My organisation traditionallly builds 32 bit software but due to user
requests we need to build 64 bit versions as well. I've managed to create
a universal binary that contains the code for both 32 bit and 64 bit
architectures targetting the Intel processor i.e. my XCode architecture
settings for configuration and target are both set to i386 and x86_64.
When I execute the unix 'file' command on the resulting executable, I can
see that it contains the code for both architectures.
Given all that waffle, my question is: how can I specify which
architecture code gets executed when I run the binary? Is it the 32 or 64
bit version that gets executed.
I suppose in order to performance test 64 bit, I could just specify 64 bit
architecture when building the application, however, I'm interested in the
answer to the above question.