Adding -O3 compiler option in Qt Creator

Hello!

I'm using MinGW and GCC for my Qt projects and I want to add the compiler option -O3 to optimize my code. I thought that the place to add compiler options was in Projects->Make->Make arguments, where I successfully already added the -j compiler option, but this time it doesn't work no matter how I try to insert -O3 there.

Should I put it in another place? And if not, how exactly to do it?


Thanks,

Momergil

You should be able to do it via .pro file:

Code:

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QMAKE_CXXFLAGS += -O3

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Quote:

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Originally Posted by stampede

You should be able to do it via .pro file:

Code:

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QMAKE_CXXFLAGS += -O3

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Thanks stampede for the reply. Although I'm not sure it's working, at least now it's not giving me any compiler errors!!


Momergil

You can always check the command used to invoke the compiler, eg

Code:

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g++ -c -O3 -g -frtti -fexceptions -mthreads -Wall -DUNICODE -DQT_LARGEFILE_SUPPO
RT -DQT_DLL -DQT_SQL_LIB -DQT_GUI_LIB -DQT_CORE_LIB -DQT_HAVE_MMX -DQT_HAVE_3DNO
W -DQT_HAVE_SSE -DQT_HAVE_MMXEXT -DQT_HAVE_SSE2 -DQT_THREAD_SUPPORT -I'../../../
../Qt/include/QtCore' -I'../../../../Qt/include/QtGui' -I'../../../../Qt/include
/QtSql' -I'../../../../Qt/include' -I'.' -I'../../../../Qt/include/ActiveQt' -I'
debug' -I'../../../../Qt/mkspecs/default' -o debug/main.o main.cpp

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You can see the -O3 flag added to compiler options.
Btw. it worked with the -j switch, because -j is the make command option, whereas "-O3" is the compiler option.

Thanks for the tip and for the explanation! :)


Momergil