| 1 | afe | 1.1 | C $Header: /u/gcmpack/MITgcm_contrib/osse/code/CPP_EEOPTIONS.h,v 1.1 2004/04/26 14:08:04 afe Exp $ | 
| 2 |  |  | C $Name:  $ | 
| 3 |  |  | C | 
| 4 |  |  | C     /==========================================================\ | 
| 5 |  |  | C     | CPP_EEOPTIONS.h                                          | | 
| 6 |  |  | C     |==========================================================| | 
| 7 |  |  | C     | C preprocessor "execution environment" supporting        | | 
| 8 |  |  | C     | flags. Use this file to set flags controlling the        | | 
| 9 |  |  | C     | execution environment in which a model runs - as opposed | | 
| 10 |  |  | C     | to the dynamical problem the model solves.               | | 
| 11 |  |  | C     | Note: Many options are implemented with both compile time| | 
| 12 |  |  | C     |       and run-time switches. This allows options to be   | | 
| 13 |  |  | C     |       removed altogether, made optional at run-time or   | | 
| 14 |  |  | C     |       to be permanently enabled. This convention helps   | | 
| 15 |  |  | C     |       with the data-dependence analysis performed by the | | 
| 16 |  |  | C     |       adjoint model compiler. This data dependency       | | 
| 17 |  |  | C     |       analysis can be upset by runtime switches that it  | | 
| 18 |  |  | C     |       is unable to recoginise as being fixed for the     | | 
| 19 |  |  | C     |       duration of an integration.                        | | 
| 20 |  |  | C     |       A reasonable way to use these flags is to          | | 
| 21 |  |  | C     |       set all options as selectable at runtime but then  | | 
| 22 |  |  | C     |       once an experimental configuration has been        | | 
| 23 |  |  | C     |       identified, rebuild the code with the appropriate  | | 
| 24 |  |  | C     |       options set at compile time.                       | | 
| 25 |  |  | C     \==========================================================/ | 
| 26 |  |  |  | 
| 27 |  |  | #ifndef _CPP_EEOPTIONS_H_ | 
| 28 |  |  | #define _CPP_EEOPTIONS_H_ | 
| 29 |  |  |  | 
| 30 |  |  | C     In general the following convention applies: | 
| 31 |  |  | C     ALLOW  - indicates an feature will be included but it may | 
| 32 |  |  | C     CAN      have a run-time flag to allow it to be switched | 
| 33 |  |  | C              on and off. | 
| 34 |  |  | C              If ALLOW or CAN directives are "undef'd" this generally | 
| 35 |  |  | C              means that the feature will not be available i.e. it | 
| 36 |  |  | C              will not be included in the compiled code and so no | 
| 37 |  |  | C              run-time option to use the feature will be available. | 
| 38 |  |  | C | 
| 39 |  |  | C     ALWAYS - indicates the choice will be fixed at compile time | 
| 40 |  |  | C              so no run-time option will be present | 
| 41 |  |  |  | 
| 42 |  |  | C     Flag used to indicate whether Fortran formatted write | 
| 43 |  |  | C     and read are threadsafe. On SGI the routines can be thread | 
| 44 |  |  | C     safe, on Sun it is not possible - if you are unsure then | 
| 45 |  |  | C     undef this option. | 
| 46 |  |  | #undef  FMTFTN_IO_THREADSAFE | 
| 47 |  |  |  | 
| 48 |  |  | C--   Control MPI based parallel processing | 
| 49 |  |  | #undef ALLOW_USE_MPI | 
| 50 |  |  | #undef ALWAYS_USE_MPI | 
| 51 |  |  |  | 
| 52 |  |  | C--   Control use of communication that might overlap computation. | 
| 53 |  |  | C     Under MPI selects/deselects "non-blocking" sends and receives. | 
| 54 |  |  | #define ALLOW_ASYNC_COMMUNICATION | 
| 55 |  |  | #undef  ALLOW_ASYNC_COMMUNICATION | 
| 56 |  |  | #undef  ALWAYS_USE_ASYNC_COMMUNICATION | 
| 57 |  |  | C--   Control use of communication that is atomic to computation. | 
| 58 |  |  | C     Under MPI selects/deselects "blocking" sends and receives. | 
| 59 |  |  | #define ALLOW_SYNC_COMMUNICATION | 
| 60 |  |  | #undef  ALWAYS_USE_SYNC_COMMUNICATION | 
| 61 |  |  |  | 
| 62 |  |  | C--   Control use of JAM routines for Artic network | 
| 63 |  |  | C     These invoke optimized versions of "exchange" and "sum" that | 
| 64 |  |  | C     utilize the programmable aspect of Artic cards. | 
| 65 |  |  | #undef  LETS_MAKE_JAM | 
| 66 |  |  | #undef  JAM_WITH_TWO_PROCS_PER_NODE | 
| 67 |  |  |  | 
| 68 |  |  | C--   Control storage of floating point operands | 
| 69 |  |  | C     On many systems it improves performance only to use | 
| 70 |  |  | C     8-byte precision for time stepped variables. | 
| 71 |  |  | C     Constant in time terms ( geometric factors etc.. ) | 
| 72 |  |  | C     can use 4-byte precision, reducing memory utilisation and | 
| 73 |  |  | C     boosting performance because of a smaller working | 
| 74 |  |  | C     set size. However, on vector CRAY systems this degrades | 
| 75 |  |  | C     performance. | 
| 76 |  |  | #define REAL4_IS_SLOW | 
| 77 |  |  |  | 
| 78 |  |  | C--   Control use of "double" precision constants. | 
| 79 |  |  | C     Use D0 where it means REAL*8 but not where it means REAL*16 | 
| 80 |  |  | #define D0 d0 | 
| 81 |  |  |  | 
| 82 |  |  | C--   Control XY periodicity in processor to grid mappings | 
| 83 |  |  | C     Note: Model code does not need to know whether a domain is | 
| 84 |  |  | C           periodic because it has overlap regions for every box. | 
| 85 |  |  | C           Model assume that these values have been | 
| 86 |  |  | C           filled in some way. | 
| 87 |  |  | #undef  ALWAYS_PREVENT_X_PERIODICITY | 
| 88 |  |  | #undef  ALWAYS_PREVENT_Y_PERIODICITY | 
| 89 |  |  | #define CAN_PREVENT_X_PERIODICITY | 
| 90 |  |  | #define CAN_PREVENT_Y_PERIODICITY | 
| 91 |  |  |  | 
| 92 |  |  | #endif /* _CPP_EEOPTIONS_H_ */ | 
| 93 |  |  |  | 
| 94 |  |  | #include "CPP_EEMACROS.h" |