The result of the division of 18446744065119617024llu by the result of (1<<31) is wrong on a 32bit platform.
Reproduce: gcc s.c && ./a.out should have exit code 0 but doesn't. Expected: gcc -DEXPECTED s.c && ./a.out has exit code 0 as expected. gcc -v Reading specs from /usr/lib/gcc/i386-redhat-linux/3.4.6/specs Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-java-awt=gtk --host=i386-redhat-linux Thread model: posix gcc version 3.4.6 20060404 (Red Hat 3.4.6-8) [lxbuild021] /afs/cern.ch/user/a/axel/tmp/gccconv > /afs/cern.ch/sw/lcg/contrib/gcc/4.1.2/slc4_ia32_gcc34/bin/gcc -v Using built-in specs. Target: i686-pc-linux-gnu Configured with: /build/LCG/gcc-4.1.2/configure --prefix=/afs/cern.ch/sw/lcg/contrib/gcc/4.1.2/slc4_ia32_gcc34 Thread model: posix gcc version 4.1.2 uname -a Linux lxbuild021.cern.ch 2.6.9-42.0.10.EL.cernsmp #1 SMP Thu Mar 1 15:11:46 CET 2007 i686 i686 i386 GNU/Linux I'll give the .c instead of .i because it shows the expected result and has no #includes: int main (){ unsigned long long a = 18446744065119617024llu; /* results expected to be identical */ #ifdef EXPECTED int b = ((int)(1<<31)); a = a / b; #else a = a / ((int)(1<<31)); #endif return a; } -- Summary: unsigned long long operator << and integer literals Product: gcc Version: 4.1.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: gcc at axel-naumann dot de GCC build triplet: i386-redhat-linux GCC host triplet: i386-redhat-linux GCC target triplet: i386-redhat-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32324