[Beowulf] Mixing 32-bit compute nodes with 64-bit head nodes

[Greg Lindahl]

On Thu, May 11, 2006 at 02:01:09PM -0400, Mark Hahn wrote:

> I don't know whether there's any way to use the extra registers
> without paying the cost of all addrs going to 64b.  I suspect this 
> could be made to work, but would be painful, ABI-wise.

It's certainly possible to have an n32 mode a-la MIPS, but then you
have to have 3 copies of all your libraries, when 2 were confusing
enough.

The Intel compiler has a funny mode in which it tries to implement
ILP32 but extend pointers and longs when making system calls or calls
to 64-bit libraries. It looks like an overly-heroic attempt to improve
SPECint to me.

-- greg