On 11/19/12 10:19, Larry Evans wrote: [snip]
In contrast to the gcc4_8 compiler, with the clangxx compiler, the relative qualitative performance, is just the opposite. IOW, the bcon12_horizontal implementation is faster than the bcon12_vertical implementation. In fact, the rate of change of the performance difference accelerates as tree depth goes from 2 to 4. The rate of change is so stark that it suggests, at least to me, there may be some bug in clang. Of course that conclusion is based on almost no knowledge, on my part, of the clang implementation.
The tuple_benchmark_filt.py can be modified to filter out other parts of the benchmark run output, which is here:
http://svn.boost.org/svn/boost/sandbox/variadic_templates/sandbox/slim/test/...
For example, when the filter criteria restricts TUPLE_UNROLL_MAX to 10 (the same as TUPLE_SIZE), then, with compiler=clangxx, bcon12_vertical performs relatively better than bcon12_horizontal as TREE_DEPTH increases, as shown in the attached. -regards, Larry