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,

	"FCMOVNU",
	"FCMOVU",
	"FCMOVUN",
	"FCOMD",
	"FCOMDP",
	"FCOMDPP",
	"FCOMF",
	"FCOMFP",
	"FCOMI",
	"FCOMIP",
	"FCOML",
	"FCOMLP",
	"FCOMW",
	"FCOMWP",
	"FCOS",
	"FDECSTP",
	"FDIVD",
	"FDIVDP",
	"FDIVF",
	"FDIVL",
	"FDIVRD",
	"FDIVRDP",
	"FDIVRF",
	"FDIVRL",
	"FDIVRW",
	"FDIVW",
	"FFREE",
	"FINCSTP",
	"FINIT",
	"FLD1",
	"FLDCW",