libgo: Update to weekly.2011-12-14.

From-SVN: r183118

4 files changed, 78 insertions, 85 deletions

diff --git a/libgo/go/regexp/exec.go b/libgo/go/regexp/exec.go
index d7057a1..e16a1b5 100644
--- a/libgo/go/regexp/exec.go
+++ b/libgo/go/regexp/exec.go
@@ -1,6 +1,9 @@
 package regexp
 
-import "regexp/syntax"
+import (
+	"io"
+	"regexp/syntax"
+)
 
 // A queue is a 'sparse array' holding pending threads of execution.
 // See http://research.swtch.com/2008/03/using-uninitialized-memory-for-fun-and.html
@@ -34,6 +37,28 @@ type machine struct {
 	pool     []*thread    // pool of available threads
 	matched  bool         // whether a match was found
 	matchcap []int        // capture information for the match
+
+	// cached inputs, to avoid allocation
+	inputBytes  inputBytes
+	inputString inputString
+	inputReader inputReader
+}
+
+func (m *machine) newInputBytes(b []byte) input {
+	m.inputBytes.str = b
+	return &m.inputBytes
+}
+
+func (m *machine) newInputString(s string) input {
+	m.inputString.str = s
+	return &m.inputString
+}
+
+func (m *machine) newInputReader(r io.RuneReader) input {
+	m.inputReader.r = r
+	m.inputReader.atEOT = false
+	m.inputReader.pos = 0
+	return &m.inputReader
 }
 
 // progMachine returns a new machine running the prog p.
@@ -74,6 +99,9 @@ func (m *machine) alloc(i *syntax.Inst) *thread {
 
 // free returns t to the free pool.
 func (m *machine) free(t *thread) {
+	m.inputBytes.str = nil
+	m.inputString.str = ""
+	m.inputReader.r = nil
 	m.pool = append(m.pool, t)
 }
 
@@ -287,8 +315,16 @@ var empty = make([]int, 0)
 
 // doExecute finds the leftmost match in the input and returns
 // the position of its subexpressions.
-func (re *Regexp) doExecute(i input, pos int, ncap int) []int {
+func (re *Regexp) doExecute(r io.RuneReader, b []byte, s string, pos int, ncap int) []int {
 	m := re.get()
+	var i input
+	if r != nil {
+		i = m.newInputReader(r)
+	} else if b != nil {
+		i = m.newInputBytes(b)
+	} else {
+		i = m.newInputString(s)
+	}
 	m.init(ncap)
 	if !m.match(i, pos) {
 		re.put(m)
diff --git a/libgo/go/regexp/exec_test.go b/libgo/go/regexp/exec_test.go
index d981f54..312bf02 100644
--- a/libgo/go/regexp/exec_test.go
+++ b/libgo/go/regexp/exec_test.go
@@ -10,7 +10,6 @@ import (
 	"fmt"
 	"io"
 	"math/rand"
-	old "old/regexp"
 	"os"
 	"path/filepath"
 	"regexp/syntax"
@@ -679,18 +678,6 @@ func benchmark(b *testing.B, re string, n int) {
 	}
 }
 
-func benchold(b *testing.B, re string, n int) {
-	r := old.MustCompile(re)
-	t := makeText(n)
-	b.ResetTimer()
-	b.SetBytes(int64(n))
-	for i := 0; i < b.N; i++ {
-		if r.Match(t) {
-			panic("match!")
-		}
-	}
-}
-
 const (
 	easy0  = "ABCDEFGHIJKLMNOPQRSTUVWXYZ$"
 	easy1  = "A[AB]B[BC]C[CD]D[DE]E[EF]F[FG]G[GH]H[HI]I[IJ]J$"
@@ -700,35 +687,23 @@ const (
 		"(N)(O)(P)(Q)(R)(S)(T)(U)(V)(W)(X)(Y)(Z)$"
 )
 
