George L MesinaRELAP5-3D Development Team

Progress Report: Fortran 90 Conversion

RELAP5 International User SeminarNov 6-8, 2007Idaho Falls, ID

Introduction

• Goals & Benefits (User and Developer)

• Phases of FORTRAN 90 Conversion

• Progress and Measurements

• Conclusion

Thanks to Contributors

The following have spent several months on the project each:

• Dr. Richard Riemke: Consulting, some conversion

• Dr. Walt Weaver: Convert kinetics & PVM, consulting

• Nolan Anderson: Convert scratch & fluids, clean-ups

• Richard Wagner: R- and I-level subroutines

• Peter Cebull: Fluid properties

• Summer students: Restructuring

Usefulness of Conversion Task

• User considerations

– Machine independence via F90 intrinsics

– Eliminate memory restrictions

– Modernize code for longevity considerations

• Development team

– Modernize language to ease transition of younger programmers into team

– Make code easier to read and understand

Task Overview: Original Scope

• Remake database

– Analyze and reorganize data layout

– Create modules with new layout in F90 constructs

– Create internal subroutines for the data

• Allocate, eliminate, restart (R&W), transfer, etc.

• Convert transient source code

– (Streamline)

– Convert code to use module data

– Apply Fortran 90 constructs

Task Overview: Revised Scope

• Eliminate container array, FA

– Convert input-read, input-processing, transient set-up, and restart-plot file source code

– Replace FA-indexing with use of ordinals where possible

– Elsewhere replace arrays of F90-pointers from SCNREQ with arrays of ordinals or F90-pointers

• Convert environmental library subroutines

• Convert fluid library subroutines

Fortran90 Conversion Major Tasks

• Database conversion

• Transient conversion

• Restart-plot conversion

• R- and I-level conversion

• Environmental conversion

• Fluids conversion

Database Conversion Progress

• Converted all fixed-length COMDECK files

– 114 files into 52 modules

• Categorized all variable-length databases (FA-files)

– Simple (11) – single stride

– complicated (3) – multiple strides & structures

– complex (19) – No fixed strides, conditional data

– eliminated (10) – Not in use anymore

– absorbed (2) – Put in module of another database

– postponed(2)- To be converted when needed

Database Conversion Progress

• All named databases converted into modules

• Module high-level structure

– Data reorganized and declared (section 1)

– Documentation (section 2)

– Internal data-related subroutines (section 3)

• Restart (Read & Write)

• Memory Allocation and deletion

• Transfers (between module & FA)

• Sometime more (size, ordinal, etc. )

Database Conversion Progress

• Most unnamed databases converted to modules

– Same module structure

• Two unnamed databases remain to convert

– Files 40, 42 (in 2 and 1 subroutines respectively)

• Total modules will be 90.

Transient Conversion Progress

• 94% (798 of 849) transient “conversions” performed

• “Conversion” of subroutine A for module B means subroutine A now uses module B’s data, not the related COMDECK data

– All arrays of related COMDECK replaced by corresponding module derived types

• Remaining conversions primarily include

– Scratch, PVM phase 2

– Elimination of FA-indexing

– Solver-related conversions

Transient Conversion Progress

• Scratch conversion by new method: Array-by-array

– Each array will be converted in all the subroutines that use it.

• Three phases

1. Arrays used in one subroutine only (192)

2. Arrays used in exactly two subroutines (162)

3. Arrays used in multiple subroutines (256)

• Create transfer routines between FA & module

Transient Conversion Progress

• Two kinds of FA-indexing to eliminate

1. Pointers from one database to a single database

• E.G. Holder array, Junction to “from” volume

2. Pointers (randomly) to any database

• E.G. PVM, minor edit, plot variables

• First kind replaced in subroutine that calculate FA-indices with calculation of ordinal

• Second kind replaced by replacing SCNREQ calss with calls to IREQUEST

Transient Conversion Progress

• All solver related data must be built and accessed in module data.

– BPLU data to modules

– Source code that builds it converted

– PGMRES and MA18 must access module data

• Via call sequence for MA18

• Direct to module for PGMRES (low priority)

Restart-Plot File Conversion

• New format for ease of use by peripheral programs

• Modules for variable-length files

– Complex routines with much safety checking

– All written except kinetics and PVM

• Fixed-length modules

– Must write restart read & write routines

– Will be automated and handled by program

• Testing has not been done for all of them

R- and I- Level

• Initial modifications

– CVIC, SQOZ, UNSQOZ modified

– INP turned into a module and converted

• Eliminates need for FTB routines

• All R-level routines changed to use new INP

• Initial R-level routines

– User-var, time-step, minor edits

Environmental Done

• Restructured and documented better

• Many routines simplified

• Converted to Fortran 90

• Common coding abstracted in to utility routines

• All conditional coding replaced or moved into either modules or one service routine

• Environmental routines from RELAP-directory brought into environmental directory

• Installation scripts improved

Fluids Directory

• Not started

• Primarily involves restructuring and converting to Fortran 90 free-format

• Mostly handled by automated software

Plan to finish

• Needed for upcoming Developmental Assessment project

• Planned conclusion: May 2008

• Probable version 2.7.8

• Completion report includes timing data

Conclusion

• Fortran 90 conversion will improve RELAP5-3D in numerous ways

• The project is nearing completion

• There are numerous interesting tasks remaining

• The code will be ready for the DA project