Mail Archives: djgpp/2001/10/17/09:58:53
DJ Delorie wrote:
> > and THIS is supposed to encourage people to start moving "up" to
> > 3.0 ???
> > > gcc 2.7.2.1 gcc 3.0
>
> Well, a couple of things.
>
> The comparison omits gcc 2.8.1 and 2.95, which were important
> releases.
>
> Gcc 3.0 has a lot more functionality than 2.7.2.1.
>
> Bigger code does not mean slower code - it can sometimes be faster
> code by avoiding cache-busting jumps.
>
> The sizes do not indicate code vs data vs overhead (debug etc).
>
> "Hello world" is a bad program to do comparisons with. You should
> choose a more real-world program, like gzip or make, and time how long
> it takes to build those and how big they are.
I agree with you DJ, but it looks like regular switchs (-O2 for example)
have a bad impact on old CPU models when using gcc 3.x.
I didn't run my battery of benchmarks yet so I can give a detailed
conclusion, but the new C++ library and code generation rules made my editor
20% bigger (we are talking about more than 200 Kb of increase) and 11%
slower.
I know the speed difference could be just because I tested with a K6 and
perhaps a Pentium II isn't affected, but isn't a nice thing. Specially when
I can clearly see the compiling time difference. I didn't meassure the time,
but I know that these differences are really notorious when a factor of at
least 2.5 or 3 is applied.
I don't blame the gcc team and I'm thinking that is time for a hardware
upgrade. I know the ISO C++ 1998 standard introduced a heavy use of
templates in the C++ standard library and is one of the reasons for the
increase in code size and compilation time. But I also realize that
compiling C++ code won't be possible using gcc 3.x and small machines (386
and 486) and quite annoying with anithing less than Pentium II of 500 MHz
with 128 Mb of memory.
When I finish with TV and setedit releases I'll try to run the
BYTE benchmarks to compare gcc 3.x with all the data I already have.
SET
--
Salvador Eduardo Tropea (SET). (Electronics Engineer)
Visit my home page: http://welcome.to/SetSoft or
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Alternative e-mail: set AT computer DOT org set AT ieee DOT org
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Buenos Aires, (1678), ARGENTINA Phone: +(5411) 4759 0013
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