What input-language is the best choice for high level synthesis (HLS)?

As of 2010, over 30 of the world´s top semiconductor / systems companies have adopted HLS. In 2009, SOCs tape-outs containing IPs developed using HLS exceeded 50 for the first time. Now that the practicality and value of HLS is established, engineers are turning to the question of “what input-language works best?” The answer is critical because it drives key decisions regarding the tool/methodology infrastructure companies will create around this new flow. ANSI-C/C++ advocates cite ease-of-learning, simulation speed. SystemC advocates make similar claims, and point to SystemC´s hardware-oriented features. Proponents of BSV (Bluespec SystemVerilog) claim that language enhances architectural transparency and control. To maximize the benefits of HLS, companies must consider many factors and tradeoffs.