_Very_ strange problem with compiling

[Mark Phillips <mark@infoeng.flinders.edu.au>]

Hi,

I thought I'd found a gcc compiler error (and still may have).  The
following program crashes with a segmentation fault.

#define N 209677

int main(int argv, char **argc) {
  int
    i;
  double
    a[N],
    b[N],
    c[N],
    d[N], 
    e[N];

  c[0]=0.0;
  i=1;
  c[i]=c[i-1];
}

If I make N slightly less, or reduce the number of arrays defined, it
runs fine.  If I write instead "c[1]=c[0]" it runs fine.  Basically, I
simplified the original program as much as I could in ways which still
caused the Seg Fault to happen.

So I thought this must be a compiler error.  The program was called
"thick4.c".  I used emacs to paste the file into a new buffer called
"test.c".  But this one worked fine when I compiled!!!!  The two files
"thick4.c" and "test.c" are identical, as both diff and cmp prove.

The executables "thick4" and "test" differ very slightly however.

-rwxrwxr-x    1 mark     mark         4731 Mar  7 02:53 test*
-rw-rw-r--    1 mark     mark          162 Mar  7 02:53 test.c
-rwxrwxr-x    1 mark     mark         4733 Mar  7 02:53 thick4*
-rw-r--r--    1 mark     mark          162 Mar  7 02:51 thick4.c

and 

$ cmp thick4 test  
thick4 test differ: char 3061, line 2

Why would identical files compile to slightly different executables?
I have included gzipped versions of these executables with this email.

Has anyone got any idea what might be going on?  Or suggestions about
what I could investigate next!

Also, can anyone else replicate the error I got (using thick4.c as
your file name).

Thanks,

Mark.

-- 
_/~~~~~~~~\___/~~~~~~\____________________________________________________
____/~~\_____/~~\__/~~\__________________________Mark_Phillips____________
____/~~\_____/~~\________________________________mark@ist.flinders.edu.au_
____/~~\HE___/~~\__/~~\APTAIN_____________________________________________
____/~~\______/~~~~~~\____________________________________________________
__________________________________________________________________________
        "They told me I was gullible ... and I believed them!"

Attachment: thick4.gz
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