> If RISC has succeeded, this is precisely because the elements were > simple enough to be implemented in hardware, and this simplicity allowed > to work reliably on optimizations.
it's interesting you bring this up. risc has largely been removed from architectures. if you tie the instruction set and machine model to the actual hardware, then you need to write new compilers and recompile everything every few years. instead, the risc is hidden and the instruction set stays the same. this allows for a lot of under-the-hood innovation in isolation from the architecture. isolation is generally a good thing, and i don't believe i've seen a compelling argument coupling architechture to implementation is necessary. (by architecture, of course, i mean what you read in the ia64 or amd64 programmer's manual, not the implementation, which intel unhelpfully calls the µarch.) - erik
