Very Computer

Matt

We also have aix 3.2.5 on an older rs/6000 power platform
with the Absoft fortran compiler

We have successfully compiled and linked on aix 3.2.5 and
run it under aix 4.  However, the absoft compiler we used
did not know about the later model rs6000 cpus, only power.
It generates machine language source source for the Power
platform and submits it to the aix assembler. It did NOT
compile in common mode as the IBM native compilers

When we spoke to absoft, they said they no longer sold a
a fortran compiler for the rs6000. In fact, the person
we spoke to did not even know that they ever had a fortran
compiler for the rs6000. We even asked about purchaing the
compiler source code to maintain for new rs600 platforms.
They had no old binaries, no source.

If you run the absoft compiled code on a later model
rs6000 (read PowerPC, 603, 604..) their will be some
compiler generated machine instructions that do
not exist on the later hardware. Although they were
handled internally on the rs6000/aix by emulation, there
was a performance hit. In one case it was really bad and
it forced us to look at alternatives to the absoft compiler.

If you transfer the absoft compiler to a machine later than
the power platform, it will generate assembler and you can
get errors during the assembler phase for the non-existant
instructions. I believe there were also problems during
the ld phase but i don't remember exactly.

If you create the objects on a 3.5.2 machine, you can't link
on version 4.

we did not try upgrading the 3.5.2 system to 4.3. since we still
need to support clients and couldn't lose that platform.

we ported the code to ibm xlf fortran, replacing encode/decodes
with internal reads, forcing common regions to be the same size
defined in all modules, and more. We currently have an older
rs6000 with aix 3.5.2 and the absoft compiler, and a newer
machines with aix 4.3.2 and the ibm xlf compiler, both sharing
the same source.

The xlf compiler includes libraries compatible with different
flavors of aix 4 but not with aix 3.

good luck
sol

Quote:> Hi,
>     We have recently upgraded from AIX 3.2 to AIX 4.3. We are trying
to
> compile Fortran executables on the AIX 4.3 machine (  Absoft FORTRAN
for the
> RS/6000 V3.2) which will run on AIX3.2 machines, but so far have run
into
> various problems.