Here are some notes from my first impressions and after skimming through the paper. And yes, I am aware that this is very very early software.

1. Bend looks like an extremely limited DSL. No FFI. No way of interacting with raw buffers. Weird 24bit floating point format.

2. There's a reason why ICs are not relevant: performance is and will always be terrible. There is no other way to put it, graph traversal simply doesn't map well on hardware.

3. The premise of optimal reduction is valid. However, you still need to write the kernels in a way that can be parallelized (ie. no data dependencies, use of recursion).

4. There are no serious examples that directly compare Bend/HVM code with it's equivalent OMP/CUDA program. How am I suppose to evaluate the reduction in implementation complexity and what to expect on performance. So many claims, so little actual comparisons.

5. In the real world of high performance parallel computing, tree-like structures are non-existent. Arrays are king. And that's because of the physical nature of how memory works on a hardware level. And do you know what works best on mutable contiguous memory buffers ? Loops. We'll see when HVM will implement this.

In the end, what we currently have is half-baked language that is (almost) fully isolated from external data, extremely slow, a massive abstraction on the underlying hardware (unutilised features: multilevel caches, tensor cores, simd, atomics).

I apologize if this comes out as harsh, I still find the technical implementation and the theoretical background to be very interesting. I'm simply not (yet) convinced of its usefulness in the real world.