Re: Floating point problem

[dewar@merv.cs.nyu.edu (Robert Dewar)]

<<> I'm not a compiler vendor, but I note in the Janus manual that the
> default is to assume no FPU - you need to set a compilation option "on"
> to generate direct FPU codes.  I also seem to recall that Aonix (at
> least with ActivAda and I think with ObjectAda) has a compiler option.>>

ObjectAda certainly *should* have such an option, since I wrote the 
floating-point emulation package for Alsys, for both the 286 and 386,
back in the days when there were real customers around with machines
that lacked floating-point.

If GNAT were that old, it undoubtedly would have the option too. Generally
I would expect all Ada 83 vintage technologies to have this capability,
because once upon a time, PC's with no floating-point were quite common.

In fact one of the most amusing revision requests was one that specifically
suggested that Ada 9X have a language feature that would ensure that
programs would operate correctly on a machine with no floating-point
coprocessor (it was worded exactly that way :-0)

I actually find it surprising that no one has investigated what would bne
needed to get this working on DJGPP (that is really all we are talking about
here, most of the other operating systems for the PC eiher require FPT
themselves, or supply transparent emulation -- so we are only talking about
running obsolete operating systems on obsolete machines). Still with all
the talk, you would think that someone would have figured out how to do
this -- can't be that difficult. 

Despite Larry's focus on a dynamic test to ensure the program not running,
I think that what most people with these old machines around would like is
for GNAT to be able to correctly execute floating-point stuff. Since there
are lots of emulators around, and indeed I ythought DJGPP came with one,
but perhaps not, it seems more useful to put in the work to get this
working rather than diagnose when it does not.