[[PageOutline]] = Constants = Meaning of MPIs defined constants = Data types = Note that the Fortran types should only be used in Fortran programs, and the C types should only be used in C programs. For example, it is in error to use MPI_INT for a Fortran INTEGER. Datatypes are of type MPI_Datatype in C and of tyep INTEGER in Fortran. = C datatypes = MPI_CHAR char MPI_BYTE See standard; like unsigned char MPI_SHORT short MPI_INT int MPI_LONG long MPI_FLOAT float MPI_DOUBLE double MPI_UNSIGNED_CHAR unsigned char MPI_UNSIGNED_SHORT unsigned short MPI_UNSIGNED unsigned int MPI_UNSIGNED_LONG unsigned long MPI_LONG_DOUBLE long double (some systems may not implement) MPI_LONG_LONG_INT long long (some systems may not implement) '''The following are datatypes for the MPI functions MPI_MAXLOC and MPI_MINLOC.''' MPI_FLOAT_INT struct { float, int } MPI_LONG_INT struct { long, int } MPI_DOUBLE_INT struct { double, int } MPI_SHORT_INT struct { short, int } MPI_2INT struct { int, int } MPI_LONG_DOUBLE_INT struct { long double, int }; this is an OPTIONAL type, and may be set to NULL '''Note that there is no MPI_LONG_LONG_INT type corresponding to a struct { long long, int }.[[BR]] Special datatypes for C and Fortran''' MPI_PACKED For MPI_Pack and MPI_Unpack MPI_UB For MPI_Type_struct; an upper-bound indicator MPI_LB For MPI_Type_struct; a lower-bound indicator = Fortran datatypes = MPI_REAL REAL MPI_INTEGER INTEGER MPI_LOGICAL LOGICAL MPI_DOUBLE_PRECISION DOUBLE PRECISION MPI_COMPLEX COMPLEX MPI_DOUBLE_COMPLEX complex*16 (or complex*32) where supported. '''The following datatypes are optional''' MPI_INTEGER1 integer*1 if supported MPI_INTEGER2 integer*2 if supported MPI_INTEGER4 integer*4 if supported MPI_REAL4 real*4 if supported MPI_REAL8 real*8 if supported '''The following are datatypes for the MPI functions MPI_MAXLOC and MPI_MINLOC. In Fortran, these datatype always consist of two elements of the same Fortran type.''' MPI_2INTEGER INTEGER,INTEGER MPI_2REAL REAL, REAL MPI_2DOUBLE_PRECISION DOUBLE PRECISION, DOUBLE PRECISION MPI_2COMPLEX COMPLEX, COMPLEX MPI_2DOUBLE_COMPLEX complex*16, complex*16 = Communicators = Communicators are of type MPI_Comm in C and INTEGER in Fortran MPI_COMM_WORLD Contains all of the processes MPI_COMM_SELF Contains only the calling process = Groups = Groups are of type MPI_Group in C and INTEGER in Fortran MPI_GROUP_EMPTY A group containing no members. Results of the compare operations MPI_IDENT Identical MPI_CONGRUENT (only for MPI_COMM_COMPARE) The groups are identical MPI_SIMILAR Same members, but in a different order MPI_UNEQUAL Different = Collective operations = The collective combination operations (MPI_REDUCE, MPI_ALLREDUCE, MPI_REDUCE_SCATTER, and MPI_SCAN) take a combination operation. This operation is of type MPI_Op in C and of type INTEGER in Fortran. The predefined operations are MPI_MAX return the maximum MPI_MIN return the minumum MPI_SUM return the sum MPI_PROD return the product MPI_LAND return the logical and MPI_BAND return the bitwise and MPI_LOR return the logical or MPI_BOR return the bitwise of MPI_LXOR return the logical exclusive or MPI_BXOR return the bitwise exclusive or MPI_MINLOC return the minimum and the location (actually, the value of the second element of the structure where the minimum of the first is found) MPI_MAXLOC return the maximum and the location = Notes on collective operations = The reduction functions (MPI_Op) do not return an error value. As a result, if the functions detect an error, all they can do is either call MPI_Abort or silently skip the problem. Thus, if you change the error handler from MPI_ERRORS_ARE_FATAL to something else, for example, MPI_ERRORS_RETURN, then no error may be indicated. The reason for this is the performance problems