-func BenchmarkMatchEasy0_1K(b *testing.B)       { benchmark(b, easy0, 1<<10) }
-func BenchmarkMatchEasy0_1K_Old(b *testing.B)   { benchold(b, easy0, 1<<10) }
-func BenchmarkMatchEasy0_1M(b *testing.B)       { benchmark(b, easy0, 1<<20) }
-func BenchmarkMatchEasy0_1M_Old(b *testing.B)   { benchold(b, easy0, 1<<20) }
-func BenchmarkMatchEasy0_32K(b *testing.B)      { benchmark(b, easy0, 32<<10) }
-func BenchmarkMatchEasy0_32K_Old(b *testing.B)  { benchold(b, easy0, 32<<10) }
-func BenchmarkMatchEasy0_32M(b *testing.B)      { benchmark(b, easy0, 32<<20) }
-func BenchmarkMatchEasy0_32M_Old(b *testing.B)  { benchold(b, easy0, 32<<20) }
-func BenchmarkMatchEasy1_1K(b *testing.B)       { benchmark(b, easy1, 1<<10) }
-func BenchmarkMatchEasy1_1K_Old(b *testing.B)   { benchold(b, easy1, 1<<10) }
-func BenchmarkMatchEasy1_1M(b *testing.B)       { benchmark(b, easy1, 1<<20) }
-func BenchmarkMatchEasy1_1M_Old(b *testing.B)   { benchold(b, easy1, 1<<20) }
-func BenchmarkMatchEasy1_32K(b *testing.B)      { benchmark(b, easy1, 32<<10) }
-func BenchmarkMatchEasy1_32K_Old(b *testing.B)  { benchold(b, easy1, 32<<10) }
-func BenchmarkMatchEasy1_32M(b *testing.B)      { benchmark(b, easy1, 32<<20) }
-func BenchmarkMatchEasy1_32M_Old(b *testing.B)  { benchold(b, easy1, 32<<20) }
-func BenchmarkMatchMedium_1K(b *testing.B)      { benchmark(b, medium, 1<<10) }
-func BenchmarkMatchMedium_1K_Old(b *testing.B)  { benchold(b, medium, 1<<10) }
-func BenchmarkMatchMedium_1M(b *testing.B)      { benchmark(b, medium, 1<<20) }
-func BenchmarkMatchMedium_1M_Old(b *testing.B)  { benchold(b, medium, 1<<20) }
-func BenchmarkMatchMedium_32K(b *testing.B)     { benchmark(b, medium, 32<<10) }
-func BenchmarkMatchMedium_32K_Old(b *testing.B) { benchold(b, medium, 32<<10) }
-func BenchmarkMatchMedium_32M(b *testing.B)     { benchmark(b, medium, 32<<20) }
-func BenchmarkMatchMedium_32M_Old(b *testing.B) { benchold(b, medium, 32<<20) }
-func BenchmarkMatchHard_1K(b *testing.B)        { benchmark(b, hard, 1<<10) }
-func BenchmarkMatchHard_1K_Old(b *testing.B)    { benchold(b, hard, 1<<10) }
-func BenchmarkMatchHard_1M(b *testing.B)        { benchmark(b, hard, 1<<20) }
-func BenchmarkMatchHard_1M_Old(b *testing.B)    { benchold(b, hard, 1<<20) }
-func BenchmarkMatchHard_32K(b *testing.B)       { benchmark(b, hard, 32<<10) }
-func BenchmarkMatchHard_32K_Old(b *testing.B)   { benchold(b, hard, 32<<10) }
-func BenchmarkMatchHard_32M(b *testing.B)       { benchmark(b, hard, 32<<20) }
-func BenchmarkMatchHard_32M_Old(b *testing.B)   { benchold(b, hard, 32<<20) }
+func BenchmarkMatchEasy0_32(b *testing.B)   { benchmark(b, easy0, 32<<0) }
+func BenchmarkMatchEasy0_1K(b *testing.B)   { benchmark(b, easy0, 1<<10) }
+func BenchmarkMatchEasy0_32K(b *testing.B)  { benchmark(b, easy0, 32<<10) }
+func BenchmarkMatchEasy0_1M(b *testing.B)   { benchmark(b, easy0, 1<<20) }
+func BenchmarkMatchEasy0_32M(b *testing.B)  { benchmark(b, easy0, 32<<20) }
+func BenchmarkMatchEasy1_32(b *testing.B)   { benchmark(b, easy1, 32<<0) }
+func BenchmarkMatchEasy1_1K(b *testing.B)   { benchmark(b, easy1, 1<<10) }
+func BenchmarkMatchEasy1_32K(b *testing.B)  { benchmark(b, easy1, 32<<10) }
+func BenchmarkMatchEasy1_1M(b *testing.B)   { benchmark(b, easy1, 1<<20) }
+func BenchmarkMatchEasy1_32M(b *testing.B)  { benchmark(b, easy1, 32<<20) }
+func BenchmarkMatchMedium_32(b *testing.B)  { benchmark(b, medium, 1<<0) }
+func BenchmarkMatchMedium_1K(b *testing.B)  { benchmark(b, medium, 1<<10) }
+func BenchmarkMatchMedium_32K(b *testing.B) { benchmark(b, medium, 32<<10) }
+func BenchmarkMatchMedium_1M(b *testing.B)  { benchmark(b, medium, 1<<20) }
+func BenchmarkMatchMedium_32M(b *testing.B) { benchmark(b, medium, 32<<20) }
+func BenchmarkMatchHard_32(b *testing.B)    { benchmark(b, hard, 32<<0) }
+func BenchmarkMatchHard_1K(b *testing.B)    { benchmark(b, hard, 1<<10) }
+func BenchmarkMatchHard_32K(b *testing.B)   { benchmark(b, hard, 32<<10) }
+func BenchmarkMatchHard_1M(b *testing.B)    { benchmark(b, hard, 1<<20) }
+func BenchmarkMatchHard_32M(b *testing.B)   { benchmark(b, hard, 32<<20) }
diff --git a/libgo/go/regexp/regexp.go b/libgo/go/regexp/regexp.go
index 59f3be3..b0c6a0b 100644
--- a/libgo/go/regexp/regexp.go
+++ b/libgo/go/regexp/regexp.go
@@ -240,10 +240,6 @@ type inputString struct {
 	str string
 }
 
