operands := []float64{2.6, 2.5, 2.1, -2.1, -2.5, -2.6}

	fmt.Print("   x")
	for mode := big.ToNearestEven; mode <= big.ToPositiveInf; mode++ {
		fmt.Printf("  %s", mode)
	}
	fmt.Println()

	for _, f64 := range operands {
		fmt.Printf("%4g", f64)
		for mode := big.ToNearestEven; mode <= big.ToPositiveInf; mode++ {
			// sample operands above require 2 bits to represent mantissa

		testFloatRound(t, x, a, prec, AwayFromZero)

		testFloatRound(t, x, z, prec, ToNegativeInf)
		testFloatRound(t, x, a, prec, ToPositiveInf)

		testFloatRound(t, -x, -a, prec, ToNegativeInf)
		testFloatRound(t, -x, -z, prec, ToPositiveInf)
	}
}

// TestFloatRound24 tests that rounding a float64 to 24 bits
// matches IEEE 754 rounding to nearest when converting a

	ToZero                            // == IEEE 754-2008 roundTowardZero
	AwayFromZero                      // no IEEE 754-2008 equivalent
	ToNegativeInf                     // == IEEE 754-2008 roundTowardNegative
	ToPositiveInf                     // == IEEE 754-2008 roundTowardPositive
)

//go:generate stringer -type=RoundingMode

// Accuracy describes the rounding error produced by the most recent

		{"NewRat", Func, 0},
		{"ParseFloat", Func, 5},
		{"Rat", Type, 0},
		{"RoundingMode", Type, 5},
		{"ToNearestAway", Const, 5},
		{"ToNearestEven", Const, 5},
		{"ToNegativeInf", Const, 5},
		{"ToPositiveInf", Const, 5},
		{"ToZero", Const, 5},
		{"Word", Type, 0},
	},
	"math/bits": {
		{"Add", Func, 12},
		{"Add32", Func, 12},
		{"Add64", Func, 12},
		{"Div", Func, 12},
		{"Div32", Func, 12},