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Singular seems to hang doing factorization over a numberfiel https://www.singular.uni-kl.de/forum/viewtopic.php?f=10&t=1639 |
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Author: | Michel [ Sun May 20, 2007 4:33 pm ] |
Post subject: | Singular seems to hang doing factorization over a numberfiel |
Hi, I am using Singular 3.0.2, the version that comes with sage (http://www.sagemath.org). I do ring r=(0,a),(x),dp; minpoly=a^2+1; factorize(x^18+1); returns very fast, whereas factorize(x^20+1); seems to hang Singular. Is this a bug? Michel |
Author: | mabshoff [ Sat Oct 13, 2007 5:44 am ] |
Post subject: | |
Hello folks, there is a problem with realloc in gmp and then omalloc: Quote: mabshoff@sage:/tmp/Work-mabshoff/sage-2.8.6/local/bin$ ./valgrind --tool=memcheck --leak-resolution=high ./Singular-3-0-3 ==25414== Memcheck, a memory error detector. ==25414== Copyright (C) 2002-2007, and GNU GPL'd, by Julian Seward et al. ==25414== Using LibVEX rev 1788, a library for dynamic binary translation. ==25414== Copyright (C) 2004-2007, and GNU GPL'd, by OpenWorks LLP. ==25414== Using valgrind-3.3.0.SVN, a dynamic binary instrumentation framework. ==25414== Copyright (C) 2000-2007, and GNU GPL'd, by Julian Seward et al. ==25414== For more details, rerun with: -v ==25414== SINGULAR / Development A Computer Algebra System for Polynomial Computations / version 3-0-3 0< by: G.-M. Greuel, G. Pfister, H. Schoenemann May 2007 FB Mathematik der Universitaet, D-67653 Kaiserslautern > ring r=(0,a),(x),dp; > minpoly=a^2+1; > factorize(x^18+1); start Factorize2(int_flag=0) end Factorize2(0) [1]: _[1]=1 _[2]=x6+(-a)*x3-1 _[3]=x6+(a)*x3-1 _[4]=x2+(a)*x-1 _[5]=x2+(-a)*x-1 _[6]=x+(-a) _[7]=x+(a) [2]: 1,1,1,1,1,1,1 > factorize(x^20+1); start Factorize2(int_flag=0) ==25414== Source and destination overlap in memcpy(0x4214460, 0x4215300, 3752) ==25414== at 0x4A1DA2B: memcpy (mc_replace_strmem.c:402) ==25414== by 0x66F7A0: rEALLOc (in /tmp/Work-mabshoff/sage-2.8.6/local/bin/Singular-3-0-3) ==25414== by 0x669788: omReallocSizeFromSystem (in /tmp/Work-mabshoff/sage-2.8.6/local/bin/Singular-3-0-3) ==25414== by 0x6698A0: omReallocLarge (in /tmp/Work-mabshoff/sage-2.8.6/local/bin/Singular-3-0-3) ==25414== by 0x5CA5F6: reallocSize (in /tmp/Work-mabshoff/sage-2.8.6/local/bin/Singular-3-0-3) ==25414== by 0x4F04E30: __gmpz_realloc (in /tmp/Work-mabshoff/sage-2.8.6/local/lib/libgmp.so.3.4.1) ==25414== by 0x4EF76FE: __gmpz_add (in /tmp/Work-mabshoff/sage-2.8.6/local/lib/libgmp.so.3.4.1) ==25414== by 0x654485: InternalInteger::addsame(InternalCF*) (in /tmp/Work-mabshoff/sage-2.8.6/local/bin/Singular-3-0-3) ==25414== by 0x628FD7: CanonicalForm::operator+=(CanonicalForm const&) (in /tmp/Work-mabshoff/sage-2.8.6/local/bin/Singular-3-0-3) ==25414== by 0x657B95: InternalPoly::mulAddTermList(term*, term*, CanonicalForm const&, int, term*&, bool) (in /tmp/Work-mabshoff/sage-2.8.6/local/bin/Singular-3-0-3) ==25414== by 0x657F4E: InternalPoly::mulsame(InternalCF*) (in /tmp/Work-mabshoff/sage-2.8.6/local/bin/Singular-3-0-3) ==25414== by 0x627D44: CanonicalForm::operator*=(CanonicalForm const&) (in /tmp/Work-mabshoff/sage-2.8.6/local/bin/Singular-3-0-3) You can reach me via #sage-devel or by email which I am sure you guys have Cheers, Michael |
Author: | mabshoff [ Sun Oct 14, 2007 6:57 pm ] |
Post subject: | |
Hello Singular folks, we are tracking the issue at http://www.sagetrac.org/sage_trac/ticket/872 There is also now a patch you might want to have a look at. Cheers, Michael |
Author: | hannes [ Tue Oct 16, 2007 8:07 pm ] |
Post subject: | Re: Singular seems to hang .... |
Really 2 different issues are reported here: - unsafe use of memcpy - (algebraic) coefficient in factorization/gcd Both are solved in Singular-3-0-3-2 (Singular version after Tue, Oct. 16) |
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