0003564: LargeInteger>>asFloat does not honour IEEE rounding mode

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Category

Severity

Reproducibility

Date Submitted

Last Update

0003564

[Squeak] Kernel

minor

always

05-06-06 21:58

07-22-06 21:38

Reporter

nicolas cellier

View Status

public

Assigned To

MarcusDenker

Priority

normal

Resolution

fixed

Status

closed

Product Version

Summary

0003564: LargeInteger>>asFloat does not honour IEEE rounding mode

Description

self assert: 16r1FFFFFFFFFFFF0801 asFloat ~= 16r1FFFFFFFFFFFF0800 asFloat.

first number should be rounded up to 16r1FFFFFFFFFFFF1000.0
second number should be rounded down to 16r1FFFFFFFFFFFF0000.0

Current implementation use only first 64 bits, but even with more bits, it would do several partial rounding operations which is not equivalent to a single global rounding.

Additional Information

ArbitraryPrecisionAsFloat (in SqueakMap and squeaksource) implement correct IEEE rounding.
I took the patch from it.

Attached Files

Kernel-Number-Integer-asFloat-Patch.1.cs [^] (2,253 bytes) 05-06-06 21:59

Kernel-Number-Integer-asFloat-Test.1.cs [^] (647 bytes) 05-06-06 22:08

Kernel-Number-Integer-asFloat-Patch.2.cs [^] (1,849 bytes) 07-08-06 01:10

Relationships

Notes
(0005608 - 75 - 75 - 75 - 75 - 75 - 75) nicolas cellier 07-08-06 01:12	Patch.2.cs is better: it will avoid creation of second method asFloatSimply

(0006130 - 15 - 15 - 15 - 15 - 15 - 15) MarcusDenker 07-21-06 09:10	already in 7045

Issue History
Date Modified	Username	Field	Change
05-06-06 21:58	nicolas cellier	New Issue
05-06-06 21:59	nicolas cellier	File Added: Kernel-Number-Integer-asFloat-Patch.1.cs
05-06-06 22:08	nicolas cellier	File Added: Kernel-Number-Integer-asFloat-Test.1.cs
07-04-06 15:40	lewis	Issue Monitored: lewis
07-08-06 01:10	nicolas cellier	File Added: Kernel-Number-Integer-asFloat-Patch.2.cs
07-08-06 01:12	nicolas cellier	Note Added: 0005608
07-21-06 09:10	MarcusDenker	Status	new => closed
07-21-06 09:10	MarcusDenker	Note Added: 0006130
07-21-06 09:10	MarcusDenker	Resolution	open => fixed
07-21-06 09:10	MarcusDenker	Fixed in Version	=> 3.9
07-22-06 12:30	MarcusDenker	Status	closed => resolved
07-22-06 12:30	MarcusDenker	Assigned To	=> MarcusDenker
07-22-06 21:38	MarcusDenker	Status	resolved => closed

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