_G_IO_NO_BACKWARD_COMPAT

[Roland McGrath]

> On Wed, 2002-11-06 at 04:04, Roland McGrath wrote:
> > > Is there any to leave _G_IO_NO_BACKWARD_COMPAT undefined in a new
> > > glibc port?  I believe defining this macro will make libio somewhat
> > > faster.
> 
> > I can't see any reason not to define it, as you say.  That has not been
> > tested so there is likely to be some bit-rot, but that is easily fixed.
> 
> Would this be useful for i386-gnu at all?

The extent of useful it gets is saving a load of a word that's always zero
and an addition.  It's a minor optimization, though one in the critical
path of most libio uses.

If it's done, I think it should be done generically contingent on SHLIB_COMPAT.