To: J3                                                     J3/20-158r3
From: Gary Klimowicz
Subject: Technical issues UTI-005 and UTI-006 in DO CONCURRENT REDUCE
Date: 2020-October-13

Reference: 19-252r2, 20-007

Background
==========

In F202x, we added a new locality clause, REDUCE.

In UTI-005, the editor noticed that the bounds of a REDUCE variable with
the POINTER attribute is not defined. We propose an edit to correct
this.

In UTI-006, the editor pointed out that REDUCE entities carry along the
POINTER attribute of the outer entity uselessly. The suggestion is to
use semantics similar to associate names. An edit is proposed.

Also, the construct entity can no longer have the POINTER attribute, so
its pointer association can't be changed.

The proposed edits lead to a slight reorganization of the new and
remaining sentences for clarity.


Edits to 20-007r1
=================

{ edits in page order }


{ 11.1.7.5 Additional semantics for DO CONCURRENT constructs }

{ UTI-005 Add bounds to attributes shared with the outer entity }

[190:22-24 p3]
  Replace
    "same type, type parameters, and rank"
  with
    "same type, type parameters, rank, and bounds"

{ the construct has the same bounds as the outer entity }



{ From plenary: Provide context to the meaning of "outside variable" }

[190:24 p3]
  Replace
    "CONCURRENT construct"
  with
    "CONCURRENT construct (the outside variable)"

{ The "outside variable" is identified }


{ From plenary: REDUCE variables should behave like temporaries }

[190:25 p3]
  Replace
    "CONTIGUOUS, POINTER, or TARGET attribute
  with
    "CONTIGUOUS attribute"


[190:26 p3]
  Replace
    "; it does not have the ALLOCATABLE, BIND, INTENT,
     PROTECTED, SAVE"
  with
    ". It does not have the ALLOCATABLE, BIND, INTENT,
     PROTECTED, SAVE, TARGET"

{ The construct entity is stripped of meaningless attributes }



{ UTI-005 Remove unnecessary reference to bounds }

[190:27-28 p3]
  Delete the sentence
    "If it is not a pointer, it has the same bounds as the outside
     variable."

{ remove exclusion of bounds when outside entity has POINTER attribute }



{ For clarity: Put sentences about outside variable together }

[190:28-29 p3]
  Move
    "The outside variable shall not be an unallocated
     allocatable variable or a pointer that is not associated."
  before the previous sentence
    "The construct entity has the..."

{ Two sentences about the outside variable are together }


{ UTI-006 Remove unnecessary reference to pointer association }

[190:30-31 p3]
  Delete sentence 6
    "The pointer association of the construct entity shall not be changed
     within the DO CONCURRENT construct."

{ Reference to changing pointer association is deleted }



{ The complete paragraph }
[190:22-32] The new paragraph with edits applied should read as follows:

  "A variable that has REDUCE locality is a construct entity with the
   same type, type parameters, rank, and bounds as the variable with the
   same name in the innermost executable construct or scoping unit that
   includes the DO CONCURRENT construct (the outside variable). The
   outside variable is inaccessible by that name within the
   construct. The outside variable shall not be an unallocated
   allocatable variable or a pointer that is not associated. The
   construct entity has the CONTIGUOUS attribute if and only if the
   outside variable has that attribute. It does not have the
   ALLOCATABLE, BIND, INTENT, POINTER, PROTECTED, SAVE, TARGET, or VALUE
   attribute, even if the outside variable has that attribute. At the
   beginning of execution of each iteration, the construct entity is
   assigned an initial value corresponding to its reduce-operation as
   specified in Table 11.1."



[190:32+]

Delete UTI-005.

[191:before line 1]

Delete UTI-006.


{ end }