ESMF Code Generation with Cupid Update and Demo October 2009 Rocky Dunlap Spencer Rugaber Leo Mark Georgia Tech College of Computing

ESMF Code Generationwith CupidUpdate and DemoOctober 2009

Rocky DunlapSpencer RugaberLeo MarkGeorgia Tech College of Computing

Goals•Cupid supports programmers of

numerical Earth System Models by:▫Raising the level of abstraction so that

modelers can think and code in terms of ESM vocabulary—not in terms of low or intermediate level programming constructs

▫Validating coupling configurations at compile time; providing error messages

▫Automatically generating FORTRAN code for coupling Earth System Modeling Framework (ESMF) components

Process Overview – Inputs & Outputs•You have:

▫Fortran source code for two (or more) ESMF Gridded Components

•You put in:▫A description of those components▫A description of a coupling configuration: composition, schedule, and deployment

•You get out:▫Fortran source code for an ESMF driver

and an ESMF coupler component

Cupid Architecture

ESMF Conceptual Model (ECM)

ECM Modeling GUI

ESMF Conceptual Modeling

ESMF Configuration InstanceESMF Configuration InstanceESMF Configuration Instances (ECIs)

ESMF Driver Generator

ESMF Code Generation

ESMF Coupler Generator

Java Fortran Object Model (JFOM)

FORTRAN Code Generation

JFOM InstancesJFOM InstancesJFOM Instances

StringTemplate Eclipse Modeling Framework (EMF)

Textual syntax and text editor (based on Xtext)

Cupid Architecture


ECM Modeling GUI


ESMF Configuration Instances (ECIs)






JFOM Instances



Cupid Architecture








JFOM Instances




ECM Modeling GUI

The ESMF Conceptual Model (ECM)• A conceptual model of ESMF API:

▫Gridded and Coupler Component, Import/Export State

▫Virtual Machine, PETs, DELayout▫DistGrid, Array▫Field, Grid (partial)▫Not included (yet): Clock, Calendar

• Also includes new structures for describing coupling configurations:▫Composition – how the components are connected▫Schedule – order of execution of components▫Deployment – map components to physical

resources

Graphical Modeling

Cupid Architecture


ECM Modeling GUI








JFOM Instances



Textual Syntax

Cupid Architecture


ECM Modeling GUI






JFOM Instances





System Architecture


ECM Modeling GUI










JFOM InstancesJFOM InstancesJFOM Instances

System Architecture


ECM Modeling GUI










JFOM Instances

Building a Coupling Configuration•There are two ways to create a coupling

configuration (ESMF Configuration Instance):▫Graphically using a tree-based model

editor▫Using a textual syntax and Eclipse-based

editor•At the end of the day, both are

represented as instances of the ESMF Conceptual Model.▫The two formats are interchangeable

Case Studies•ESMF_ArrayRedistSTest

▫Two components, one-way coupling▫user_model1 populates 100x150 global array▫user_model2 verifies array data▫user_model1 runs on 4 processors (PETs) with a

4x1 DELayout (i.e., four 25x150 local arrays)▫user_model2 runs on 2 PETs with a 1x2

DELayout (i.e., two 100x75 local arrays)•ESMF_FieldSparseMatMulSTest

▫Similar to above except data is packaged in Fields and redistribution is done via ESMF_ArraySMM

Demo

Models and Instances


ESMF Configuration Instance (ECI)

Java Fortran Object Model

(JFOM)

JFOM Instance

FORTRAN 90ISO Standard

FORTRANsource code

Model level

Instance level

transform transform

conform

Current Status

•ECM is partially complete (~70%)▫missing some elements from the ESMF API

• JFOM is partially complete (~33%)▫missing FORTRAN constructs

•Code generator is “rigid”▫geared toward the two system test cases▫needs to be stretched with real world

models•Hurdles

▫How to best represent interpolation weights for Sparse Matrix Multiply.

Future Work

•Examples, examples, examples▫Need to generate couplers for more

realistic models•Discussions with modelers/scientists

▫How can code generation increase productivity, simplify coding, and enhance model understanding?

•Coupling in general▫What are the hard parts of coupling

models? How can this system address them?

Thanks!Questions?

code generationSpringtime has finally come

a happy climate

Additional slides

Existing Infrastructure Pieces• Eclipse Modeling Framework

▫http://www.eclipse.org/emf/▫“…a modeling framework and code generation

facility for building tools and other applications based on a structured data model”

▫Models are built using a UML-like, object-oriented metamodel called Ecore

• StringTemplate▫http://www.stringtemplate.org/▫a Java-based template engine for generating

formatted text output▫templates are strings with “holes” that can be

populated programmatically and then output

JFOM: Fortran Conceptual Model•ECIs are input to the code generation

phase. We need an API for manipulating Fortran programs.

•Java Fortran Object Model (JFOM)▫built with the Eclipse Modeling Framework▫a set of Java classes that represent the

syntactic structures of Fortran programs▫based on the Fortran 90 grammar▫allows programmatic manipulation of

Fortran programs•JFOM instances are serialized with

StringTemplate

JFOM Classes

JFOM classes represent the syntactic structures of Fortran 90

Generated Code Examples

•Examples of generated code can be found here:

•http://swiki.cc.gatech.edu:8080/Curator/49

Documents

ESMF Code Generation with Cupid Update and Demo October 2009 Rocky Dunlap Spencer Rugaber Leo Mark Georgia Tech College of Computing