MPI_Data_types(3)

NAME
     MPI_Data_type - Defines C and Fortran data types

STANDARDS
     This release implements the MPI 1.2 standard, as documented by the MPI
     Forum in the spring 1997 release of MPI:  A Message Passing Interface
     Standard.

DESCRIPTION
     The MPI_Data_type routine defines special data types for both C and
     Fortran and data types of type MPI_Datatype for C programs and of type
     integer for Fortran programs.  The C types should be used only in C
     programs and the Fortran types should be used only in Fortran programs.
     For example, it is an error to use MPI_INT for a Fortran integer.

   Special Data Types
     The following data types can be used in C or Fortran programs:

     MPI_PACKED               Used for the  MPI_Pack(3) and MPI_Unpack(3)
                              routines

     MPI_UB                   Used for the MPI_Type_struct(3) routine (an
                              upper-bound indicator)

     MPI_LB                   Used for the MPI_Type_struct(3) routine (a
                              lower-bound indicator)

   C Data Types
     The following data types can be used in all C programs:

     MPI_CHAR                 Specifies char

     MPI_BYTE                 Specifies unsigned char (see the standard)

     MPI_SHORT                Specifies short

     MPI_INT                  Specifies int

     MPI_LONG                 Specifies long

     MPI_FLOAT                Specifies float

     MPI_DOUBLE               Specifies double

     MPI_UNSIGNED_CHAR        Specifies unsigned char

     MPI_UNSIGNED_SHORT       Specifies unsigned short

     MPI_UNSIGNED             Specifies unsigned int
     MPI_UNSIGNED_LONG        Specifies unsigned long

     MPI_LONG_DOUBLE          Specifies long double (some systems may not
                              implement)

     The following data types can be used for the MPI functions MPI_MAXLOC and
     MPI_MINLOC:

     MPI_FLOAT_INT            Specifies struct { float, int }

     MPI_LONG_INT             Specifies struct { long, int }

     MPI_DOUBLE_INT           Specifies struct { double, int }

     MPI_SHORT_INT            Specifies struct { short, int }

     MPI_2INT                 Specifies struct { int, int }

     MPI_LONG_DOUBLE_INT      Specifies struct { long double, int } (this is
                              an optional type and can be set to NULL)

     MPI_LONG_LONG_INT        Specifies struct { long long, int } (this is an
                              optional type and can be set to NULL)

   Fortran Data Types
     The following data types can be used in all Fortran programs:

     MPI_REAL                 Specifies REAL

     MPI_INTEGER              Specifies INTEGER

     MPI_LOGICAL              Specifies LOGICAL

     MPI_DOUBLE_PRECISION     Specifies DOUBLE PRECISION

     MPI_COMPLEX              Specifies COMPLEX

     MPI_DOUBLE_COMPLEX       Specifies COMPLEX*16 (or COMPLEX*32) where
                              supported

     The following data types are optional:

     MPI_INTEGER1             Specifies INTEGER*1 if supported

     MPI_INTEGER2             Specifies INTEGER*2 if supported

     MPI_INTEGER4             Specifies INTEGER*4 if supported

     MPI_REAL4                Specifies REAL*4 if supported
     MPI_REAL8                Specifies REAL*8 if supported

     The following data types are for the MPI functions MPI_MAXLOC and
     MPI_MINLOC.  In Fortran, these data types always consist of two elements
     of the same Fortran type.

     MPI_2INTEGER                  Specifies INTEGER, INTEGER

     MPI_2REAL                     Specifies REAL, REAL

     MPI_2DOUBLE_PRECISION         Specifies DOUBLE PRECISION, DOUBLE
                                   PRECISION

     MPI_2COMPLEX                  Specifies COMPLEX, COMPLEX

     MPI_2DOUBLE_COMPLEX           Specifies COMPLEX*16, COMPLEX*16