Re: Floating point problem

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

Larry says

<<And if Ada is intended to be source-compatible between platforms,
why should a programmer need to know the Intel instruction set and
differences betwee chips.>>

That seems to be getting a little absurd to me. Larry, do you think the
compiler should be careful to generate code that detects that it is running
on an 8080 and aborts if so (it is definitely possible to write such
discriminating code, in fact you can find it in Intel manuals).

If you try to run a program for one architecture on a computer with a
different architecture, you should hardly be surprised if it does not
work. You cannot possibly derive from the intention that Ada be
source-compatible between platforms that a compiler for a specific
architecture (x86 with fpt support) must diagnose at runtime an attempt
to run on some other architecture (x86 without fpt??? 286??? 186??? ...)

All you can deduce is that if you have an Ada program that works on
architecture X and is written portably, then *if* you have a compiler
for architecture Y, and *if* you recompile for architecture Y, then
you can run on architecture Y.

Larry if you are really interested in running GNAT on an x86 with no
floating-point and an OS that does not support fpt, why not investigate
how to fix the problem, I doubt it is that hard. The reason we don't
spend any effort on this problem is that we don't really have an interest
in running GNAT on such platforms!