Python is far from a top performer according to benchmarktest...

[Robin Becker]

In article <mailman.310.1073949030.12720.python-list at python.org>, Tim
Peters <tim.one at comcast.net> writes
.......
>That's the magic of Fortran:  the F77 standard says (in part):
>
>    If a subprogram reference causes a dummy argument in the
>    referenced subprogram to become associated with another
>    dummy argument in the referenced subprogram, neither
>    dummy argument may become defined during execution of
>    that subprogram.
>
>It bascially says you can alias all you want, so long as you only read the
>aliased entities and don't modify them.  If effect, if you do anything with
>aliases that would inhibit optimizations that assume there isn't any
>aliasing, then it's your *program* that's not legitimate Fortran.  The
>Fortran standard has lots of text "like that", imposing (often unenforcable)
>restrictions on conforming programs for the benefit of optimizing compilers.
>That was the right choice for Fortran's audience.
>

this was also my understanding, the difficulty is that humans can't do
the correct analysis in their heads for all, but the most simple
programs. I seem to remember that almost all the compilers I used had
mechanisms for turning off the most aggressive optimisations so if the
card deck suddenly started working with them off then you could try and
figure out what was wrong. Another nastiness was that by putting prints
in you often disrupted the optimisations and the values you got printed
seemed to indicate everything was fine.
-Common blocks are an invention of the Devil-ly yrs- 
Robin Becker