ryuFtoaFixed64(&digs, mant, exp-int(flt.mantbits), digits)
			ok = true
		}
	}
	if !ok {
		return bigFtoa(dst, prec, fmt, neg, mant, exp, flt)
	}
	return formatDigits(dst, shortest, neg, digs, prec, fmt)
}

// bigFtoa uses multiprecision computations to format a float.
func bigFtoa(dst []byte, prec int, fmt byte, neg bool, mant uint64, exp int, flt *floatInfo) []byte {
	d := new(decimal)
	d.Assign(mant)