libgo: Update to current sources.

From-SVN: r192704

9 files changed, 132 insertions, 145 deletions

diff --git a/libgo/go/hash/adler32/adler32.go b/libgo/go/hash/adler32/adler32.go
index 64fe68c..7c80796 100644
--- a/libgo/go/hash/adler32/adler32.go
+++ b/libgo/go/hash/adler32/adler32.go
@@ -3,7 +3,8 @@
 // license that can be found in the LICENSE file.
 
 // Package adler32 implements the Adler-32 checksum.
-// Defined in RFC 1950:
+//
+// It is defined in RFC 1950:
 //	Adler-32 is composed of two sums accumulated per byte: s1 is
 //	the sum of all bytes, s2 is the sum of all s1 values. Both sums
 //	are done modulo 65521. s1 is initialized to 1, s2 to zero.  The
@@ -14,20 +15,22 @@ package adler32
 import "hash"
 
 const (
+	// mod is the largest prime that is less than 65536.
 	mod = 65521
+	// nmax is the largest n such that
+	// 255 * n * (n+1) / 2 + (n+1) * (mod-1) <= 2^32-1.
+	// It is mentioned in RFC 1950 (search for "5552").
+	nmax = 5552
 )
 
 // The size of an Adler-32 checksum in bytes.
 const Size = 4
 
 // digest represents the partial evaluation of a checksum.
-type digest struct {
-	// invariant: (a < mod && b < mod) || a <= b
-	// invariant: a + b + 255 <= 0xffffffff
-	a, b uint32
-}
+// The low 16 bits are s1, the high 16 bits are s2.
+type digest uint32
 
-func (d *digest) Reset() { d.a, d.b = 1, 0 }
+func (d *digest) Reset() { *d = 1 }
 
 // New returns a new hash.Hash32 computing the Adler-32 checksum.
 func New() hash.Hash32 {
@@ -40,47 +43,36 @@ func (d *digest) Size() int { return Size }
 
 func (d *digest) BlockSize() int { return 1 }
 
-// Add p to the running checksum a, b.
-func update(a, b uint32, p []byte) (aa, bb uint32) {
-	for _, pi := range p {
-		a += uint32(pi)
-		b += a
-		// invariant: a <= b
-		if b > (0xffffffff-255)/2 {
-			a %= mod
-			b %= mod
-			// invariant: a < mod && b < mod
-		} else {
-			// invariant: a + b + 255 <= 2 * b + 255 <= 0xffffffff
+// Add p to the running checksum d.
+func update(d digest, p []byte) digest {
+	s1, s2 := uint32(d&0xffff), uint32(d>>16)
+	for len(p) > 0 {
+		var q []byte
+		if len(p) > nmax {
+			p, q = p[:nmax], p[nmax:]
 		}
+		for _, x := range p {
+			s1 += uint32(x)
+			s2 += s1
+		}
+		s1 %= mod
+		s2 %= mod
+		p = q
 	}
-	return a, b
-}
-
-// Return the 32-bit checksum corresponding to a, b.
-func finish(a, b uint32) uint32 {
-	if b >= mod {
-		a %= mod
-		b %= mod
-	}
-	return b<<16 | a
+	return digest(s2<<16 | s1)
 }
 
 func (d *digest) Write(p []byte) (nn int, err error) {
-	d.a, d.b = update(d.a, d.b, p)
+	*d = update(*d, p)
 	return len(p), nil
 }
 
-func (d *digest) Sum32() uint32 { return finish(d.a, d.b) }
+func (d *digest) Sum32() uint32 { return uint32(*d) }
 
 func (d *digest) Sum(in []byte) []byte {
-	s := d.Sum32()
-	in = append(in, byte(s>>24))
-	in = append(in, byte(s>>16))
-	in = append(in, byte(s>>8))
-	in = append(in, byte(s))
-	return in
+	s := uint32(*d)
+	return append(in, byte(s>>24), byte(s>>16), byte(s>>8), byte(s))
 }
 
 // Checksum returns the Adler-32 checksum of data.
-func Checksum(data []byte) uint32 { return finish(update(1, 0, data)) }
+func Checksum(data []byte) uint32 { return uint32(update(1, data)) }
diff --git a/libgo/go/hash/adler32/adler32_test.go b/libgo/go/hash/adler32/adler32_test.go
index 01f931c..0e9c938 100644
--- a/libgo/go/hash/adler32/adler32_test.go
+++ b/libgo/go/hash/adler32/adler32_test.go
@@ -5,26 +5,23 @@
 package adler32
 
 import (
-	"bytes"
-	"io"
+	"strings"
 	"testing"
 )
 
