if dfrac != 0 {
		d0 = false
	}
	// Proceed to the requested number of digits
	formatDecimal(d, di, !d0, roundUp, prec)
	// Adjust exponent
	d.dp -= q
}

var uint64pow10 = [...]uint64{
	1, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
	1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
}

// formatDecimal fills d with at most prec decimal digits
// of mantissa m. The boolean trunc indicates whether m