Re: c compilation - gcc vs visual c

On May 10, 1:18=A0pm, moi <r...@[EMAIL PROTECTED]
> wrote:
> On Sat, 10 May 2008 09:49:58 -0700, kumarchi wrote:
> > guys:
> > i have zeroed in and created a simple test program. This progrma just
> > has floating point addition and integer addition. it does 20 loops x
> > 1million times. in relase version of visual c it takes 0 time. gcc O3
> > takes 6 secs in my machine.
> > :
> > this cannot be rocket science; there seems to some fundamental
> > deficiency in gcc. i will treat this as a bug. This should have
serious
> > implications for linux platforms
>
> > here is the code; test it for yourself
>
> In gcc 4.1.2, with -O3 , on a 686,
> the whole function is elimated and inlined,
> leading to :
>
> $ time ./a.out
> =A0times=3D1000000000 loops=3D20 dtime =3D 0
>
> real =A0 =A00m0.001s
> user =A0 =A00m0.000s
> sys =A0 =A0 0m0.003s
> $
> In this case, there is no difference in generated code when
> -march=3Di686 -msse2 are added to the -O3 flag.
>
> I guess, you'll have to invent a better benchmark :-)
>
> AvK

you are right; my ubuntu box has gcc 4.2.1 and the gcc in cygwin is
3.4.4. but what a difference!! so my alarm hopefully is a false alarm.
I was also confused my laptop is inter core do t2400 and my hardy box
is amr 4200 x2. and the lapt top + visual c beat out the ubuntu + gcc
in my linux box also. if gcc 4.2.2 can hold up against visual c, then
that means intel beats out amd!!

i will still do more test. and hoep gcc 4.2.2  is a champ.  I do not
want to be on teh dark side (=3D!!