-func newInputString(str string) *inputString {
-	return &inputString{str: str}
-}
-
 func (i *inputString) step(pos int) (rune, int) {
 	if pos < len(i.str) {
 		c := i.str[pos]
@@ -283,10 +279,6 @@ type inputBytes struct {
 	str []byte
 }
 
-func newInputBytes(str []byte) *inputBytes {
-	return &inputBytes{str: str}
-}
-
 func (i *inputBytes) step(pos int) (rune, int) {
 	if pos < len(i.str) {
 		c := i.str[pos]
@@ -328,10 +320,6 @@ type inputReader struct {
 	pos   int
 }
 
-func newInputReader(r io.RuneReader) *inputReader {
-	return &inputReader{r: r}
-}
-
 func (i *inputReader) step(pos int) (rune, int) {
 	if !i.atEOT && pos != i.pos {
 		return endOfText, 0
@@ -373,19 +361,19 @@ func (re *Regexp) LiteralPrefix() (prefix string, complete bool) {
 // RuneReader.  The return value is a boolean: true for match, false for no
 // match.
 func (re *Regexp) MatchReader(r io.RuneReader) bool {
-	return re.doExecute(newInputReader(r), 0, 0) != nil
+	return re.doExecute(r, nil, "", 0, 0) != nil
 }
 
 // MatchString returns whether the Regexp matches the string s.
 // The return value is a boolean: true for match, false for no match.
 func (re *Regexp) MatchString(s string) bool {
-	return re.doExecute(newInputString(s), 0, 0) != nil
+	return re.doExecute(nil, nil, s, 0, 0) != nil
 }
 
 // Match returns whether the Regexp matches the byte slice b.
 // The return value is a boolean: true for match, false for no match.
 func (re *Regexp) Match(b []byte) bool {
-	return re.doExecute(newInputBytes(b), 0, 0) != nil
+	return re.doExecute(nil, b, "", 0, 0) != nil
 }
 
