haveES = true
		case FS:
			haveFS = true
		case GS:
			haveGS = true
		case SS:
			haveSS = true
		}
		switch inst.Op {
		case INSB, INSW, INSD, STOSB, STOSW, STOSD, STOSQ, SCASB, SCASW, SCASD, SCASQ:
			// These do not accept segment prefixes, at least in the GNU rendering.
		default:
			if *usedPrefixes {
				break
			}
			for i := len(inst.Prefix) - 1; i >= 0; i-- {

		case STOSQ:
			inst.Args[1] = RAX
		}
		usedAddrSize = true

	case SCASB, SCASW, SCASD, SCASQ:
		inst.Args[1] = Mem{Segment: ES, Base: baseRegForBits(addrMode) + DI - AX}
		switch inst.Op {
		case SCASB:
			inst.Args[0] = AL
		case SCASW:
			inst.Args[0] = AX
		case SCASD:
			inst.Args[0] = EAX
		case SCASQ:
			inst.Args[0] = RAX
		}
		usedAddrSize = true