SHMEM\_LONGLONG\_ADD(3) Open MPI SHMEM\_LONGLONG\_ADD(3)

shmem\_int\_add <#shmem-int-add>(3), [shmem\_int4\_add(3)](/man/enterprise-packages/openmpi-cuda-13.2/shmem_int4_add.3), [shmem\_int8\_add(3)](/man/enterprise-packages/openmpi-cuda-13.2/shmem_int8_add.3), shmem\_long\_add <#shmem-long-add>(3), [shmem\_longlong\_add(3)](/man/enterprise-packages/openmpi-cuda-13.2/shmem_longlong_add.3) - Performs an atomic add operation.

# [SYNOPSIS](#SYNOPSIS)

C or C++:

```
#include <mpp/shmem.h>
void shmem_int_add(int *target, int value, int pe)
void shmem_long_add(long *target, long value, int pe)
void shmem_longlong_add(long long *target, long long value,


  int pe)
```

Fortran:

```
include 'mpp/shmem.h'
INTEGER pe
CALL SHMEM_INT4_ADD(target, value, pe)
CALL SHMEM_INT8_ADD(target, value, pe)
```

# [DESCRIPTION](#DESCRIPTION)

The atomic add routines add **value** to the data at address **target** on PE **pe**. The operation completes without the possibility of another process updating target between the time of the fetch and the update.

The arguments are as follows:

[**target**](#target)

The remotely accessible integer data object to be updated on the remote PE. If you are using C/C++, the type of target should match that implied in the SYNOPSIS section. If you are using the Fortran compiler, it must be of type integer with an element size of 4 bytes for SHMEM\_INT4\_ADD and 8 bytes for SHMEM\_INT8\_ADD.

[**value**](#value)

The value to be atomically added to target. If you are using C/C++, the type of value should match that implied in the SYNOPSIS section. If you are using Fortran, it must be of type integer with an element size of target.

[**pe**](#pe)

An integer that indicates the PE number upon which target is to be updated. If you are using Fortran, it must be a default integer value.

# [NOTES](#NOTES)

The term remotely accessible is defined in [*intro\_shmem*(3)](/man/enterprise-packages/openmpi-cuda-13.2/intro_shmem.3).

**See also:**

[*intro\_shmem*(3)](/man/enterprise-packages/openmpi-cuda-13.2/intro_shmem.3) [*shmem\_cache*(3)](/man/enterprise-packages/openmpi-cuda-13.2/shmem_cache.3)

# [Copyright](#Copyright)

2003-2026, The Open MPI Community

September 11, 2026

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Document: shmem_longlong_add(3) from openmpi-cuda-13.2 5.0.11-r0 (Chainguard OS)
Source: https://github.com/open-mpi/ompi