Math::BigInt gives completely when Math::BigInt::GMP is used

[p5pRT]

Migrated from rt.perl.org#56608 (status was 'rejected')

Searchable as RT56608$

[p5pRT]

From pcg@goof.com

Created by pcg@goof.com

When Math​::BigInt uses GMP as backend, it gives completely bogus results​:

  perl -MMath​::BigInt=lib,GMP -e 'my $b = 0xc0010203; my $m = Math​::BigInt->new (2) ** 24 - 1; warn $m + $b'
  -105689855 at -e line 1.

  perl -MMath​::BigInt=lib,GMP -e 'my $b = 0xc0010203; my $m = Math​::BigInt->new (2) ** 32 - 1; warn $m + $b'
  3221291522 at -e line 1.

This only seems to happen with 32-bit perls.

Perl Info

Flags:
    category=library
    severity=low

Site configuration information for perl 5.10.0:

Configured by Marc Lehmann at Sat Jan 19 07:46:38 CET 2008.

Summary of my perl5 (revision 5 version 10 subversion 0 patch 33007) configuration:
  Platform:
    osname=linux, osvers=2.6.23-1-amd64, archname=amd64-linux
    uname='linux cerebro 2.6.23-1-amd64 #1 smp fri dec 21 12:00:17 utc 2007 x86_64 gnulinux '
    config_args='-Duselargefiles -Dxxxxuse64bitint -Uuse64bitall -Dusemymalloc=n -Dcc=gcc -Dccflags=-DPERL_DONT_CREATE_GVSV_disabled -ggdb -Dcppflags=-DPERL_DONT_CREATE_GVSV_disabled -D_GNU_SOURCE -I/opt/include -Doptimize=-O6 -march=opteron -mtune=opteron -funroll-loops -fno-strict-aliasing -Dcccdlflags=-fPIC -Dldflags=-L/opt/perl/lib -L/opt/lib -Dlibs=-ldl -lm -lcrypt -Darchname=amd64-linux -Dprefix=/opt/perl -Dprivlib=/opt/perl/lib/perl5 -Darchlib=/opt/perl/lib/perl5 -Dvendorprefix=/opt/perl -Dvendorlib=/opt/perl/lib/perl5 -Dvendorarch=/opt/perl/lib/perl5 -Dsiteprefix=/opt/perl -Dsitelib=/opt/perl/lib/perl5 -Dsitearch=/opt/perl/lib/perl5 -Dsitebin=/opt/perl/bin -Dman1dir=/opt/perl/man/man1 -Dman3dir=/opt/perl/man/man3 -Dsiteman1dir=/opt/perl/man/man1 -Dsiteman3dir=/opt/perl/man/man3 -Dman1ext=1 -Dman3ext=3 -Dpager=/usr/bin/less -Uafs -Uusesfio -Uusenm -Uuseshrplib -Dd_dosuid -Dusethreads=undef -Duse5005threads=undef -Duseithreads=undef -Dusemultiplicity=undef -Demail=perl-binary@plan9.de -Dcf_email=perl-binary@plan9.de -Dcf_by=Marc Lehmann -Dlocincpth=/opt/perl/include /opt/include -Dmyhostname=localhost -Dmultiarch=undef -Dbin=/opt/perl/bin -Dxxxusedevel -des'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=undef, usemultiplicity=undef
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='gcc', ccflags ='-DPERL_DONT_CREATE_GVSV_disabled -ggdb -fno-strict-aliasing -pipe -I/opt/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O6 -march=opteron -mtune=opteron -funroll-loops -fno-strict-aliasing',
    cppflags='-DPERL_DONT_CREATE_GVSV_disabled -D_GNU_SOURCE -I/opt/include -DPERL_DONT_CREATE_GVSV_disabled -ggdb -fno-strict-aliasing -pipe -I/opt/include'
    ccversion='', gccversion='4.2.3 20080102 (prerelease) (Debian 4.2.2-5)', gccosandvers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='gcc', ldflags ='-L/opt/perl/lib -L/opt/lib -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /lib64 /usr/lib64
    libs=-ldl -lm -lcrypt
    perllibs=-ldl -lm -lcrypt
    libc=/lib/libc-2.7.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.7'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O6 -march=opteron -mtune=opteron -funroll-loops -fno-strict-aliasing -L/opt/perl/lib -L/opt/lib -L/usr/local/lib'

