MPI_TYPE_HINDEXED(3)

MPI_TYPE_HINDEXED 💖

okay bestie, buckle UP — this is the Open MPI manual page for MPI_Type_hindexed, and it's giving "iconic but retired" energy ngl 💅

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✨ NAME ✨

MPI_Type_hindexed — creates an indexed datatype with offsets in bytes — but lowkey, this routine is deprecated in favor of MPI_Type_create_hindexed 💀

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🌸 SYNTAX 🌸

🎀 C Syntax 🎀

#include <mpi.h>

int MPI_Type_hindexed(int count, int *array_of_blocklengths,
     MPI_Aint *array_of_displacements, MPI_Datatype oldtype,
     MPI_Datatype *newtype)

🦋 Fortran Syntax 🦋

USE MPI
! or the older form: INCLUDE 'mpif.h'

MPI_TYPE_HINDEXED(COUNT, ARRAY_OF_BLOCKLENGTHS,
             ARRAY_OF_DISPLACEMENTS, OLDTYPE, NEWTYPE, IERROR)
     INTEGER COUNT, ARRAY_OF_BLOCKLENGTHS(*)
     INTEGER ARRAY_OF_DISPLACEMENTS(*), OLDTYPE, NEWTYPE
     INTEGER IERROR

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💜 INPUT PARAMETERS 💜

• count — the number of blocks, which is also the number of entries in array_of_displacements and array_of_blocklengths (integer). like, they all gotta match bestie 🫶
• array_of_blocklengths — how many elements live in each block (array of nonnegative integers).
• array_of_displacements — the byte displacement of each block (C: array of MPI_Aint, Fortran: array of integer).
• oldtype — the old datatype (handle).

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🌈 OUTPUT PARAMETERS 🌈

• newtype — the new datatype (handle). slay, you made a whole new type ✨
• ierror — Fortran only: error status (integer).

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👑 DESCRIPTION 👑

okay so real talk: use of this routine is deprecated as of MPI-2. Use MPI_Type_create_hindexed instead. periodt 💅

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💀 ERRORS 💀

Almost all MPI routines return an error value; C routines as the return result of the function and Fortran routines in the last argument. yes, the Fortran girlies get it as that final argument, iykyk 😭

Before the error value is returned, the current MPI error handler associated with the communication object (e.g., communicator, window, file) is called. If no communication object is associated with the MPI call, then the call is considered attached to MPI_COMM_SELF and will call the associated MPI error handler. When MPI_COMM_SELF is not initialized (i.e., before MPI_Init/MPI_Init_thread, after MPI_Finalize, or when using the Sessions Model exclusively) the error raises the initial error handler. The initial error handler can be changed by calling MPI_Comm_set_errhandler on MPI_COMM_SELF when using the World model, or the mpi_initial_errhandler CLI argument to mpiexec or info key to MPI_Comm_spawn/MPI_Comm_spawn_multiple. If no other appropriate error handler has been set, then the MPI_ERRORS_RETURN error handler is called for MPI I/O functions and the MPI_ERRORS_ABORT error handler is called for all other MPI functions. 💅

Open MPI includes three predefined error handlers that can be used:

• MPI_ERRORS_ARE_FATAL — causes the program to abort all connected MPI processes. dramatic, but make it permanent 💀
• MPI_ERRORS_ABORT — an error handler that can be invoked on a communicator, window, file, or session. When called on a communicator, it acts as if MPI_Abort was called on that communicator. If called on a window or file, acts as if MPI_Abort was called on a communicator containing the group of processes in the corresponding window or file. If called on a session, aborts only the local process.
• MPI_ERRORS_RETURN — returns an error code to the application.

MPI applications can also implement their own error handlers by calling:

• MPI_Comm_create_errhandler then MPI_Comm_set_errhandler
• MPI_File_create_errhandler then MPI_File_set_errhandler
• MPI_Session_create_errhandler then MPI_Session_set_errhandler or at MPI_Session_init
• MPI_Win_create_errhandler then MPI_Win_set_errhandler

note that MPI does not guarantee that an MPI program can continue past an error. fr fr, no cap 🫠

See the MPI man page for a full list of MPI error codes.

See the Error Handling section of the MPI-3.1 standard for more information.

See also:

• MPI_Type_create_hindexed
• MPI_Type_create_struct
• MPI_Type_indexed

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🎀 Copyright 🎀

2003-2026, The Open MPI Community

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and that's the whole page bestie 🫶 tysm for reading, this was Open MPI documentation, dated Sep 10, 2026 — go call MPI_Type_create_hindexed instead of this one, mwah 💖✨