There was nothing unique about the size or the object code of Dennis's C compiler. In the 1960s, Digitek had a thriving business of making Fortran compilers for all manner of machines. To optimize space usage, the compilers' internal memory model comprised  variable-size movable tables, called "rolls". To exploit this non-native architecture, the compilers themselves were interpreted, although they generated native code. Bob McClure tells me he used one on an SDS910 that had 8K 16-bit words.

Dennis was one-up on Digitek in having a self-maintaining compiler. Thus, when he implemented an optimization, the source would grow, but the compiler binary might even shrink thanks to self-application.

Doug