The use of commodity mobile processors in wearable computing and field-deployed applications has risen as these processors have become increasingly powerful and inexpensive. Battery technology, however, has not advanced as quickly, and as the processing power of these systems has increased, so has their power consumption. To maximize endurance without compromising performance, fine-grained control of power consumption by these devices is often desired. Various methodologies exist to affect system-level bias with respect to the prioritization of performance or efficiency, but these are often specific to the underlying hardware. The PowerMP toolchain translates power-saving intent expressed in compiler directives into instructions to control the hardware, reducing power consumption when possible, while still providing high performance when required. PowerMP offers an API that can target a wide class of mobile devices, particularly those which make use of a multi-core ARM processor.