Subject: Re: porting ccm3 to linux
From: Jim Rosinski (rosinski@cgd.ucar.edu)
Date: Fri Sep 12 1997 - 09:45:55 MDT
CCM-users:
Regarding the issue of porting CCM3 to non-Cray platforms, the good news is
that there are only 2 aspects of the code which do not comply with the
Fortran 77 standard that need to be addressed. The bad news is that they're
both whoppers.
First, the use of run-time memory allocation via Cray pointers and "malloc"
calls is very pervasive in CCM3. This is particularly true in the land
model. If you don't have a compiler that supports Cray pointers you're
pretty close to dead in the water. The reason CCM3 runs on a wide variety of
platforms is that Sun, IBM, and SGI all support this non f77-compliant
construct. Your best bet is to rewrite the Cray pointer syntax in Fortran 90
if such a compiler is available.
The second major porting issue has to do with promotion of default floating
point precision to real*8. Many vendors provide such an auto-promotion flag
with their f77 compiler (e.g. -r8 on SUN and SGI). Going into the CCM3
code and changing all "real" declarations to "real*8" is an unpleasant task,
though with good editors like emacs it may not be all that time consuming.
Jim Rosinski
CCM Core Group
This archive was generated by hypermail 2b27 : Thu Jun 01 2000 - 09:11:31 MDT