Bug in LCM function (possibly 32bit integer overflow) octave 3.0.3 64bit linux
Mikael Leiviskä
mikael at zero-kelvin.org
Tue Mar 24 19:33:39 CDT 2009
Bug report for Octave 3.0.3 configured for x86_64-pc-linux-gnu
Description:
-----------
There seems to be an odd problem with the implementation of LCM and/or
possibly errornous memory handling.
Repeat-By:
---------
Here is how I produce the bug.
~$ octave
GNU Octave, version 3.0.3
Copyright (C) 2008 John W. Eaton and others.
This is free software; see the source code for copying conditions.
There is ABSOLUTELY NO WARRANTY; not even for MERCHANTIBILITY or
FITNESS FOR A PARTICULAR PURPOSE. For details, type `warranty'.
Octave was configured for "x86_64-pc-linux-gnu".
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Please contribute if you find this software useful.
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Report bugs to <bug at octave.org> (but first, please read
http://www.octave.org/bugs.html to learn how to write a helpful report).
For information about changes from previous versions, type `news'.
octave:1> A = 1.89e9/88, B = 4*A
A = 2.1477e+07
B = 8.5909e+07
octave:2> A = int32(A), B = int32(B)
A = 21477273
B = 85909091
octave:3> lcm(A,B), lcm([A,B])
ans = 2147483647
ans = 1.8451e+15
octave:4> A = 21477273, B = 85909091
A = 21477273
B = 85909091
octave:5> lcm(A,B), lcm([A,B])
ans = 1.8451e+15
ans = 1.8451e+15
Note that the answer is not correct in any of the cases, it should be
85909091 (which is B) It's not only incorrect but it's off by a
magnitude of 7...
The number 2147483647 that occurs as a result after the first call to
lcm(A,B) is suspiciously close to 2^31 - 1 = 2147483647 which is max for
signed 32bit ints. Perhaps it's an integer overflow bug?
Configuration (please do not edit this section):
-----------------------------------------------
uname output: Linux QuadChan 2.6.27-gentoo-r1 #3 SMP Tue Oct 28
14:10:01 CET 2008 x86_64 Intel(R) Core(TM)2 Quad CPU @ 2.40GHz
GenuineIntel GNU/Linux
configure opts: '--prefix=/usr' '--host=x86_64-pc-linux-gnu'
'--mandir=/usr/share/man' '--infodir=/usr/share/info'
'--datadir=/usr/share' '--sysconfdir=/etc' '--localstatedir=/$
Fortran compiler: x86_64-pc-linux-gnu-gfortran
FFLAGS: -O
F2C: @F2C@
F2CFLAGS: @F2CFLAGS@
FLIBS: -L/usr/lib/gcc/x86_64-pc-linux-gnu/4.1.2
-L/usr/lib/gcc/x86_64-pc-linux-gnu/4.1.2/../../../../lib64
-L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/lib/gcc/x86_64-pc$
CPPFLAGS:
INCFLAGS: -I. -I. -I./liboctave -I./src -I./libcruft/misc
C compiler: x86_64-pc-linux-gnu-gcc, version 4.1.2 (Gentoo 4.1.2 p1.1)
CFLAGS: -O2 -march=nocona -pipe -fomit-frame-pointer
CPICFLAG: -fPIC
C++ compiler: x86_64-pc-linux-gnu-g++, version 4.1.2
CXXFLAGS: -O2 -march=nocona -pipe -fomit-frame-pointer
CXXPICFLAG: -fPIC
LD_CXX: x86_64-pc-linux-gnu-g++
LDFLAGS: -Wl,-O1
LIBFLAGS: -L.
