To: J3                                                     J3/26-187
From: Steve Lionel
Subject: US19, UTI033 Some IEEE functions moved to Annex C
Date: 2026-June-18

References: 23-234r2, 25-143, 25-190r3, 26-123r4, 26-176, 26-007r1

Quoting from 23-234r2:

 IEEE-754 provides a table of recommended operations that languages
 should provide. Specifically it states:

 > Language standards should define, to be implemented according to
 > this subclause, as many of the operations in Table 9.1 as is
 > appropriate to the language.

These have been added in past papers, but 26-176 argues that
some are not generally useful to Fortran programmers and that they
have straightforward replacements using existing syntax.

After discussion, J3 agreed to add informational text to Annex C
that provides the Fortran equivalent of each.

Edits to 26-007r1
=================

[723:26+] C11.3+ Clause 17 Notes

Insert a new subclause:

C11.4 IEEE-754 Recommended Operations

\theIEEEstd lists operations recommended for inclusion in language
standards. For those that are not provided as intrinsic functions
in this standard, Table C.x shows the equivalent expression.

Table C.x

IEEE-754 Operation | Fortran Operation
--------------------------------------
expm1(x)           | exp(x)-1)
exp2m1(x)          | 2**x-1
exp10m1(x)         | 10**x-1
logp1(x)           | log(1+x)
log2p1(x)          | log2(1+x)
log10p1(x)         | log10(1+x)
compound(x,n)      | (1+x)**n
pow(x,y)           | x**y
pown(x,n)          | x**n
powr(x,y)          | x**y

--END--