bugGNU Octave - Bugs: bug #41831, image 2.2.1 - miscomilation of...

 
 

bug #41831: image 2.2.1 - miscomilation of bwdist.cc on i386

Submitter:  Thomas Weber <tweber>
Submitted:  Tue 11 Mar 2014 08:27:52 AM UTC
   
 
Category:  Octave Package Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Incorrect Result
Status:  Fixed Assigned to:  None
Originator Name:  Open/Closed:  * Closed
Release:  * other Operating System:  * GNU/Linux
Fixed Release:  None Planned Release:  None
* Mandatory Fields

Add a New Comment Rich Markup
   

Tue 11 Mar 2014 04:20:28 PM UTC, comment #1: 

Hi Thomas, thank for you reporting this bug.

I have already fixed this with cset 43cd1c5e0955. As you, I couldn't find any issue with the code and could only reproduce on i686. I found that changing those variable to double fixes it. Also, changing the sqrt2_1 inside quasi_euclidean() to double would also fix it. I still think there must be a proper fix somewhere else, but for the time being, this seems to work.

Also, this bug happens in one of the tests, but it was luck. When I tried with random matrices, only some of them would trigger it.

By the way, this problem should already been present on the image package version 2.2.0. It was caused in 27d87f06dd99 when I changed from double to single for Matlab compatibility.

Carnë Draug <carandraug>
Group Member
Tue 11 Mar 2014 08:27:52 AM UTC, original submission:  

Hi,
we are seeing a miscompilation of bwdist in Debian for the i386 (32bit, x86) platfor. When compiled with -O2, the test suite hangs in an infinite loop. Investigation showed that the problem occurs in the quasi-euclidean test case (and only there). We tried gcc 4.8 and 4.9, both exhibit this problem.
Marking newdist2 as volatile (volatile float newdist2;) fixed this issue as well. However, I don't see a problem in the code, so this may indeed be a problem with gcc. Using clang 3.5 does not exhibit this problem, either.

Thomas Weber <tweber>

 

(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach Files:
   
   
Comment:
   

No files currently attached

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -email is unavailable- added by tweber (Submitted the item)
  •  

    There are 0 votes so far. Votes easily highlight which items people would like to see resolved in priority, independently of the priority of the item set by tracker managers.

    Only group members can vote.

     

    Follow 2 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2014-03-11 carandraug StatusNone Fixed
        Open/ClosedOpen Closed

    Back to the top

    Powered by Savane 3.13-02a9.
    Corresponding source code