obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.

if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
files in the upstream repository.

7 files changed, 2154 insertions, 0 deletions

diff --git a/libgo/go/bytes/buffer.go b/libgo/go/bytes/buffer.go
new file mode 100644
index 000000000..62cf82810
--- /dev/null
+++ b/libgo/go/bytes/buffer.go
@@ -0,0 +1,315 @@
+// 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 bytes
+
+// Simple byte buffer for marshaling data.
+
+import (
+	"io"
+	"os"
+	"utf8"
+)
+
+// A Buffer is a variable-sized buffer of bytes with Read and Write methods.
+// The zero value for Buffer is an empty buffer ready to use.
+type Buffer struct {
+	buf       []byte            // contents are the bytes buf[off : len(buf)]
+	off       int               // read at &buf[off], write at &buf[len(buf)]
+	runeBytes [utf8.UTFMax]byte // avoid allocation of slice on each WriteByte or Rune
+	bootstrap [64]byte          // memory to hold first slice; helps small buffers (Printf) avoid allocation.
+	lastRead  readOp            // last read operation, so that Unread* can work correctly.
+}
+
+// The readOp constants describe the last action performed on
+// the buffer, so that UnreadRune and UnreadByte can
+// check for invalid usage.
+type readOp int
+
+const (
+	opInvalid  readOp = iota // Non-read operation.
+	opReadRune               // Read rune.
+	opRead                   // Any other read operation.
+)
+
+// Bytes returns a slice of the contents of the unread portion of the buffer;
+// len(b.Bytes()) == b.Len().  If the caller changes the contents of the
+// returned slice, the contents of the buffer will change provided there
+// are no intervening method calls on the Buffer.
+func (b *Buffer) Bytes() []byte { return b.buf[b.off:] }
+
+// String returns the contents of the unread portion of the buffer
+// as a string.  If the Buffer is a nil pointer, it returns "<nil>".
+func (b *Buffer) String() string {
+	if b == nil {
+		// Special case, useful in debugging.
+		return "<nil>"
+	}
+	return string(b.buf[b.off:])
+}
+
+// Len returns the number of bytes of the unread portion of the buffer;
+// b.Len() == len(b.Bytes()).
+func (b *Buffer) Len() int { return len(b.buf) - b.off }
+
+// Truncate discards all but the first n unread bytes from the buffer.
+// It is an error to call b.Truncate(n) with n > b.Len().
+func (b *Buffer) Truncate(n int) {
+	b.lastRead = opInvalid
+	if n == 0 {
+		// Reuse buffer space.
+		b.off = 0
+	}
+	b.buf = b.buf[0 : b.off+n]
+}
+
+// Reset resets the buffer so it has no content.
+// b.Reset() is the same as b.Truncate(0).
+func (b *Buffer) Reset() { b.Truncate(0) }
+
+// Grow buffer to guarantee space for n more bytes.
+// Return index where bytes should be written.
+func (b *Buffer) grow(n int) int {
+	m := b.Len()
+	// If buffer is empty, reset to recover space.
+	if m == 0 && b.off != 0 {
+		b.Truncate(0)
+	}
+	if len(b.buf)+n > cap(b.buf) {
+		var buf []byte
+		if b.buf == nil && n <= len(b.bootstrap) {
+			buf = b.bootstrap[0:]
+		} else {
+			// not enough space anywhere
+			buf = make([]byte, 2*cap(b.buf)+n)
+			copy(buf, b.buf[b.off:])
+		}
+		b.buf = buf
+		b.off = 0
+	}
+	b.buf = b.buf[0 : b.off+m+n]
+	return b.off + m
+}
+
+// Write appends the contents of p to the buffer.  The return
+// value n is the length of p; err is always nil.
+func (b *Buffer) Write(p []byte) (n int, err os.Error) {
+	b.lastRead = opInvalid
+	m := b.grow(len(p))
+	copy(b.buf[m:], p)
+	return len(p), nil
+}
+
+// WriteString appends the contents of s to the buffer.  The return
+// value n is the length of s; err is always nil.
+func (b *Buffer) WriteString(s string) (n int, err os.Error) {
+	b.lastRead = opInvalid
+	m := b.grow(len(s))
+	return copy(b.buf[m:], s), nil
+}
+
+// MinRead is the minimum slice size passed to a Read call by
+// Buffer.ReadFrom.  As long as the Buffer has at least MinRead bytes beyond
+// what is required to hold the contents of r, ReadFrom will not grow the
+// underlying buffer.
+const MinRead = 512
+
+// ReadFrom reads data from r until EOF and appends it to the buffer.
+// The return value n is the number of bytes read.
+// Any error except os.EOF encountered during the read
+// is also returned.
+func (b *Buffer) ReadFrom(r io.Reader) (n int64, err os.Error) {
+	b.lastRead = opInvalid
+	// If buffer is empty, reset to recover space.
+	if b.off >= len(b.buf) {
+		b.Truncate(0)
+	}
+	for {
+		if cap(b.buf)-len(b.buf) < MinRead {
+			var newBuf []byte
+			// can we get space without allocation?
+			if b.off+cap(b.buf)-len(b.buf) >= MinRead {
+				// reuse beginning of buffer
+				newBuf = b.buf[0 : len(b.buf)-b.off]
+			} else {
+				// not enough space at end; put space on end
+				newBuf = make([]byte, len(b.buf)-b.off, 2*(cap(b.buf)-b.off)+MinRead)
+			}
+			copy(newBuf, b.buf[b.off:])
+			b.buf = newBuf
+			b.off = 0
+		}
+		m, e := r.Read(b.buf[len(b.buf):cap(b.buf)])
+		b.buf = b.buf[0 : len(b.buf)+m]
+		n += int64(m)
+		if e == os.EOF {
+			break
+		}
+		if e != nil {
+			return n, e
+		}
+	}
+	return n, nil // err is EOF, so return nil explicitly
+}
+
+// WriteTo writes data to w until the buffer is drained or an error
+// occurs. The return value n is the number of bytes written.
+// Any error encountered during the write is also returned.
+func (b *Buffer) WriteTo(w io.Writer) (n int64, err os.Error) {
+	b.lastRead = opInvalid
+	for b.off < len(b.buf) {
+		m, e := w.Write(b.buf[b.off:])
+		n += int64(m)
+		b.off += m
+		if e != nil {
+			return n, e
+		}
+	}
+	// Buffer is now empty; reset.
+	b.Truncate(0)
+	return
+}
+
+// WriteByte appends the byte c to the buffer.
+// The returned error is always nil, but is included
+// to match bufio.Writer's WriteByte.
+func (b *Buffer) WriteByte(c byte) os.Error {
+	b.lastRead = opInvalid
+	m := b.grow(1)
+	b.buf[m] = c
+	return nil
+}
+
+// WriteRune appends the UTF-8 encoding of Unicode
+// code point r to the buffer, returning its length and
+// an error, which is always nil but is included
+// to match bufio.Writer's WriteRune.
+func (b *Buffer) WriteRune(r int) (n int, err os.Error) {
+	if r < utf8.RuneSelf {
+		b.WriteByte(byte(r))
+		return 1, nil
+	}
+	n = utf8.EncodeRune(b.runeBytes[0:], r)
+	b.Write(b.runeBytes[0:n])
+	return n, nil
+}
+
+// Read reads the next len(p) bytes from the buffer or until the buffer
+// is drained.  The return value n is the number of bytes read.  If the
+// buffer has no data to return, err is os.EOF even if len(p) is zero;
+// otherwise it is nil.
+func (b *Buffer) Read(p []byte) (n int, err os.Error) {
+	b.lastRead = opInvalid
+	if b.off >= len(b.buf) {
+		// Buffer is empty, reset to recover space.
+		b.Truncate(0)
+		return 0, os.EOF
+	}
+	n = copy(p, b.buf[b.off:])
+	b.off += n
+	if n > 0 {
+		b.lastRead = opRead
+	}
+	return
+}
+
+// Next returns a slice containing the next n bytes from the buffer,
+// advancing the buffer as if the bytes had been returned by Read.
+// If there are fewer than n bytes in the buffer, Next returns the entire buffer.
+// The slice is only valid until the next call to a read or write method.
+func (b *Buffer) Next(n int) []byte {
+	b.lastRead = opInvalid
+	m := b.Len()
+	if n > m {
+		n = m
+	}
+	data := b.buf[b.off : b.off+n]
+	b.off += n
+	if n > 0 {
+		b.lastRead = opRead
+	}
+	return data
+}
+
+// ReadByte reads and returns the next byte from the buffer.
+// If no byte is available, it returns error os.EOF.
+func (b *Buffer) ReadByte() (c byte, err os.Error) {
+	b.lastRead = opInvalid
+	if b.off >= len(b.buf) {
+		// Buffer is empty, reset to recover space.
+		b.Truncate(0)
+		return 0, os.EOF
+	}
+	c = b.buf[b.off]
+	b.off++
+	b.lastRead = opRead
+	return c, nil
+}
+
+// ReadRune reads and returns the next UTF-8-encoded
+// Unicode code point from the buffer.
+// If no bytes are available, the error returned is os.EOF.
+// If the bytes are an erroneous UTF-8 encoding, it
+// consumes one byte and returns U+FFFD, 1.
+func (b *Buffer) ReadRune() (r int, size int, err os.Error) {
+	b.lastRead = opInvalid
+	if b.off >= len(b.buf) {
+		// Buffer is empty, reset to recover space.
