SAHF--Store AH into Flags

Opcode

Instruction

Clocks

Description

9E

SAHF

2

Loads SF, ZF, AF, PF, and CF from AH into EFLAGS register

Description

Loads the SF, ZF, AF, PF, and CF flags of the EFLAGS register with values from the corresponding bits in the AH register (bits 7, 6, 4, 2, and 0, respectively). Bits 1, 3, and 5 of register AH are ignored; the corresponding reserved bits (1, 3, and 5) in the EFLAGS register remain as shown in the "Operation" section below.

Operation

EFLAGS(SF:ZF:0:AF:0:PF:1:CF) AH;

Flags Affected

The SF, ZF, AF, PF, and CF flags are loaded with values from the AH register. Bits 1, 3, and 5 of the EFLAGS register are unaffected, with the values remaining 1, 0, and 0, respectively.

Exceptions (All Operating Modes)

None.

 

 

 

 

 

 

 


For details, see Volume 2A and Volume 2B of the Intel(R) 64 and IA-32 Intel Architecture Software Developer's Manual. For the latest updates on the instruction set information, go to the web site.