Re: [MinGW-dvlpr] _alloca/_chkstk??

[Danny S. <dan...@cl...>]

----- Original Message -----
From: "Luke Dunstan" <cod...@ho...>
To: <min...@li...>
Sent: Tuesday, 7 October 2003 13:24
Subject: Re: [MinGW-dvlpr] _alloca/_chkstk??


>
> ----- Original Message -----
> From: "Danny Smith" <dan...@cl...>
> To: "mingw-dvlpr" <min...@li...>
> Sent: Tuesday, October 07, 2003 6:08 PM
> Subject: [MinGW-dvlpr] _alloca/_chkstk??
>
>
> > Does any one really know why GCC (and other windows compilers)
insert
> > code for checking stack when allocating more than a page?
> >
> > I can see where it would be useful with SEH exceptions (the OS
throws an
> > 0x80010001 exception if stack cannot be grown) but how else is
needed?
> >
> > Danny
>
> http://msdn.microsoft.com/library/en-us/vccore98/HTML/_core_.2f.gs.asp
>
> I guess it is for efficiency to make page faults more predictable but
it's
> hard to imagine that it would have a significant effect. A number of
smaller
> stack frames could also cause a fault so I can't see that it would
actually
> be *needed* for correctness. Is there a particular reason to remove it
> though, apart from when statically linking GCC-compiled objects with
MSVC
> programs or vice versa?

Yes, it plays up with optimisation using -funit-at-a-time in CVS gcc,

(I'm thinking of the undefined references to
> __alloca). It could be useful to have a GCC equivalent of "/Gs" to
> optionally disable this feature, if there isn't one already.

 -mno-stack-arg-probe  turns it off.


Danny

>
> Luke
>
>
> -------------------------------------------------------
> This sf.net email is sponsored by:ThinkGeek
> Welcome to geek heaven.
> http://thinkgeek.com/sf
> _______________________________________________
> MinGW-dvlpr mailing list
> Min...@li...
> https://lists.sourceforge.net/lists/listinfo/mingw-dvlpr