longest:     longest,
		matchcap:    matchcap,
		minInputLen: minInputLen(re),
	}
	if regexp.onepass == nil {
		regexp.prefix, regexp.prefixComplete = prog.Prefix()
		regexp.maxBitStateLen = maxBitStateLen(prog)
	} else {
		regexp.prefix, regexp.prefixComplete, regexp.prefixEnd = onePassPrefix(prog)
	}
	if regexp.prefix != "" {
		// TODO(rsc): Remove this allocation by adding