 // MatchReader checks whether a textual regular expression matches the text
@@ -437,7 +425,7 @@ func (re *Regexp) ReplaceAllStringFunc(src string, repl func(string) string) str
 	searchPos := 0    // position where we next look for a match
 	buf := new(bytes.Buffer)
 	for searchPos <= len(src) {
-		a := re.doExecute(newInputString(src), searchPos, 2)
+		a := re.doExecute(nil, nil, src, searchPos, 2)
 		if len(a) == 0 {
 			break // no more matches
 		}
@@ -489,7 +477,7 @@ func (re *Regexp) ReplaceAllFunc(src []byte, repl func([]byte) []byte) []byte {
 	searchPos := 0    // position where we next look for a match
 	buf := new(bytes.Buffer)
 	for searchPos <= len(src) {
-		a := re.doExecute(newInputBytes(src), searchPos, 2)
+		a := re.doExecute(nil, src, "", searchPos, 2)
 		if len(a) == 0 {
 			break // no more matches
 		}
@@ -577,13 +565,7 @@ func (re *Regexp) allMatches(s string, b []byte, n int, deliver func([]int)) {
 	}
 
 	for pos, i, prevMatchEnd := 0, 0, -1; i < n && pos <= end; {
-		var in input
-		if b == nil {
-			in = newInputString(s)
-		} else {
-			in = newInputBytes(b)
-		}
-		matches := re.doExecute(in, pos, re.prog.NumCap)
+		matches := re.doExecute(nil, b, s, pos, re.prog.NumCap)
 		if len(matches) == 0 {
 			break
 		}
@@ -623,7 +605,7 @@ func (re *Regexp) allMatches(s string, b []byte, n int, deliver func([]int)) {
 // Find returns a slice holding the text of the leftmost match in b of the regular expression.
 // A return value of nil indicates no match.
 func (re *Regexp) Find(b []byte) []byte {
-	a := re.doExecute(newInputBytes(b), 0, 2)
+	a := re.doExecute(nil, b, "", 0, 2)
 	if a == nil {
 		return nil
 	}
@@ -635,7 +617,7 @@ func (re *Regexp) Find(b []byte) []byte {
 // b[loc[0]:loc[1]].
 // A return value of nil indicates no match.
 func (re *Regexp) FindIndex(b []byte) (loc []int) {
-	a := re.doExecute(newInputBytes(b), 0, 2)
+	a := re.doExecute(nil, b, "", 0, 2)
 	if a == nil {
 		return nil
 	}
@@ -648,7 +630,7 @@ func (re *Regexp) FindIndex(b []byte) (loc []int) {
 // an empty string.  Use FindStringIndex or FindStringSubmatch if it is
 // necessary to distinguish these cases.
 func (re *Regexp) FindString(s string) string {
-	a := re.doExecute(newInputString(s), 0, 2)
+	a := re.doExecute(nil, nil, s, 0, 2)
 	if a == nil {
 		return ""
 	}
@@ -660,7 +642,7 @@ func (re *Regexp) FindString(s string) string {
 // itself is at s[loc[0]:loc[1]].
 // A return value of nil indicates no match.
 func (re *Regexp) FindStringIndex(s string) []int {
-	a := re.doExecute(newInputString(s), 0, 2)
+	a := re.doExecute(nil, nil, s, 0, 2)
 	if a == nil {
 		return nil
 	}
@@ -672,7 +654,7 @@ func (re *Regexp) FindStringIndex(s string) []int {
 // the RuneReader.  The match itself is at s[loc[0]:loc[1]].  A return
 // value of nil indicates no match.
 func (re *Regexp) FindReaderIndex(r io.RuneReader) []int {
-	a := re.doExecute(newInputReader(r), 0, 2)
+	a := re.doExecute(r, nil, "", 0, 2)
 	if a == nil {
 		return nil
 	}
@@ -685,7 +667,7 @@ func (re *Regexp) FindReaderIndex(r io.RuneReader) []int {
 // comment.
 // A return value of nil indicates no match.
 func (re *Regexp) FindSubmatch(b []byte) [][]byte {
-	a := re.doExecute(newInputBytes(b), 0, re.prog.NumCap)
+	a := re.doExecute(nil, b, "", 0, re.prog.NumCap)
 	if a == nil {
 		return nil
 	}
@@ -704,7 +686,7 @@ func (re *Regexp) FindSubmatch(b []byte) [][]byte {
 // in the package comment.
 // A return value of nil indicates no match.
 func (re *Regexp) FindSubmatchIndex(b []byte) []int {
-	return re.pad(re.doExecute(newInputBytes(b), 0, re.prog.NumCap))
+	return re.pad(re.doExecute(nil, b, "", 0, re.prog.NumCap))
 }
 
