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
// float64 to a float32 (excluding denormal numbers).
func TestFloatRound24(t *testing.T) {
	const x0 = 1<<26 - 0x10 // 11...110000 (26 bits)
	for d := 0; d <= 0x10; d++ {
		x := float64(x0 + d)