[Tinyos-devel] external (nx*) types and floating point

[David Gay]

On Mon, May 5, 2008 at 10:44 AM, Vlado Handziski
<handzisk at tkn.tu-berlin.de> wrote:
> Sure, that sounds reasonable. Do we have any use cases for nx_double? MSPGCC
> supports only single precision floats which take 2 bytes.

I assume you mean 4 for single precision floats ;-) I agree that
double is unlikely to be useful in the short term. Btw, the work in
doing all this is digging up exactly what floating-point rep avr-gcc,
msp430-gcc and x86-gcc are currently using.

David

>
> Vlado
>
>
>
> On Mon, May 5, 2008 at 7:30 PM, David Gay <dgay42 at gmail.com> wrote:
>
> >
> > On Mon, May 5, 2008 at 9:28 AM, Vlado Handziski
> > <handzisk at tkn.tu-berlin.de> wrote:
> > > I think I lost you there. What do you understand under MCU specific
> > > nx_float/nx_double definitions? How the serialization is implemented?
> Cause
> > > the whole point of nx_* was to provide platform independent types, so
> the
> > > "semantics" of the type should be the same all over, isn't it?
> >
> > The platform-independent rep of floating point types would be the
> > standard IEEE 32 (or 64) bit floating point formats, in some standard
> > bit order. The platform-specific code would convert to/from that rep
> > (I can't think of any efficient, or even practical, way to write that
> > code in a platform-independent way).
> >
> > David
> >
>
>