C $Header: /home/ubuntu/mnt/e9_copy/MITgcm/eesupp/inc/CPP_EEOPTIONS.h,v 1.10 1998/10/28 03:11:33 cnh Exp $ 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 Flag used to indicate which flavour of multi-threading C compiler directives to use. Only set one of these. C USE_SOLARIS_THREADING - Takes directives for SUN Workshop C compiler. C USE_KAP_THREADING - Takes directives for Kuck and C Associates multi-threading compiler C ( used on Digital platforms ). C USE_IRIX_THREADING - Takes directives for SGI MIPS C Pro Fortran compiler. C USE_EXEMPLAR_THREADING - Takes directives for HP SPP series C compiler. C USE_C90_THREADING - Takes directives for CRAY/SGI C90 C system F90 compiler. #ifdef TARGET_SUN #define USE_SOLARIS_THREADING #endif #ifdef TARGET_DEC #define USE_KAP_THREADING #endif #ifdef TARGET_SGI #define USE_IRIX_THREADING #endif #ifdef TARGET_HP #define USE_EXEMPLAR_THREADING #endif #ifdef TARGET_CRAY_VECTOR #define USE_C90_THREADING #endif C-- Define the mapping for the _BARRIER macro C On some systems low-level hardware support can be accessed through C compiler directives here. #define _BARRIER CALL BARRIER(myThid) C-- Define the mapping for the BEGIN_CRIT() and END_CRIT() macros. C On some systems we simply execute this section only using the C master thread i.e. its not really a critical section. We can C do this because we do not use critical sections in any critical C sections of our code! #define _BEGIN_CRIT(a) _BEGIN_MASTER(a) #define _END_CRIT(a) _END_MASTER(a) C-- Define the mapping for the BEGIN_MASTER_SECTION() and C END_MASTER_SECTION() macros. These are generally implemented by C simply choosing a particular thread to be "the master" and have C it alone execute the BEGIN_MASTER..., END_MASTER.. sections. #define _BEGIN_MASTER(a) IF ( a .EQ. 1 ) THEN #define _END_MASTER(a) ENDIF 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 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 #ifdef REAL4_IS_SLOW #define real Real*8 #define REAL Real*8 #define _RS Real*8 #define _RL Real*8 #define RS_IS_REAL8 #define _EXCH_XY_R4(a,b) CALL EXCH_XY_R8 ( a, b ) #define _EXCH_XYZ_R4(a,b) CALL EXCH_XYZ_R8 ( a, b ) #define _GLOBAL_SUM_R4(a,b,c) CALL GLOBAL_SUM_R8( a, b , c) #define _GLOBAL_MAX_R4(a,b,c) CALL GLOBAL_MAX_R8( a, b , c) #endif #ifndef REAL4_IS_SLOW #define real Real*4 #define REAL Real*8 #define _RS Real*4 #define _RL Real*8 #define RS_IS_REAL4 #define _EXCH_XY_R4(a,b) CALL EXCH_XY_R4 ( a, b ) #define _EXCH_XYZ_R4(a,b) CALL EXCH_XYZ_R4 ( a, b ) #define _GLOBAL_SUM_R4(a,b,c) CALL GLOBAL_SUM_R4( a, b , c) #define _GLOBAL_MAX_R4(a,b,c) CALL GLOBAL_MAX_R4( a, b , c) #endif #define _EXCH_XY_R8(a,b) CALL EXCH_XY_R8 ( a, b ) #define _EXCH_XYZ_R8(a,b) CALL EXCH_XYZ_R8 ( a, b ) #define _GLOBAL_SUM_R8(a,b,c) CALL GLOBAL_SUM_R8( a, b , c) #define _GLOBAL_MAX_R8(a,b,c) CALL GLOBAL_MAX_R8( a, b , c) 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 #ifdef REAL_D0_IS_16BYTES #define D0 #endif 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 C-- Substitue for 1.D variables C Sun compilers do not use 8-byte precision for literals C unless .Dnn is specified. CRAY vector machines use 16-byte C precision when they see .Dnn which runs very slowly! #ifdef REAL_D0_IS_16BYTES #define _d #define _F64( a ) a #endif #ifndef REAL_D0_IS_16BYTES #define _d D #define _F64( a ) DFLOAT( a ) #endif #endif /* _CPP_EEOPTIONS_H_ */