in ensuring that all collective routines return the same error value. Note that not all datatypes are valid for these functions. For example, MPI_COMPLEX is not valid for MPI_MAX and MPI_MIN. In addition, the MPI 1.1 standard did not include the C types MPI_CHAR and MPI_UNSIGNED_CHAR among the lists of arithmetic types for operations like MPI_SUM. However, since the C type char is an integer type (like short), it should have been included. The MPI Forum will probably include char and unsigned char as a clarification to MPI 1.1; until then, users are advised that MPI implementations may not accept MPI_CHAR and MPI_UNSIGNED_CHAR as valid datatypes for MPI_SUM, MPI_PROD, etc. MPICH does allow these datatypes. = Permanent key values = These are the same in C and Fortran MPI_TAG_UB Largest tag value MPI_HOST Rank of process that is host, if any MPI_IO Rank of process that can do I/O MPI_WTIME_IS_GLOBAL Has value 1 if MPI_WTIME is globally synchronized. = Null objects = MPI_COMM_NULL Null communicator MPI_OP_NULL Null operation MPI_GROUP_NULL Null group MPI_DATATYPE_NULL Null datatype MPI_REQUEST_NULL Null request MPI_ERRHANDLER_NULL Null error handler = Predefined Constants = MPI_MAX_PROCESSOR_NAME Maximum length of name returned by MPI_GET_PROCESSOR_NAME MPI_MAX_ERROR_STRING Maximum length of string return by MPI_ERROR_STRING MPI_UNDEFINED Used by many routines to indicated undefined or unknown integer value MPI_UNDEFINED_RANK Unknown rank MPI_KEYVAL_INVALID Special keyval that may be used to detect uninitialized keyvals. MPI_BSEND_OVERHEAD Add this to the size of a MPI_BSEND buffer for each outstanding message MPI_PROC_NULL This rank may be used to send or receive from no-one. MPI_ANY_SOURCE In a receive, accept a message from anyone. MPI_ANY_TAG In a receive, accept a message with any tag value. MPI_BOTTOM May be used to indicate the bottom of the address space = Topology types = MPI_GRAPH General graph MPI_CART Cartesian grid = MPI Status = The MPI_Status datatype is a structure. The three elements for use by programmers are MPI_SOURCE Who sent the message MPI_TAG What tag the message was sent with MPI_ERROR Any error return = Special MPI types and functions = MPI_Aint C type that holds any valid address. MPI_Handler_function C function for handling errors (see MPI_Errhandler_create) . MPI_User_function C function to combine values (see collective operations and MPI_Op_create) MPI_Copy_function Function to copy attributes (see MPI_Keyval_create) MPI_NULL_COPY_FN Predefined copy function MPI_Delete_function Function to delete attributes (see MPI_Keyval_create) MPI_NULL_DELETE_FN Predefined delete function MPI_DUP_FN Predefined duplication function MPI_ERRORS_ARE_FATAL Error handler that forces exit on error MPI_ERRORS_RETURN Error handler that returns error codes (as value of MPI routine in C and through last argument in Fortran) = MPI Error classes = MPI_SUCCESS Successful return code MPI_ERR_BUFFER Invalid buffer pointer MPI_ERR_COUNT Invalid count argument MPI_ERR_TYPE Invalid datatype argument MPI_ERR_TAG Invalid tag argument MPI_ERR_COMM Invalid communicator MPI_ERR_RANK Invalid rank MPI_ERR_ROOT Invalid root MPI_ERR_GROUP Null group passed to function MPI_ERR_OP Invalid operation MPI_ERR_TOPOLOGY Invalid topology MPI_ERR_DIMS Illegal dimension argument MPI_ERR_ARG Invalid argument MPI_ERR_UNKNOWN Unknown error MPI_ERR_TRUNCATE message truncated on receive MPI_ERR_OTHER Other error; use Error_string MPI_ERR_INTERN internal error code MPI_ERR_IN_STATUS Look in status for error value MPI_ERR_PENDING Pending request MPI_ERR_REQUEST illegal mpi_request handle MPI_ERR_LASTCODE Last error code -- always at end Location:/home/MPI/mansrc/mpiconsts.txt from:[http://www-unix.mcs.anl.gov/mpi/www/www3/Constants.html]