I've been able to get today's snapshot of PostgreSQL 6.5 beta to run
on an SGI running Irix 6.4. The following steps must be taken.

1.Add the following block to src/Makefile.shlib

ifeq ($(PORTNAME), irix5)
  install-shlib-dep   := install-shlib
  shlib                               := lib$(NAME)$(DLSUFFIX).$(SO_MAJOR_VERSION).$(SO_MINOR_VERSION)
  LDFLAGS_SL          := -shared
  CFLAGS                      += $(CFLAGS_SL)
endif

2. Make src/Makefile.custome with

CUSTOM_CC = cc -32
LD += -32
MK_NO_LORDER = 1

3. Modify the install script to always copy, never move. The following install will work:

#!/bin/ksh
# Stripping is ignored in this version of install.

cmd=/bin/cp
strip=""
chmod="/bin/chmod 755"
user=`/usr/bin/whoami`
if [ $user = "root" ] 
then
        chown="/bin/chown bin"
        chgrp="/bin/chgrp bin"
else
        chown="/bin/chown $user"
        set -A groups `/usr/bin/groups`
        chgrp="/bin/chgrp ${groups[0]}"
fi
while :
do
        case $1 in
        -s )    strip=""
                ;;
        -c )    cmd="/bin/cp"
                ;;
        -m )    chmod="/bin/chmod $2"
                shift
                ;;
        -o )    chown="/bin/chown $2"
                shift
                ;;
        -g )    chgrp="/bin/chgrp $2"
                shift
                ;;
        * )     break
                ;;
        esac
        shift
done

case "$2" in
"")     echo "install: no destination specified"
        exit 1
        ;;
.|"$1") echo "install: can't move $1 onto itself"
        exit 1
        ;;
esac
case "$3" in
"")     ;;
*)      echo "install: too many files specified -> $*"
        exit 1
        ;;
esac
if [ -d $2 ]
then    file=$2/$1
else    file=$2
fi
/bin/rm -f $file
$cmd $1 $file
[ $strip ] && $strip $file
$chown $file
$chgrp $file
$chmod $file

4. Configure nsl off and make sure the correct install program is
used. The following shell statements will do this. 

cd src
rm config.cache
cat >config.cache <<EOF
ac_cv_lib_nsl_main=${ac_cv_lib_nsl_main='no'}
EOF
gmake clean
INSTALL="your install program as above" ./configure --prefix=/pg/pgsql --without-CXX ...

========================================================================

I haven't yet gotten libpq++ to build correctly and one regression test,
misc.out, fails due to a segmentation error in the copying of binary
data. The traceback is

dbx ../../../bin/postgres (wd: /pg/pgsql/data/base/regression)
use /pg/pgsql/src/backend/commands
(dbx) where
>  0 CopyFrom(0x10147450, 0x1, 0x0, 0xfb4d6f4) ["copy.c":809, 0x48e1f0]
   1 DoCopy(0x1013a5d0, 0x1, 0x0, 0x1) ["copy.c":304, 0x48c760]
   2 ProcessUtility(0x1013a630, 0x3, 0x0, 0x1013ab78) ["utility.c":227, 0x5598f8]
   3 pg_exec_query_dest(0x7ffee364, 0x3, 0x0, 0x1013ab78) ["postgres.c":718, 0x556eb8]
   4 pg_exec_query(0x7ffee364, 0x1014e1d0, 0x0, 0x1013ab78) ["postgres.c":654, 0x556d34]
   5 PostgresMain(0x8, 0x7fff28f0, 0x7, 0x7fff2e84) ["postgres.c":1649, 0x5586f4]
   6 DoBackend(0x100e2b10, 0x1014e1d0, 0x0, 0x1013ab78) ["postmaster.c":1611, 0x525a6c]
   7 BackendStartup(0x100e2b10, 0x1014e1d0, 0x0, 0x1013ab78) ["postmaster.c":1356, 0x525260]
   8 ServerLoop(0x1013ab88, 0x1014e1d0, 0x0, 0x1013ab78) ["postmaster.c":806, 0x524060]
   9 PostmasterMain(0x7, 0x7fff2e84, 0x0, 0x1013ab78) ["postmaster.c":599, 0x5237cc]
   10 main(0x7, 0x7fff2e84, 0x0, 0x1013ab78) ["main.c":93, 0x4cc92c]
   11 __istart() ["crt1tinit.s":13, 0x42a490]
(dbx) l
>* 809                                                  ptr = att_addlength(ptr, attr[i]->attlen, ptr);
   810                                          }
   811                                  }
   812                          }
   813                  }
   814                  if (done)
   815                          continue;
   816  
   817                  /*
   818                   * Does it have any sence ? - vadim 12/14/96

Sincerely,
Bob

+----------------------------------+------------------------------------+
| Robert E. Bruccoleri, Ph.D.      | Phone: 609 737 6383                |
| President, Congenomics, Inc.     | Fax:   609 737 7528                |
| 114 W. Franklin Ave, Suite K1,10 | email: bruc@acm.org                |
| P.O. Box 314                     | URL:   http://www.congen.com/~bruc |
| Pennington, NJ 08534             |                                    |
+----------------------------------+------------------------------------+

Thu, 27 May 1999 16:59:48 -0400 (EDT)
Robert Bruccoleri <bruc@pluto.njcc.com>
Port for SGI Irix using today's snapshot.