모두의 코드
MOVSX, MOVSXDs (Intel x86/64 assembly instruction)

작성일 : 2020-09-01 이 글은 2476 번 읽혔습니다.

MOVSX, MOVSXD

Move with Sign-Extension

참고 사항

아래 표를 해석하는 방법은 x86-64 명령어 레퍼런스 읽는 법 글을 참조하시기 바랍니다.

Opcode

Instruction

Op/
En

64-Bit
Mode

Compat/
Leg Mode

Description

0F BE /r

MOVSX r16 r/m8

RM

Valid

Valid

Move byte to word with sign-extension.

0F BE /r

MOVSX r32 r/m8

RM

Valid

Valid

Move byte to doubleword with sign-extension.

REX + 0F BE /r

MOVSX r64 r/m8*

RM

Valid

N.E.

Move byte to quadword with sign-extension.

0F BF /r

MOVSX r32 r/m16

RM

Valid

Valid

Move word to doubleword, with sign-extension.

REX.W + 0F BF /r

MOVSX r64 r/m16

RM

Valid

N.E.

Move word to quadword with sign-extension.

REX.W** + 63 /r

MOVSXD r64 r/m32

RM

Valid

N.E.

Move doubleword to quadword with sign-extension.

* 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.

**The use of MOVSXD without REX.W in 64-bit mode is discouraged, Regular MOV should be used instead of using MOVSXD without REX.W.

Instruction Operand Encoding

Op/En

Operand 1

Operand 2

Operand 3

Operand 4

RM

ModRM:reg (w)

ModRM:r/m (r)

NA

NA

Description

Copies the contents of the source operand (register or memory location) to the destination operand (register) and sign extends the value to 16 or 32 bits (see Figure 7-6 in the Intel(R) 64 and IA-32 Architectures Software Devel-oper's Manual, Volume 1). The size of the converted value depends on the operand-size attribute.

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

Operation

DEST <- SignExtend(SRC);

Flags Affected

None.

Protected Mode Exceptions

#GP(0)

  • 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.

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.

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.

#UD

  • If the LOCK prefix is used.

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.

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