C $Header: /u/gcmpack/MITgcm/verification/rotating_tank/code/CPP_EEOPTIONS.h,v 1.1 2004/06/24 20:38:17 afe Exp $ C $Name: $ C C /==========================================================\ C | CPP_EEOPTIONS.h | C |==========================================================| C | C preprocessor "execution environment" supporting | C | flags. Use this file to set flags controlling the | C | execution environment in which a model runs - as opposed | C | to the dynamical problem the model solves. | C | Note: Many options are implemented with both compile time| C | and run-time switches. This allows options to be | C | removed altogether, made optional at run-time or | C | to be permanently enabled. This convention helps | C | with the data-dependence analysis performed by the | C | adjoint model compiler. This data dependency | C | analysis can be upset by runtime switches that it | C | is unable to recoginise as being fixed for the | C | duration of an integration. | C | A reasonable way to use these flags is to | C | set all options as selectable at runtime but then | C | once an experimental configuration has been | C | identified, rebuild the code with the appropriate | C | options set at compile time. | C \==========================================================/ #ifndef _CPP_EEOPTIONS_H_ #define _CPP_EEOPTIONS_H_ C In general the following convention applies: C ALLOW - indicates an feature will be included but it may C CAN have a run-time flag to allow it to be switched C on and off. C If ALLOW or CAN directives are "undef'd" this generally C means that the feature will not be available i.e. it C will not be included in the compiled code and so no C run-time option to use the feature will be available. C C ALWAYS - indicates the choice will be fixed at compile time C so no run-time option will be present C Flag used to indicate whether Fortran formatted write C and read are threadsafe. On SGI the routines can be thread C safe, on Sun it is not possible - if you are unsure then C undef this option. #undef FMTFTN_IO_THREADSAFE C-- Control MPI based parallel processing #undef ALLOW_USE_MPI #undef ALWAYS_USE_MPI C-- Control use of communication that might overlap computation. C Under MPI selects/deselects "non-blocking" sends and receives. #define ALLOW_ASYNC_COMMUNICATION #undef ALLOW_ASYNC_COMMUNICATION #undef ALWAYS_USE_ASYNC_COMMUNICATION C-- Control use of communication that is atomic to computation. C Under MPI selects/deselects "blocking" sends and receives. #define ALLOW_SYNC_COMMUNICATION #undef ALWAYS_USE_SYNC_COMMUNICATION C-- Control use of JAM routines for Artic network C These invoke optimized versions of "exchange" and "sum" that C utilize the programmable aspect of Artic cards. #undef LETS_MAKE_JAM #undef JAM_WITH_TWO_PROCS_PER_NODE C-- Control storage of floating point operands C On many systems it improves performance only to use C 8-byte precision for time stepped variables. C Constant in time terms ( geometric factors etc.. ) C can use 4-byte precision, reducing memory utilisation and C boosting performance because of a smaller working C set size. However, on vector CRAY systems this degrades C performance. #define REAL4_IS_SLOW C-- Control use of "double" precision constants. C Use D0 where it means REAL*8 but not where it means REAL*16 #define D0 d0 C-- Control XY periodicity in processor to grid mappings C Note: Model code does not need to know whether a domain is C periodic because it has overlap regions for every box. C Model assume that these values have been C filled in some way. #undef ALWAYS_PREVENT_X_PERIODICITY #undef ALWAYS_PREVENT_Y_PERIODICITY #define CAN_PREVENT_X_PERIODICITY #define CAN_PREVENT_Y_PERIODICITY #endif /* _CPP_EEOPTIONS_H_ */ #include "CPP_EEMACROS.h"