HPVM Runtime System

The HPVM Runtime System handles interfacing with the appropriate device run time based on what device is being used. The runtime system introduces unified methods that set up kernel arguments, copy data between host and device, launch kernels, wait on kernels, etc. These methods are used by the device back ends (described here) when performing code-generation. Internally, the runtime system interfaces with the appropriate OpenCL runtime depending what target devices are being used during run time of a given application.

One feature that the HPVM Runtime introduces is the ability to automatically determine when data needs to be copied between host and devices, and when copies are not necessary. This optimizes the execution of a program, making sure that unnecessary copy operations are not perfomred. Internally, the Runtime uses a memory tracker to keep track of where the latest copy of a given memory pointer is residing, and accordingly makes descisions on when the memory needs to be copied.