In Xcode 4.3.2, I get this build recommendation:
Upgrade ARMV6 assembler codegen from THUMB to ARM mode.
I can either accept or reject the recommendation and the change gets made for me. The problem is that this recommendation seems to pop up only after I've built and run it a few times. I would like to integrate this setting into my defaults, but I can't find the setting in Build Settings that would let me do this preemptively.