alt Hacker NewsIf you happen to know... what was the reasoning behind the oddball stack architecture? It feels like Intel must have had this already designed for some other purpose so they tossed it in. I can't imagine why anyone would think this arch was a good idea.
Then again... they did try to force VLIW and APX on us so Intel has a history of "interesting" ideas about processor design.
edit: You addressed it in the article and I guess that's probably the reason but for real... what a ridiculous hand-wavy thing to do. Just assume it will be fine? If the anecdotes about Itanium/VLIW are true they committed the same sin on that project: some simulations with 50 instructions were the (claimed) basis for that fiasco. Methinks cutting AMD out of the market might have been the real reason but I have no proof for that.
Stack-based architectures have an appeal, especially for mathematics. (Think of the HP calculator.) And the explanation that they didn't have enough instruction bits also makes sense. (The co-processor uses 8086 "ESCAPE" instructions, but 5 bits get used up by the ESCAPE itself.) I think that the 8087's stack could have been implemented a lot better, but even so, there's probably a reason that hardly any other systems use a stack-based architecture. And the introduction of out-of-order execution made stacks even less practical.