RLD_FLAG: -Wl,-rpath -Wl,/usr/lib64/octave-3.0.3
BLAS_LIBS: -llapack -lblas -lblas
FFTW_LIBS:
LIBS: -lreadline -lncurses -ldl -lz -lm
LEXLIB:
LIBGLOB:
SED: /bin/sed
DEFS:
-DPACKAGE_NAME="" -DPACKAGE_TARNAME="" -DPACKAGE_VERSION=""
uname output: Linux QuadChan 2.6.27-gentoo-r1 #3 SMP Tue Oct 28
14:10:01 CET 2008 x86_64 Intel(R) Core(TM)2 Quad CPU @ 2.40GHz
GenuineIntel GNU/Linux
configure opts: '--prefix=/usr' '--host=x86_64-pc-linux-gnu'
'--mandir=/usr/share/man' '--infodir=/usr/share/info'
'--datadir=/usr/share' '--sysconfdir=/etc' '--localstatedir=/$
Fortran compiler: x86_64-pc-linux-gnu-gfortran
FFLAGS: -O
F2C: @F2C@
F2CFLAGS: @F2CFLAGS@
FLIBS: -L/usr/lib/gcc/x86_64-pc-linux-gnu/4.1.2
-L/usr/lib/gcc/x86_64-pc-linux-gnu/4.1.2/../../../../lib64
-L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/lib/gcc/x86_64-pc$
CPPFLAGS:
INCFLAGS: -I. -I. -I./liboctave -I./src -I./libcruft/misc
C compiler: x86_64-pc-linux-gnu-gcc, version 4.1.2 (Gentoo 4.1.2 p1.1)
CFLAGS: -O2 -march=nocona -pipe -fomit-frame-pointer
CPICFLAG: -fPIC
C++ compiler: x86_64-pc-linux-gnu-g++, version 4.1.2
CXXFLAGS: -O2 -march=nocona -pipe -fomit-frame-pointer
CXXPICFLAG: -fPIC
LD_CXX: x86_64-pc-linux-gnu-g++
LDFLAGS: -Wl,-O1
LIBFLAGS: -L.
RLD_FLAG: -Wl,-rpath -Wl,/usr/lib64/octave-3.0.3
BLAS_LIBS: -llapack -lblas -lblas
FFTW_LIBS:
LIBS: -lreadline -lncurses -ldl -lz -lm
LEXLIB:
LIBGLOB:
SED: /bin/sed
DEFS:
-DPACKAGE_NAME="" -DPACKAGE_TARNAME="" -DPACKAGE_VERSION=""
-DPACKAGE_STRING="" -DPACKAGE_BUGREPORT="" -DOCTAVE_SOURCE=1
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-DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1
-DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DSEPCHAR=':'
-DSEPCHAR_STR=":" -D__NO_MATH_INLINES=1 -DCXX_NEW_FRIEND_TEMPLATE_DECL=1
-DCXX_ISO_COMPLIANT_LIBRARY=1 -DCXX_ABI=gnu_v3 -DHAVE_LIBM=1
-DHAVE_QHULL=1 -DHAVE_PCRE=1 -DHAVE_REGEXEC=1 -DHAVE_REGEX=1
-DHAVE_ZLIB_H=1 -DHAVE_ZLIB=1 -DHAVE_GLPK_H=1 -DHAVE_GLPK=1
-DHAVE_IEEE754_DATA_FORMAT=1 -DF77_FUNC(name,NAME)=name ## _
-DF77_FUNC_(name,NAME)=name ## _ -DHAVE_BLAS=1 -DHAVE_GETHOSTNAME=1
-DHAVE_GETPWNAM=1 -DHAVE_DEV_T=1 -DHAVE_INO_T=1 -DHAVE_NLINK_T=1
-DHAVE_NLINK_T=1 -DHAVE_LONG_LONG_INT=1 -DHAVE_UNSIGNED_LONG_LONG_INT=1
-DHAVE_SIGSET_T=1 -DHAVE_SIG_ATOMIC_T=1 -DSIZEOF_SHORT=2
-DSIZEOF_INT=4 -DSIZEOF_LONG=8 -DSIZEOF_LONG_LONG=8 -DHAVE_ALLOCA_H=1
-DHAVE_ALLOCA=1 -DNPOS=std::string::npos -DHAVE_PLACEMENT_DELETE=1
