Error: Assert failure at ...MemBankPortAssign.cpp(191)

What do you mean by getting "stuck"? The OpenCL to LLVM conversion, after which the area estimation report is generated, could take up to an hour depending on the complexity of the kernel.

The code snippet you have posted compiles fine on my machine using AOC 16.1.2. Note that the barriers in your code snippet are unnecessary since you do not have any local memory constructs in your kernel. Furthermore, atomic global memory operations will result in extremely poor performance.