CMake Multiarchitecture Compilation
It would be great if CMake had an 32/64bit option out of the box. It does not, so you will need to apply one of different compiler or generator dependend methods. E.g.:
GCC (on Linux) and some other compilers, e.g. Sun Studio. Set
CFLAGS
andCXXFLAGS
to include-m32
(32-bit build) or-m64
(64-bit build).Windows, Visual Studio generator. Use 64 bit generator, e.g.
cmake -G "Visual Studio 10 Win64" path\to\source\dir
to compile 64-bit (x64). Omit "Win64" in generator name, to build for 32 bit
Mac OS X. Use
CMAKE_OSX_ARCHITECTURES
CMake variable.cmake -DCMAKE_OSX_ARCHITECTURES=i386 /path/to/source/dir
will compile 32 bit buildcmake -DCMAKE_OSX_ARCHITECTURES=x86_64 /path/to/source/dir
will compile 64 bit.cmake "-DCMAKE_OSX_ARCHITECTURES=x86_64;i386" /path/to/source/dir
will create 96-bit universal binaries :)
The above is slightly reworded.
http://dev.mysql.com/doc/internals/en/compiling-for-different-hardware-achitectures.html
Update April 2019
This is an old answer, some things have changed, especially for VS generator on Windows.
with cmake 3.14, and Visual Studio 2019 installed
cmake -G "Visual Studio 16 2019" -A x64 path\to\source\dir
to compile 64-bit (x64). You can usually omit both -G and -A parameter on x64 machine (you're using x64 OS in 2019, right?)
cmake -G "Visual Studio 16 2019" -A Win32 path\to\source\dir
to compile 32bit.
If CMAKE_OSX_ARCHITECTURES=i386 gives you the error "unrecognized option -arch" start over and instead try:
cmake -DCMAKE_SYSTEM_NAME=Darwin -DCMAKE_SYSTEM_PROCESSOR=i386 -DCMAKE_SYSTEM_VERSION=10