+		b.Truncate(0)
+		return 0, 0, os.EOF
+	}
+	b.lastRead = opReadRune
+	c := b.buf[b.off]
+	if c < utf8.RuneSelf {
+		b.off++
+		return int(c), 1, nil
+	}
+	r, n := utf8.DecodeRune(b.buf[b.off:])
+	b.off += n
+	return r, n, nil
+}
+
+// UnreadRune unreads the last rune returned by ReadRune.
+// If the most recent read or write operation on the buffer was
+// not a ReadRune, UnreadRune returns an error.  (In this regard
+// it is stricter than UnreadByte, which will unread the last byte
+// from any read operation.)
+func (b *Buffer) UnreadRune() os.Error {
+	if b.lastRead != opReadRune {
+		return os.ErrorString("bytes.Buffer: UnreadRune: previous operation was not ReadRune")
+	}
+	b.lastRead = opInvalid
+	if b.off > 0 {
+		_, n := utf8.DecodeLastRune(b.buf[0:b.off])
+		b.off -= n
+	}
+	return nil
+}
+
+// UnreadByte unreads the last byte returned by the most recent
+// read operation.  If write has happened since the last read, UnreadByte
+// returns an error.
+func (b *Buffer) UnreadByte() os.Error {
+	if b.lastRead != opReadRune && b.lastRead != opRead {
+		return os.ErrorString("bytes.Buffer: UnreadByte: previous operation was not a read")
+	}
+	b.lastRead = opInvalid
+	if b.off > 0 {
+		b.off--
+	}
+	return nil
+}
+
+// NewBuffer creates and initializes a new Buffer using buf as its initial
+// contents.  It is intended to prepare a Buffer to read existing data.  It
+// can also be used to size the internal buffer for writing.  To do that,
+// buf should have the desired capacity but a length of zero.
+func NewBuffer(buf []byte) *Buffer { return &Buffer{buf: buf} }
+
+// NewBufferString creates and initializes a new Buffer using string s as its
+// initial contents.  It is intended to prepare a buffer to read an existing
+// string.
+func NewBufferString(s string) *Buffer {
+	return &Buffer{buf: []byte(s)}
+}
diff --git a/libgo/go/bytes/buffer_test.go b/libgo/go/bytes/buffer_test.go
new file mode 100644
index 000000000..509793d24
--- /dev/null
+++ b/libgo/go/bytes/buffer_test.go
@@ -0,0 +1,349 @@
+// 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 bytes_test
+
+import (
+	. "bytes"
+	"rand"
+	"testing"
+	"utf8"
+)
+
+
+const N = 10000  // make this bigger for a larger (and slower) test
+var data string  // test data for write tests
+var bytes []byte // test data; same as data but as a slice.
+
+
+func init() {
+	bytes = make([]byte, N)
+	for i := 0; i < N; i++ {
+		bytes[i] = 'a' + byte(i%26)
+	}
+	data = string(bytes)
+}
+
+// Verify that contents of buf match the string s.
+func check(t *testing.T, testname string, buf *Buffer, s string) {
+	bytes := buf.Bytes()
+	str := buf.String()
+	if buf.Len() != len(bytes) {
+		t.Errorf("%s: buf.Len() == %d, len(buf.Bytes()) == %d", testname, buf.Len(), len(bytes))
+	}
+
+	if buf.Len() != len(str) {
+		t.Errorf("%s: buf.Len() == %d, len(buf.String()) == %d", testname, buf.Len(), len(str))
+	}
+
+	if buf.Len() != len(s) {
+		t.Errorf("%s: buf.Len() == %d, len(s) == %d", testname, buf.Len(), len(s))
+	}
+
+	if string(bytes) != s {
+		t.Errorf("%s: string(buf.Bytes()) == %q, s == %q", testname, string(bytes), s)
+	}
+}
+
+
+// Fill buf through n writes of string fus.
+// The initial contents of buf corresponds to the string s;
+// the result is the final contents of buf returned as a string.
+func fillString(t *testing.T, testname string, buf *Buffer, s string, n int, fus string) string {
+	check(t, testname+" (fill 1)", buf, s)
+	for ; n > 0; n-- {
+		m, err := buf.WriteString(fus)
+		if m != len(fus) {
+			t.Errorf(testname+" (fill 2): m == %d, expected %d", m, len(fus))
+		}
+		if err != nil {
+			t.Errorf(testname+" (fill 3): err should always be nil, found err == %s", err)
+		}
+		s += fus
+		check(t, testname+" (fill 4)", buf, s)
+	}
+	return s
+}
+
+
+// Fill buf through n writes of byte slice fub.
+// The initial contents of buf corresponds to the string s;
+// the result is the final contents of buf returned as a string.
+func fillBytes(t *testing.T, testname string, buf *Buffer, s string, n int, fub []byte) string {
+	check(t, testname+" (fill 1)", buf, s)
+	for ; n > 0; n-- {
+		m, err := buf.Write(fub)
+		if m != len(fub) {
+			t.Errorf(testname+" (fill 2): m == %d, expected %d", m, len(fub))
+		}
+		if err != nil {
+			t.Errorf(testname+" (fill 3): err should always be nil, found err == %s", err)
+		}
+		s += string(fub)
+		check(t, testname+" (fill 4)", buf, s)
+	}
+	return s
+}
+
+
+func TestNewBuffer(t *testing.T) {
+	buf := NewBuffer(bytes)
+	check(t, "NewBuffer", buf, data)
+}
+
+
+func TestNewBufferString(t *testing.T) {
+	buf := NewBufferString(data)
+	check(t, "NewBufferString", buf, data)
+}
+
+
+// Empty buf through repeated reads into fub.
+// The initial contents of buf corresponds to the string s.
+func empty(t *testing.T, testname string, buf *Buffer, s string, fub []byte) {
+	check(t, testname+" (empty 1)", buf, s)
+
+	for {
+		n, err := buf.Read(fub)
+		if n == 0 {
+			break
+		}
+		if err != nil {
+			t.Errorf(testname+" (empty 2): err should always be nil, found err == %s", err)
+		}
+		s = s[n:]
+		check(t, testname+" (empty 3)", buf, s)
+	}
+
+	check(t, testname+" (empty 4)", buf, "")
+}
+
+
+func TestBasicOperations(t *testing.T) {
+	var buf Buffer
+
+	for i := 0; i < 5; i++ {
+		check(t, "TestBasicOperations (1)", &buf, "")
+
+		buf.Reset()
+		check(t, "TestBasicOperations (2)", &buf, "")
+
+		buf.Truncate(0)
+		check(t, "TestBasicOperations (3)", &buf, "")
+
+		n, err := buf.Write([]byte(data[0:1]))
+		if n != 1 {
+			t.Errorf("wrote 1 byte, but n == %d", n)
+		}
+		if err != nil {
+			t.Errorf("err should always be nil, but err == %s", err)
+		}
+		check(t, "TestBasicOperations (4)", &buf, "a")
+
+		buf.WriteByte(data[1])
+		check(t, "TestBasicOperations (5)", &buf, "ab")
+
+		n, err = buf.Write([]byte(data[2:26]))
+		if n != 24 {
+			t.Errorf("wrote 25 bytes, but n == %d", n)
+		}
+		check(t, "TestBasicOperations (6)", &buf, string(data[0:26]))
+
+		buf.Truncate(26)
+		check(t, "TestBasicOperations (7)", &buf, string(data[0:26]))
+
+		buf.Truncate(20)
+		check(t, "TestBasicOperations (8)", &buf, string(data[0:20]))
+
+		empty(t, "TestBasicOperations (9)", &buf, string(data[0:20]), make([]byte, 5))
+		empty(t, "TestBasicOperations (10)", &buf, "", make([]byte, 100))
+
+		buf.WriteByte(data[1])
+		c, err := buf.ReadByte()
+		if err != nil {
+			t.Error("ReadByte unexpected eof")
+		}
+		if c != data[1] {
+			t.Errorf("ReadByte wrong value c=%v", c)
+		}
+		c, err = buf.ReadByte()
+		if err == nil {
+			t.Error("ReadByte unexpected not eof")
+		}
+	}
+}
+
+
+func TestLargeStringWrites(t *testing.T) {
+	var buf Buffer
+	for i := 3; i < 30; i += 3 {
+		s := fillString(t, "TestLargeWrites (1)", &buf, "", 5, data)
+		empty(t, "TestLargeStringWrites (2)", &buf, s, make([]byte, len(data)/i))
+	}
+	check(t, "TestLargeStringWrites (3)", &buf, "")
+}
+
+
+func TestLargeByteWrites(t *testing.T) {
+	var buf Buffer
+	for i := 3; i < 30; i += 3 {
+		s := fillBytes(t, "TestLargeWrites (1)", &buf, "", 5, bytes)
+		empty(t, "TestLargeByteWrites (2)", &buf, s, make([]byte, len(data)/i))
+	}
+	check(t, "TestLargeByteWrites (3)", &buf, "")
+}
+
+
+func TestLargeStringReads(t *testing.T) {
+	var buf Buffer
+	for i := 3; i < 30; i += 3 {
+		s := fillString(t, "TestLargeReads (1)", &buf, "", 5, data[0:len(data)/i])
+		empty(t, "TestLargeReads (2)", &buf, s, make([]byte, len(data)))
+	}
+	check(t, "TestLargeStringReads (3)", &buf, "")
+}
+
+
+func TestLargeByteReads(t *testing.T) {
+	var buf Buffer
+	for i := 3; i < 30; i += 3 {
