By: Anon (no.delete@this.spam.com), June 2, 2022 2:49 pm
Room: Moderated Discussions
Heikki Kultala (heikk.i.kultal.a.delete@this.gmail.com) on June 2, 2022 12:04 pm wrote:
> Everything is about tradeoffs. Before 1980's, what mattered was code size. But
> then, in 1980's simpler decoding allowed pipelining, and the RISCs hype came.
Reviewing RISC history I don't think it was simpler decoding that made RISC partical in the 80's, but rather simpler design which allowed CPUs to hit market earlier, we would be using 68k derivatives had it hit the market one year earlier.
With 80's tech the optimal ISA for those in-order pipelined scalar cores would likely be more expressive than RISC because the expressiveness would allow the resources to be used more efficiently but far simpler than x86 which wasn't designed with pipeling in mind at all.
> Everything is about tradeoffs. Before 1980's, what mattered was code size. But
> then, in 1980's simpler decoding allowed pipelining, and the RISCs hype came.
Reviewing RISC history I don't think it was simpler decoding that made RISC partical in the 80's, but rather simpler design which allowed CPUs to hit market earlier, we would be using 68k derivatives had it hit the market one year earlier.
With 80's tech the optimal ISA for those in-order pipelined scalar cores would likely be more expressive than RISC because the expressiveness would allow the resources to be used more efficiently but far simpler than x86 which wasn't designed with pipeling in mind at all.
