// The size of a CRC-64 checksum in bytes.
const Size = 8

// Predefined polynomials.
const (
	// The ISO polynomial, defined in ISO 3309 and used in HDLC.
	ISO = 0xD800000000000000

	// The ECMA polynomial, defined in ECMA 182.
	ECMA = 0xC96C5795D7870F42
)

// Table is a 256-word table representing the polynomial for efficient processing.
type Table [256]uint64

var (
	slicing8TablesBuildOnce sync.Once

	tabISO := MakeTable(ISO)
	tabECMA := MakeTable(ECMA)
	for i := 0; i < len(golden); i++ {
		g := golden[i]
		c := New(tabISO)
		io.WriteString(c, g.in)
		s := c.Sum64()
		if s != g.outISO {
			t.Fatalf("ISO crc64(%s) = 0x%x want 0x%x", g.in, s, g.outISO)
		}
		c = New(tabECMA)
		io.WriteString(c, g.in)
		s = c.Sum64()
		if s != g.outECMA {
			t.Fatalf("ECMA crc64(%s) = 0x%x want 0x%x", g.in, s, g.outECMA)
		}
	}

		fastlog2Table[i] = log2(1.0 + float64(i)/(1<<fastlogNumBits))
	}
	return fastlog2Table
}

// log2 is a local copy of math.Log2 with an explicit float64 conversion
// to disable FMA. This lets us generate the same output on all platforms.
func log2(x float64) float64 {
	frac, exp := math.Frexp(x)
	// Make sure exact powers of two give an exact answer.

	MTLSHTTP    FilterChainType = "mTLS HTTP"
	Unknown     FilterChainType = "unknown"
)

func classifyFilterChain(have *listener.FilterChain) FilterChainType {
	fcm := have.GetFilterChainMatch()
	alpn := sets.New(fcm.GetApplicationProtocols()...)
	switch fcm.GetTransportProtocol() {
	case xdsfilters.TLSTransportProtocol:
		if alpn.Contains("istio-http/1.1") {
			return MTLSHTTP
		}
		if alpn.Contains("istio") {

using different register names.

Examples:

	ADC R24, R14, R12          <=>     adc x12, x14, x24
	ADDW R26->24, R21, R15     <=>     add w15, w21, w26, asr #24
	FCMPS F2, F3               <=>     fcmp s3, s2
	FCMPD F2, F3               <=>     fcmp d3, d2
	FCVTDH F2, F3              <=>     fcvt h3, d2

2. Go uses .P and .W suffixes to indicate post-increment and pre-increment.

Examples:

		}
	}
}

func TestFMA(t *testing.T) {
	for _, tt := range []struct {
		x, y, z, want float64
	}{
		{2, 3, 4, 10},
		{3, 4, 5, 17},
	} {
		if got := math.FMA(tt.x, tt.y, tt.z); got != tt.want {
			t.Errorf("FMA(%f,%f,%f) = %f, want %f", tt.x, tt.y, tt.z, got, tt.want)
		}
	}

			option{Name: "avx", Feature: &X86.HasAVX},
			option{Name: "avx2", Feature: &X86.HasAVX2},
			option{Name: "bmi1", Feature: &X86.HasBMI1},
			option{Name: "bmi2", Feature: &X86.HasBMI2},
			option{Name: "fma", Feature: &X86.HasFMA})
	}
	if level < 4 {
		// These options are required at level 4. At lower levels
		// they can be turned off.
		options = append(options,
			option{Name: "avx512f", Feature: &X86.HasAVX512F},

}

// See
// - https://developer.mozilla.org/en-US/docs/Glossary/Truthy
// - https://stackoverflow.com/questions/19839952/all-falsey-values-in-javascript/19839953#19839953
// - http://www.ecma-international.org/ecma-262/5.1/#sec-9.2
func TestTruthy(t *testing.T) {
	want := true
	for _, key := range []string{
		"someBool", "someString", "someInt", "someFloat", "someArray", "someDate",
		"stringZero", // "0" is truthy

		{Name: "amxbf16", Feature: &X86.HasAMXBF16},
		{Name: "bmi1", Feature: &X86.HasBMI1},
		{Name: "bmi2", Feature: &X86.HasBMI2},
		{Name: "cx16", Feature: &X86.HasCX16},
		{Name: "erms", Feature: &X86.HasERMS},
		{Name: "fma", Feature: &X86.HasFMA},
		{Name: "osxsave", Feature: &X86.HasOSXSAVE},
		{Name: "pclmulqdq", Feature: &X86.HasPCLMULQDQ},
		{Name: "popcnt", Feature: &X86.HasPOPCNT},
		{Name: "rdrand", Feature: &X86.HasRDRAND},

		t.Errorf("Yn(0, 0) = %g, want %g", f, Inf(-1))
	}
}

var PortableFMA = FMA // hide call from compiler intrinsic; falls back to portable code

func TestFMA(t *testing.T) {
	for _, c := range fmaC {
		got := FMA(c.x, c.y, c.z)
		if !alike(got, c.want) {
			t.Errorf("FMA(%g,%g,%g) == %g; want %g", c.x, c.y, c.z, got, c.want)
		}
		got = PortableFMA(c.x, c.y, c.z)