On Tuesday 04 August 2015 21:41:47 Liang, Kan wrote:
> Hi Milian,
>
> Is it possible to share your test case/steps with me?
Sure, I hope Qt is fine with you.
main.cpp:
~~~~~~~~~~~~~~~~~~~~~~
#include <QString>
#include <QTextStream>
int main()
{
QStringList haystack;
for (int i = 0; i < 1000; ++i) {
haystack << QString::number(i);
}
uint matches = 0;
for (int i = 0; i < 1000; ++i) {
foreach (const QString &str, haystack) {
if (str == "needle") {
++matches;
}
}
}
QTextStream out(stdout);
out << "Matches: " << matches << endl;
return 0;
}
~~~~~~~~~~~~~~~~~~~~~~
lbr.pro:
~~~~~~~~~~~~~~~~~~~~~~
TEMPLATE = app
SOURCES = main.cpp
CONFIG += release
QMAKE_CXXFLAGS += -g
~~~~~~~~~~~~~~~~~~~~~~
To build, put both into a folder and then do:
~~~~~~~~~~~~~~~~~~~~~~
mkdir build
cd build
qmake-qt5 ..
make
perf record --call-graph lbr ./lbr
perf report --stdio
~~~~~~~~~~~~~~~~~~~~~~
> Does --call-graph fp work?
No, I'm on a 64bit architecture, and most libs (esp. Qt) is built without
framepointers. --call-graph dwarf does work though.
Bye
--
Milian Wolff
[email protected]
http://milianw.de
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