Re: math-emu issue with fp divide

[David Miller <davem at davemloft dot net>]

From: "Joseph S. Myers" <joseph@codesourcery.com>
Date: Wed, 4 Jun 2008 21:42:55 +0000 (UTC)

> On Wed, 4 Jun 2008, Kumar Gala wrote:
> 
> > I'm trying to move the powerpc math-emu
> > code to use the include/math-emu bits.
> 
> I'd like to remind people that the include/math-emu code is based on an 
> old, buggy version of the soft-fp code in glibc.  RTH previously noted 
> <http://sourceware.org/ml/libc-alpha/2006-02/msg00075.html> that the fixes 
> should go in the kernel, when approving a patch of mine fixing various 
> bugs and speeding up soft-fp, and several more bugs have been fixed since 
> then in the course of GCC work on soft-float for Power and __float128 
> support for x86_64.
> 
> So it may be better than the old code you're replacing, but it might still 
> be a good idea to merge things with the current glibc code, as a matter of 
> both correctness and performance.  (And there may well still be bugs left 
> in the code.)

Once the GCC folks started looking into using the soft-fp bits I knew
this situation would develop.  The kernel side would have some set of
fixes and the glibc/gcc side would have yet another set.

To be honest this doesn't surprise me...