Mercury Bugs - mercury
View Issue Details
IDProjectCategoryView StatusDate SubmittedLast Update
0000128mercuryBugpublic2010-01-14 18:192010-09-15 12:29
Reporterjuliensf 
Assigned Tozs 
PrioritynormalSeverityminorReproducibilityhave not tried
StatusresolvedResolutionfixed 
PlatformOSOS Version
Product Version 
Target VersionFixed in Version 
Summary0000128: merge_instmapping_delta_2: error merging var 20
Description(This was originally reported by Michael Day on the mercury-bugs list; responses from
zs are included below as well.)

Hi,
                                                                                                                                                                                                                 
The attached program triggers a compiler error when building with -O5:
                                                                                                                                                                                                                 
Making Mercury/int3s/bug.int3
Making Mercury/ints/bug.int
Making Mercury/cs/bug.c
Uncaught Mercury exception:
Software Error: instmap.m: Unexpected: merge_instmapping_delta_2: error merging var 20
                                                                                                                                                                                                                 
It succeeds at lower optimisation levels. Tested with rotd-2009-10-08 and rotd-2008-01-30.
                                                                                                                                                                                                                 
Michael

============
Date: Mon, 9 Nov 2009 17:43:53 +1100
From: Zoltan Somogyi <zs@csse.unimelb.edu.au>
To: Michael Day <mikeday@yeslogic.com>
Cc: mercury-bugs@csse.unimelb.edu.au
Subject: Re: merge_instmapping_delta_2: error merging var 20
                                                                                                                                                                          
On 09-Nov-2009, Michael Day <mikeday@yeslogic.com> wrote:
> The attached program triggers a compiler error when building with -O5:
>
> Making Mercury/int3s/bug.int3
> Making Mercury/ints/bug.int
> Making Mercury/cs/bug.c
> Uncaught Mercury exception:
> Software Error: instmap.m: Unexpected: merge_instmapping_delta_2: error
> merging var 20
>
> It succeeds at lower optimisation levels. Tested with rotd-2009-10-08 and
> rotd-2008-01-30.
                                                                                                                                                                                                                 
It also succeeds with -O5 --no-loop-invariants, and the exception is thrown
*during* the loop invariants pass. I think that makes this Ralph's to fix.
                                                                                                                                                                                                                 
Zoltan.

=======
Hi Zoltan,
                                                                                                                                                                          
> It also succeeds with -O5 --no-loop-invariants, and the exception is thrown
> *during* the loop invariants pass. I think that makes this Ralph's to fix.
                                                                                                                                                                                                                 
Suits me! :)
                                                                                                                                                                                                                 
The bug can be worked around by creating lots of little helper predicates, although it is a bit tedious.
                                                                                                                                                                                                                 
We always build with -O5 rather than waiting until just before release, as it's very frustrating to suddenly be hit with an unexpected internal compiler error.
                                                                                                                                                                                                                 
Best regards,
                                                                                                                                                                                                                 
Michael
                                                                                                                                                                                                                 
--
Print XML with Prince!
http://www.princexml.com
TagsNo tags attached.
Relationships
Attached Files? bug.m (1,078) 2010-01-14 18:20
https://bugs.mercurylang.org/file_download.php?file_id=93&type=bug

Notes
(0000290)
zs   
2010-09-15 12:29   
Fix committed 15 sep 2010.

Issue History
Date ModifiedUsernameFieldChange
2010-01-14 18:19juliensfNew Issue
2010-01-14 18:20juliensfFile Added: bug.m
2010-09-14 19:47zsStatusnew => assigned
2010-09-14 19:47zsAssigned To => zs
2010-09-15 12:29zsNote Added: 0000290
2010-09-15 12:29zsStatusassigned => resolved
2010-09-15 12:29zsResolutionopen => fixed