Re: [Xen-devel] [PATCH 11/34] xen/arm: Introduce __builtin_stack_pointer

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Tue, 2014-03-25 at 18:01 +0000, Julien Grall wrote:
> Hi Ian,
> 
> On 03/25/2014 05:18 PM, Ian Campbell wrote:
> > On Tue, 2014-03-25 at 16:55 +0000, Julien Grall wrote:
> >> Clang doesn't support named register. Introduce __builtin_stack_pointer
> >> to be able to use named register with gcc.
> > 
> > I think gcc considers the __builtin namespace to be its own, not sure
> > about clang.
> 
> I'm able to compile on GCC without any issue.

That's not the point. The point of a namespacing rule is that gcc can
add such a function at any time it likes, and if that breaks your
application then that is tough luck.

> > I think get_stack_pointer() would be a fine name for this macro. It
> > seems like the clang version should work for both gcc and clang.
> > 
> > Google seems to suggest that __builtin_stack_pointer might become a real
> > compiler builtin at some point.
> 
> I took the idea to the llvmlinux project:
> http://git.linuxfoundation.org/?p=llvmlinux.git;a=blob;f=arch/arm/patches/current_stack_pointer_arm.patch;
> 
> But I can rename into get_stack_pointer for the next version.

Sounds good, thanks.

Ian.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel