What should I do to change 32 bit compiler to 64 bit one in Qt?

Question

I'm new to Qt, and I really need a 64 bit compiler instead of a 32 bit one. I'm using Qt SDK from Nokia's website and don't know anything about compile, make, etc. Here I attached the configuration window of my Qt, and I'm using windows 7 64 bit. Could someone show me step by step how to change the 32 bit compiler to a 64 bit compiler? Thanks!

Answer 1

You shouldn't be using this old SDK. Download the most recent mingw version from http://qt-project.org/downloads - it includes the compiler.

If you intend to create code with Qt, the precompiled version has only 32 bit Qt. When installing, you need to enable the installation of the source code. Then you have to recompile the Qt itself targeting 64 bits:

mkdir %USERPROFILE%/qt64
cd %USERPROFILE%/qt64
c:\Qt\....\Src\configure -xplatform win32-g++ -device-option CROSS_COMPILE=i686-w64-mingw32-
make

I'm not sure whether the mingw bundled with Qt can target 64 bits - someone else please edit/chip in.