64-Bit PostgreSQL on RHEL4 on IBM pSeries (Power5)

I'm currently trying to build a 64-Bit PostgreSQL installation on a
RedHat AS4 platform running on an IBM pSeries p570 (Power5) machine:

uname -ompi
ppc64 ppc64 ppc64 GNU/Linux

The installed OS is 32-Bit but runs a 64-Bit ppc64 kernel. Building 64-Bit
executables on this platform should be possible with the -m64 (as some fast
tests proves) compiler switch, however:

./configure --build=ppc64-redhat-linux --enable-integer-datetimes
--without-readline --with-gnu-ld CFLAGS="-mpowerpc64 -m64" CC="gcc4"

gives the following error:

make[2]: Entering directory
`/home/credativ/postgresql/src/postgresql-8.1.9/src/timezone'
/usr/bin/ld -r -o SUBSYS.o localtime.o strftime.o pgtz.o
/usr/bin/ld: Relocatable linking with relocations from format elf64-powerpc
(localtime.o) to format elf32-powerpc  (SUBSYS.o) is not supported

My first thought was that the linker accidently wants to create a wrong
output format, but trying manually gives me the following:

/usr/bin/ld  -b elf64-powerpc --oformat elf64-powerpc -r -o SUBSYS.o
localtime.o strftime.o pgtz.o
/usr/bin/ld: Relocatable linking with relocations from format elf64-powerpc
(localtime.o) to format elf64-powerpc
(SUBSYS.o) is not supported

I'm puzzled, seems like this platform doesn't want to do partial
linking....?

--
  Thanks

                    Bernd