Wouldn't this kind of architecture yield a slower compiler, regardless of output quality? Conceptually, trying to implement the least-amount of passes with each doing as much work as possible would make more sense to me.
There is nothing stopping you from building an old-fashioned single-pass compiler, if compile time is your only concern. The code it generates just wouldn't be very good.
This highly depends on the language and your skill as a compiler writer. You can write a single pass assembler that generates great code but you have to of course write the low level code yourself (including manual register assignment). To do decent automatic register assignment, I agree you need at least two passes, but not 10 or more.
> There is nothing stopping you from building an old-fashioned single-pass compiler, if compile time is your only concern. The code it generates just wouldn't be very good.
Define "very good".
The very simplest optimizations get you almost all the benefit. Proebsting's Law applies: Compiler Advances Double Computing Power Every 18 Years