int8 regression fails on Irix 6.4

Dear Postgres Admins,

failing to install PostgreSQL 6.4.2 on our Digital Alpha workstations,
I tried to get it running on a Silicon Graphics Octane running Irix 6.4.
Here, I managed to compile, install and test the basic backend function,
but the regression test revealed that the int8 type is broken. It
appears that no matter what values are inserted, they all appear as
9223091371479335140. Also, I found that no indices can be created
on int8 type keys:

    postgres=> create table a (b int8);
    CREATE
    postgres=> create index c on a(b);
    ERROR:  Can't find a default operator class for type 20.

Any ideas on this problem? Many thanx in advance.

Greetinx, Jan
--
 +- Jan T. Kim -------------------------------------------------------+
 |             email: kim@mpiz-koeln.mpg.de                           |
 |             WWW:   http://www.mpiz-koeln.mpg.de/~kim/              |
 *-----=<  hierarchical systems are for files, not for humans  >=-----*