// The size of a CRC-32 checksum in bytes.
const Size = 4

// Predefined polynomials.
const (
	// IEEE is by far and away the most common CRC-32 polynomial.
	// Used by ethernet (IEEE 802.3), v.42, fddi, gzip, zip, png, ...
	IEEE = 0xedb88320

	// Castagnoli's polynomial, used in iSCSI.
	// Has better error detection characteristics than IEEE.
	// https://dx.doi.org/10.1109/26.231911
	Castagnoli = 0x82f63b78

	// Koopman's polynomial.

// testGoldenIEEE verifies that the given function returns
// correct IEEE checksums.
func testGoldenIEEE(t *testing.T, crcFunc func(b []byte) uint32) {
	for _, g := range golden {
		if crc := crcFunc([]byte(g.in)); crc != g.ieee {
			t.Errorf("IEEE(%s) = 0x%x want 0x%x", g.in, crc, g.ieee)
		}
	}
}

// testGoldenCastagnoli verifies that the given function returns
// correct IEEE checksums.

// license that can be found in the LICENSE file.

package runtime

import "unsafe"

var inf = float64frombits(0x7FF0000000000000)

// isNaN reports whether f is an IEEE 754 “not-a-number” value.
func isNaN(f float64) (is bool) {
	// IEEE 754 says that only NaNs satisfy f != f.
	return f != f
}

// isFinite reports whether f is neither NaN nor an infinity.
func isFinite(f float64) bool {
	return !isNaN(f - f)
}

//
//go:linkname Float32bits

// Float32bits returns the IEEE 754 binary representation of f,
// with the sign bit of f and the result in the same bit position.
// Float32bits(Float32frombits(x)) == x.
func Float32bits(f float32) uint32 { return *(*uint32)(unsafe.Pointer(&f)) }

// Float32frombits returns the floating-point number corresponding
// to the IEEE 754 binary representation b, with the sign bit of b

//
// csin(z) = -i csinh(iz).
//
// ACCURACY:
//
//                      Relative error:
// arithmetic   domain     # trials      peak         rms
//    DEC       -10,+10      8400       5.3e-17     1.3e-17
//    IEEE      -10,+10     30000       3.8e-16     1.0e-16
// Also tested by csin(casin(z)) = z.

// Sin returns the sine of x.
func Sin(x complex128) complex128 {
	switch re, im := real(x), imag(x); {

	if sign >= 0 {
		v = uvinf
	} else {
		v = uvneginf
	}
	return Float64frombits(v)
}

// NaN returns an IEEE 754 “not-a-number” value.
func NaN() float64 { return Float64frombits(uvnan) }

// IsNaN reports whether f is an IEEE 754 “not-a-number” value.
func IsNaN(f float64) (is bool) {
	// IEEE 754 says that only NaNs satisfy f != f.
	// To avoid the floating-point hardware, could use:
	//	x := Float64bits(f);

	return cpu.ARM64.HasCRC32
}

func archInitIEEE() {
	if !cpu.ARM64.HasCRC32 {
		panic("arch-specific crc32 instruction for IEEE not available")
	}
}

func archUpdateIEEE(crc uint32, p []byte) uint32 {
	if !cpu.ARM64.HasCRC32 {
		panic("arch-specific crc32 instruction for IEEE not available")
	}

	return ^ieeeUpdate(^crc, p)

//
//                      Relative error:
// arithmetic   domain     # trials      peak         rms
//    DEC      -34, 34      10000       1.3e-16     2.5e-17
//    IEEE    -170,-33      20000       2.3e-15     3.3e-16
//    IEEE     -33,  33     20000       9.4e-16     2.2e-16
//    IEEE      33, 171.6   20000       2.3e-15     3.2e-16
//
// Error for arguments outside the test range will be larger

//
//                      Relative error:
// arithmetic   domain     # trials      peak         rms
//    DEC       -10,+10      7000       8.5e-17     1.9e-17
//    IEEE      -10,+10     30000       5.0e-15     1.1e-16
//
// Larger relative error can be observed for z near 1 +i0.
// In IEEE arithmetic the peak absolute error is 5.2e-16, rms
// absolute error 1.0e-16.

// Log returns the natural logarithm of x.
func Log(x complex128) complex128 {

        buf.enc_ndr_small(0); /* minor version */
        buf.enc_ndr_small(this.ptype);
        buf.enc_ndr_small(this.flags);
        buf.enc_ndr_long(0x00000010); /* Little-endian / ASCII / IEEE */
        buf.enc_ndr_short(this.length);
        buf.enc_ndr_short(0); /* length of auth_value */
        buf.enc_ndr_long(this.call_id);
    }


    void decode_header ( NdrBuffer buf ) throws NdrException {