[m-dev.] 32-bit sources on 64-bit target

[Julien Fischer]

Hi Peter,

On Thu, Mar 7, 2013 at 12:17 PM, Peter Wang <novalazy at gmail.com> wrote:

> I think I can fix the first by allocating two words to a `float'
> constructor argument whenever --no-unboxed-float is used, even when it
> is unnecessary on 64-bit.
>
> The second, I'm guessing, does not actually occur in the standard
> library.  A solution would be to restrict enum packing to using at
> most 32 bits of a word, with an option like --max-arg-packing-bits=32.

I think we already have an option that is appropriate here, --cross-compiling.
You just need to make it do the above.  The only catch I can think of is
that when I reconfigure the source distribution on my build machine, then you
need to make sure that settings like --max-arg-packing-bits end up being
consistent with the pre-generated C files.

...

> PS. I'd still like to see generated C sources for 64-bit...

That should just be a matter of:

        mercury_cv_low_tag_bits=3 \
        mercury_cv_bits_per_word=64 \
        mercury_cv_unboxed_floats=yes \

And indeed if you change the grade to hlc.gc you will get a source
distribution whose C files are
high-level C code.

Is it worth having multiple versions of the source distribution or is
it just going to be confusing though?

Cheers,
Julien.