gcc/fortran/doc/gfortran/intrinsic-procedures/cobroadcast.rst

   1 ..
   2   Copyright 1988-2022 Free Software Foundation, Inc.
   3   This is part of the GCC manual.
   4   For copying conditions, see the copyright.rst file.
   5
   6 .. _co_broadcast:
   7
   8 CO_BROADCAST --- Copy a value to all images the current set of images
   9 *********************************************************************
  10
  11 .. index:: CO_BROADCAST, Collectives, value broadcasting
  12
  13 .. function:: CO_BROADCAST(A, SOURCE_IMAGE, STAT, ERRMSG)
  14
  15   ``CO_BROADCAST`` copies the value of argument :samp:`{A}` on the image with
  16   image index ``SOURCE_IMAGE`` to all images in the current team.  :samp:`{A}`
  17   becomes defined as if by intrinsic assignment.  If the execution was
  18   successful and :samp:`{STAT}` is present, it is assigned the value zero.  If the
  19   execution failed, :samp:`{STAT}` gets assigned a nonzero value and, if present,
  20   :samp:`{ERRMSG}` gets assigned a value describing the occurred error.
  21
  22   :param A:
  23     INTENT(INOUT) argument; shall have the same
  24     dynamic type and type parameters on all images of the current team. If it
  25     is an array, it shall have the same shape on all images.
  26
  27   :param SOURCE_IMAGE:
  28     a scalar integer expression.
  29     It shall have the same value on all images and refer to an
  30     image of the current team.
  31
  32   :param STAT:
  33     (optional) a scalar integer variable
  34
  35   :param ERRMSG:
  36     (optional) a scalar character variable
  37
  38   Standard:
  39     Technical Specification (TS) 18508 or later
  40
  41   Class:
  42     Collective subroutine
  43
  44   Syntax:
  45     .. code-block:: fortran
  46
  47       CALL CO_BROADCAST(A, SOURCE_IMAGE [, STAT, ERRMSG])
  48
  49   Example:
  50     .. code-block:: fortran
  51
  52       program test
  53         integer :: val(3)
  54         if (this_image() == 1) then
  55           val = [1, 5, 3]
  56         end if
  57         call co_broadcast (val, source_image=1)
  58         print *, this_image, ":", val
  59       end program test
  60
  61   See also:
  62     :ref:`CO_MAX`,
  63     :ref:`CO_MIN`,
  64     :ref:`CO_SUM`,
  65     :ref:`CO_REDUCE`