CMC

CMC — Complement Carry Flag

Opcode	Instruction	Op/ En	64-bit Mode	Compat/ Leg Mode	Description
F5	CMC	ZO	Valid	Valid	Complement CF flag.

Instruction Operand Encoding

Op/En	Operand 1	Operand 2	Operand 3	Operand 4
ZO	NA	NA	NA	NA

Description

Complements the CF flag in the EFLAGS register. CMC operation is the same in non-64-bit modes and 64-bit mode.

Operation

EFLAGS.CF[bit 0]← NOT EFLAGS.CF[bit 0];

Flags Affected

The CF flag contains the complement of its original value. The OF, ZF, SF, AF, and PF flags are unaffected.

Exceptions (All Operating Modes)

#UD If the LOCK prefix is used.

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Source: Intel® Architecture Software Developer's Manual (May 2018)
Generated: 5-6-2018