STD

Set Direction Flag

stableVMJITAOTinstruction

Encodings

Opcode	Instruction	Op/En	64-bit	Compat/Legacy	Description
`FD`	`STD`	ZO	Valid	Valid	Set DF flag.

Measured cost

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Flags named

CF Carry
PF Parity
AF Auxiliary carry
ZF Zero
SF Sign
DF Direction
OF Overflow

Description

Sets the DF flag in the EFLAGS register. When the DF flag is set to 1, string operations decrement the index registers (ESI and/or EDI). Operation is the same in all modes.

Operation

DF := 1;