To: J3                                                     J3/25-190
From: Lorri Menard
Subject: US19 - Missing IEEE functions
Date: 2025-October-20

Reference: 23-234r2, 25-143, 25-007r1

I  Introduction

Paper 23-234r2 provides a comprehensive list of the IEEE-754
recommended operations, and calls out the subset that are not
yet part of the Fortran standard.

Paper 25-143 contains the Requirements and Specifications.  It further
lists each operation and connects each to its related Fortran operation.

This paper is to be the Edits paper

II Semantics

Only generic functions are to be added for these names, with
behavior to match that listed in IEEE 754 latest.

III Edits

16.9  Specifications of the standard intrinsic procedures

[412:13+] insert one new intrinsic {note: after COMMAND_ARGUMENT_COUNT}
- COMPOUND(X, N)
  Description: Computes an exponential growth
  Class: Elemental function
  Arguments: X shall be of type real or complex, and must be >-1
             N shall be of numeric type
  Result characteristics: Same as X
  Result value. The result has a value equal to a processor-dependent
                approximation to (1+X)**N.


[423:28+] add these three new intrinsics {note: after EXP}
- EXPM1(X)
  Description: Computes the exponential of the given value and
               subtracts one.
  Class: Elemental function.
  Argument: X shall be of type real or complex.
  Result characteristics: Same as X.
  Result value. The result has a value equal to a processor-dependent
                approximation to EXP(X)-1.  If X is of type complex,
                its imaginary part is regarded as a value in radians.

- EXP10M1(X)
  Description: Computes 10 raised to a given power and subtracts one
  Class: Elemental function
  Argument: X shall be of type real or complex
  Result characteristics: Same as X
  Result value. The result has a value equal to a processor-dependent
                approximation to (10**X)-1. If X is of type complex,
                its imaginary part is regarded as a value in radians.

- EXP2M1(X)
  Description: Computes 2 raised to a given power and subtracts one
  Class: Elemental function
  Argument: X shall be of type real or complex
  Result characteristics: Same as X
  Result value. The result has a value equal to a processor-dependent
                approximation to (2**X)-1. If X is of type complex,
                its imaginary part is regarded as a value in radians.

[445:12+] insert one intrinsic: {note: after LOG}

- LOGP1(X)
  Description: Computes the natural logarithm of the given value plus one
  Class: Elemental function.
  Argument: X shall be of type real or complex.  If X is real its
  value shall be greater than -1.  If X is complex its value shall not
  be -1.
  Result characteristics: Same as X.
  Result value. The result has a value equal to a processor-dependent
  approximation to LOG(X+1).  A result of type complex is the principal
  value with imaginary part 'w' in the range -pi <= 'w' <= pi.  If the
  real part of X is less than -1 and the imaginary part of X is zero,
  then the imaginary part of the result is approximately pi if the
  imaginary part of X is positive real zero or the processor does not
  distinguish between positive and negative real zero, and approximately
  -pi if the imaginary part of X is negative real zero.

[445:27+] insert three intrinsics:  {note: after LOG10)

- LOG10P1(X)
  Description: Computes the base-10 logarithm of a given value plus one
  Class: Elemental function
  Argument: X shall be of type real
  Result characteristics: Same as X
  Result value. The result has a value equal to a processor-dependent
                approximation to LOG10(X+1)

- LOG2(X)
  Description: Computes the base-2 logarithm of the given value
  Class: Elemental function
  Argument: X shall be of type real or complex. If X is real its
  value shall be greater than zero.  If X is complex its value shall
  not be zero.
  Result characteristics: Same as X
  Result value. The result has a value equal to a processor-dependent
                approximation to LOG(X)/LOG(2.)

- LOG2P1(X)
  Description: Computes the base-2 logarithm of the given value plus one
  Class: Elemental function
  Argument: X shall be of type real or complex
  Result characteristics: Same as X
  Result value. The result has a value equal to a processor-dependent
                approximation to LOG2(X+1).

[463:7+] insert one intrinsic {note: after POPPAR}
- POW(x,y)
  Description: Computes the value of 'x' raised to the power 'y'
  Class: Elemental function
  Arguments: 'x' shall be of type real or complex
             'y' shall be of type numeric
  Result characteristics: Same as 'x'
  Result value. The result is x**y

[470:21+] insert one intrinsic {note: after RESHAPE}
- ROOTN(X,N)
  Description: Computes the 'Nth' root of a given value
  Class: Elemental function
  Arguments: X shall be of type real or complex
             N shall be of type integer, and shall not be zero
  Result characteristics: Same as X
  Result value. The result is X**(1./N)

[470:31+] insert one intrinsic {note: after RRSPACING}
- RSQRT(x)
  Description: Computes the reciprocal of the square root of a given value
  Class: Elemental function
  Argument: 'x' shall be of type real or complex
  Result characteristics: Same as 'x'
  Result value. The result is 1/SQRT(x)