View Issue Details

IDProjectCategoryView StatusLast Update
0001754Issue 8 draftsBase Definitions and Headerspublic2024-06-11 09:12
ReporterVincent Lefevre Assigned To 
PrioritynormalSeverityObjectionTypeError
Status ClosedResolutionAccepted As Marked 
Product VersionDraft 3 
NameVincent Lefevre
OrganizationInria
User Reference
Section<float.h> header
Page Number259
Line Number9089
Final Accepted Text0001754:0006401
Summary0001754: formula for LDBL_MAX may be incorrect, e.g. for the double-double IBM format
DescriptionFor the maximum representable finite floating-point number, the formula (1−b^(−p))b^emax is given, but this formula is incorrect for LDBL_MAX on PowerPC, where the double-double IBM format is used.

For the reference: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61399

For the LDBL_MAX issue, this was resolved as a defect in the C standard by DR 467, mentioned here: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2092.htm
Desired ActionDo the same change as in the C standard, i.e. add "if that number is normalized, its value is".

Note that the ISO C23 draft has:
"maximum representable finite floating-point number; if that number is normalized, its value is [the formula]"
Tagsapplied_after_i8d3, issue8

Activities

geoffclare

2023-07-24 16:22

manager   bugnote:0006401

On page 260 line 9123 section <float.h>, change FUTURE DIRECTIONS from "None" to:
The formula for calculating FLT_MAX, DBL_MAX, and LDBL_MAX is expected to change in the next revision of the ISO C standard such that it only applies if the values are normalized.

Issue History

Date Modified Username Field Change
2023-06-29 11:15 Vincent Lefevre New Issue
2023-06-29 11:15 Vincent Lefevre Name => Vincent Lefevre
2023-06-29 11:15 Vincent Lefevre Organization => Inria
2023-06-29 11:15 Vincent Lefevre Section => <float.h> header
2023-06-29 11:15 Vincent Lefevre Page Number => 259
2023-06-29 11:15 Vincent Lefevre Line Number => 9089
2023-07-24 16:22 geoffclare Note Added: 0006401
2023-07-24 16:23 geoffclare Final Accepted Text => 0001754:0006401
2023-07-24 16:23 geoffclare Status New => Resolved
2023-07-24 16:23 geoffclare Resolution Open => Accepted As Marked
2023-07-24 16:24 geoffclare Tag Attached: issue8
2023-08-22 14:38 geoffclare Status Resolved => Applied
2023-08-22 14:38 geoffclare Tag Attached: applied_after_i8d3
2024-06-11 09:12 agadmin Status Applied => Closed