[cfp-interest 3878] Re: Comments re Annex F Introduction

[Damian McGuckin]

Hi all,

I would like to raise one of the discussion items for which we ran out of 
time earlier today. These are editorial issues and seek to improve clarity 
by eliminating repitition.

In C2Y, the two wildly separate paragraphs F.3#20 and F.10.1#16 exist, the 
later under a heading of Recommended Practice.

 	The C functions in Table F.3 correspond to mathematical operations
 	recommended by ISO/IEC 60559.  However, correct rounding, which
 	ISO/IEC 60559 specifies for its operations, is not required for
 	the C functions in the table. 7.35.9 (potentially) reserves cr_
 	prefixed names for functions fully matching the ISO/IEC 60559
 	mathematical operations. In the table, the C functions are
 	represented by the function name without a type suffix

 	ISO/IEC 60559 specifies correct rounding for the operations in
 	Table F.3 recommended by ISO/IEC 60559, and thereby preserves
 	useful mathematical properties such as symmetry, mono- tonicity,
 	and periodicity. The corresponding functions with (potentially)
 	reserved cr_-prefixed names (7.35.9) do the same. The C functions
 	in the table, however, are not required to be correctly rounded,
 	but implementations should still preserve as many of these useful
 	mathematical properties as possible.

They talk about the same thing, i.e. the functions in Table F.3. They also 
both reference 7.35.9, the reservation of cr_-prefixed names for correctly 
rounded recommended operations of mathematical functions.

I propose to being them together. I suggest four (4) paragraphs and one 
(1) footnote, the first of paragraph appearing before the table when Table 
F.3 is first mentioned, the last three paragraphs appearing after the 
table appears. Those last 2 appear under a heading of Recommended Practice:

 	The C functions in Table F.3 correspond to mathematical operations
 	recommended by ISO/IEC 60559.

 	The C functions in Table F.3 are not required to be correctly
 	rounded. [this should be very blunt and obvious]

Recommended Practice

 	Since ISO/IEC 60559 preserves useful mathematical properties such
 	as symmetry, monotonicity, and periodicity for its operations in
 	Table F.3 by specifying their correct rounding, C implementations
 	of those operations should still preserve as many of these
 	properties as possible.

 	For any function f in Table F.3, an implementation may provide a
 	corresponding function cr_f with the same underlying functionality
 	as f but with a correctly rounded result guaranteed.

There is a footnote against cr_f which says ...:

 	Those cr_-prefixed names are (potentially) reserved (7.35.9).

Should this cross reference appear within the paragraph like it does
currently?

Please comment before the next meeting to save time during the meeting.

Thanks - Damian