-type _Adler32Test struct {
+var golden = []struct {
 	out uint32
 	in  string
-}
-
-var golden = []_Adler32Test{
-	{0x1, ""},
-	{0x620062, "a"},
-	{0x12600c4, "ab"},
-	{0x24d0127, "abc"},
-	{0x3d8018b, "abcd"},
-	{0x5c801f0, "abcde"},
-	{0x81e0256, "abcdef"},
-	{0xadb02bd, "abcdefg"},
-	{0xe000325, "abcdefgh"},
+}{
+	{0x00000001, ""},
+	{0x00620062, "a"},
+	{0x012600c4, "ab"},
+	{0x024d0127, "abc"},
+	{0x03d8018b, "abcd"},
+	{0x05c801f0, "abcde"},
+	{0x081e0256, "abcdef"},
+	{0x0adb02bd, "abcdefg"},
+	{0x0e000325, "abcdefgh"},
 	{0x118e038e, "abcdefghi"},
 	{0x158603f8, "abcdefghij"},
 	{0x3f090f02, "Discard medicine more than two years old."},
@@ -48,30 +45,61 @@ var golden = []_Adler32Test{
 	{0x91dd304f, "The fugacity of a constituent in a mixture of gases at a given temperature is proportional to its mole fraction.  Lewis-Randall Rule"},
 	{0x2e5d1316, "How can you write a big system without C++?  -Paul Glick"},
 	{0xd0201df6, "'Invariant assertions' is the most elegant programming technique!  -Tom Szymanski"},
+	{0x211297c8, strings.Repeat("\xff", 5548) + "8"},
+	{0xbaa198c8, strings.Repeat("\xff", 5549) + "9"},
+	{0x553499be, strings.Repeat("\xff", 5550) + "0"},
+	{0xf0c19abe, strings.Repeat("\xff", 5551) + "1"},
+	{0x8d5c9bbe, strings.Repeat("\xff", 5552) + "2"},
+	{0x2af69cbe, strings.Repeat("\xff", 5553) + "3"},
+	{0xc9809dbe, strings.Repeat("\xff", 5554) + "4"},
+	{0x69189ebe, strings.Repeat("\xff", 5555) + "5"},
+	{0x86af0001, strings.Repeat("\x00", 1e5)},
+	{0x79660b4d, strings.Repeat("a", 1e5)},
+	{0x110588ee, strings.Repeat("ABCDEFGHIJKLMNOPQRSTUVWXYZ", 1e4)},
+}
+
+// checksum is a slow but simple implementation of the Adler-32 checksum.
+// It is a straight port of the sample code in RFC 1950 section 9.
+func checksum(p []byte) uint32 {
+	s1, s2 := uint32(1), uint32(0)
+	for _, x := range p {
+		s1 = (s1 + uint32(x)) % mod
+		s2 = (s2 + s1) % mod
+	}
+	return s2<<16 | s1
 }
 
 func TestGolden(t *testing.T) {
-	for i := 0; i < len(golden); i++ {
-		g := golden[i]
-		c := New()
-		io.WriteString(c, g.in)
-		s := c.Sum32()
-		if s != g.out {
-			t.Errorf("adler32(%s) = 0x%x want 0x%x", g.in, s, g.out)
-			t.FailNow()
+	for _, g := range golden {
+		in := g.in
+		if len(in) > 220 {
+			in = in[:100] + "..." + in[len(in)-100:]
+		}
+		p := []byte(g.in)
+		if got := checksum(p); got != g.out {
+			t.Errorf("simple implementation: checksum(%q) = 0x%x want 0x%x", in, got, g.out)
+			continue
+		}
+		if got := Checksum(p); got != g.out {
+			t.Errorf("optimized implementation: Checksum(%q) = 0x%x want 0x%x", in, got, g.out)
+			continue
 		}
 	}
 }
 
