#13947: zn_poly segfaults during tuning and tests on OS X and Cygwin when built
on
a busy system
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Reporter: jpflori | Owner: tbd
Type: defect | Status: new
Priority: major | Milestone:
sage-5.10
Component: packages: standard | Resolution:
Keywords: zn_poly spkg cygwin osx nuss_mul fail | Work issues:
Report Upstream: N/A | Reviewers:
Authors: | Merged in:
Dependencies: | Stopgaps:
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Comment (by dmharvey):
Hi, I am the original author.
I have debugged this issue outside of sage, using the version of zn_poly
0.9 on my web page. I can reproduce the issue with "test/test nuss_mul" on
sage.math (or maybe I've logged into boxen?), using the tuning file
provided by wdj above.
After some debugging, I have found a genuine bug in the test code. In
nuss-test.c, line 60 currently reads
{{{
ulong x = nuss_mul_fudge (lgL, 0, mod);
}}}
It should be
{{{
ulong x = nuss_mul_fudge (lgL, sqr, mod);
}}}
Basically what's happening is that {{{nuss_mul}}} returns its results
multiplied by a fudge factor, and the test code has to undo that fudge
factor to compare the results. The current version always uses the
thresholds from the "multiplication" version of the code to figure out the
fudge factor. But when sqr == 1, it should be using the "squaring"
thresholds.
Please let me know if that solves the problem.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/13947#comment:32>
Sage <http://www.sagemath.org>
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