#8185: numerical noise + crash on sage/calculus/functional.py
------------------------+---------------------------------------------------
Reporter: drkirkby | Owner: drkirkby
Type: defect | Status: new
Priority: major | Milestone: sage-4.3.2
Component: solaris | Keywords:
Author: | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
------------------------+---------------------------------------------------
== Build environment ==
This was built on a very old / low spec SPARC. But there are some
interesting results when built on newer hardware - see later.
* Sun Netra T1 UltraSPARC IIe @ 500 MHz.
* Solaris 10 03/05 (first Solaris release of Solaris 10)
* Sage 4.3.0.1 (special build by Minh for Solaris SPARC. 4.3.0 source,
but with #6595 added)
* gcc 4.4.2 configured with Sun linker and Sun assembler.
* 32-bit mode - SAGE64 was '''not''' set to 'yes'
== The problem ==
drkir...@kestrel:~/sage-4.3.0.1$ ./sage -t "devel/sage-
main/build/sage/calculus/functional.py"
init.sage does not exist ... creating
sage -t "devel/sage-main/build/sage/calculus/functional.py"
{{{
**********************************************************************
File "/export/home/drkirkby/sage-4.3.0.1/devel/sage-
main/build/sage/calculus/functional.py", line 195:
sage: float(area)
Expected:
0.85914091422952255
Got:
0.85914091422952277
********************************************************************
}}}
This in itself looks easy to fix.
== Interesting side notes ==
* Copying the binary to 't2' results in the same problem - no great
surprise there.
* Building this test on a Sun Blade 2000 with gcc 4.4.1 and running it on
the Sun Blade 2000, results in not just numerical noise, but a complete
crash
{{{
drkir...@swan:[~/sage-4.3.0.1] $ ./sage -t "devel/sage-
main/build/sage/calculus/functional.py"
sage -t "devel/sage-main/build/sage/calculus/functional.py"
A mysterious error (perhaps a memory error?) occurred, which may have
crashed doctest.
[3.1 s]
exit code: 768
----------------------------------------------------------------------
The following tests failed:
}}}
== Conclusions ==
* There is definitely an issue with numerical noise on this test due no
doubt to SPARC processor having slightly different to those of an Intel.
That is observed both on the Netra T1 and the T5240.
* A crash is occurring whilst running this test on the Sun Blade 2000.
This could potentially be the use of a slightly older compiler (gcc
4.4.1). The RAM is a lot more (8 GB) than on the Sun Netra T1 (1.5 GB)
where there is just numerical noise, so it's not a lack of RAM causing
this.
* Copying this from a very old SPARC to the Sun T5240 results in no
crashes - only the numerical noise issue.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/8185>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
