Решил посмотреть на скорость Qt+mingw, собранной с поддержкой LTO. Сперва смутило, что для mingw опция configure.exe -ltcg ничего не делает, это только для msvc. Тогда просто дописал в mkspecs/win32-g++/qmake.conf опции -flto. Но не компилится uic, вываливается куча ошибок. Кто-нибудь пробовал эту опцию (с mingw) в работе?
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`QTextStream::operator<<(QChar)' referenced in section `.text' of ./tmp\obj\release_s
hared\cppwriteincludes.o: defined in discarded section `.text' of qtextstream.o (symb
ol from plugin)
`QString::number(unsigned long long, int)' referenced in section `.text' of ./tmp\obj
\release_shared\cppwriteinitialization.o: defined in discarded section `.text' of qst
ring.o (symbol from plugin)
`QString::number(unsigned int, int)' referenced in section `.text' of ./tmp\obj\relea
se_shared\cppwriteinitialization.o: defined in discarded section `.text' of qstring.o
(symbol from plugin)
`QString::indexOf(QLatin1String const&, int, Qt::CaseSensitivity) const' referenced i
n section `.text' of ./tmp\obj\release_shared\cppwriteinitialization.o: defined in di
scarded section `.text' of qstring.o (symbol from plugin)
`QDateTime::currentDateTime()' referenced in section `.text' of ./tmp\obj\release_sha
red\uic.o: defined in discarded section `.text' of qdatetime.o (symbol from plugin)
`QXmlStreamReader::atEnd() const' referenced in section `.text' of ./tmp\obj\release_
shared\uic.o: defined in discarded section `.text' of qxmlstream.o (symbol from plugi
n)
`QString::compare_helper(QChar const*, int, QChar const*, int, Qt::CaseSensitivity)'
referenced in section `.text' of ./tmp\obj\release_shared\uic.o: defined in discarded
section `.text' of qstring.o (symbol from plugin)
`QXmlStreamReader::errorString() const' referenced in section `.text' of ./tmp\obj\re
lease_shared\uic.o: defined in discarded section `.text' of qxmlstream.o (symbol from
plugin)
`QXmlStreamReader::columnNumber() const' referenced in section `.text' of ./tmp\obj\r
elease_shared\uic.o: defined in discarded section `.text' of qxmlstream.o (symbol fro
m plugin)
`QXmlStreamReader::lineNumber() const' referenced in section `.text' of ./tmp\obj\rel
ease_shared\uic.o: defined in discarded section `.text' of qxmlstream.o (symbol from
plugin)
collect2: ld returned 1 exit status
jom: F:\Qt\src\tools\uic\Makefile.Release [..\..\..\bin\uic.exe] Error 1
jom: F:\Qt\src\tools\uic\Makefile [release] Error 2
jom: F:\Qt\Makefile [sub-uic-make_default-ordered] Error 2
В составе mingw: gcc 4.6.2, ld 2.22.
