SHMEM_FLOAT_PUT(3)

💖 SHMEM_FLOAT_PUT(3) — the Open MPI put family 💖

okay bestie, sit down, hydrate, because this is the whole put squad from Open MPI — shmem_character_put(3), shmem_complex_put(3), shmem_double_put(3), shmem_float_put(3), shmem_int_put(3), shmem_integer_put(3), shmem_logical_put(3), shmem_long_put(3), shmem_longdouble_put(3), shmem_longlong_put(3), shmem_put4(3), shmem_put8(3), shmem_put32(3), shmem_put64(3), shmem_put128(3), shmem_putmem(3), shmem_real_put(3), and shmem_short_put(3) — and every single one of them transfers data to a specified processing element (PE). one job, many types, iconic behavior 🫶

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✨ SYNOPSIS ✨

C or C++:

#include <mpp/shmem.h>

void shmem_double_put(double *target, const double *source,
  size_t len, int pe)

void shmem_float_put(float *target, const float *source,
  size_t len, int pe)

void shmem_int_put(int *target, const int *source, size_t len,
  int pe)

void shmem_long_put(long *target, const long *source,
  size_t len, int pe)

void shmem_longdouble_put(long double *target,
  const long double *source, size_t len, int pe)

void shmem_longlong_put(long long *target,
  const long long *source, size_t len, int pe)

void shmem_put32(void *target, const void *source, size_t len,
  int pe)

void shmem_put64(void *target, const void *source, size_t len,
  int pe)

void shmem_put128(void *target, const void *source, size_t len,
  int pe)

void shmem_putmem(void *target, const void *source, size_t len,
  int pe)

void shmem_short_put(short *target, const short *source,
  size_t len, int pe)

Fortran:

INCLUDE "mpp/shmem.fh"

INTEGER len, pe

CALL SHMEM_CHARACTER_PUT(target, source, len, pe)

CALL SHMEM_COMPLEX_PUT(target, source, len, pe)

CALL SHMEM_DOUBLE_PUT(target, source, len, pe)

CALL SHMEM_INTEGER_PUT(target, source, len, pe)

CALL SHMEM_LOGICAL_PUT(target, source, len, pe)

CALL SHMEM_PUT(target, source, len, pe)

CALL SHMEM_PUT4(target, source, len, pe)

CALL SHMEM_PUT8(target, source, len, pe)

CALL SHMEM_PUT32(target, source, len, pe)

CALL SHMEM_PUT64(target, source, len, pe)

CALL SHMEM_PUT128(target, source, len, pe)

CALL SHMEM_PUTMEM(target, source, len, pe)

CALL SHMEM_REAL_PUT(target, source, len, pe)

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🌸 DESCRIPTION 🌸

so basically: these routines transfer nelems elements of the data object at address source on the calling PE, over to the data object at address target on the remote PE pe. and here's the spicy part — they start the remote transfer and may return before the data is actually delivered to the remote PE. it's giving "sent the text, no read receipt" 😭

the delivery of data into the data object on the destination PE from different put calls may occur in any order. which means two back-to-back put operations can totally deliver data out of order unless you slip a call to shmem_fence(3) between the two calls. fence = the group-chat moderator keeping things in order, no cap.

🎀 The arguments 🎀

• target — the data object to be updated on the remote PE. it must be remotely accessible or this whole thing falls apart, bestie.
• source — the data object holding the data that's getting copied.
• len — number of elements in the target and source arrays. len must be of type integer. if you're in Fortran, it has to be a constant, variable, or array element of default integer type.
• pe — the PE number of the remote PE. pe must be of type integer. Fortran girlies: it must be a constant, variable, or array element of default integer type.

🦋 Typing constraints 🦋

the target and source data objects have rules, and honestly they're non-negotiable. here's the whole vibe check:

• shmem_putmem — Fortran: any noncharacter type. C: any data type. len is scaled in bytes.
• shmem_put4, shmem_put32 — any noncharacter type that has a storage size equal to 32 bits.
• shmem_put8, shmem_put64 — any noncharacter type that has a storage size equal to 64 bits.
• shmem_put128 — any noncharacter type that has a storage size equal to 128 bits.
• shmem_short_put — elements of type short.
• shmem_int_put — elements of type int.
• shmem_long_put — elements of type long.
• shmem_longlong_put — elements of type long long.
• shmem_float_put — elements of type float.
• shmem_double_put — elements of type double.
• shmem_longdouble_put — elements of type long double.
• SHMEM_CHARACTER_PUT — elements of type character. len is the number of characters to transfer. and get this — the actual character lengths of the source and target variables are ignored. periodt.
• SHMEM_COMPLEX_PUT — elements of type complex of default size.
• SHMEM_DOUBLE_PUT — (Fortran) elements of type double precision.
• SHMEM_INTEGER_PUT — elements of type integer.
• SHMEM_LOGICAL_PUT — elements of type logical.
• SHMEM_REAL_PUT — elements of type real.

⚠️ if you're using Fortran, data types must be of default size. for example, a real variable must be declared as REAL, REAL*4, or REAL(KIND=4). no sneaky custom kinds, bestie 🙈

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👑 EXAMPLES 👑

the following shmem_put example is for C/C++ programs — look how clean:

#include <stdio.h>
#include <mpp/shmem.h>

main()
{
  long source[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
  static long target[10];
  shmem_init();

  if (shmem_my_pe() == 0) {
    /* put 10 words into target on PE 1 */
    shmem_long_put(target, source, 10, 1);
  }
  shmem_barrier_all();  /* sync sender and receiver */
  if (shmem_my_pe() == 1)
    shmem_udcflush();  /* not required on Altix systems */
  printf("target[0] on PE %d is %d\n", shmem_my_pe(), target[0]);
}

🌈 See also 🌈

• intro_shmem(3)
• shmem_iput(3)
• shmem_quiet(3)

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💅 Copyright 💅

2003-2026, The Open MPI Community

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aaaand that's the whole page, bestie, you ate it 💖 huge love to The Open MPI Community for the copyright 2003-2026, and this little masterpiece was dated Sep 10, 2026 — so go forth, shmem_*_put responsibly, and remember: fence your puts or chaos wins 🧚✨💜