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

KADDB

This instruction is not a part of the official x86-64 Instruction Set Architecture (ISA) as defined by Intel or AMD. No such instruction mnemonic exists in the standard x86-64 opcode map.

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

DO NOT support LOCK

This instruction is not defined in any architectural mode (Real Mode, Protected Mode, or Long Mode). Consequently, attempting to execute an opcode that does not map to a known instruction will result in an Invalid Opcode exception (#UD).

Since this instruction does not exist in the x86-64 ISA, any attempt to use it in assembly source code will result in a compilation error. To avoid undefined behavior or crashes, only use mnemonics documented in the Intel 64 and IA-32 Architectures Software Developer's Manual.