RE: g77 executable with largish array fails (solved?)

["Dave Korn" <dk at artimi dot com>]

> -----Original Message-----
> From: cygwin-owner On Behalf Of Gerrit P. Haase
> Sent: 26 October 2004 08:37

> Billinghurst, David (CALCRTS) wrote:
> 
> >>From: David Billinghurst
> >>
> >>The following test case is distilled from the LAPACK timing 
> test cases.  
> >>These used to work on some previous versions of cygwin/g77, 
> but now fail.
> > 
> > 
> > I translated the problem into C using f2c.  It becomes:
> > 
> > $ cat labugc.c
> > int main() {
> >   static float a[39*1024*1024];
> > }
> > 
> > $ gcc -O0 -o labugc.exe labugc.c
> > $ ./labugc
> > C:\cygwin\usr\people\billingd\labugc.exe (3372): *** 
> MapViewOfFileEx(0x728, in_h 0x728) failed, Win32 error 6
> > 
> > 
> > Aha, I says.  Looks like stack overflow.  Google pointed me 
> to an work around
> > gcc -Wl,--stack,200000000 -O0 -o labugc.exe labugc.c
> > 
> > 	David
> 
> Interesting, it works without special flags when using gcc-3.4.1.
> 
> Gerrit

  I can explain that: here's why a static variable might cause a MapViewOfFileEx,
and also why changing the stack size might fix it:

http://www.cygwin.com/ml/cygwin/2004-07/msg00646.html

and so I reckon the difference between 3.3.3 and 3.4.1 in this regard will be
cause by the change in placement of statically zero initialised data.  Gerrit,
does adding -fzero-initialized-in-bss or -fno-zero-initialized-in-bss to the
compile flags cause the problem to return for 3.4.1, and then adding the
-Wl,--stack option fix it again?


    cheers, 
      DaveK
-- 
Can't think of a witty .sigline today....


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