Cakemark is a framework for benchmarking tweaked versions of pocl, maybe against
the AMD OpenCL runtime.

The src directory contains the availble benchmarks.

A test run needs a set of benchmarks to run and a set of permutations to try
for "opt" flags to pass in when kernels are compiled by the custom pocl.

The benchmarks will print timing information, which will be parsed out of their
stdout.

The following timings are interesting:
 - Full kernel JIT process.
 - Each step of the JIT process.
 - Kernel execution time.

Useful environment variables supported by either stock or custom POCL:

    CAKE_SPEC          - When set to 1, POCL will enable the extra Cake
                         optimizations, including specialization.

    CAKE_TIMINGS       - When set to a file name, records timings for all pocl
                         operations to that file.

    CAKE_OPT_HARDER    - Extra LLVM transformation passes.
                         

    POCL_LEAVE_TEMP_DIRS - If set to 1, temp dirs are not deleted.

    POCL_MAX_PTHREAD_COUNT - Sets number of pthreads to use.