+		s := fillBytes(t, "TestLargeReads (1)", &buf, "", 5, bytes[0:len(bytes)/i])
+		empty(t, "TestLargeReads (2)", &buf, s, make([]byte, len(data)))
+	}
+	check(t, "TestLargeByteReads (3)", &buf, "")
+}
+
+
+func TestMixedReadsAndWrites(t *testing.T) {
+	var buf Buffer
+	s := ""
+	for i := 0; i < 50; i++ {
+		wlen := rand.Intn(len(data))
+		if i%2 == 0 {
+			s = fillString(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, data[0:wlen])
+		} else {
+			s = fillBytes(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, bytes[0:wlen])
+		}
+
+		rlen := rand.Intn(len(data))
+		fub := make([]byte, rlen)
+		n, _ := buf.Read(fub)
+		s = s[n:]
+	}
+	empty(t, "TestMixedReadsAndWrites (2)", &buf, s, make([]byte, buf.Len()))
+}
+
+
+func TestNil(t *testing.T) {
+	var b *Buffer
+	if b.String() != "<nil>" {
+		t.Errorf("expcted <nil>; got %q", b.String())
+	}
+}
+
+
+func TestReadFrom(t *testing.T) {
+	var buf Buffer
+	for i := 3; i < 30; i += 3 {
+		s := fillBytes(t, "TestReadFrom (1)", &buf, "", 5, bytes[0:len(bytes)/i])
+		var b Buffer
+		b.ReadFrom(&buf)
+		empty(t, "TestReadFrom (2)", &b, s, make([]byte, len(data)))
+	}
+}
+
+
+func TestWriteTo(t *testing.T) {
+	var buf Buffer
+	for i := 3; i < 30; i += 3 {
+		s := fillBytes(t, "TestReadFrom (1)", &buf, "", 5, bytes[0:len(bytes)/i])
+		var b Buffer
+		buf.WriteTo(&b)
+		empty(t, "TestReadFrom (2)", &b, s, make([]byte, len(data)))
+	}
+}
+
+
+func TestRuneIO(t *testing.T) {
+	const NRune = 1000
+	// Built a test array while we write the data
+	b := make([]byte, utf8.UTFMax*NRune)
+	var buf Buffer
+	n := 0
+	for r := 0; r < NRune; r++ {
+		size := utf8.EncodeRune(b[n:], r)
+		nbytes, err := buf.WriteRune(r)
+		if err != nil {
+			t.Fatalf("WriteRune(%U) error: %s", r, err)
+		}
+		if nbytes != size {
+			t.Fatalf("WriteRune(%U) expected %d, got %d", r, size, nbytes)
+		}
+		n += size
+	}
+	b = b[0:n]
+
+	// Check the resulting bytes
+	if !Equal(buf.Bytes(), b) {
+		t.Fatalf("incorrect result from WriteRune: %q not %q", buf.Bytes(), b)
+	}
+
+	p := make([]byte, utf8.UTFMax)
+	// Read it back with ReadRune
+	for r := 0; r < NRune; r++ {
+		size := utf8.EncodeRune(p, r)
+		nr, nbytes, err := buf.ReadRune()
+		if nr != r || nbytes != size || err != nil {
+			t.Fatalf("ReadRune(%U) got %U,%d not %U,%d (err=%s)", r, nr, nbytes, r, size, err)
+		}
+	}
+
+	// Check that UnreadRune works
+	buf.Reset()
+	buf.Write(b)
+	for r := 0; r < NRune; r++ {
+		r1, size, _ := buf.ReadRune()
+		if err := buf.UnreadRune(); err != nil {
+			t.Fatalf("UnreadRune(%U) got error %q", r, err)
+		}
+		r2, nbytes, err := buf.ReadRune()
+		if r1 != r2 || r1 != r || nbytes != size || err != nil {
+			t.Fatalf("ReadRune(%U) after UnreadRune got %U,%d not %U,%d (err=%s)", r, r2, nbytes, r, size, err)
+		}
+	}
+}
+
+
+func TestNext(t *testing.T) {
+	b := []byte{0, 1, 2, 3, 4}
+	tmp := make([]byte, 5)
+	for i := 0; i <= 5; i++ {
+		for j := i; j <= 5; j++ {
+			for k := 0; k <= 6; k++ {
+				// 0 <= i <= j <= 5; 0 <= k <= 6
+				// Check that if we start with a buffer
+				// of length j at offset i and ask for
+				// Next(k), we get the right bytes.
+				buf := NewBuffer(b[0:j])
+				n, _ := buf.Read(tmp[0:i])
+				if n != i {
+					t.Fatalf("Read %d returned %d", i, n)
+				}
+				bb := buf.Next(k)
+				want := k
+				if want > j-i {
+					want = j - i
+				}
+				if len(bb) != want {
+					t.Fatalf("in %d,%d: len(Next(%d)) == %d", i, j, k, len(bb))
+				}
+				for l, v := range bb {
+					if v != byte(l+i) {
+						t.Fatalf("in %d,%d: Next(%d)[%d] = %d, want %d", i, j, k, l, v, l+i)
+					}
+				}
+			}
+		}
+	}
+}
diff --git a/libgo/go/bytes/bytes.go b/libgo/go/bytes/bytes.go
new file mode 100644
index 000000000..bfe2ef39d
--- /dev/null
+++ b/libgo/go/bytes/bytes.go
@@ -0,0 +1,602 @@
+// 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.
+
+// The bytes package implements functions for the manipulation of byte slices.
+// Analogous to the facilities of the strings package.
+package bytes
+
+import (
+	"unicode"
+	"utf8"
+)
+
+// Compare returns an integer comparing the two byte arrays lexicographically.
+// The result will be 0 if a==b, -1 if a < b, and +1 if a > b
+func Compare(a, b []byte) int {
+	m := len(a)
+	if m > len(b) {
+		m = len(b)
+	}
+	for i, ac := range a[0:m] {
+		bc := b[i]
+		switch {
+		case ac > bc:
+			return 1
+		case ac < bc:
+			return -1
+		}
+	}
+	switch {
+	case len(a) < len(b):
+		return -1
+	case len(a) > len(b):
+		return 1
+	}
+	return 0
+}
+
+// Equal returns a boolean reporting whether a == b.
+func Equal(a, b []byte) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i, c := range a {
+		if c != b[i] {
+			return false
+		}
+	}
+	return true
+}
+
+// explode splits s into an array of UTF-8 sequences, one per Unicode character (still arrays of bytes),
+// up to a maximum of n byte arrays. Invalid UTF-8 sequences are chopped into individual bytes.
+func explode(s []byte, n int) [][]byte {
+	if n <= 0 {
+		n = len(s)
+	}
+	a := make([][]byte, n)
+	var size int
+	na := 0
+	for len(s) > 0 {
+		if na+1 >= n {
+			a[na] = s
+			na++
+			break
+		}
+		_, size = utf8.DecodeRune(s)
+		a[na] = s[0:size]
+		s = s[size:]
+		na++
+	}
+	return a[0:na]
+}
+
+// Count counts the number of non-overlapping instances of sep in s.
+func Count(s, sep []byte) int {
+	if len(sep) == 0 {
+		return utf8.RuneCount(s) + 1
+	}
+	c := sep[0]
+	n := 0
+	for i := 0; i+len(sep) <= len(s); i++ {
+		if s[i] == c && (len(sep) == 1 || Equal(s[i:i+len(sep)], sep)) {
+			n++
+			i += len(sep) - 1
+		}
+	}
+	return n
+}
+
+// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
+func Index(s, sep []byte) int {
+	n := len(sep)
+	if n == 0 {
+		return 0
+	}
+	c := sep[0]
+	for i := 0; i+n <= len(s); i++ {
+		if s[i] == c && (n == 1 || Equal(s[i:i+n], sep)) {
+			return i
+		}
+	}
+	return -1
+}
+
+func indexBytePortable(s []byte, c byte) int {
+	for i, b := range s {
+		if b == c {
+			return i
+		}
+	}
+	return -1
+}
+
+// LastIndex returns the index of the last instance of sep in s, or -1 if sep is not present in s.
+func LastIndex(s, sep []byte) int {
+	n := len(sep)
+	if n == 0 {
+		return len(s)
+	}
+	c := sep[0]
+	for i := len(s) - n; i >= 0; i-- {
+		if s[i] == c && (n == 1 || Equal(s[i:i+n], sep)) {
+			return i
+		}
+	}
+	return -1
+}
+
+// IndexRune interprets s as a sequence of UTF-8-encoded Unicode code points.
+// It returns the byte index of the first occurrence in s of the given rune.
+// It returns -1 if rune is not present in s.
+func IndexRune(s []byte, rune int) int {
+	for i := 0; i < len(s); {
+		r, size := utf8.DecodeRune(s[i:])
+		if r == rune {
+			return i
+		}
+		i += size
+	}
+	return -1
+}
+
+// IndexAny interprets s as a sequence of UTF-8-encoded Unicode code points.
+// It returns the byte index of the first occurrence in s of any of the Unicode
+// code points in chars.  It returns -1 if chars is empty or if there is no code
+// point in common.
+func IndexAny(s []byte, chars string) int {
+	if len(chars) > 0 {
+		var rune, width int
+		for i := 0; i < len(s); i += width {
+			rune = int(s[i])
+			if rune < utf8.RuneSelf {
+				width = 1
+			} else {
+				rune, width = utf8.DecodeRune(s[i:])
+			}
+			for _, r := range chars {
+				if rune == r {
+					return i
+				}
+			}
+		}
+	}
+	return -1
+}
+
+// LastIndexAny interprets s as a sequence of UTF-8-encoded Unicode code
+// points.  It returns the byte index of the last occurrence in s of any of
+// the Unicode code points in chars.  It returns -1 if chars is empty or if
+// there is no code point in common.
