Progress Report: Fortran 90 Conversion

1. Progress Report: Fortran 90 Conversion RELAP5 International User Seminar Nov 6-8, 2007 Idaho Falls, ID George L Mesina RELAP5-3D Development Team

2. Introduction • Goals & Benefits (User and Developer) • Phases of FORTRAN 90 Conversion • Progress and Measurements • Conclusion

3. 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

4. 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

5. 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

6. 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

7. Fortran90 Conversion Major Tasks • Database conversion • Transient conversion • Restart-plot conversion • R- and I-level conversion • Environmental conversion • Fluids conversion

8. 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

9. 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. )

10. 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.

11. 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

12. 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 • Arrays used in one subroutine only (192) • Arrays used in exactly two subroutines (162) • Arrays used in multiple subroutines (256) • Create transfer routines between FA & module

13. Transient Conversion Progress • Two kinds of FA-indexing to eliminate • Pointers from one database to a single database • E.G. Holder array, Junction to “from” volume • 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

14. 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)

15. 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

16. 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

17. 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

18. Fluids Directory • Not started • Primarily involves restructuring and converting to Fortran 90 free-format • Mostly handled by automated software

19. Plan to finish • Needed for upcoming Developmental Assessment project • Planned conclusion: May 2008 • Probable version 2.7.8 • Completion report includes timing data

20. 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