[daip] AIPS for 64-bit computers

Eric Greisen egreisen at nrao.edu
Wed Jul 11 12:41:20 EDT 2007

Marija Stankovic writes:

 > I was wondering if the latest AIPS release will run on a 64-bit computers? 
 > If not, is such a release going to be available in the near future?

It depends on what you mean by the term "64-bit computer".  The binary
releases of AIPS are all computed on machines that are basically
32-bit computers.  Nonetheless, they Linux load modules work fine on
our 64-bit AMD computer.  They run faster by ~7% than the GNU load
modules computed allowing the addressing (pointers to variables) to be
64-bits.  The data within aips are fundamentally 32-bit and do not
need extended accuracy.  One might well have trouble if you compiled
it on a machine that made REAL and INTEGER be 64 bits in length (the Z
routines that translate FITS formats are not prepared for this).  It
compiles and runs well however when pointers are 64 bits but standard
Fortran variables are 32.  We do use dynamic memory and our
preprocessor detects the size of pointers and makes our internal
pointers (we call them Fortran variables of type LONGINT) 64 bit
integers (INTEGER*8) rather than 32-bit ones.

I would also need to know what architecture of machine/OS you are
talking about to provide more details.

Eric Greisen

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