+func LastIndexAny(s []byte, chars string) int {
+	if len(chars) > 0 {
+		for i := len(s); i > 0; {
+			rune, size := utf8.DecodeLastRune(s[0:i])
+			i -= size
+			for _, m := range chars {
+				if rune == m {
+					return i
+				}
+			}
+		}
+	}
+	return -1
+}
+
+// Generic split: splits after each instance of sep,
+// including sepSave bytes of sep in the subarrays.
+func genSplit(s, sep []byte, sepSave, n int) [][]byte {
+	if n == 0 {
+		return nil
+	}
+	if len(sep) == 0 {
+		return explode(s, n)
+	}
+	if n < 0 {
+		n = Count(s, sep) + 1
+	}
+	c := sep[0]
+	start := 0
+	a := make([][]byte, n)
+	na := 0
+	for i := 0; i+len(sep) <= len(s) && na+1 < n; i++ {
+		if s[i] == c && (len(sep) == 1 || Equal(s[i:i+len(sep)], sep)) {
+			a[na] = s[start : i+sepSave]
+			na++
+			start = i + len(sep)
+			i += len(sep) - 1
+		}
+	}
+	a[na] = s[start:]
+	return a[0 : na+1]
+}
+
+// Split slices s into subslices separated by sep and returns a slice of
+// the subslices between those separators.
+// If sep is empty, Split splits after each UTF-8 sequence.
+// The count determines the number of subslices to return:
+//   n > 0: at most n subslices; the last subslice will be the unsplit remainder.
+//   n == 0: the result is nil (zero subslices)
+//   n < 0: all subslices
+func Split(s, sep []byte, n int) [][]byte { return genSplit(s, sep, 0, n) }
+
+// SplitAfter slices s into subslices after each instance of sep and
+// returns a slice of those subslices.
+// If sep is empty, Split splits after each UTF-8 sequence.
+// The count determines the number of subslices to return:
+//   n > 0: at most n subslices; the last subslice will be the unsplit remainder.
+//   n == 0: the result is nil (zero subslices)
+//   n < 0: all subslices
+func SplitAfter(s, sep []byte, n int) [][]byte {
+	return genSplit(s, sep, len(sep), n)
+}
+
+// Fields splits the array s around each instance of one or more consecutive white space
+// characters, returning a slice of subarrays of s or an empty list if s contains only white space.
+func Fields(s []byte) [][]byte {
+	return FieldsFunc(s, unicode.IsSpace)
+}
+
+// FieldsFunc interprets s as a sequence of UTF-8-encoded Unicode code points.
+// It splits the array s at each run of code points c satisfying f(c) and
+// returns a slice of subarrays of s.  If no code points in s satisfy f(c), an
+// empty slice is returned.
+func FieldsFunc(s []byte, f func(int) bool) [][]byte {
+	n := 0
+	inField := false
+	for i := 0; i < len(s); {
+		rune, size := utf8.DecodeRune(s[i:])
+		wasInField := inField
+		inField = !f(rune)
+		if inField && !wasInField {
+			n++
+		}
+		i += size
+	}
+
+	a := make([][]byte, n)
+	na := 0
+	fieldStart := -1
+	for i := 0; i <= len(s) && na < n; {
+		rune, size := utf8.DecodeRune(s[i:])
+		if fieldStart < 0 && size > 0 && !f(rune) {
+			fieldStart = i
+			i += size
+			continue
+		}
+		if fieldStart >= 0 && (size == 0 || f(rune)) {
+			a[na] = s[fieldStart:i]
+			na++
+			fieldStart = -1
+		}
+		if size == 0 {
+			break
+		}
+		i += size
+	}
+	return a[0:na]
+}
+
+// Join concatenates the elements of a to create a single byte array.   The separator
+// sep is placed between elements in the resulting array.
+func Join(a [][]byte, sep []byte) []byte {
+	if len(a) == 0 {
+		return []byte{}
+	}
+	if len(a) == 1 {
+		return a[0]
+	}
+	n := len(sep) * (len(a) - 1)
+	for i := 0; i < len(a); i++ {
+		n += len(a[i])
+	}
+
+	b := make([]byte, n)
+	bp := 0
+	for i := 0; i < len(a); i++ {
+		s := a[i]
+		for j := 0; j < len(s); j++ {
+			b[bp] = s[j]
+			bp++
+		}
+		if i+1 < len(a) {
+			s = sep
+			for j := 0; j < len(s); j++ {
+				b[bp] = s[j]
+				bp++
+			}
+		}
+	}
+	return b
+}
+
+// HasPrefix tests whether the byte array s begins with prefix.
+func HasPrefix(s, prefix []byte) bool {
+	return len(s) >= len(prefix) && Equal(s[0:len(prefix)], prefix)
+}
+
+// HasSuffix tests whether the byte array s ends with suffix.
+func HasSuffix(s, suffix []byte) bool {
+	return len(s) >= len(suffix) && Equal(s[len(s)-len(suffix):], suffix)
+}
+
+// Map returns a copy of the byte array s with all its characters modified
+// according to the mapping function. If mapping returns a negative value, the character is
+// dropped from the string with no replacement.  The characters in s and the
+// output are interpreted as UTF-8-encoded Unicode code points.
+func Map(mapping func(rune int) int, s []byte) []byte {
+	// In the worst case, the array can grow when mapped, making
+	// things unpleasant.  But it's so rare we barge in assuming it's
+	// fine.  It could also shrink but that falls out naturally.
+	maxbytes := len(s) // length of b
+	nbytes := 0        // number of bytes encoded in b
+	b := make([]byte, maxbytes)
+	for i := 0; i < len(s); {
+		wid := 1
+		rune := int(s[i])
+		if rune >= utf8.RuneSelf {
+			rune, wid = utf8.DecodeRune(s[i:])
+		}
+		rune = mapping(rune)
+		if rune >= 0 {
+			if nbytes+utf8.RuneLen(rune) > maxbytes {
+				// Grow the buffer.
+				maxbytes = maxbytes*2 + utf8.UTFMax
+				nb := make([]byte, maxbytes)
+				copy(nb, b[0:nbytes])
+				b = nb
+			}
+			nbytes += utf8.EncodeRune(b[nbytes:maxbytes], rune)
+		}
+		i += wid
+	}
+	return b[0:nbytes]
+}
+
+// Repeat returns a new byte slice consisting of count copies of b.
+func Repeat(b []byte, count int) []byte {
+	nb := make([]byte, len(b)*count)
+	bp := 0
+	for i := 0; i < count; i++ {
+		for j := 0; j < len(b); j++ {
+			nb[bp] = b[j]
+			bp++
+		}
+	}
+	return nb
+}
+
+// ToUpper returns a copy of the byte array s with all Unicode letters mapped to their upper case.
+func ToUpper(s []byte) []byte { return Map(unicode.ToUpper, s) }
+
+// ToUpper returns a copy of the byte array s with all Unicode letters mapped to their lower case.
+func ToLower(s []byte) []byte { return Map(unicode.ToLower, s) }
+
+// ToTitle returns a copy of the byte array s with all Unicode letters mapped to their title case.
+func ToTitle(s []byte) []byte { return Map(unicode.ToTitle, s) }
+
+// ToUpperSpecial returns a copy of the byte array s with all Unicode letters mapped to their
+// upper case, giving priority to the special casing rules.
+func ToUpperSpecial(_case unicode.SpecialCase, s []byte) []byte {
+	return Map(func(r int) int { return _case.ToUpper(r) }, s)
+}
+
+// ToLowerSpecial returns a copy of the byte array s with all Unicode letters mapped to their
+// lower case, giving priority to the special casing rules.
+func ToLowerSpecial(_case unicode.SpecialCase, s []byte) []byte {
+	return Map(func(r int) int { return _case.ToLower(r) }, s)
+}
+
+// ToTitleSpecial returns a copy of the byte array s with all Unicode letters mapped to their
+// title case, giving priority to the special casing rules.
+func ToTitleSpecial(_case unicode.SpecialCase, s []byte) []byte {
+	return Map(func(r int) int { return _case.ToTitle(r) }, s)
+}
+
+
+// isSeparator reports whether the rune could mark a word boundary.
+// TODO: update when package unicode captures more of the properties.
+func isSeparator(rune int) bool {
+	// ASCII alphanumerics and underscore are not separators
+	if rune <= 0x7F {
+		switch {
+		case '0' <= rune && rune <= '9':
+			return false
+		case 'a' <= rune && rune <= 'z':
+			return false
+		case 'A' <= rune && rune <= 'Z':
+			return false
+		case rune == '_':
+			return false
+		}
+		return true
+	}
+	// Letters and digits are not separators
+	if unicode.IsLetter(rune) || unicode.IsDigit(rune) {
+		return false
+	}
+	// Otherwise, all we can do for now is treat spaces as separators.
+	return unicode.IsSpace(rune)
+}
+
+// BUG(r): The rule Title uses for word boundaries does not handle Unicode punctuation properly.
+
+// Title returns a copy of s with all Unicode letters that begin words
+// mapped to their title case.
+func Title(s []byte) []byte {
+	// Use a closure here to remember state.
+	// Hackish but effective. Depends on Map scanning in order and calling
+	// the closure once per rune.
+	prev := ' '
+	return Map(
+		func(r int) int {
+			if isSeparator(prev) {
+				prev = r
+				return unicode.ToTitle(r)
+			}
+			prev = r
+			return r
+		},
+		s)
+}
+
+// TrimLeftFunc returns a subslice of s by slicing off all leading UTF-8-encoded
+// Unicode code points c that satisfy f(c).
