if (getARMSubtarget().isThumb2())
addPass(&UnpackMachineBundlesID);
- addPass(createARMOptimizeBarriersPass());
+ // Don't optimize barriers at -O0.
+ if (getOptLevel() != CodeGenOpt::None)
+ addPass(createARMOptimizeBarriersPass());
+
addPass(createARMConstantIslandPass());
}