GCC_THUMB_SUPPORT: Can it be turned OFF for just one module?

Is there a way to turn off GCC_THUMB_SUPPORT mode for sections of code or a module only rather than switching the entire application to ARM mod开发者_开发技巧e?

In Xcode 3, you can follow the process described by Paul in his answer here to set per-file build settings. Using that, you can add a custom setting to not use Thumb support for a file.

Xcode 4 moves these per-file configuration options. Joshua Nozzi describes where they end up in his short article here. Basically, they're now under the Build Phases tab within the project settings, under the Compile Sources grouping.

Be aware, however, that turning off building for Thumb is only recommended for the non-ARMv7 devices. Building using the Thumb2 instruction set in the ARMv7 devices (the iPhone 3G S and newer) is recommended in almost all cases. The Thumb instruction set can lead to a smaller binary, and it only slows down floating-point-heavy calculations on the older ARMv6 devices, not the overwhelming majority of hardware out there right now.