This content has not been validated; it was AI-generated following the x86-64 ISA Documentation generation process to maintain high quality. However, as no human has verified this data, errors may exist. If the accuracy of this data is critical, please consult the Intel SDM. The model used to generate this is gemma4:31b

CMC

Complements the Carry Flag (CF).

The table after the description covers what the source and destinations can be.

DO NOT support LOCK

The CMC instruction is available in 64-bit mode, 32-bit mode, and 16-bit mode. It does not have any architectural constraints regarding the operating mode.

The instruction only affects the CF flag; all other flags in the RFLAGS register remain unchanged. Since it does not take any operands, it cannot trigger memory-related exceptions.