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-DHAVE_CURSES_H=1 -DHAVE_DLFCN_H=1 -DHAVE_FCNTL_H=1 -DHAVE_FLOAT_H=1
-DHAVE_GRP_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_LIMITS_H=1 -DHAVE_LOCALE_H=1
-DHAVE_MEMORY_H=1 -DHAVE_NCURSES_H=1 -DHAVE_POLL_H=1 -DHAVE_PWD_H=1
-DHAVE_STDINT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1
-DHAVE_SYS_IOCTL_H=1
-DHAVE_SYS_PARAM_H=1 -DHAVE_SYS_POLL_H=1 -DHAVE_SYS_RESOURCE_H=1
-DHAVE_SYS_SELECT_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_SYS_TIME_H=1
-DHAVE_SYS_TIMES_H=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_UTSNAME_H=1
-DHAVE_TERMCAP_H=1 -DHAVE_UNISTD_H=1 -DHAVE_UTIME_H=1 -DHAVE_SSTREAM=1
-DHAVE_TERMIO_H=1 -DHAVE_SGTTY_H=1 -DHAVE_GLOB_H=1 -DHAVE_FNMATCH_H=1
-DHAVE_FNMATCH=1 -DHAVE_GLOB=1 -DHAVE_ATEXIT=1 -DHAVE_BASENAME=1
-DHAVE_BCOPY=1 -DHAVE_BZERO=1 -DHAVE_CANONICALIZE_FILE_NAME=1
-DHAVE_CHMOD=1 -DHAVE_DUP2=1 -DHAVE_ENDGRENT=1 -DHAVE_ENDPWENT=1
-DPACKAGE_STRING="" -DPACKAGE_BUGREPORT="" -DOCTAVE_SOURCE=1
-D_GNU_SOURCE=1 -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1
-DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1
-DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DSEPCHAR=':'
-DSEPCHAR_STR=":" -D__NO_MATH_INLINES=1 -DCXX_NEW_FRIEND_TEMPLATE_DECL=1
-DCXX_ISO_COMPLIANT_LIBRARY=1 -DCXX_ABI=gnu_v3 -DHAVE_LIBM=1
-DHAVE_QHULL=1 -DHAVE_PCRE=1 -DHAVE_REGEXEC=1 -DHAVE_REGEX=1
-DHAVE_ZLIB_H=1 -DHAVE_ZLIB=1 -DHAVE_GLPK_H=1 -DHAVE_GLPK=1
-DHAVE_IEEE754_DATA_FORMAT=1 -DF77_FUNC(name,NAME)=name ## _
-DF77_FUNC_(name,NAME)=name ## _ -DHAVE_BLAS=1 -DHAVE_GETHOSTNAME=1
-DHAVE_GETPWNAM=1 -DHAVE_DEV_T=1 -DHAVE_INO_T=1 -DHAVE_NLINK_T=1
-DHAVE_NLINK_T=1 -DHAVE_LONG_LONG_INT=1 -DHAVE_UNSIGNED_LONG_LONG_INT=1
-DHAVE_SIGSET_T=1 -DHAVE_SIG_ATOMIC_T=1 -DSIZEOF_SHORT=2
-DSIZEOF_INT=4 -DSIZEOF_LONG=8 -DSIZEOF_LONG_LONG=8 -DHAVE_ALLOCA_H=1
-DHAVE_ALLOCA=1 -DNPOS=std::string::npos -DHAVE_PLACEMENT_DELETE=1
-DHAVE_DYNAMIC_AUTO_ARRAYS=1 -DSTDC_HEADERS=1 -DHAVE_DIRENT_H=1
-DTIME_WITH_SYS_TIME=1 -DHAVE_SYS_WAIT_H=1 -DHAVE_ASSERT_H=1
-DHAVE_CURSES_H=1 -DHAVE_DLFCN_H=1 -DHAVE_FCNTL_H=1 -DHAVE_FLOAT_H=1
-DHAVE_GRP_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_LIMITS_H=1 -DHAVE_LOCALE_H=1
-DHAVE_MEMORY_H=1 -DHAVE_NCURSES_H=1 -DHAVE_POLL_H=1 -DHAVE_PWD_H=1
-DHAVE_STDINT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1
-DHAVE_SYS_IOCTL_H=1
-DHAVE_SYS_PARAM_H=1 -DHAVE_SYS_POLL_H=1 -DHAVE_SYS_RESOURCE_H=1
