To: J3                                                     J3/19-211
From: Bill Long
Subject: US-23 Part 1, ATOMIC oversight with BOZ constants
Date: 2019-August-08


Discussion:
-----------

This paper describes Part 1 (of 3) of the BITS proposal, US-23.

The bitwise logical operations functions in 16.9 (IAND, IOR, IEOR)
allow their INTENT(IN) arguments to be either type INTEGER or a BOZ
constant.  It was overlooked that the same operations performed by
ATOMIC_AND, ATOMIC_FETCH_AND, ATOMIC_OR, ATOMIC_FETCH_OR, ATOMIC_XOR,
and ATOMIC_FETCH_XOR do not permit a BOZ constant for the INTENT(IN)
VALUE argument.  This represents an inconsistency in the F2018
standard. Part 1 of the BITS proposal proposes to fix this.


Requirement
-----------

Allow BOZ constants as the VALUE arguments to the ATOMIC intrinsics
that perform bitwise operations.


Sematics and Syntax
-------------------

The intrinics ATOMIC_AND, ATOMIC_FETCH_AND, ATOMIC_OR,
ATOMIC_FETCH_OR, ATOMIC_XOR, and ATOMIC_FETCH_XOR should permit a BOZ
constant for the INTENT(IN) VALUE argument.

The value of a VALUE argument that is a BOZ constant is the integer
value INT(VALUE, ATOMIC_INT_KIND).


Edits to 18-007r1
-----------------
(to be supplied)