> On Oct 23, 2018, at 7:08 PM, Noel Chiappa via cctalk <cctalk@classiccmp.org>
> wrote:
>
> ...
> There was a recent discussion about code density (I forget whether here, or
> on TUHS), and someone mentioned this paper:
>
> http://web.eece.maine.edu/~vweaver/papers/iccd09/iccd09_density.pdf
>
> which shows that for a combo of benchmarks, the PDP-11 had the densest code
> out of all the ones they looked at. (They didn't look at the PDP-8, but I
> suspect that since it's a single-address design, it's almost ceertainly not
> as dense.)
>
> The PDP-11 dates back to the days of core (it went through several generations
> before DRAM arrived - e.g. the -11/70 originally shipped with core), and given
> core prices, minimizing code size was pretty important - hence the results
> above.
What's interesting is that the paper uses compiled code. The gcc back end for
pdp11 is still a work in progress and clearly doesn't deliver best possible
code, certainly not back then.
paul
