MPI_TYPE_CREATE_RESIZED(3)

✨ MPI_TYPE_CREATE_RESIZED 💫

okay bestie, this is the Open MPI manual page for MPI_Type_create_resized — and it's literally giving "new data type, new extent, new bounds, new me" 🌸

🦋 NAME

MPI_Type_create_resized — returns a new data type with new extent and upper and lower bounds. periodt 💅

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🎀 SYNTAX

C Syntax

#include <mpi.h>

int MPI_Type_create_resized(MPI_Datatype oldtype, MPI_Aint lb,
     MPI_Aint extent, MPI_Datatype *newtype)

Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_TYPE_CREATE_RESIZED(OLDTYPE, LB, EXTENT, NEWTYPE, IERROR)
     INTEGER OLDTYPE, NEWTYPE, IERROR
     INTEGER(KIND=MPI_ADDRESS_KIND)  LB, EXTENT

Fortran 2008 Syntax

USE mpi_f08
MPI_Type_create_resized(oldtype, lb, extent, newtype, ierror)
     INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(IN) :: lb, extent
     TYPE(MPI_Datatype), INTENT(IN) :: oldtype
     TYPE(MPI_Datatype), INTENT(OUT) :: newtype
     INTEGER, OPTIONAL, INTENT(OUT) :: ierror

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🌸 INPUT PARAMETERS

• oldtype — the input data type, as a handle. it's the og, the source material 💖
• lb — the new lower bound of the data type (integer).
• extent — the new extent of the data type (integer).

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🫶 OUTPUT PARAMETERS

• newtype — the output data type (handle). the glow-up ✨
• ierror — Fortran only: error status (integer).

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👑 DESCRIPTION

MPI_Type_create_resized hands you back, in newtype, a handle to a brand new data type that is identical to oldtype — with one little twist 🌈 the lower bound of this new data type is set to lb, and its upper bound is set to lb + extent.

The way that any previous lb and ub markers are erased 😭 and a fresh pair of lower bound and upper bound markers get placed exactly where the lb and extent arguments say. iconic behaviour, no cap.

This affects how the data type acts when it's used in communication operations with count > 1, and also when it's used to construct new derived data types. so like… it matters, fr fr 💀

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💜 NOTE

please bestie, use MPI_Type_create_resized — it's strongly recommended over the legacy MPI-1 functions MPI_Type_extent and MPI_Type_lb. the old ones are giving ancient, we don't do that here 🙈

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🔥 ERRORS

so basically, almost all MPI routines return an error value — C routines as the return result of the function, and Fortran routines in the last argument. iykyk 💅

Before that error value comes back, the current MPI error handler associated with the communication object (e.g., communicator, window, file) gets called. And if there's no communication object attached to 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.

And 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 much 😭
• 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, it 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, it 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. like… it might just be over 💀

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_get_extent

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🌟 Copyright

2003-2026, The Open MPI Community

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and that's the whole page bestie 🎀 that was the MPI_TYPE_CREATE_RESIZED(3) page from the Open MPI manual, dated Sep 10, 2026 — go forth and resize your extents, you absolute main character 👑 💖✨