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Boost performance of QChar::isDigit

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

On ia32, this change makes isDigit ~370x faster for
ascii digit characters, ~250x faster for non-digit
ascii characters, and ~1.5x 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: I718fadecda3f591d6f4c22374d8e476f4724fd83
Reviewed-on: http://codereview.qt-project.org/4902
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
This commit is contained in:
Kent Hansen 2011-09-14 12:53:20 +02:00 committed by Qt by Nokia
parent 4cd9d267e7
commit 5639423ea7
3 changed files with 34 additions and 3 deletions
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11
src/corelib/tools/qchar.cpp
View File

@ -601,12 +601,19 @@ bool QChar::isLetterOrNumber() const
}
/*!
\fn bool QChar::isDigit() const
Returns true if the character is a decimal digit
(Number_DecimalDigit); otherwise returns false.
*/
bool QChar::isDigit() const
/*!
\internal
\overload
*/
bool QChar::isDigit(ushort ucs2)
{
return (qGetProp(ucs)->category == Number_DecimalDigit);
return (qGetProp(ucs2)->category == Number_DecimalDigit);
}
/*!

5
src/corelib/tools/qchar.h
View File

@ -237,7 +237,8 @@ public:
bool isLetter() const;
bool isNumber() const;
bool isLetterOrNumber() const;
bool isDigit() const;
inline bool isDigit() const
{ return (ucs <= '9' && ucs >= '0') || (ucs > 127 && isDigit(ucs)); }
bool isSymbol() const;
inline bool isLower() const {
return (ucs >= 'a' && ucs <= 'z')
@ -315,6 +316,8 @@ public:
static QString QT_FASTCALL decomposition(uint ucs4);
private:
static bool QT_FASTCALL isDigit(ushort ucs2);
#ifdef QT_NO_CAST_FROM_ASCII
QChar(char c);
QChar(uchar c);

21
tests/auto/corelib/tools/qchar/tst_qchar.cpp
View File

@ -73,6 +73,8 @@ private slots:
void toLower();
void toTitle();
void toCaseFolded();
void isDigit_data();
void isDigit();
void isPrint();
void isUpper();
void isLower();
@ -223,6 +225,25 @@ void tst_QChar::toCaseFolded()
QVERIFY(QChar::toCaseFolded((ushort)0xb5) == 0x3bc);
}
void tst_QChar::isDigit_data()
{
QTest::addColumn<ushort>("ucs");
QTest::addColumn<bool>("expected");
for (ushort ucs = 0; ucs < 256; ++ucs) {
bool isDigit = (ucs <= '9' && ucs >= '0');
QString tag = QString::fromLatin1("0x%0").arg(QString::number(ucs, 16));
QTest::newRow(tag.toLatin1()) << ucs << isDigit;
}
}
void tst_QChar::isDigit()
{
QFETCH(ushort, ucs);
QFETCH(bool, expected);
QCOMPARE(QChar(ucs).isDigit(), expected);
}
void tst_QChar::isPrint()
{
QVERIFY(QChar('A').isPrint());