+func TrimLeftFunc(s []byte, f func(r int) bool) []byte {
+	i := indexFunc(s, f, false)
+	if i == -1 {
+		return nil
+	}
+	return s[i:]
+}
+
+// TrimRightFunc returns a subslice of s by slicing off all trailing UTF-8
+// encoded Unicode code points c that satisfy f(c).
+func TrimRightFunc(s []byte, f func(r int) bool) []byte {
+	i := lastIndexFunc(s, f, false)
+	if i >= 0 && s[i] >= utf8.RuneSelf {
+		_, wid := utf8.DecodeRune(s[i:])
+		i += wid
+	} else {
+		i++
+	}
+	return s[0:i]
+}
+
+// TrimFunc returns a subslice of s by slicing off all leading and trailing
+// UTF-8-encoded Unicode code points c that satisfy f(c).
+func TrimFunc(s []byte, f func(r int) bool) []byte {
+	return TrimRightFunc(TrimLeftFunc(s, f), f)
+}
+
+// IndexFunc interprets s as a sequence of UTF-8-encoded Unicode code points.
+// It returns the byte index in s of the first Unicode
+// code point satisfying f(c), or -1 if none do.
+func IndexFunc(s []byte, f func(r int) bool) int {
+	return indexFunc(s, f, true)
+}
+
+// LastIndexFunc interprets s as a sequence of UTF-8-encoded Unicode code points.
+// It returns the byte index in s of the last Unicode
+// code point satisfying f(c), or -1 if none do.
+func LastIndexFunc(s []byte, f func(r int) bool) int {
+	return lastIndexFunc(s, f, true)
+}
+
+// indexFunc is the same as IndexFunc except that if
+// truth==false, the sense of the predicate function is
+// inverted.
+func indexFunc(s []byte, f func(r int) bool, truth bool) int {
+	start := 0
+	for start < len(s) {
+		wid := 1
+		rune := int(s[start])
+		if rune >= utf8.RuneSelf {
+			rune, wid = utf8.DecodeRune(s[start:])
+		}
+		if f(rune) == truth {
+			return start
+		}
+		start += wid
+	}
+	return -1
+}
+
+// lastIndexFunc is the same as LastIndexFunc except that if
+// truth==false, the sense of the predicate function is
+// inverted.
+func lastIndexFunc(s []byte, f func(r int) bool, truth bool) int {
+	for i := len(s); i > 0; {
+		rune, size := utf8.DecodeLastRune(s[0:i])
+		i -= size
+		if f(rune) == truth {
+			return i
+		}
+	}
+	return -1
+}
+
+func makeCutsetFunc(cutset string) func(rune int) bool {
+	return func(rune int) bool {
+		for _, c := range cutset {
+			if c == rune {
+				return true
+			}
+		}
+		return false
+	}
+}
+
+// Trim returns a subslice of s by slicing off all leading and
+// trailing UTF-8-encoded Unicode code points contained in cutset.
+func Trim(s []byte, cutset string) []byte {
+	return TrimFunc(s, makeCutsetFunc(cutset))
+}
+
+// TrimLeft returns a subslice of s by slicing off all leading
+// UTF-8-encoded Unicode code points contained in cutset.
+func TrimLeft(s []byte, cutset string) []byte {
+	return TrimLeftFunc(s, makeCutsetFunc(cutset))
+}
+
+// TrimRight returns a subslice of s by slicing off all trailing
+// UTF-8-encoded Unicode code points that are contained in cutset.
+func TrimRight(s []byte, cutset string) []byte {
+	return TrimRightFunc(s, makeCutsetFunc(cutset))
+}
+
+// TrimSpace returns a subslice of s by slicing off all leading and
+// trailing white space, as defined by Unicode.
+func TrimSpace(s []byte) []byte {
+	return TrimFunc(s, unicode.IsSpace)
+}
+
+// Runes returns a slice of runes (Unicode code points) equivalent to s.
+func Runes(s []byte) []int {
+	t := make([]int, utf8.RuneCount(s))
+	i := 0
+	for len(s) > 0 {
+		r, l := utf8.DecodeRune(s)
+		t[i] = r
+		i++
+		s = s[l:]
+	}
+	return t
+}
+
+// Replace returns a copy of the slice s with the first n
+// non-overlapping instances of old replaced by new.
+// If n < 0, there is no limit on the number of replacements.
+func Replace(s, old, new []byte, n int) []byte {
+	if n == 0 {
+		return s // avoid allocation
+	}
+	// Compute number of replacements.
+	if m := Count(s, old); m == 0 {
+		return s // avoid allocation
+	} else if n <= 0 || m < n {
+		n = m
+	}
+
+	// Apply replacements to buffer.
+	t := make([]byte, len(s)+n*(len(new)-len(old)))
+	w := 0
+	start := 0
+	for i := 0; i < n; i++ {
+		j := start
+		if len(old) == 0 {
+			if i > 0 {
+				_, wid := utf8.DecodeRune(s[start:])
+				j += wid
+			}
+		} else {
+			j += Index(s[start:], old)
+		}
+		w += copy(t[w:], s[start:j])
+		w += copy(t[w:], new)
+		start = j + len(old)
+	}
+	w += copy(t[w:], s[start:])
+	return t[0:w]
+}
diff --git a/libgo/go/bytes/bytes_decl.go b/libgo/go/bytes/bytes_decl.go
new file mode 100644
index 000000000..5d2b9e639
--- /dev/null
+++ b/libgo/go/bytes/bytes_decl.go
@@ -0,0 +1,8 @@
+// Copyright 2010 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 bytes
+
+// IndexByte returns the index of the first instance of c in s, or -1 if c is not present in s.
+func IndexByte(s []byte, c byte) int // asm_$GOARCH.s
diff --git a/libgo/go/bytes/bytes_test.go b/libgo/go/bytes/bytes_test.go
new file mode 100644
index 000000000..063686ec5
--- /dev/null
+++ b/libgo/go/bytes/bytes_test.go
@@ -0,0 +1,844 @@
+// 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 bytes_test
+
+import (
+	. "bytes"
+	"testing"
+	"unicode"
+	"utf8"
+)
+
+func eq(a, b []string) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := 0; i < len(a); i++ {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func arrayOfString(a [][]byte) []string {
+	result := make([]string, len(a))
+	for j := 0; j < len(a); j++ {
+		result[j] = string(a[j])
+	}
+	return result
+}
+
+// For ease of reading, the test cases use strings that are converted to byte
+// arrays before invoking the functions.
+
+var abcd = "abcd"
+var faces = "☺☻☹"
+var commas = "1,2,3,4"
+var dots = "1....2....3....4"
+
+type BinOpTest struct {
+	a string
+	b string
+	i int
+}
+
+var comparetests = []BinOpTest{
+	{"", "", 0},
+	{"a", "", 1},
+	{"", "a", -1},
+	{"abc", "abc", 0},
+	{"ab", "abc", -1},
+	{"abc", "ab", 1},
+	{"x", "ab", 1},
+	{"ab", "x", -1},
+	{"x", "a", 1},
+	{"b", "x", -1},
+}
+
+func TestCompare(t *testing.T) {
+	for _, tt := range comparetests {
+		a := []byte(tt.a)
+		b := []byte(tt.b)
+		cmp := Compare(a, b)
+		eql := Equal(a, b)
+		if cmp != tt.i {
+			t.Errorf(`Compare(%q, %q) = %v`, tt.a, tt.b, cmp)
+		}
+		if eql != (tt.i == 0) {
+			t.Errorf(`Equal(%q, %q) = %v`, tt.a, tt.b, eql)
+		}
+	}
+}
+
+var indexTests = []BinOpTest{
+	{"", "", 0},
+	{"", "a", -1},
+	{"", "foo", -1},
+	{"fo", "foo", -1},
+	{"foo", "foo", 0},
+	{"oofofoofooo", "f", 2},
+	{"oofofoofooo", "foo", 4},
+	{"barfoobarfoo", "foo", 3},
+	{"foo", "", 0},
+	{"foo", "o", 1},
+	{"abcABCabc", "A", 3},
+	// cases with one byte strings - test IndexByte and special case in Index()
+	{"", "a", -1},
+	{"x", "a", -1},
+	{"x", "x", 0},
+	{"abc", "a", 0},
+	{"abc", "b", 1},
+	{"abc", "c", 2},
+	{"abc", "x", -1},
+	{"barfoobarfooyyyzzzyyyzzzyyyzzzyyyxxxzzzyyy", "x", 33},
+	{"foofyfoobarfoobar", "y", 4},
+	{"oooooooooooooooooooooo", "r", -1},
+}
+
+var lastIndexTests = []BinOpTest{
+	{"", "", 0},
+	{"", "a", -1},
+	{"", "foo", -1},
+	{"fo", "foo", -1},
+	{"foo", "foo", 0},
+	{"foo", "f", 0},
+	{"oofofoofooo", "f", 7},
+	{"oofofoofooo", "foo", 7},
+	{"barfoobarfoo", "foo", 9},
+	{"foo", "", 3},
+	{"foo", "o", 2},
+	{"abcABCabc", "A", 3},
+	{"abcABCabc", "a", 6},
+}
+
+var indexAnyTests = []BinOpTest{
+	{"", "", -1},
+	{"", "a", -1},
+	{"", "abc", -1},
+	{"a", "", -1},
+	{"a", "a", 0},
+	{"aaa", "a", 0},
+	{"abc", "xyz", -1},
+	{"abc", "xcz", 2},
+	{"ab☺c", "x☺yz", 2},
+	{"aRegExp*", ".(|)*+?^$[]", 7},
+	{dots + dots + dots, " ", -1},
+}
+
+var lastIndexAnyTests = []BinOpTest{
+	{"", "", -1},
+	{"", "a", -1},
+	{"", "abc", -1},
+	{"a", "", -1},
+	{"a", "a", 0},
+	{"aaa", "a", 2},
+	{"abc", "xyz", -1},
+	{"abc", "ab", 1},
+	{"a☺b☻c☹d", "uvw☻xyz", 2 + len("☺")},
+	{"a.RegExp*", ".(|)*+?^$[]", 8},
+	{dots + dots + dots, " ", -1},
+}
+
+var indexRuneTests = []BinOpTest{
+	{"", "a", -1},
+	{"", "☺", -1},
+	{"foo", "☹", -1},
+	{"foo", "o", 1},
+	{"foo☺bar", "☺", 3},
+	{"foo☺☻☹bar", "☹", 9},
+}
+
+// Execute f on each test case.  funcName should be the name of f; it's used
+// in failure reports.
