Some feedback on AC datatypes:
We have found AC datatypes to be an invaluable tool for large DSP ASIC designs. My experience is mostly on the simulation front where speed, bit- (but not necessarily cycle-) accuracy, and seamless integration with standard C++ code is important. AC datatypes provide all the relevant digital system design features (clipping/rounding/bit-slicing), as well as support for complex data types, with very little overhead. The ability to customize/expand AC datatype functionality via private headers (for simulation only) is another great benefit that minimizes the need for instrumentation code around HLS code during system simulations.