PARSING BYTES: f0 00 00 ADD_LOCK ADD_LOCK_MEMb_GPR8 EASZ:2, EOSZ:2, HAS_MODRM:1, LOCK, LZCNT, MAX_BYTES:3, MEM0:ptr DS[EAX], MODE:1, NPREFIXES:1, OUTREG:EFLAGS, P4, POS_MODRM:2, POS_NOMINAL_OPCODE:1, REG0:AL, REG1:EFLAGS, SMODE:1, TZCNT, USING_DEFAULT_SEGMENT0 0 MEM0/RW/B/EXPLICIT/IMM_CONST/1 1 REG0/R/B/EXPLICIT/NT_LOOKUP_FN/GPR8_R 2 REG1/W/Y/SUPPRESSED/NT_LOOKUP_FN/RFLAGS YDIS: lock add byte ptr [eax], al XED syntax: ADD_LOCK EASZ:2, EOSZ:2, HAS_MODRM:1, LOCK, LZCNT, MAX_BYTES:3, MEM0:ptr DS[EAX], MODE:1, NPREFIXES:1, OUTREG:EFLAGS, P4, POS_MODRM:2, POS_NOMINAL_OPCODE:1, REG0:AL, REG1:EFLAGS, SMODE:1, TZCNT, USING_DEFAULT_SEGMENT0 ATT syntax: lock addb %al, (%eax) INTEL syntax: lock add byte ptr [eax], al