if p == PrefixPT || p == PrefixPN {
				inst.Prefix[i] |= PrefixImplicit
			}
		}
	}

	switch inst.Op {
	case AAA, AAS, CBW, CDQE, CLC, CLD, CLI, CLTS, CMC, CPUID, CQO, CWD, DAA, DAS,
		FDECSTP, FINCSTP, FNCLEX, FNINIT, FNOP, FWAIT, HLT,
		ICEBP, INSB, INSD, INSW, INT, INTO, INVD, IRET, IRETQ,
		LAHF, LEAVE, LRET, MONITOR, MWAIT, NOP, OUTSB, OUTSD, OUTSW,
		PAUSE, POPA, POPF, POPFQ, PUSHA, PUSHF, PUSHFQ,