// See golang.org/issue/6384 and golang.org/issue/14135.
	// Like fmt %g, but the exponent cutoffs are different
	// and exponents themselves are not padded to two digits.
	abs := math.Abs(f)
	fmt := byte('f')
	if abs != 0 {
		if abs < 1e-6 || abs >= 1e21 {
			fmt = 'e'
		}
	}
	dst = strconv.AppendFloat(dst, f, fmt, -1, 64)
	if fmt == 'e' {
		// clean up e-09 to e-9
		n := len(dst)