[igouy]

> would not have resulted in accurate comparison

Because? Is the reasoning for that spelled-out somewhere in the paper?

> Section 4.5.2

> Section 4.5.1

After the paper had discussed “Pereira et al.” I repeatedly confused discussion of your new measurements with discussion of the old “Pereira et al.” measurements.

> "forcing benchmarks to run on a single core" p2&3

> "we eliminate the effect of varying concurrency in different benchmark implementations by limiting benchmarks to execute on a single core" p6

> "the JavaScript version uses 28 cores on average" p14

fwiw I am now very confused.

[emeryberger]

We only pin to one core for one experiment described in Section 4.3. All the remaining experiments are run with full access to all cores.

[igouy]

Thank you.

I'm concerned that section 2.2.1 is a misreading of Pereira et al.

[29] "… the performance of a language is influenced by the quality of its compiler, virtual machine, garbage collector, available libraries, etc."

In that context it seems plain that "language" must be understood as a shortening of "language implementation."

> "For instance, Pereira et al. treat Ruby and JRuby as different languages, while they are in fact two separate implementations of the same Ruby language."

It seems to me that Pereira et al. treat Ruby and JRuby as different "language implementations" and compare each one independently against the other language implementations.

(In the "corpus of small benchmark implementations" it was simply convenient to keep separate programs for Ruby and JRuby.)

[emeryberger]

Those papers say "language" over and over again, in the titles, in the body of the text. That work confounds languages and their implementations, and make it sound like there is a one-to-one connection between the two (of course, there is not necessarily such a correspondence).

With respect to Ruby vs. JRuby: my student just checked and verified that some but not all of the benchmarks are implemented differently (k-nucleotide, mandelbrot, pidigits, spectral-norm).

[igouy]

> Those papers say "language" over and over again, in the titles, in the body of the text.

Yes they do! And over and over again in-context we sensibly read that to mean what you wish to term more precisely "language implementation".

> Fig. 4 Fig. 5 "We are in fact comparing implementations of programming languages, not the languages themselves."

They know. They just prefer shorter names.

Here's their short-name precise-name lookup table:

https://sites.google.com/view/energy-efficiency-languages/se...