18.2.7. MPI_Aint_add — Open MPI 5.0.0 documentation

# 18.2.7. MPI_Aint_add

MPI_Aint_add, MPI_Aint_diff - Portable functions for arithmetic on MPI_Aint values.

## 18.2.7.1. SYNTAX

### 18.2.7.1.1. C Syntax

    #include <mpi.h>

    MPI_Aint MPI_Aint_add(MPI_Aint base, MPI_Aint disp)

    MPI_Aint MPI_Aint_diff(MPI_Aint addr1, MPI_Aint addr2)

### 18.2.7.1.2. Fortran Syntax

    USE MPI
    ! or the older form: INCLUDE 'mpif.h'
    INTEGER(KIND=MPI_ADDRESS_KIND) MPI_AINT_ADD(BASE, DISP)
            INTEGER(KIND=MPI_ADDRESS_KIND) BASE, DISP

    INTEGER(KIND=MPI_ADDRESS_KIND) MPI_AINT_DIFF(ADDR1, ADDR2)
            INTEGER(KIND=MPI_ADDRESS_KIND) ADDR1, ADDR2

### 18.2.7.1.3. Fortran 2008 Syntax

    USE mpi_f08
    INTEGER(KIND=MPI_ADDRESS_KIND) MPI_AINT_ADD(BASE, DISP)
            INTEGER(KIND=MPI_ADDRESS_KIND) BASE, DISP

    INTEGER(KIND=MPI_ADDRESS_KIND) MPI_AINT_DIFF(ADDR1, ADDR2)
            INTEGER(KIND=MPI_ADDRESS_KIND) ADDR1, ADDR2

## 18.2.7.2. INPUT PARAMETERS

- `base`: Base address (integer).

- `disp`: Displacement (integer).

- `addr1`: Minuend address (integer).

- `addr2`: Subtrahend address (integer).

## 18.2.7.3. DESCRIPTION

MPI_Aint_add produces a new MPI_Aint value that is equivalent to the sum of the base and disp arguments, where base represents a base address returned by a call to MPI_Get_address and disp represents a signed integer displacement. The resulting address is valid only at the process that generated base, and it must correspond to a location in the same object referenced by base, as described in MPI-3.1 section 4.1.12. The addition is performed in a manner that results in the correct MPI_Aint representation of the output address, as if the process that originally produced base had called:

    MPI_Get_address ((char *) base + disp, &result);

MPI_Aint_diff produces a new MPI_Aint value that is equivalent to the difference between addr1 and addr2 arguments, where addr1 and addr2 represent addresses returned by calls to MPI_Get_address. The resulting address is valid only at the process that generated addr1 and addr2, and addr1 and addr2 must correspond to locations in the same object in the same process, as described in MPI-3.1 section 4.1.12. The difference is calculated in a manner that results in the signed difference from addr1 to addr2, as if the process that originally produced the addresses had called `(char *) addr1` - `(char *) addr2` on the addresses initially passed to MPI_Get_address.

See also

- MPI_Get_address