 // FindStringSubmatch returns a slice of strings holding the text of the
@@ -713,7 +695,7 @@ func (re *Regexp) FindSubmatchIndex(b []byte) []int {
 // package comment.
 // A return value of nil indicates no match.
 func (re *Regexp) FindStringSubmatch(s string) []string {
-	a := re.doExecute(newInputString(s), 0, re.prog.NumCap)
+	a := re.doExecute(nil, nil, s, 0, re.prog.NumCap)
 	if a == nil {
 		return nil
 	}
@@ -732,7 +714,7 @@ func (re *Regexp) FindStringSubmatch(s string) []string {
 // 'Index' descriptions in the package comment.
 // A return value of nil indicates no match.
 func (re *Regexp) FindStringSubmatchIndex(s string) []int {
-	return re.pad(re.doExecute(newInputString(s), 0, re.prog.NumCap))
+	return re.pad(re.doExecute(nil, nil, s, 0, re.prog.NumCap))
 }
 
 // FindReaderSubmatchIndex returns a slice holding the index pairs
@@ -741,7 +723,7 @@ func (re *Regexp) FindStringSubmatchIndex(s string) []int {
 // by the 'Submatch' and 'Index' descriptions in the package comment.  A
 // return value of nil indicates no match.
 func (re *Regexp) FindReaderSubmatchIndex(r io.RuneReader) []int {
-	return re.pad(re.doExecute(newInputReader(r), 0, re.prog.NumCap))
+	return re.pad(re.doExecute(r, nil, "", 0, re.prog.NumCap))
 }
 
 const startSize = 10 // The size at which to start a slice in the 'All' routines.
diff --git a/libgo/go/regexp/syntax/parse.go b/libgo/go/regexp/syntax/parse.go
index 2ad682f..ba641c1 100644
--- a/libgo/go/regexp/syntax/parse.go
+++ b/libgo/go/regexp/syntax/parse.go
@@ -1694,7 +1694,7 @@ func appendFoldedClass(r []rune, x []rune) []rune {
 // appendNegatedClass returns the result of appending the negation of the class x to the class r.
 // It assumes x is clean.
 func appendNegatedClass(r []rune, x []rune) []rune {
-	nextLo := rune('\u0000')
+	nextLo := '\u0000'
 	for i := 0; i < len(x); i += 2 {
 		lo, hi := x[i], x[i+1]
 		if nextLo <= lo-1 {
@@ -1735,7 +1735,7 @@ func appendTable(r []rune, x *unicode.RangeTable) []rune {
 
 // appendNegatedTable returns the result of appending the negation of x to the class r.
 func appendNegatedTable(r []rune, x *unicode.RangeTable) []rune {
-	nextLo := rune('\u0000') // lo end of next class to add
+	nextLo := '\u0000' // lo end of next class to add
 	for _, xr := range x.R16 {
 		lo, hi, stride := rune(xr.Lo), rune(xr.Hi), rune(xr.Stride)
 		if stride == 1 {
@@ -1777,8 +1777,8 @@ func appendNegatedTable(r []rune, x *unicode.RangeTable) []rune {
 // negateClass overwrites r and returns r's negation.
 // It assumes the class r is already clean.
 func negateClass(r []rune) []rune {
-	nextLo := rune('\u0000') // lo end of next class to add
-	w := 0                   // write index
+	nextLo := '\u0000' // lo end of next class to add
+	w := 0             // write index
 	for i := 0; i < len(r); i += 2 {
 		lo, hi := r[i], r[i+1]
 		if nextLo <= lo-1 {