-DHAVE_SYS_SELECT_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_SYS_TIME_H=1
-DHAVE_SYS_TIMES_H=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_UTSNAME_H=1
-DHAVE_TERMCAP_H=1 -DHAVE_UNISTD_H=1 -DHAVE_UTIME_H=1 -DHAVE_SSTREAM=1
-DHAVE_TERMIO_H=1 -DHAVE_SGTTY_H=1 -DHAVE_GLOB_H=1 -DHAVE_FNMATCH_H=1
-DHAVE_FNMATCH=1 -DHAVE_GLOB=1 -DHAVE_ATEXIT=1 -DHAVE_BASENAME=1
-DHAVE_BCOPY=1 -DHAVE_BZERO=1 -DHAVE_CANONICALIZE_FILE_NAME=1
-DHAVE_CHMOD=1 -DHAVE_DUP2=1 -DHAVE_ENDGRENT=1 -DHAVE_ENDPWENT=1
-DHAVE_EXECVP=1 -DHAVE_FCNTL=1 -DHAVE_FORK=1 -DHAVE_GETCWD=1
-DHAVE_GETEGID=1 -DHAVE_GETEUID=1 -DHAVE_GETGID=1 -DHAVE_GETGRENT=1
-DHAVE_GETGRGID=1 -DHAVE_GETGRNAM=1 -DHAVE_GETPGRP=1 -DHAVE_GETPID=1
-DHAVE_GETPPID=1 -DHAVE_GETPWENT=1 -DHAVE_GETPWUID=1
-DHAVE_GETTIMEOFDAY=1
-DHAVE_GETUID=1 -DHAVE_GETWD=1 -DHAVE_KILL=1 -DHAVE_LGAMMA=1
-DHAVE_LINK=1 -DHAVE_LOCALTIME_R=1 -DHAVE_LSTAT=1 -DHAVE_MEMMOVE=1
-DHAVE_MKDIR=1 -DHAVE_MKFIFO=1 -DHAVE_MKSTEMP=1 -DHAVE_ON_EXIT=1
-DHAVE_PIPE=1 -DHAVE_POLL=1 -DHAVE_PUTENV=1 -DHAVE_RAISE=1
-DHAVE_READLINK=1 -DHAVE_REALPATH=1 -DHAVE_RENAME=1 -DHAVE_RINDEX=1
-DHAVE_RMDIR=1 -DHAVE_ROUND=1 -DHAVE_SELECT=1 -DHAVE_SETGRENT=1
-DHAVE_SETLOCALE=1 -DHAVE_SETPWENT=1 -DHAVE_SETVBUF=1 -DHAVE_SIGACTION=1
-DHAVE_SIGLONGJMP=1 -DHAVE_SIGPENDING=1 -DHAVE_SIGPROCMASK=1
-DHAVE_SIGSUSPEND=1 -DHAVE_SNPRINTF=1 -DHAVE_STAT=1 -DHAVE_STRCASECMP=1
-DHAVE_STRDUP=1 -DHAVE_STRERROR=1 -DHAVE_STRNCASECMP=1 -DHAVE_STRPTIME=1
-DHAVE_STRSIGNAL=1 -DHAVE_SYMLINK=1 -DHAVE_TEMPNAM=1 -DHAVE_TGAMMA=1
-DHAVE_UMASK=1 -DHAVE_UNAME=1 -DHAVE_UNLINK=1 -DHAVE_USLEEP=1
-DHAVE_UTIME=1 -DHAVE_VFPRINTF=1 -DHAVE_VSPRINTF=1 -DHAVE_VSNPRINTF=1
-DHAVE_WAITPID=1 -DHAVE_STRFTIME=1 -DHAVE_LIBDL=1 -DHAVE_DLOPEN=1
-DHAVE_DLSYM=1 -DHAVE_DLERROR=1 -DHAVE_DLCLOSE=1 -DHAVE_DLOPEN_API=1
-DENABLE_DYNAMIC_LINKING=1 -DHAVE_TIMEVAL=1 -DHAVE_FINITE=1
-DHAVE_ISNAN=1 -DHAVE_ISINF=1 -DHAVE_COPYSIGN=1 -DHAVE_DECL_SIGNBIT=1
-DHAVE_ACOSH=1 -DHAVE_ASINH=1 -DHAVE_ATANH=1 -DHAVE_ERF=1 -DHAVE_ERFC=1
-DHAVE_EXP2=1 -DHAVE_LOG2=1 -DHAVE_STRUCT_STAT_ST_BLKSIZE=1
-DHAVE_STRUCT_STAT_ST_BLOCKS=1 -DHAVE_STRUCT_STAT_ST_RDEV=1
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-DEXCEPTION_IN_MATH=1 -DRETSIGTYPE=void -DHAVE_DECL_SYS_SIGLIST=1
-DHAVE_POSIX_SIGNALS=1 -DRETSIGTYPE_IS_VOID=1 -DHAVE_GETRUSAGE=1
-DHAVE_TIMES=1 -DYYTEXT_POINTER=1 -DGNUPLOT_BINARY="gnuplot"
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