12. The LAHF and SAHF Instructions

• LAHF instruction loads lower byte of the EFLAGS register into AH register.

• The lowest 8 bits of the flags are transferred:

  • Sign

  • Zero

  • Auxiliary Carry

  • Parity

  • Carry

• Instruction format:

      lahf
  

• SAHF restores the value of lower byte flags. Format:

      sahf