On Monday, 11 May 2015 at 23:32:48 UTC, Dzhon Smit wrote:
The point was to compare the performance of nearly identical
pieces of code in D and in CL. However, when I compile this
idiomatic sample with `dmd fib2`, I get
$ time ./fib2
0
real 0m2.226s
user 0m2.223s
sys 0m0.003s
which is still slower.
we already know dmd doesn't produce the fastest code, and
obviously you are not comparing languages but a complex set of
things particularly compilers. nobody who cares about
performance will stick with dmd without trying alternatives (and
these are free, readily available alternatives not special things
you need to pay a fortune for as with some of the 'java GC can be
realtime' guys argued indicated as having relevance to the
commercial choice in ordinary circumstances to use java or not).
if one wanted to spend a couple hundred k bucks on rewriting the
codegen, I am sure you would see dmd fast again, but what would
that demonstrate about D the language?
it's fair play to compare naive code using fast compilers, but
just like micro benchmarks, one shouldn't make more of the result
than may be justified. ie the real question is in practical use
cases (bearing in mind you are going to pick one or two languages
and stick with them, figuring out the tricks with experience),
given reasonable effort, what is relative performance like? and
I doubt anyone is going to not use D because "it's slower than
common lisp".
what I have read of the facebook experience (although hardly a
controlled experiment by a neutral observer) is intriguing from
that perspective.