+func runIndexTests(t *testing.T, f func(s, sep []byte) int, funcName string, testCases []BinOpTest) {
+	for _, test := range testCases {
+		a := []byte(test.a)
+		b := []byte(test.b)
+		actual := f(a, b)
+		if actual != test.i {
+			t.Errorf("%s(%q,%q) = %v; want %v", funcName, a, b, actual, test.i)
+		}
+	}
+}
+
+func runIndexAnyTests(t *testing.T, f func(s []byte, chars string) int, funcName string, testCases []BinOpTest) {
+	for _, test := range testCases {
+		a := []byte(test.a)
+		actual := f(a, test.b)
+		if actual != test.i {
+			t.Errorf("%s(%q,%q) = %v; want %v", funcName, a, test.b, actual, test.i)
+		}
+	}
+}
+
+func TestIndex(t *testing.T)     { runIndexTests(t, Index, "Index", indexTests) }
+func TestLastIndex(t *testing.T) { runIndexTests(t, LastIndex, "LastIndex", lastIndexTests) }
+func TestIndexAny(t *testing.T)  { runIndexAnyTests(t, IndexAny, "IndexAny", indexAnyTests) }
+func TestLastIndexAny(t *testing.T) {
+	runIndexAnyTests(t, LastIndexAny, "LastIndexAny", lastIndexAnyTests)
+}
+
+func TestIndexByte(t *testing.T) {
+	for _, tt := range indexTests {
+		if len(tt.b) != 1 {
+			continue
+		}
+		a := []byte(tt.a)
+		b := tt.b[0]
+		pos := IndexByte(a, b)
+		if pos != tt.i {
+			t.Errorf(`IndexByte(%q, '%c') = %v`, tt.a, b, pos)
+		}
+		posp := IndexBytePortable(a, b)
+		if posp != tt.i {
+			t.Errorf(`indexBytePortable(%q, '%c') = %v`, tt.a, b, posp)
+		}
+	}
+}
+
+// test a larger buffer with different sizes and alignments
+func TestIndexByteBig(t *testing.T) {
+	const n = 1024
+	b := make([]byte, n)
+	for i := 0; i < n; i++ {
+		// different start alignments
+		b1 := b[i:]
+		for j := 0; j < len(b1); j++ {
+			b1[j] = 'x'
+			pos := IndexByte(b1, 'x')
+			if pos != j {
+				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
+			}
+			b1[j] = 0
+			pos = IndexByte(b1, 'x')
+			if pos != -1 {
+				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
+			}
+		}
+		// different end alignments
+		b1 = b[:i]
+		for j := 0; j < len(b1); j++ {
+			b1[j] = 'x'
+			pos := IndexByte(b1, 'x')
+			if pos != j {
+				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
+			}
+			b1[j] = 0
+			pos = IndexByte(b1, 'x')
+			if pos != -1 {
+				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
+			}
+		}
+		// different start and end alignments
+		b1 = b[i/2 : n-(i+1)/2]
+		for j := 0; j < len(b1); j++ {
+			b1[j] = 'x'
+			pos := IndexByte(b1, 'x')
+			if pos != j {
+				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
+			}
+			b1[j] = 0
+			pos = IndexByte(b1, 'x')
+			if pos != -1 {
+				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
+			}
+		}
+	}
+}
+
+func TestIndexRune(t *testing.T) {
+	for _, tt := range indexRuneTests {
+		a := []byte(tt.a)
+		r, _ := utf8.DecodeRuneInString(tt.b)
+		pos := IndexRune(a, r)
+		if pos != tt.i {
+			t.Errorf(`IndexRune(%q, '%c') = %v`, tt.a, r, pos)
+		}
+	}
+}
+
+func BenchmarkIndexByte4K(b *testing.B) { bmIndex(b, IndexByte, 4<<10) }
+
+func BenchmarkIndexByte4M(b *testing.B) { bmIndex(b, IndexByte, 4<<20) }
+
+func BenchmarkIndexByte64M(b *testing.B) { bmIndex(b, IndexByte, 64<<20) }
+
+func BenchmarkIndexBytePortable4K(b *testing.B) {
+	bmIndex(b, IndexBytePortable, 4<<10)
+}
+
+func BenchmarkIndexBytePortable4M(b *testing.B) {
+	bmIndex(b, IndexBytePortable, 4<<20)
+}
+
+func BenchmarkIndexBytePortable64M(b *testing.B) {
+	bmIndex(b, IndexBytePortable, 64<<20)
+}
+
+var bmbuf []byte
+
+func bmIndex(b *testing.B, index func([]byte, byte) int, n int) {
+	if len(bmbuf) < n {
+		bmbuf = make([]byte, n)
+	}
+	b.SetBytes(int64(n))
+	buf := bmbuf[0:n]
+	buf[n-1] = 'x'
+	for i := 0; i < b.N; i++ {
+		j := index(buf, 'x')
+		if j != n-1 {
+			println("bad index", j)
+			panic("bad index")
+		}
+	}
+	buf[n-1] = '0'
+}
+
+type ExplodeTest struct {
+	s string
+	n int
+	a []string
+}
+
+var explodetests = []ExplodeTest{
+	{"", -1, []string{}},
+	{abcd, -1, []string{"a", "b", "c", "d"}},
+	{faces, -1, []string{"☺", "☻", "☹"}},
+	{abcd, 2, []string{"a", "bcd"}},
+}
+
+func TestExplode(t *testing.T) {
+	for _, tt := range explodetests {
+		a := Split([]byte(tt.s), nil, tt.n)
+		result := arrayOfString(a)
+		if !eq(result, tt.a) {
+			t.Errorf(`Explode("%s", %d) = %v; want %v`, tt.s, tt.n, result, tt.a)
+			continue
+		}
+		s := Join(a, []byte{})
+		if string(s) != tt.s {
+			t.Errorf(`Join(Explode("%s", %d), "") = "%s"`, tt.s, tt.n, s)
+		}
+	}
+}
+
+
+type SplitTest struct {
+	s   string
+	sep string
+	n   int
+	a   []string
+}
+
+var splittests = []SplitTest{
+	{abcd, "a", 0, nil},
+	{abcd, "a", -1, []string{"", "bcd"}},
+	{abcd, "z", -1, []string{"abcd"}},
+	{abcd, "", -1, []string{"a", "b", "c", "d"}},
+	{commas, ",", -1, []string{"1", "2", "3", "4"}},
+	{dots, "...", -1, []string{"1", ".2", ".3", ".4"}},
+	{faces, "☹", -1, []string{"☺☻", ""}},
+	{faces, "~", -1, []string{faces}},
+	{faces, "", -1, []string{"☺", "☻", "☹"}},
+	{"1 2 3 4", " ", 3, []string{"1", "2", "3 4"}},
+	{"1 2", " ", 3, []string{"1", "2"}},
+	{"123", "", 2, []string{"1", "23"}},
+	{"123", "", 17, []string{"1", "2", "3"}},
+}
+
+func TestSplit(t *testing.T) {
+	for _, tt := range splittests {
+		a := Split([]byte(tt.s), []byte(tt.sep), tt.n)
+		result := arrayOfString(a)
+		if !eq(result, tt.a) {
+			t.Errorf(`Split(%q, %q, %d) = %v; want %v`, tt.s, tt.sep, tt.n, result, tt.a)
+			continue
+		}
+		if tt.n == 0 {
+			continue
+		}
+		s := Join(a, []byte(tt.sep))
+		if string(s) != tt.s {
+			t.Errorf(`Join(Split(%q, %q, %d), %q) = %q`, tt.s, tt.sep, tt.n, tt.sep, s)
+		}
+	}
+}
+
+var splitaftertests = []SplitTest{
+	{abcd, "a", -1, []string{"a", "bcd"}},
+	{abcd, "z", -1, []string{"abcd"}},
+	{abcd, "", -1, []string{"a", "b", "c", "d"}},
+	{commas, ",", -1, []string{"1,", "2,", "3,", "4"}},
+	{dots, "...", -1, []string{"1...", ".2...", ".3...", ".4"}},
+	{faces, "☹", -1, []string{"☺☻☹", ""}},
+	{faces, "~", -1, []string{faces}},
+	{faces, "", -1, []string{"☺", "☻", "☹"}},
+	{"1 2 3 4", " ", 3, []string{"1 ", "2 ", "3 4"}},
+	{"1 2 3", " ", 3, []string{"1 ", "2 ", "3"}},
+	{"1 2", " ", 3, []string{"1 ", "2"}},
+	{"123", "", 2, []string{"1", "23"}},
+	{"123", "", 17, []string{"1", "2", "3"}},
+}
+
+func TestSplitAfter(t *testing.T) {
+	for _, tt := range splitaftertests {
+		a := SplitAfter([]byte(tt.s), []byte(tt.sep), tt.n)
+		result := arrayOfString(a)
+		if !eq(result, tt.a) {
+			t.Errorf(`Split(%q, %q, %d) = %v; want %v`, tt.s, tt.sep, tt.n, result, tt.a)
+			continue
+		}
+		s := Join(a, nil)
+		if string(s) != tt.s {
+			t.Errorf(`Join(Split(%q, %q, %d), %q) = %q`, tt.s, tt.sep, tt.n, tt.sep, s)
+		}
+	}
+}
+
+type FieldsTest struct {
+	s string
+	a []string
+}
+
+var fieldstests = []FieldsTest{
+	{"", []string{}},
+	{" ", []string{}},
+	{" \t ", []string{}},
+	{"  abc  ", []string{"abc"}},
+	{"1 2 3 4", []string{"1", "2", "3", "4"}},
+	{"1  2  3  4", []string{"1", "2", "3", "4"}},
+	{"1\t\t2\t\t3\t4", []string{"1", "2", "3", "4"}},
+	{"1\u20002\u20013\u20024", []string{"1", "2", "3", "4"}},
+	{"\u2000\u2001\u2002", []string{}},
+	{"\n™\t™\n", []string{"™", "™"}},
+	{faces, []string{faces}},
+}
+
+func TestFields(t *testing.T) {
+	for _, tt := range fieldstests {
+		a := Fields([]byte(tt.s))
+		result := arrayOfString(a)
+		if !eq(result, tt.a) {
+			t.Errorf("Fields(%q) = %v; want %v", tt.s, a, tt.a)
+			continue
+		}
+	}
+}
+
+func TestFieldsFunc(t *testing.T) {
+	pred := func(c int) bool { return c == 'X' }
+	var fieldsFuncTests = []FieldsTest{
+		{"", []string{}},
+		{"XX", []string{}},
+		{"XXhiXXX", []string{"hi"}},
+		{"aXXbXXXcX", []string{"a", "b", "c"}},
+	}
+	for _, tt := range fieldsFuncTests {
+		a := FieldsFunc([]byte(tt.s), pred)
+		result := arrayOfString(a)
+		if !eq(result, tt.a) {
+			t.Errorf("FieldsFunc(%q) = %v, want %v", tt.s, a, tt.a)
+		}
+	}
+}
+
+// Test case for any function which accepts and returns a byte array.
