0003482: Float readFrom: '-0.0' => +0.0

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Category

Severity

Reproducibility

Date Submitted

Last Update

0003482

[Squeak] Kernel

minor

always

04-19-06 10:13

07-22-06 23:18

Reporter

andreas

View Status

public

Assigned To

Priority

normal

Resolution

fixed

Platform

Status

closed

Projection

none

OS Version

ETA

none

Fixed in Version

3.9

Product Version

3.8

Product Build

Summary

0003482: Float readFrom: '-0.0' => +0.0

Description

Negative zero is well-defined in IEEE 754 format, for example:
  x := 0.0 clone.
  x basicAt: 1 put: 16r80000000.
  x
and prints correctly for -0.0. However, *parsing* -0.0 does not create negative zero but rather positive zero which is a problem for numerical code that relies on the assumption of correct floating point parsing.

Steps To Reproduce

Additional Information

Annex A of the standard actually notes this issue:
"2) –x is x copied with its sign reversed, not 0–x; the distinction is germane when x is ±0 or NaN."

Attached Files

Relationships

Notes
(0006163 - 17 - 17 - 17 - 17 - 17 - 17) MarcusDenker 07-22-06 23:18	No problem in 3.9

Issue History
Date Modified	Username	Field	Change
04-19-06 10:13	andreas	New Issue
04-19-06 10:14	andreas	Additional Information Updated
07-22-06 23:18	MarcusDenker	Status	new => closed
07-22-06 23:18	MarcusDenker	Note Added: 0006163
07-22-06 23:18	MarcusDenker	Resolution	open => fixed
07-22-06 23:18	MarcusDenker	Fixed in Version	=> 3.9

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