Make GCC build x86_64 code on default

If you want the architecture changed for all future projects, you need to make a build configuration file, import it into your project, then select it as the configuration you want your build settings "based on" at the very bottom of your build info screen.

You can read about configuration files here: http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/XcodeBuildSystem/400-Build_Configurations/build_configs.html#//apple_ref/doc/uid/TP40002692-SW8

 

Alternatively, I believe clang defaults to 64 bit. Switching to it has other benefits as well.

 

Theres also a compiler switch. I think it's -xarch_x86_64 (check the man page for valid architectures). Then, you could create an alias if you compile in your terminal. For bash & co. that would be

Code:

alias gcc_64 gcc -xarch_x86_64

Then you can just type gcc_64 instead of gcc.