Layout of 80-bit Reals on Mac

[Walter Bright]

dsimcha wrote:
> I understand that 80-bit reals are padded to 12 bytes on Linux and 16 bytes on
> Mac.  Oversight of this issue caused bug 4306
> (http://d.puremagic.com/issues/show_bug.cgi?id=4306) since the code was only
> initially tested on Windows.  On Linux my testing indicates that the lowest
> order 16 bits of a real are zero padding and can be ignored.  However, I don't
> own any Mac equipment.  Is it true on Mac that the lowest 32 bits are padding
> and can be ignored?  More generally, is it true for the foreseeable future
> that, for x86 hardware with reals that occupy N bits of storage, the lowest
> order 80 - N bits will be where the padding is?

The padding trails the 80 bit real, not precedes it.