RELEASE BLOCKER: Linux doesn't follow x86/x86-64 ABI wrt direction flag

[Joe Buck]

On Wed, Mar 05, 2008 at 03:10:12PM -0800, David Miller wrote:
> From: Michael Matz <matz@suse.de>
> Date: Thu, 6 Mar 2008 00:07:39 +0100 (CET)
> 
> > The fix lies in the kernel, the work-around in gcc.
> 
> This depends upon how you interpret this ABI situation.
> 
> There is at least some agreement that how things have
> actually been implemented by these kernels for more
> than 15 years trumps whatever a paper standard states.

We had a similar argument about the undefinedness of signed int
overflow.  That's what the standard says, yet code that assumes
otherwise is pervasive, including in gcc itself.

If a standard is widely violated in a very consistent way, the violation
in effect becomes standard.