Number: 1127

Date: 18-May-84 12':29':20



Subject: Floating multiply of -1.0 by 0.0 produces illegal format number on Dorado

Assigned To:

Attn: Release

Status: Superseded


Problem Type: 

Impact: Fatal

Difficulty: Moderate

Frequency: Everytime

Priority: Perhaps

System: Language Support

Subsystem: Arithmetic

Machine: 1132


Lisp Version: 14-May-84 21':12':25

Source Files: 

Microcode Version: 5124

Memory Size: 4096

File Server: 

Server Software Version: 

Disposition: Superseded by AR 1290.'
["" "23-Sep-84 22':13':55" Attn': Status':(Open->Superseded) Subsystem':(Microcode->Arithmetic) Disposition': Description':]

Description: (FTIMES -1.0 0.0) produces a "negative zero", which is a legal IEEE format number, but which Interlisp-D can''t deal with; additionally, "negative zero" should only be produced by dividing a "positive zero" by "negative infinity" or dividing a "negative zero" by "positive infinity". -- JonL 5/16/84 '
Correction': negative zero may also be produced by multiplication exactly as in the reported case.   Since it appears that the Dorado ucode was doing exactly the right thing,  I''ve superseded this AR by AR 1290.  -- JonL 23-Sep-84 --  


Test Case: 


Edit-Date: 23-Sep-84 22':13':57