Re: GCC3.0 Produce REALLY slower code!

[Luigi Genoni]

On Sun, 24 Jun 2001, Rik van Riel wrote:

> On Mon, 25 Jun 2001, Alexander V. Bilichenko wrote:
>
> > Some tests that I have recently check out. kernel compiled with
> > 3.0 (2.4.5) function call: 1000000 iteration. 3% slower than
> > 2.95. test example - hash table add/remove - 4% slower (compiled
> > both with -O2 -march=i686).
>
> > Why have this version been released?
>
> It would be better to ask that to the GCC people, but I
> suspect it was released because it was (almost) stable
> and the only way to do the last small tweaks to the code
> would be to have it tested in the field ?
>
Actually I think the just one very good reason to use gcc 3.0 is if you
are programming using C++. It's a kind of paradise for C++ programmers.
So I had to install it on my servers used by C++ programmers, they were
so happy...
To use C, it's better to avoid gcc 3.0, it's just slower.
All bench i did, it's slower about 3/5% depending on the kind of code.
It is faster just on some floating point with really small
code, (I used optimizzations for athlon CPU).

Luigi