV r/m8, imm8 Valid Valid Move imm8 to r/m8.
REX + C6 /0 MOV r/m8***, imm8 Valid N.E. Move imm8 to r/m8.
C7 /0 MOV r/m16, imm16 Valid Valid Move imm16 to r/m16.
3-588 Vol. 2A
INSTRUCTION SET REFERENCE, A-M
MOV―Move
Description
Copies the second operand (source operand) to the first operand (destination operand). The
source operand can be an immediate value, general-purpose register, segment register, or
memory location; the destination register can be a general-purpose register, segment register, or
memory location. Both operands must be the same size, which can be a byte, a word, or a
doubleword.
The MOV instruction cannot be used to load the CS register. Attempting to do so results in an
invalid opcode exception (#UD). To load the CS register, use the far JMP, CALL, or RET
instruction.
If the destination operand is a segment register (DS, ES, FS, GS, or SS), the source operand must
be a valid segment selector. In protected mode, moving a segment selector into a segment
register automatically causes the segment descriptor information associated with that segment
selector to be loaded into the hidden (shadow) part of the segment register. While loading this
information, the segment selector and segment descriptor information is validated (see the
“Operation” algorithm below). The segment descriptor data is obtained from the GDT or LDT
entry for the specified segment selector.
A NULL segment selector (values 0000-0003) can be loaded into the DS, ES, FS, and GS registers
without causing a protection exception. However, any subsequent attempt to reference a
segment whose corresponding segment register is loaded with a NULL value causes a general
protection exception (#GP) and no memory reference occurs.
Loading the SS register with a MOV instruction inhibits all interrupts until after the execution of
the next instruction. This operation allows a stack pointer to be loaded into the ESP register with
the next instruction (MOV ESP, stack-pointer value) before an interrupt occurs1. Be aware that
the LSS instruction offers a more efficient method of loading the SS and ESP registers.
When operating in 32-bit mode and moving data between a segment register and a generalpurpose
register, the 32-bit IA-32 processors do not require the use of the 16-bit operand-size
prefix (a byte with the value 66H) with this instruction, but most assemblers will insert it if the
standard form of the instruction is used (for example, MOV DS, AX). The processor will
