[julia-users] Efficiency of julia compiler on a simple program (from a julia newbie)

[Ronald L. Rivest]

I'm a julia newbie trying to get a sense of how efficient the Julia compiler
is, for a very simple little program.  I attach copies of
foo.py and foo.jl, which compute the same thing.

I then ran them (for the python version with both
pypy and with python).  The results:

    pypy:         2 seconds
    julia:        30 seconds
    python:    43 seconds

I was surprised to see julia so badly beaten by pypy,
and to see that the difference between julia and ordinary
python was less than a factor of two... 

Is there an optimization trick or optimization switch that
I missed for Julia??

Thanks!

Cheers,
Ron Rivest

11:36:12 temp $ date; pypy foo.py; date
Fri Nov 21 23:36:22 EST 2014
0.726947459371
Done.
Fri Nov 21 23:36:24 EST 2014
11:36:24 temp $ date; julia foo.jl; date
Fri Nov 21 23:36:37 EST 2014
0.726947459370689
Done.Fri Nov 21 23:37:07 EST 2014
11:37:07 temp $ date; python foo.py; date
Fri Nov 21 23:37:32 EST 2014
0.726947459371
Done.
Fri Nov 21 23:38:15 EST 2014

n = 100000000
x = 0.234
for i in range(n):
    x = max(x*x,1.0-x*x)
print(x)
print("Done.")
    

foo.jl
Description: Binary data