Re: compiler benchmark comparisons

[andreatta@mail.chem.sc.edu (Dan Andreatta)]

> First of all I think you mean gnu-c here (or you can just

Yes. My apologies.

> Second, if the gnu-c code runs 2-3 times as fast as the
> C code it is simply NOT the same code.

Yes and no. In this particular example the execution time is
determined mainly by performance of the I/O library. And the GNU/Ada
I/O library is slower than the GNU/C library. For fun I wrote some of
the "shootout" programs in Ada and the result was that the execution
times were comparable, except the ones that used heavily text I/O,
where the Ada times were 2-3 times higher. I admit I am a newby, so my
code was not so good, but, as I said, where the I/O wasn't the main
part of the program, I wrote pretty fast code.

> examples like this in detail, we discover that what
> people think are "identical" programs are in fact totally

Well, the core of the code was a repeated series of for loops:

for i in 1..100 loop
  ada.text_io.put_line( Integer'Image(i) )
end loop;

for Ada and for C:

for (i=0; i<100 : ++i)
  printf("%d\n",i);

What are the differences between the two?

BTW, the test was ment to test the compiler speed, not the quality of
the produced code. Maybe it wasn't clear in my previous posts.

Dan