Issue 0CFP.25: P1 totalorder parameters

This issue has been automatically converted from the original issue lists and some formatting may not have been preserved.

Authors: WG14, C Floating Point Group
Date: 2018-09-05
Reference document: N2292
Submitted against: Floating-point TS 18661 (C11 version, 2014-2016)
Status: Fixed
Fixed in: C23
Converted from: n2397.htm

Summary

The IEC 60559 totalOrder operation provides a total ordering of the canonical members of the format, including signaling NaNs. Therefore the binding C function totalorder, specified in TS 18661-1, must be able to accept signaling NaN inputs. Currently the parameters for totalorder have floating type, whose argument passing may convert a signaling NaN argument into a quiet NaN parameter value. The following suggested changes use pointers to preserve signaling NaN inputs.

Suggested Technical Corrigendum

In F.10.12.1 (TS 18661-1), change:

int totalorder(double x, double y);

to:

int totalorder(double * x, double * y);

and similarly for the other prototypes in F.10.12.1 and F.10.12.2.

In F.10.12.1 (TS 18661-1), change:

Description

[2] The totalorder functions determine whether the total order relationship, defined by IEC 60559, is true for the ordered pair of its arguments x, y. These functions are fully specified in IEC 60559. These functions are independent of the current rounding direction mode and raise no floating-point exceptions, even if an argument is a signaling NaN.

Returns

[3] The totalorder functions return nonzero if and only if the total order relation is true for the ordered pair of its arguments x, y.

to:

Description

[2] The totalorder functions determine whether the total order relationship, defined by IEC 60559, is true for the ordered pair *x, *y. These functions are fully specified in IEC 60559. These functions are independent of the current rounding direction mode and raise no floating-point exceptions, even if *x or *y is a signalling NaN.

Returns

[3] The totalorder functions return nonzero if and only if the total order relation is true for the ordered pair *x, *y.

and similarly for F.10.12.2.

Comment from WG14 on 2019-05-03:

Oct 2018 meeting

Committee Discussion

The committee accepts the Suggested Technical Corrigendum as the Proposed Change to resolve this issue.

Proposed Change

In F.10.12.1 (TS 18661-1), change:

int totalorder(double x, double y);

to:

int totalorder(double * x, double * y);

and similarly for the other prototypes in F.10.12.1 and F.10.12.2.

In F.10.12.1 (TS 18661-1), change:

Description

[2] The totalorder functions determine whether the total order relationship, defined by IEC 60559, is true for the ordered pair of its arguments x, y. These functions are fully specified in IEC 60559. These functions are independent of the current rounding direction mode and raise no floating-point exceptions, even if an argument is a signaling NaN.

Returns

[3] The totalorder functions return nonzero if and only if the total order relation is true for the ordered pair of its arguments x, y.

to:

Description

[2] The totalorder functions determine whether the total order relationship, defined by IEC 60559, is true for the ordered pair *x, *y. These functions are fully specified in IEC 60559. These functions are independent of the current rounding direction mode and raise no floating-point exceptions, even if *x or *y is a signalling NaN.

Returns

[3] The totalorder functions return nonzero if and only if the total order relation is true for the ordered pair *x, *y.

and similarly for F.10.12.2.