AuroraMiddleware/qt5base-lts
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Boost performance of QChar::is{Upper,Lower}

Browse Source 
Calling QChar::category() is slow; do some fast checks to
detect ascii characters before falling back to the generic
handling.

On ia32, this change makes isUpper ~260x faster for uppercase
ascii characters, and ~180x faster for non-uppercase ascii
characters. Similar numbers for isLower.

Even with the additional checks, these versions are slightly
faster than before for non-ascii characters as well, since
we now call the static fastcall category(ushort) function,
which is faster than the category() member function (which
uses the stack to pass the unicode value).

Change-Id: I6ae0df466bb4835ca0d5319fd6018862c849313b
Reviewed-on: http://codereview.qt-project.org/4901
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 12:15:07 +02:00 committed by Qt by Nokia
parent 6e55715581
commit 4cd9d267e7
1 changed files with 8 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
src/corelib/tools/qchar.h
View File

@ -239,8 +239,14 @@ public:
bool isLetterOrNumber() const;
bool isDigit() const;
bool isSymbol() const;
inline bool isLower() const { return category() == Letter_Lowercase; }
inline bool isUpper() const { return category() == Letter_Uppercase; }
inline bool isLower() const {
return (ucs >= 'a' && ucs <= 'z')
|| (ucs > 127 && category(ucs) == Letter_Lowercase);
}
inline bool isUpper() const {
return (ucs <= 'Z' && ucs >= 'A')
|| (ucs > 127 && category(ucs) == Letter_Uppercase);
}
inline bool isTitleCase() const { return category() == Letter_Titlecase; }
inline bool isHighSurrogate() const {