-func BenchmarkGolden(b *testing.B) {
-	b.StopTimer()
-	c := New()
-	var buf bytes.Buffer
-	for _, g := range golden {
-		buf.Write([]byte(g.in))
+func BenchmarkAdler32KB(b *testing.B) {
+	b.SetBytes(1024)
+	data := make([]byte, 1024)
+	for i := range data {
+		data[i] = byte(i)
 	}
-	b.StartTimer()
+	h := New()
+	in := make([]byte, 0, h.Size())
+
+	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		c.Write(buf.Bytes())
+		h.Reset()
+		h.Write(data)
+		h.Sum(in)
 	}
 }
diff --git a/libgo/go/hash/crc32/crc32.go b/libgo/go/hash/crc32/crc32.go
index 236d778..a2a21a0 100644
--- a/libgo/go/hash/crc32/crc32.go
+++ b/libgo/go/hash/crc32/crc32.go
@@ -123,11 +123,7 @@ func (d *digest) Sum32() uint32 { return d.crc }
 
 func (d *digest) Sum(in []byte) []byte {
 	s := d.Sum32()
-	in = append(in, byte(s>>24))
-	in = append(in, byte(s>>16))
-	in = append(in, byte(s>>8))
-	in = append(in, byte(s))
-	return in
+	return append(in, byte(s>>24), byte(s>>16), byte(s>>8), byte(s))
 }
 
 // Checksum returns the CRC-32 checksum of data
diff --git a/libgo/go/hash/crc32/crc32_amd64.go b/libgo/go/hash/crc32/crc32_amd64.go
index 83349bc..b5bc6d3 100644
--- a/libgo/go/hash/crc32/crc32_amd64.go
+++ b/libgo/go/hash/crc32/crc32_amd64.go
@@ -13,7 +13,7 @@ func haveSSE42() bool
 
 // castagnoliSSE42 is defined in crc_amd64.s and uses the SSE4.2 CRC32
 // instruction.
-func castagnoliSSE42(uint32, []byte) uint32
+func castagnoliSSE42(crc uint32, p []byte) uint32
 
 var sse42 = haveSSE42()
 
diff --git a/libgo/go/hash/crc32/crc32_test.go b/libgo/go/hash/crc32/crc32_test.go
index 7e82dd7..75dc26e 100644
--- a/libgo/go/hash/crc32/crc32_test.go
+++ b/libgo/go/hash/crc32/crc32_test.go
@@ -82,16 +82,18 @@ func TestGolden(t *testing.T) {
 }
 
 func BenchmarkCrc32KB(b *testing.B) {
-	b.StopTimer()
-	data := make([]uint8, 1024)
-	for i := 0; i < 1024; i++ {
-		data[i] = uint8(i)
+	b.SetBytes(1024)
+	data := make([]byte, 1024)
+	for i := range data {
+		data[i] = byte(i)
 	}
-	c := NewIEEE()
-	b.StartTimer()
-	b.SetBytes(int64(len(data)))
+	h := NewIEEE()
+	in := make([]byte, 0, h.Size())
 
+	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		c.Write(data)
+		h.Reset()
+		h.Write(data)
+		h.Sum(in)
 	}
 }
diff --git a/libgo/go/hash/crc64/crc64.go b/libgo/go/hash/crc64/crc64.go
index 5b64390..6925867 100644
--- a/libgo/go/hash/crc64/crc64.go
+++ b/libgo/go/hash/crc64/crc64.go
@@ -79,15 +79,7 @@ func (d *digest) Sum64() uint64 { return d.crc }
 
 func (d *digest) Sum(in []byte) []byte {
 	s := d.Sum64()
-	in = append(in, byte(s>>56))
-	in = append(in, byte(s>>48))
-	in = append(in, byte(s>>40))
-	in = append(in, byte(s>>32))
-	in = append(in, byte(s>>24))
-	in = append(in, byte(s>>16))
-	in = append(in, byte(s>>8))
-	in = append(in, byte(s))
-	return in
+	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
diff --git a/libgo/go/hash/crc64/crc64_test.go b/libgo/go/hash/crc64/crc64_test.go
index e932524..81a87b5 100644
--- a/libgo/go/hash/crc64/crc64_test.go
+++ b/libgo/go/hash/crc64/crc64_test.go
@@ -64,15 +64,18 @@ func TestGolden(t *testing.T) {
 }
 
 func BenchmarkCrc64KB(b *testing.B) {
-	b.StopTimer()
-	data := make([]uint8, 1024)
-	for i := 0; i < 1024; i++ {
-		data[i] = uint8(i)
+	b.SetBytes(1024)
+	data := make([]byte, 1024)
+	for i := range data {
+		data[i] = byte(i)
 	}
-	c := New(tab)
-	b.StartTimer()
+	h := New(tab)
+	in := make([]byte, 0, h.Size())
 
