To: J3                                                     J3/23-157r2
From: John Reid & Malcolm Cohen
Subject: IEEE_SCALB real argument interp
Date: 2023-June-16

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NUMBER: F23/008
TITLE: Real argument I in IEEE_SCALB
KEYWORDS: Real, IEEE_SCALB
DEFECT TYPE: Erratum
STATUS: Passed by J3 meeting

QUESTION:

The first sentence of 17.1 Overview of IEEE arithmetic support, states
    "The intrinsic modules IEEE_EXCEPTIONS, IEEE_ARITHMETIC, and
     IEEE_FEATURES provide support for the facilities defined by
     ISO/IEC 60559:2020."
However, nothing claims to support the IEEE function scaleB. This is
very like IEEE_SCALB (X,I) except that the IEEE standard requires
that the second argument to scaleB be the same type as logB, and that
is Real type whereas IEEE_SCALB only accepts Integer type.

Was it intended to support the IEEE scaleB operation?
If so, is that intended to be provided by IEEE_SCALB?

ANSWER:

Yes, the IEEE scaleB operation should have been supported.

Yes, IEEE_SCALB should provide the scaleB operation.

EDITS to N2218:

[xiv] Introduction, bullet "Changes to the intrinsic module
        IEEE_ARITHMETIC for conformance with ISO/IEC 60559:2020",
      append sentence
    "The function IEEE_SCALB from the intrinsic module
     IEEE_ARITHMETIC now performs the scaleB operation."

[470:6-7] 17.9 IEEE arithmetic, p1, bullet list, last item,
    After "logB," insert "scaleB,",
    After "IEEE_LOGB," insert "IEEE_SCALB".

[487:6] 17.11.37 IEEE_SCALB, Arguments, I, change "integer" to
    "integer or of type real with the same kind type parameter as X"
  so that the line reads
    "I shall be of type integer or of type real with the same kind
     type parameter as X.".

[487:9+] Same subclause, Result Value, before "Case (i)", insert
    "The value of the result shall conform to the scaleB operation
     of \theIEEEstd.".

SUBMITTED BY: John Reid

HISTORY: 23-157   m230  Submitted
         23-157r1 m230  Revised
         23-157r2 m230  Revised, passed by J3 meeting

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