+// For ease of creation, we write the byte arrays as strings.
+type StringTest struct {
+	in, out string
+}
+
+var upperTests = []StringTest{
+	{"", ""},
+	{"abc", "ABC"},
+	{"AbC123", "ABC123"},
+	{"azAZ09_", "AZAZ09_"},
+	{"\u0250\u0250\u0250\u0250\u0250", "\u2C6F\u2C6F\u2C6F\u2C6F\u2C6F"}, // grows one byte per char
+}
+
+var lowerTests = []StringTest{
+	{"", ""},
+	{"abc", "abc"},
+	{"AbC123", "abc123"},
+	{"azAZ09_", "azaz09_"},
+	{"\u2C6D\u2C6D\u2C6D\u2C6D\u2C6D", "\u0251\u0251\u0251\u0251\u0251"}, // shrinks one byte per char
+}
+
+const space = "\t\v\r\f\n\u0085\u00a0\u2000\u3000"
+
+var trimSpaceTests = []StringTest{
+	{"", ""},
+	{"abc", "abc"},
+	{space + "abc" + space, "abc"},
+	{" ", ""},
+	{" \t\r\n \t\t\r\r\n\n ", ""},
+	{" \t\r\n x\t\t\r\r\n\n ", "x"},
+	{" \u2000\t\r\n x\t\t\r\r\ny\n \u3000", "x\t\t\r\r\ny"},
+	{"1 \t\r\n2", "1 \t\r\n2"},
+	{" x\x80", "x\x80"},
+	{" x\xc0", "x\xc0"},
+	{"x \xc0\xc0 ", "x \xc0\xc0"},
+	{"x \xc0", "x \xc0"},
+	{"x \xc0 ", "x \xc0"},
+	{"x \xc0\xc0 ", "x \xc0\xc0"},
+	{"x ☺\xc0\xc0 ", "x ☺\xc0\xc0"},
+	{"x ☺ ", "x ☺"},
+}
+
+// Execute f on each test case.  funcName should be the name of f; it's used
+// in failure reports.
+func runStringTests(t *testing.T, f func([]byte) []byte, funcName string, testCases []StringTest) {
+	for _, tc := range testCases {
+		actual := string(f([]byte(tc.in)))
+		if actual != tc.out {
+			t.Errorf("%s(%q) = %q; want %q", funcName, tc.in, actual, tc.out)
+		}
+	}
+}
+
+func tenRunes(rune int) string {
+	r := make([]int, 10)
+	for i := range r {
+		r[i] = rune
+	}
+	return string(r)
+}
+
+// User-defined self-inverse mapping function
+func rot13(rune int) int {
+	step := 13
+	if rune >= 'a' && rune <= 'z' {
+		return ((rune - 'a' + step) % 26) + 'a'
+	}
+	if rune >= 'A' && rune <= 'Z' {
+		return ((rune - 'A' + step) % 26) + 'A'
+	}
+	return rune
+}
+
+func TestMap(t *testing.T) {
+	// Run a couple of awful growth/shrinkage tests
+	a := tenRunes('a')
+
+	// 1.  Grow.  This triggers two reallocations in Map.
+	maxRune := func(rune int) int { return unicode.MaxRune }
+	m := Map(maxRune, []byte(a))
+	expect := tenRunes(unicode.MaxRune)
+	if string(m) != expect {
+		t.Errorf("growing: expected %q got %q", expect, m)
+	}
+
+	// 2. Shrink
+	minRune := func(rune int) int { return 'a' }
+	m = Map(minRune, []byte(tenRunes(unicode.MaxRune)))
+	expect = a
+	if string(m) != expect {
+		t.Errorf("shrinking: expected %q got %q", expect, m)
+	}
+
+	// 3. Rot13
+	m = Map(rot13, []byte("a to zed"))
+	expect = "n gb mrq"
+	if string(m) != expect {
+		t.Errorf("rot13: expected %q got %q", expect, m)
+	}
+
+	// 4. Rot13^2
+	m = Map(rot13, Map(rot13, []byte("a to zed")))
+	expect = "a to zed"
+	if string(m) != expect {
+		t.Errorf("rot13: expected %q got %q", expect, m)
+	}
+
+	// 5. Drop
+	dropNotLatin := func(rune int) int {
+		if unicode.Is(unicode.Latin, rune) {
+			return rune
+		}
+		return -1
+	}
+	m = Map(dropNotLatin, []byte("Hello, 세계"))
+	expect = "Hello"
+	if string(m) != expect {
+		t.Errorf("drop: expected %q got %q", expect, m)
+	}
+}
+
+func TestToUpper(t *testing.T) { runStringTests(t, ToUpper, "ToUpper", upperTests) }
+
+func TestToLower(t *testing.T) { runStringTests(t, ToLower, "ToLower", lowerTests) }
+
+func TestTrimSpace(t *testing.T) { runStringTests(t, TrimSpace, "TrimSpace", trimSpaceTests) }
+
+type RepeatTest struct {
+	in, out string
+	count   int
+}
+
+var RepeatTests = []RepeatTest{
+	{"", "", 0},
+	{"", "", 1},
+	{"", "", 2},
+	{"-", "", 0},
+	{"-", "-", 1},
+	{"-", "----------", 10},
+	{"abc ", "abc abc abc ", 3},
+}
+
+func TestRepeat(t *testing.T) {
+	for _, tt := range RepeatTests {
+		tin := []byte(tt.in)
+		tout := []byte(tt.out)
+		a := Repeat(tin, tt.count)
+		if !Equal(a, tout) {
+			t.Errorf("Repeat(%q, %d) = %q; want %q", tin, tt.count, a, tout)
+			continue
+		}
+	}
+}
+
+func runesEqual(a, b []int) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i, r := range a {
+		if r != b[i] {
+			return false
+		}
+	}
+	return true
+}
+
+type RunesTest struct {
+	in    string
+	out   []int
+	lossy bool
+}
+
+var RunesTests = []RunesTest{
+	{"", []int{}, false},
+	{" ", []int{32}, false},
+	{"ABC", []int{65, 66, 67}, false},
+	{"abc", []int{97, 98, 99}, false},
+	{"\u65e5\u672c\u8a9e", []int{26085, 26412, 35486}, false},
+	{"ab\x80c", []int{97, 98, 0xFFFD, 99}, true},
+	{"ab\xc0c", []int{97, 98, 0xFFFD, 99}, true},
+}
+
+func TestRunes(t *testing.T) {
+	for _, tt := range RunesTests {
+		tin := []byte(tt.in)
+		a := Runes(tin)
+		if !runesEqual(a, tt.out) {
+			t.Errorf("Runes(%q) = %v; want %v", tin, a, tt.out)
+			continue
+		}
+		if !tt.lossy {
+			// can only test reassembly if we didn't lose information
+			s := string(a)
+			if s != tt.in {
+				t.Errorf("string(Runes(%q)) = %x; want %x", tin, s, tin)
+			}
+		}
+	}
+}
+
+
+type TrimTest struct {
+	f               func([]byte, string) []byte
+	in, cutset, out string
+}
+
+var trimTests = []TrimTest{
+	{Trim, "abba", "a", "bb"},
+	{Trim, "abba", "ab", ""},
+	{TrimLeft, "abba", "ab", ""},
+	{TrimRight, "abba", "ab", ""},
+	{TrimLeft, "abba", "a", "bba"},
+	{TrimRight, "abba", "a", "abb"},
+	{Trim, "<tag>", "<>", "tag"},
+	{Trim, "* listitem", " *", "listitem"},
+	{Trim, `"quote"`, `"`, "quote"},
+	{Trim, "\u2C6F\u2C6F\u0250\u0250\u2C6F\u2C6F", "\u2C6F", "\u0250\u0250"},
+	//empty string tests
+	{Trim, "abba", "", "abba"},
+	{Trim, "", "123", ""},
+	{Trim, "", "", ""},
+	{TrimLeft, "abba", "", "abba"},
+	{TrimLeft, "", "123", ""},
+	{TrimLeft, "", "", ""},
+	{TrimRight, "abba", "", "abba"},
+	{TrimRight, "", "123", ""},
+	{TrimRight, "", "", ""},
+	{TrimRight, "☺\xc0", "☺", "☺\xc0"},
+}
+
+func TestTrim(t *testing.T) {
+	for _, tc := range trimTests {