Locally applied patches:
    MAINT


@INC for perl 5.10.0:
    /root/src/sex
    /opt/perl/lib/perl5
    /opt/perl/lib/perl5
    /opt/perl/lib/perl5
    /opt/perl/lib/perl5
    /opt/perl/lib/perl5
    .


Environment for perl 5.10.0:
    HOME=/root
    LANG (unset)
    LANGUAGE (unset)
    LC_CTYPE=de_DE.UTF-8
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/root/s2:/root/s:/opt/bin:/opt/sbin:/bin:/sbin:/usr/bin:/usr/sbin:/usr/X11/bin:/usr/games:/usr/local/bin:/usr/local/sbin:/root/pserv:.
    PERL5LIB=/root/src/sex
    PERL5_CPANPLUS_CONFIG=/root/.cpanplus/config
    PERLDB_OPTS=ornaments=0
    PERL_ANYEVENT_EDNS0=1
    PERL_ANYEVENT_PROTOCOLS=ipv4
    PERL_BADLANG (unset)
    PERL_UNICODE=0
    SHELL=/bin/bash

[p5pRT]

From p5p@perl.wizbit.be

Citeren Marc Lehmann <perlbug-followup@​perl.org>​:

-----------------------------------------------------------------
[Please enter your report here]

When Math​::BigInt uses GMP as backend, it gives completely bogus results​:

perl -MMath​::BigInt=lib,GMP -e 'my $b = 0xc0010203; my $m =
Math​::BigInt->new (2) ** 24 - 1; warn $m + $b'
-105689855 at -e line 1.

perl -MMath​::BigInt=lib,GMP -e 'my $b = 0xc0010203; my $m =
Math​::BigInt->new (2) ** 32 - 1; warn $m + $b'
3221291522 at -e line 1.

This only seems to happen with 32-bit perls.

[Please do not change anything below this line]
-----------------------------------------------------------------

Can you run​:

perl -MMath​::BigInt=lib,GMP -Mbignum=version

Kind regards,

Bram

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'

[p5pRT]

From nospam-abuse@bloodgate.com

On Saturday 05 July 2008 10​:28​:54 Bram wrote​:

Citeren Marc Lehmann <perlbug-followup@​perl.org>​:

-----------------------------------------------------------------
[Please enter your report here]

When Math​::BigInt uses GMP as backend, it gives completely bogus
results​:

perl -MMath​::BigInt=lib,GMP -e 'my $b = 0xc0010203; my $m =
Math​::BigInt->new (2) ** 24 - 1; warn $m + $b'
-105689855 at -e line 1.

perl -MMath​::BigInt=lib,GMP -e 'my $b = 0xc0010203; my $m =
Math​::BigInt->new (2) ** 32 - 1; warn $m + $b'
3221291522 at -e line 1.

This only seems to happen with 32-bit perls.

I am pretty sure that is because the value is in-between treated as
signed vs. unsigned integer and thus arrives wrongly in libgmp.

Can you please run​:

  perl -Mbignum,l,GMP=v

?

All the best,

Tels

--
Signed on Sat Jul 5 10​:50​:08 2008 with key 0x93B84C15.
View my photo gallery​: http​://bloodgate.com/photos
PGP key on http​://bloodgate.com/tels.asc or per email.

"Un bon mot ne prouve rien."

