I’m not sure I (or many others) would agree that “_javascript_ is extremely well designed and powerful” [1]. And in general attempts to add language-specific optimizations to CPU instruction sets have rarely fared well (e.g. Java native bytecode on ARM). The whole point (to my mind) of RISC was to move to a model where a very streamlined CPU + low-latency L1 cache was, in effect, an engine for efficient execution of VMs like Lua’s.
Another example of custom architectures that did not survive:
The LMI and Symbolics Lisp machines became obsolete when Lisp implementations on commodity microprocessors started to outperform them, at only a small fraction of the price.
Gé