+		actual := string(tc.f([]byte(tc.in), tc.cutset))
+		var name string
+		switch tc.f {
+		case Trim:
+			name = "Trim"
+		case TrimLeft:
+			name = "TrimLeft"
+		case TrimRight:
+			name = "TrimRight"
+		default:
+			t.Error("Undefined trim function")
+		}
+		if actual != tc.out {
+			t.Errorf("%s(%q, %q) = %q; want %q", name, tc.in, tc.cutset, actual, tc.out)
+		}
+	}
+}
+
+type predicate struct {
+	f    func(r int) bool
+	name string
+}
+
+var isSpace = predicate{unicode.IsSpace, "IsSpace"}
+var isDigit = predicate{unicode.IsDigit, "IsDigit"}
+var isUpper = predicate{unicode.IsUpper, "IsUpper"}
+var isValidRune = predicate{
+	func(r int) bool {
+		return r != utf8.RuneError
+	},
+	"IsValidRune",
+}
+
+type TrimFuncTest struct {
+	f       predicate
+	in, out string
+}
+
+func not(p predicate) predicate {
+	return predicate{
+		func(r int) bool {
+			return !p.f(r)
+		},
+		"not " + p.name,
+	}
+}
+
+var trimFuncTests = []TrimFuncTest{
+	{isSpace, space + " hello " + space, "hello"},
+	{isDigit, "\u0e50\u0e5212hello34\u0e50\u0e51", "hello"},
+	{isUpper, "\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", "hello"},
+	{not(isSpace), "hello" + space + "hello", space},
+	{not(isDigit), "hello\u0e50\u0e521234\u0e50\u0e51helo", "\u0e50\u0e521234\u0e50\u0e51"},
+	{isValidRune, "ab\xc0a\xc0cd", "\xc0a\xc0"},
+	{not(isValidRune), "\xc0a\xc0", "a"},
+}
+
+func TestTrimFunc(t *testing.T) {
+	for _, tc := range trimFuncTests {
+		actual := string(TrimFunc([]byte(tc.in), tc.f.f))
+		if actual != tc.out {
+			t.Errorf("TrimFunc(%q, %q) = %q; want %q", tc.in, tc.f.name, actual, tc.out)
+		}
+	}
+}
+
+type IndexFuncTest struct {
+	in          string
+	f           predicate
+	first, last int
+}
+
+var indexFuncTests = []IndexFuncTest{
+	{"", isValidRune, -1, -1},
+	{"abc", isDigit, -1, -1},
+	{"0123", isDigit, 0, 3},
+	{"a1b", isDigit, 1, 1},
+	{space, isSpace, 0, len(space) - 3}, // last rune in space is 3 bytes
+	{"\u0e50\u0e5212hello34\u0e50\u0e51", isDigit, 0, 18},
+	{"\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", isUpper, 0, 34},
+	{"12\u0e50\u0e52hello34\u0e50\u0e51", not(isDigit), 8, 12},
+
+	// tests of invalid UTF-8
+	{"\x801", isDigit, 1, 1},
+	{"\x80abc", isDigit, -1, -1},
+	{"\xc0a\xc0", isValidRune, 1, 1},
+	{"\xc0a\xc0", not(isValidRune), 0, 2},
+	{"\xc0☺\xc0", not(isValidRune), 0, 4},
+	{"\xc0☺\xc0\xc0", not(isValidRune), 0, 5},
+	{"ab\xc0a\xc0cd", not(isValidRune), 2, 4},
+	{"a\xe0\x80cd", not(isValidRune), 1, 2},
+}
+
+func TestIndexFunc(t *testing.T) {
+	for _, tc := range indexFuncTests {
+		first := IndexFunc([]byte(tc.in), tc.f.f)
+		if first != tc.first {
+			t.Errorf("IndexFunc(%q, %s) = %d; want %d", tc.in, tc.f.name, first, tc.first)
+		}
+		last := LastIndexFunc([]byte(tc.in), tc.f.f)
+		if last != tc.last {
+			t.Errorf("LastIndexFunc(%q, %s) = %d; want %d", tc.in, tc.f.name, last, tc.last)
+		}
+	}
+}
+
+type ReplaceTest struct {
+	in       string
+	old, new string
+	n        int
+	out      string
+}
+
+var ReplaceTests = []ReplaceTest{
+	{"hello", "l", "L", 0, "hello"},
+	{"hello", "l", "L", -1, "heLLo"},
+	{"hello", "x", "X", -1, "hello"},
+	{"", "x", "X", -1, ""},
+	{"radar", "r", "<r>", -1, "<r>ada<r>"},
+	{"", "", "<>", -1, "<>"},
+	{"banana", "a", "<>", -1, "b<>n<>n<>"},
+	{"banana", "a", "<>", 1, "b<>nana"},
+	{"banana", "a", "<>", 1000, "b<>n<>n<>"},
+	{"banana", "an", "<>", -1, "b<><>a"},
+	{"banana", "ana", "<>", -1, "b<>na"},
+	{"banana", "", "<>", -1, "<>b<>a<>n<>a<>n<>a<>"},
+	{"banana", "", "<>", 10, "<>b<>a<>n<>a<>n<>a<>"},
+	{"banana", "", "<>", 6, "<>b<>a<>n<>a<>n<>a"},
+	{"banana", "", "<>", 5, "<>b<>a<>n<>a<>na"},
+	{"banana", "", "<>", 1, "<>banana"},
+	{"banana", "a", "a", -1, "banana"},
+	{"banana", "a", "a", 1, "banana"},
+	{"☺☻☹", "", "<>", -1, "<>☺<>☻<>☹<>"},
+}
+
+func TestReplace(t *testing.T) {
+	for _, tt := range ReplaceTests {
+		if s := string(Replace([]byte(tt.in), []byte(tt.old), []byte(tt.new), tt.n)); s != tt.out {
+			t.Errorf("Replace(%q, %q, %q, %d) = %q, want %q", tt.in, tt.old, tt.new, tt.n, s, tt.out)
+		}
+	}
+}
+
+type TitleTest struct {
+	in, out string
+}
+
+var TitleTests = []TitleTest{
+	{"", ""},
+	{"a", "A"},
+	{" aaa aaa aaa ", " Aaa Aaa Aaa "},
+	{" Aaa Aaa Aaa ", " Aaa Aaa Aaa "},
+	{"123a456", "123a456"},
+	{"double-blind", "Double-Blind"},
+	{"ÿøû", "Ÿøû"},
+}
+
+func TestTitle(t *testing.T) {
+	for _, tt := range TitleTests {
+		if s := string(Title([]byte(tt.in))); s != tt.out {
+			t.Errorf("Title(%q) = %q, want %q", tt.in, s, tt.out)
+		}
+	}
+}
diff --git a/libgo/go/bytes/export_test.go b/libgo/go/bytes/export_test.go
new file mode 100644
index 000000000..b65428d9c
--- /dev/null
+++ b/libgo/go/bytes/export_test.go
@@ -0,0 +1,8 @@
+// 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 bytes
+
+// Export func for testing
+var IndexBytePortable = indexBytePortable
diff --git a/libgo/go/bytes/indexbyte.c b/libgo/go/bytes/indexbyte.c
new file mode 100644
index 000000000..a0a963e93
--- /dev/null
+++ b/libgo/go/bytes/indexbyte.c
@@ -0,0 +1,28 @@
+/* indexbyte.c -- implement bytes.IndexByte for Go.
+
+   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.  */
+
+#include <stddef.h>
+
+#include "array.h"
+
+/* This is in C so that the compiler can optimize it appropriately.
+   We deliberately don't split the stack in case it does call the
+   library function, which shouldn't need much stack space.  */
+
+int IndexByte (struct __go_open_array, char)
+  asm ("libgo_bytes.bytes.IndexByte")
+  __attribute__ ((no_split_stack));
+
+int
+IndexByte (struct __go_open_array s, char b)
+{
+  char *p;
+
+  p = __builtin_memchr (s.__values, b, s.__count);
+  if (p == NULL)
+    return -1;
+  return p - (char *) s.__values;
+}