Difference between revisions of "GULP"

@@ Line 1: / Line 1: @@
-GULP is a program for performing a variety of types of simulation on materials using boundary conditions of 0-D (molecules and clusters), 1-D (polymers), 2-D (surfaces, slabs and grain boundaries), or 3-D (periodic solids).
-==Software Location==
-The software is located on the system in the following location:
-<pre>
-/apps/gulp
-</pre>
-The most recent executable is located here:
- /apps/gulp/3.1/intel/ompi-1.2.2/bin/gulp
-==Compilation on 64-bit Systems with Intel compiler==
-When I tried to compile the GULP software on the cluster, the
-compilation went quite smoothly (with the exception of a couple of extra
-characters in format specifications in a couple of files... they are
-ignored by the fortran compiler, but it would be nice if those were
-cleaned up sometime so that the compile is truly clean... I have diffs
-of the four files that have this problem if you want).
-The problem came about with execution of the software, which failed
-miserably with the following error:
-<pre>
-forrtl: error (69): process interrupted (SIGINT)
-</pre>
-I then proceeded to compile the software with debug enabled (by the way,
-doing a make gulp_debug appears to be broken) and ran it through the
-debugger. The line it was breaking on each time seemed very innocent:
-<pre>
-(channels.F:L103)
-       if (nunit.lt.0) nunit = - nunit
-</pre>
-In a comment above this you mention that taking abs(nunit) crashes on a
-DEC. Well, this appears to crash on x86_64. I never tried using
-abs(nunit) as I figured the code you had should just work, so I thought
-that something else must be wrong.
-That was when I started messing with optimization levels of the code. I
-first turned optimization off completely, and the code worked fine with
-test input. I then started ramping up the optimizations only to find
-that optimization of any level on the standard files would break the
-program at this point.
-As it stands now, the optimizations I currently have in the file
-getmachine are as follow:
-<pre>
-# Intel compiler
-                echo 'OPT=-O0 -mp1 ' > makefile
-                echo 'OPT1=-O1 ' >> makefile
-</pre>
-I then thought to myself that there must be a way to get better
-optimization than this, so I specifically singled out channels.F and
-reduced the optimization on that particular file to nothing, while
-leaving the rest at -O3. This just propagated the fault to a new file.
-It was at this point I gave up as I don't have the time to chase this
-down through all of the different files, so leaving a good portion of
-the code un-optimized is my current option.

Difference between revisions of "GULP"

Revision as of 00:42, 6 May 2013

Navigation menu

Search