  -- Voltaire

[p5pRT]

From nospam-abuse@bloodgate.com

On Saturday 05 July 2008 10​:50​:59 you wrote​:

On Saturday 05 July 2008 10​:28​:54 Bram wrote​:

Citeren Marc Lehmann <perlbug-followup@​perl.org>​:

-----------------------------------------------------------------
[Please enter your report here]

When Math​::BigInt uses GMP as backend, it gives completely bogus
results​:

perl -MMath​::BigInt=lib,GMP -e 'my $b = 0xc0010203; my $m =
Math​::BigInt->new (2) ** 24 - 1; warn $m + $b'
-105689855 at -e line 1.

perl -MMath​::BigInt=lib,GMP -e 'my $b = 0xc0010203; my $m =
Math​::BigInt->new (2) ** 32 - 1; warn $m + $b'
3221291522 at -e line 1.

This only seems to happen with 32-bit perls.

I am pretty sure that is because the value is in-between treated as
signed vs. unsigned integer and thus arrives wrongly in libgmp.

Can you please run​:

perl \-Mbignum\,l\,GMP=v

Sorry,

  perl -Mbignum=l,GMP,v

But I think I found the bug, GMP,xs contains​:

  if (SvUOK(x))
  {
  mpz_init_set_si(*RETVAL, (UV)SvUV(x));
  }
  else
  {
  ...

That should probably be​:

  if (SvUOK(x))
  {
  mpz_init_set_ui(*RETVAL, (UV)SvUV(x)); // _ui to fix [perl #56608]
  }
  else
  {
  ...

Marc, could you please patch, recompile and test with this and see if it
resolves it? I only have a 64bit Perl on this machine.

All the best,

Tels

--
Signed on Sat Jul 5 10​:54​:34 2008 with key 0x93B84C15.
Get one of my photo posters​: http​://bloodgate.com/posters
PGP key on http​://bloodgate.com/tels.asc or per email.

"In my opiniation, "burglarize" is a perfectionally validative
wordification. How else would reportization of the securitial/policial
forceship appearize to be importantive enoughly to be respectative by
the massmediaship and influentate the societyness?"

  -- SharpFang (651121) on 2004-12-13 at /. about "burgle"
vs. "burglarize"

[p5pRT]

From kraai@ftbfs.org

Howdy,

I was able to reproduce the original problem on my system and, after
making the change suggested by Tels, found that the commands produced
the following output​:

$ perl -MMath​::BigInt=lib,GMP -e 'my $b = 0xc0010203; my $m = Math​::BigInt->new (2) ** 24 - 1; warn $m + $b'
3238068738 at -e line 1.
$ perl -MMath​::BigInt=lib,GMP -e 'my $b = 0xc0010203; my $m = Math​::BigInt->new (2) ** 32 - 1; warn $m + $b'
7516258818 at -e line 1.

These match the results produced by bc.

Here's the output requested by Bram​:

$ perl -MMath​::BigInt=lib,GMP -Mbignum=version
bignum v0.23
Math​::BigInt v1.89 lib => Math​::BigInt​::GMP v1.24
Math​::BigFloat v1.60

The output requested by Tels was the same.

--
Matt http​://ftbfs.org/

[p5pRT]

From dana@acm.org

Just to make the connection, this is in Math​::BigInt​::GMP's queue as RT 71548, and still open.

[p5pRT]

From @dcollinsn

On Sun Mar 02 22​:53​:47 2014, danaj wrote​:

Just to make the connection, this is in Math​::BigInt​::GMP's queue as
RT 71548, and still open.

In that ticket, which is still open, the maintainer reports that Math-BigInt-GMP-1.46 has been uploaded, which fixes this bug.

In any event, Math​::BigInt​::GMP is not a core module, so this should be closed rejected. Please visit https://rt.cpan.org/Public/Bug/Display.html?id=71548 for further discussion related to this issue. (In particular, if this is confirmed fixed on a system that was previously broken, please report this there, so that the maintainer knows that they can close that ticket.)

--
Respectfully,
Dan Collins

[p5pRT]

@dcollinsn - Status changed from 'open' to 'rejected'