To: J3                                                     J3/26-221
From: Soren Rasmussen & HPC
Subject: Edits to replace the THIS_IMAGE example
Date: 2026-October-26


1. Introduction
---------------

This paper contains edits to 17.9.220 THIS_IMAGE, paragraph 6, Examples Case
(ii).



The issues with this example are
  1. Performs a naive pull-broadcast through a coarray, instead of calling
     the CO_BROADCAST collective subroutine, which should be expected
     to provide more scalable performance at large image counts.
  2. P is never declared, and it would have to be a coarray for P[1] to work.

2. Edits to 26-007r2
--------------------

[537:24-27] 17.9.220 THIS_IMAGE, paragraph 6 (Examples), Case (ii)

Replace the current text and code of Case (ii):

"
Case (ii): The following code uses image 1 to read data. The other images then
           copy the data.

   IF (THIS_IMAGE()==1) READ (*,*) P
   SYNC ALL
   P = P[1]
"

with:

"
Case (ii): The following statement prints the index of the invoking image and
           the number of images in the current team.

  PRINT *, "This is image", THIS_IMAGE(), "of", NUM_IMAGES()
"

The replacement represents the customary "hello world" example often
shown in tutorials of SPMD (single program, multiple data) programming
models such as MPI and multi-image Fortran: each image
reports its own image index and the number of images in the current team.

This example is identical to the one recommended as the replacement for
the NUM_IMAGES intrinsic, whose subclause appears 30 pages away.
There is precedent elsewhere in the standard for using repeated
examples in subclauses of closely related procedures, for example:

- 18.11.7 IEEE_GET_MODES and 18.11.41 IEEE_SET_MODES
- 18.11.8 IEEE_GET_ROUNDING_MODE and 18.11.42 IEEE_SET_ROUNDING_MODE
- 18.11.9 IEEE_GET_STATUS and 18.11.43 IEEE_SET_STATUS, nearly identical,
  different comments and use statements