FW: lo_ieee_init: unrecognized floating point format! on ARM platform

[Simon Pickering]

> | warning: invalid value specified for `gnuplot_binary'
> | octave:1> format bit
> | octave:2> eps
> | eps =
> 0000000000000000000000000000000000111100101100000000000000000000
> | octave:3> realmax
> | realmax =
> | 1111111111111111111111111111111101111111111011111111111111111111
> | octave:4> realmin
> | realmin =
> | 0000000000000000000000000000000000000000000100000000000000000000
> | octave:5> exit
> | address@hidden:~#
> 
> Doesn't this system use IEEE floating point?

I believe it does. To be specific, the kernel & system, and Octave are
compiled using GCC 3.4.4 (patched for arm) using soft-float in its fpa form.
I've never seen any troubles, but am willing to perform some tests for ieee
conformance (the arm soft-float patches purport to be conformant) if you
think this may be an issue.

> If not, adding proper and complete support for it will be hard.
> 
> Are you sure that the problem isn't that the values of realmin, 
> realmax, and eps are computed incorrectly?  What are the decimal 
> values of these on your system?
> 

I don't know, I was hoping you or someone else on the list could point me in
the right direction to try to work out why it doesn't work, and why the
numbers may be different. 

>From looking at the code, it looks like there's a set of test routines which
try to work out the fp format for whatever platform the code is
generated/run on(?) and 4 sets of test data against which this is compared
to determine which fp type it matches. I'll have to have a look through this
code which is used to determine the fp type; the numbers hard-coded in the
oct_mach_info::flt_fmt_* types are presumably pre-calculated somehow (on a
known platform from the fp type test code I guess - I'll see if I can work
out what my PXA255 produces for these).

Here are the results in decimal with 'format long':

In decimal:
Eps =     2.22044604925031e-16
Realmin = 2.22507385850720e-308
Realmax = 1.79769313486232e+308

Thanks,



Simon



-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------