Comment by Someone
3 hours ago
> 68k was much harder to optimize than x86
Harder to optimize or because of its orthogonal instruction set easier to write code for?
3 hours ago
> 68k was much harder to optimize than x86
Harder to optimize or because of its orthogonal instruction set easier to write code for?
Harder to optimize at microarchitectural level because each individual instruction represents way more complex execution model, including to even decode what the CPU is supposed to do.
X86 is comparatively simple, with limited indirect addressing support to the point it can be inlined in execution pipeline, and many instructions either being actually "simple" to implement, or acceptable to do in slow path. M68k (and VAX even more) are comparatively harder to build modern superscalar chip for.
What matters is how easy it is to create an out-of-order implementation of an ISA, there isn't a 680x0 equivalent of the Pentium Pro.