func mulByLog10Log2(x int) int {
	// log(10)/log(2) ≈ 3.32192809489 ≈ 108853 / 2^15
	return (x * 108853) >> 15
}

// computeBounds returns a floating-point vector (l, c, u)×2^e2
// where the mantissas are 55-bit (or 26-bit) integers, describing the interval
// represented by the input float64 or float32.
func computeBounds(mant uint64, exp int, flt *floatInfo) (lower, central, upper uint64, e2 int) {