Boost performance of QChar::isLetterOrNumber

Make it inline; add fast checks for ascii letters
and digits; add fallback function that uses the
fastcall calling convention.

On ia32, this change makes isLetterOrNumber ~120x
faster for ascii letters and digits, ~150x faster
for non-letter/digit ascii characters, and ~1.3x
faster for non-ascii characters.

Note that this change is NOT binary compatible.

Also add an autotest with expected results from
before the optimization, to ensure that the
behavior is the same.

Change-Id: Ia4e13692f4dd79f6aa0b96da29449e0487971b0e
Reviewed-on: http://codereview.qt-project.org/4904
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

3 files changed, 41 insertions, 3 deletions

diff --git a/src/corelib/tools/qchar.cpp b/src/corelib/tools/qchar.cpp
index a1978037c1..56773bd527 100644
--- a/src/corelib/tools/qchar.cpp
+++ b/src/corelib/tools/qchar.cpp
@@ -591,10 +591,17 @@ bool QChar::isNumber() const
 }
 
 /*!
+    \fn bool QChar::isLetterOrNumber() const
+
     Returns true if the character is a letter or number (Letter_* or
     Number_* categories); otherwise returns false.
 */
-bool QChar::isLetterOrNumber() const
+
+/*!
+    \internal
+    \overload
+*/
+bool QChar::isLetterOrNumber(ushort ucs2)
 {
     const int test = FLAG(Letter_Uppercase) |
                      FLAG(Letter_Lowercase) |
@@ -604,7 +611,7 @@ bool QChar::isLetterOrNumber() const
                      FLAG(Number_DecimalDigit) |
                      FLAG(Number_Letter) |
                      FLAG(Number_Other);
-    return FLAG(qGetProp(ucs)->category) & test;
+    return FLAG(qGetProp(ucs2)->category) & test;
 }
 
 /*!
diff --git a/src/corelib/tools/qchar.h b/src/corelib/tools/qchar.h
index fc5a9b051d..36e185ebce 100644
--- a/src/corelib/tools/qchar.h
+++ b/src/corelib/tools/qchar.h
@@ -240,7 +240,13 @@ public:
                 || (ucs > 127 && isLetter(ucs));
     }
     bool isNumber() const;
-    bool isLetterOrNumber() const;
+    inline bool isLetterOrNumber() const
+    {
+        return (ucs >= 'a' && ucs <= 'z')
+                || (ucs <= 'Z' && ucs >= 'A')
+                || (ucs <= '9' && ucs >= '0')
+                || (ucs > 127 && isLetterOrNumber(ucs));
+    }
     inline bool isDigit() const
     { return (ucs <= '9' && ucs >= '0') || (ucs > 127 && isDigit(ucs)); }
     bool isSymbol() const;
@@ -322,6 +328,7 @@ public:
 private:
     static bool QT_FASTCALL isDigit(ushort ucs2);
     static bool QT_FASTCALL isLetter(ushort ucs2);
+    static bool QT_FASTCALL isLetterOrNumber(ushort ucs2);
 
 #ifdef QT_NO_CAST_FROM_ASCII
     QChar(char c);
diff --git a/tests/auto/corelib/tools/qchar/tst_qchar.cpp b/tests/auto/corelib/tools/qchar/tst_qchar.cpp
index 0c51422f75..f16d32a4f9 100644
--- a/tests/auto/corelib/tools/qchar/tst_qchar.cpp
+++ b/tests/auto/corelib/tools/qchar/tst_qchar.cpp
@@ -77,6 +77,8 @@ private slots:
     void isDigit();
     void isLetter_data();
     void isLetter();
+    void isLetterOrNumber_data();
+    void isLetterOrNumber();
     void isPrint();
     void isUpper();
     void isLower();
@@ -273,6 +275,28 @@ void tst_QChar::isLetter()
     QCOMPARE(QChar(ucs).isLetter(), expected);
 }
 
+void tst_QChar::isLetterOrNumber_data()
+{
+    QTest::addColumn<ushort>("ucs");
+    QTest::addColumn<bool>("expected");
+
+    for (ushort ucs = 0; ucs < 256; ++ucs) {
+        bool isLetterOrNumber = isExpectedLetter(ucs)
+                || (ucs >= '0' && ucs <= '9')
+                || ucs == 0xB2 || ucs == 0xB3 || ucs == 0xB9
+                || (ucs >= 0xBC && ucs <= 0xBE);
+        QString tag = QString::fromLatin1("0x%0").arg(QString::number(ucs, 16));
+        QTest::newRow(tag.toLatin1()) << ucs << isLetterOrNumber;
+    }
+}
+
+void tst_QChar::isLetterOrNumber()
+{
+    QFETCH(ushort, ucs);
+    QFETCH(bool, expected);
+    QCOMPARE(QChar(ucs).isLetterOrNumber(), expected);
+}
+
 void tst_QChar::isPrint()
 {
     QVERIFY(QChar('A').isPrint());