@lupyuen

At least the time of checking whether the compiler produced the correct code is mostly over. Back in the 1980s, it was very common that the PC-based compilers (I think we had a whole bunch, MS, Borland, Lattice,...) just generated the wrong code, typically in optimizing but due to the constrained memory we almost always needed size optimization (our case, M model, 64k code, >64k for data).