To:      J3                                                     07-282r2
From:    Bill Long (original from Michael Ingrassia)
Subject: Interp F03/0080 Formatted output of a negative real zero value
Date: 2007 November 14


NUMBER: F03/0080
TITLE: Formatted output of a negative real zero value
KEYWORDS: formatted output, negative zero, IEEE
DEFECT TYPE: ERRATUM
STATUS: J3 consideration in progress

QUESTION:

     Suppose a Fortran processor's representation of the real zero
     value is signed.  When a negative real zero value is written
     using formatted output, does the Fortran 2003 standard require
     the representation of the zero value in the output field to be
     prefixed with a minus sign?

ANSWER:

     Yes, the negative sign is required to appear in formatted output
     of a negative zero value. In subclause 10.6.1, list item (3) at
     [227:3-4] says "The representation of a negative internal value
     in the field shall be prefixed with a minus sign." For a
     processor that distinguishes between positive and negative zero,
     there is no exemption for output at [38:1-6]. For the case of
     IEEE reals, the IEEE_IS_NEGATIVE function at [375:25] explicitly
     says that -0.0 is "negative".


EDITS:

none.


SUBMITTED BY: Michael Ingrassia

HISTORY:  06-126    m175  F03/0080 Submitted
          07-282r1  m182