+	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		c.Write(data)
+		h.Reset()
+		h.Write(data)
+		h.Sum(in)
 	}
 }
diff --git a/libgo/go/hash/fnv/fnv.go b/libgo/go/hash/fnv/fnv.go
index ea50198..b5ecd4a 100644
--- a/libgo/go/hash/fnv/fnv.go
+++ b/libgo/go/hash/fnv/fnv.go
@@ -111,44 +111,20 @@ func (s *sum64a) BlockSize() int { return 1 }
 
 func (s *sum32) Sum(in []byte) []byte {
 	v := uint32(*s)
-	in = append(in, byte(v>>24))
-	in = append(in, byte(v>>16))
-	in = append(in, byte(v>>8))
-	in = append(in, byte(v))
-	return in
+	return append(in, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
 }
 
 func (s *sum32a) Sum(in []byte) []byte {
 	v := uint32(*s)
-	in = append(in, byte(v>>24))
-	in = append(in, byte(v>>16))
-	in = append(in, byte(v>>8))
-	in = append(in, byte(v))
-	return in
+	return append(in, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
 }
 
 func (s *sum64) Sum(in []byte) []byte {
 	v := uint64(*s)
-	in = append(in, byte(v>>56))
-	in = append(in, byte(v>>48))
-	in = append(in, byte(v>>40))
-	in = append(in, byte(v>>32))
-	in = append(in, byte(v>>24))
-	in = append(in, byte(v>>16))
-	in = append(in, byte(v>>8))
-	in = append(in, byte(v))
-	return in
+	return append(in, byte(v>>56), byte(v>>48), byte(v>>40), byte(v>>32), byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
 }
 
 func (s *sum64a) Sum(in []byte) []byte {
 	v := uint64(*s)
-	in = append(in, byte(v>>56))
-	in = append(in, byte(v>>48))
-	in = append(in, byte(v>>40))
-	in = append(in, byte(v>>32))
-	in = append(in, byte(v>>24))
-	in = append(in, byte(v>>16))
-	in = append(in, byte(v>>8))
-	in = append(in, byte(v))
-	return in
+	return append(in, byte(v>>56), byte(v>>48), byte(v>>40), byte(v>>32), byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
 }
diff --git a/libgo/go/hash/fnv/fnv_test.go b/libgo/go/hash/fnv/fnv_test.go
index 17454de..89d39b3 100644
--- a/libgo/go/hash/fnv/fnv_test.go
+++ b/libgo/go/hash/fnv/fnv_test.go
@@ -11,8 +11,6 @@ import (
 	"testing"
 )
 
-const testDataSize = 40
-
 type golden struct {
 	sum  []byte
 	text string
@@ -134,34 +132,34 @@ func testIntegrity(t *testing.T, h hash.Hash) {
 	}
 }
 
-func Benchmark32(b *testing.B) {
-	benchmark(b, New32())
+func BenchmarkFnv32KB(b *testing.B) {
+	benchmarkKB(b, New32())
 }
 
-func Benchmark32a(b *testing.B) {
-	benchmark(b, New32a())
+func BenchmarkFnv32aKB(b *testing.B) {
+	benchmarkKB(b, New32a())
 }
 
-func Benchmark64(b *testing.B) {
-	benchmark(b, New64())
+func BenchmarkFnv64KB(b *testing.B) {
+	benchmarkKB(b, New64())
 }
 
-func Benchmark64a(b *testing.B) {
-	benchmark(b, New64a())
+func BenchmarkFnv64aKB(b *testing.B) {
+	benchmarkKB(b, New64a())
 }
 
-func benchmark(b *testing.B, h hash.Hash) {
-	b.ResetTimer()
-	b.SetBytes(testDataSize)
-	data := make([]byte, testDataSize)
+func benchmarkKB(b *testing.B, h hash.Hash) {
+	b.SetBytes(1024)
+	data := make([]byte, 1024)
 	for i := range data {
-		data[i] = byte(i + 'a')
+		data[i] = byte(i)
 	}
+	in := make([]byte, 0, h.Size())
 
-	b.StartTimer()
-	for todo := b.N; todo != 0; todo-- {
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
 		h.Reset()
 		h.Write(data)
-		h.Sum(nil)
+		h.Sum(in)
 	}
 }