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 }.
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
