Simon Burge <simonb@wasabisystems.com> writes:

> On Sat, Aug 03, 2002 at 01:07:24AM +0930, Ian Dall wrote:
> 
> > This is a heads up for anyone interested in the status of ns32k
> > toolchain development.
> > 
> > I have had patches accepted for GNU gcc and binutils.  I also have an
> > updated fp emulation library for the kernel. It didn't used to do
> > rounding properly on denormalized numbers or provide a way for gcc to
> > do the right thing on unordered comparisons (with NaN). These
> > deficiencies were causing failures in the gcc testsuite.
> 
> I wonder how this compares with the genericish softfloat code we have
> already.  I know there's a couple of ports that use this library at the
> userland level (powerpc, arm, sh3 I think), but I'm not sure if any
> ports use it for kernel FP emulation yet.
> 
> We have FP emulation for pc532's that don't have an FPU?

The 32081 and 32381 only impliment a subset of ieee fp. There are enough
hooks to allow software emulation of the missing bits. Essentially, by
default, the fpu traps on NaN, Inf, and denormal operands, divide by zero
etc. If you want to get the right answers, you need to do the right thing
with those traps, which is what my handler does. It does not do full
fp emulation and will not suffice if you don't have a fpu, so it fills
a different niche to a softfloat library.

> Very cool.  I'll echo Jon's question - which gcc branches got the
> updates?  I'll assume that gcc 2.9x hasn't :-)

No ;-( This is the 3.2 branch. I think the changes should backport with
relatively little trouble if anyone is interested in doing that.

Ian