MOVSX
Usage: MOVSX dest,src Modifies flags: None
Copies the value of the 'src' operand to the 'dest' register with the sign extended.
Move Data with Sign or Zero Extend
MOVSX reg16,r/m8 ; o16 0F BE /r [386]
MOVSX reg32,r/m8 ; o32 0F BE /r [386]
MOVSX reg32,r/m16 ; o32 0F BF /r [386]
MOVZX reg16,r/m8 ; o16 0F B6 /r [386]
MOVZX reg32,r/m8 ; o32 0F B6 /r [386]
MOVZX reg32,r/m16 ; o32 0F B7 /r [386]
MOVSX sign-extends its source (second) operand to the length of its destination (first) operand, and copies the result into the destination operand. MOVZX does the same, but zero-extends rather than sign-extending.
EXAMPLE:
movsx ebx Label