1 files changed, 87 insertions, 0 deletions
diff --git a/gcc-4.9/libgo/go/hash/crc64/crc64.go b/gcc-4.9/libgo/go/hash/crc64/crc64.go
new file mode 100644
index 000000000..692586798
--- /dev/null
+++ b/gcc-4.9/libgo/go/hash/crc64/crc64.go
@@ -0,0 +1,87 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package crc64 implements the 64-bit cyclic redundancy check, or CRC-64,
+// checksum. See http://en.wikipedia.org/wiki/Cyclic_redundancy_check for
+// information.
+package crc64
+
+import "hash"
+
+// 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
+
+// MakeTable returns the Table constructed from the specified polynomial.
+func MakeTable(poly uint64) *Table {
+	t := new(Table)
+	for i := 0; i < 256; i++ {
+		crc := uint64(i)
+		for j := 0; j < 8; j++ {
+			if crc&1 == 1 {
+				crc = (crc >> 1) ^ poly
+			} else {
+				crc >>= 1
+			}
+		}
+		t[i] = crc
+	}
+	return t
+}
+
+// digest represents the partial evaluation of a checksum.
+type digest struct {
+	crc uint64
+	tab *Table
+}
+
+// New creates a new hash.Hash64 computing the CRC-64 checksum
+// using the polynomial represented by the Table.
+func New(tab *Table) hash.Hash64 { return &digest{0, tab} }
+
+func (d *digest) Size() int { return Size }
+
+func (d *digest) BlockSize() int { return 1 }
+
+func (d *digest) Reset() { d.crc = 0 }
+
+func update(crc uint64, tab *Table, p []byte) uint64 {
+	crc = ^crc
+	for _, v := range p {
+		crc = tab[byte(crc)^v] ^ (crc >> 8)
+	}
+	return ^crc
+}
+
+// Update returns the result of adding the bytes in p to the crc.
+func Update(crc uint64, tab *Table, p []byte) uint64 {
+	return update(crc, tab, p)
+}
+
+func (d *digest) Write(p []byte) (n int, err error) {
+	d.crc = update(d.crc, d.tab, p)
+	return len(p), nil
+}
+
+func (d *digest) Sum64() uint64 { return d.crc }
+
+func (d *digest) Sum(in []byte) []byte {
+	s := d.Sum64()
+	return append(in, byte(s>>56), byte(s>>48), byte(s>>40), byte(s>>32), byte(s>>24), byte(s>>16), byte(s>>8), byte(s))
+}
+
+// Checksum returns the CRC-64 checksum of data
+// using the polynomial represented by the Table.
+func Checksum(data []byte, tab *Table) uint64 { return update(0, tab, data) }