movsx

Move with Sign-Extension

MOVSX r, r/m

Copies and sign-extends a smaller value to a larger register.

Details

The Move with Sign-Extension instruction copies and sign-extends a smaller value to a larger register.

Pseudocode Operation

DEST <- SRC

Example

MOVSX rax, rbx

Encoding

Binary Layout
0F
+0
BE
+1
 
Format Legacy
Opcode 0F BE
Extension Base

Operands

  • dest
    General-purpose register
  • src
    Register or memory operand